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Sample records for axial computarizada con

  1. Tomografía axial computarizada en pacientes con enfermedades cerebrovasculares hemorrágicas Computerized axial tomography in patients with hemorrhagic cerebrovascular diseases

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    Solángel Bolaños Vaillant

    2009-10-01

    Full Text Available Se efectuó un estudio descriptivo y transversal de 196 pacientes con enfermedad cerebrovascular hemorrágica, que abarcó desde enero del 2004 hasta igual mes del 2005 en el Hospital Provincial Docente “Saturnino Lora” de Santiago de Cuba, a los cuales se indicó una tomografía axial computarizada. Al relacionar las imágenes tomográficas con los síntomas y signos presentados por los enfermos, se halló lenguaje tropeloso en todos ellos; predominio de hematomas intraparenquimatosos, generalmente en ganglios basales y región temporal, así como primacía de la hipertensión arterial entre los antecedentes patológicos más importantes. Se concluyó que la tomografía axial computarizada es un medio para diagnóstico certero en las urgencias médicas por esa grave afección.A descriptive and cross sectional study of 196 patients with cerebrovascular hemorrhagic disease was carried out from January, 2004 to the same month of 2005 in "Saturnino Lora" Teaching Provincial Hospital from Santiago de Cuba, to whom a computerized axial tomography was indicated. When relating the tomographic images with the symptoms and signs which they presented, trouble speaking was detected in all of them; prevalence of intraparenchymatous hematomas, generally in basal ganglia and temporal region, as well as prevalence of hypertension among the most important pathological history. It was concluded that computarized axial tomography is a mean for precise diagnosis in medical emergencies due to that serious disorder.

  2. DETERMINACIÓN DEL COLOR EN EPICARPIO DE TOMATES (LYCOPERSICUM ESCULENTUM MILL. CON SISTEMA DE VISIÓN COMPUTARIZADA DURANTE LA MADURACIÓN

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    Carlos Alberto Padrón Pereira

    2012-01-01

    Full Text Available Se estudió la evolución del color de muestras de tomates durante la maduración a temperatura ambiente y otras en refrigeración, mediante Sistema de Visión Computarizada (SVC. El SVC lo constituye un escenario iluminado, una cámara digital CCD y un computador (Laptop ambos calibrados. El procesamiento digital de las imágenes se llevó a cabo con el software Adobe® Photoshop® CS3 Extended, con los cuales generaron imágenes promediadas en coordenadas L*, a* y b*. La relación a*/b* y las coordenadas polares c* y hº, que presentaron diferencias estadísticas significativas entre las muestras determinadas (p<0,05.

  3. Application of the axial tomography computed for the detection of bags of dampness in dry wood of Gmelina arborea (Roxb.); Aplicacion de la tomografia axial computarizada para la deteccion de bolsas de humedad en madera seca de Gmelina arborea (Roxb.)

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    Moya R, Roger; Munoz A, Freddy [Inst. Tecnologico de Costa Rica, Escuela de Ingenieria Forestal, Apdo. 159-7050, Cartago 7050(Costa Rica); Escalante, Ivan [Clinica Santa Fe, San Jose (Costa Rica)

    2006-07-01

    detectar y establecer los limites de la presencia de humedad en la madera de Gmelina arborea al lado de la exploracion de tomografia computarizada (CT-escaner), una tecnica aplicada en el diagnostico medico. Junto con las bolsas humedas, en la CT-del escaner se presentan imagenes de color gris y con valores bajos de la Unidad Hounsfield (UH) o numero CT. Cuando estos valores fueron transformados a la densidad de la madera, se determino que las bolsas humedas estaban a una densidad de unos 190 kg/m{sup 3}, un valor superior al normal de la madera. Ademas, fue posible observar el crecimiento de anillos de arboles en la CT-del escaneo de imagenes, una caracteristica importante para la investigacion dendrocronologica. Los resultados obtenidos permitieron demostrar que es posible aplicar esta tecnica en el proceso de produccion de madera, para detectar las zonas con un alto MC en el secado de la madera de Gmelina arborea. (autor)

  4. Diseño y validación de una tarea computarizada tipo Stroop para evaluar sesgos de la atención en bulimia nerviosa

    OpenAIRE

    Camacho-Ruíz, Esteban Jaime; Mancilla-Díaz, Juan Manuel; Escoto-Ponce De León, María Del Consuelo; Yáñez-Tellez, María Guillermina

    2009-01-01

    Objetivo: Desarrollar una tarea computarizada tipo Stroop para evaluar sesgos en la atención hacia palabras relacionadas con la comida y la figura, en pacientes con bulimia nerviosa. Se desarrollaron cuatro listas de palabras con valencia positiva y negativa, relacionadas con la comida y la figura corporal. Método: treinta y dos mujeres con bulimia nerviosa emparejadas con 32 mujeres sin trastorno, respondieron la versión original y una modificada de la Prueba de Stroop computarizada. Resulta...

  5. Diseño y Validación de una Tarea Computarizada Tipo Stroop para Evaluar Sesgos de la Atención en Bulimia Nerviosa

    OpenAIRE

    Esteban Jaime Camacho-Ruíz

    2009-01-01

    Objetivo: Desarrollar una tarea computarizada tipo Stroop para evaluar sesgos en la atención hacia palabras relacionadas con la comida y la figura, en pacientes con bulimia nerviosa. Se desarrollaron cuatro listas de palabras con valencia positiva y negativa, relacionadas con la comida y la figura corporal. Método: treinta y dos mujeres con bulimia nerviosa emparejadas con 32 mujeres sin trastorno, respondieron la versión original y una modificada de la Prueba de Stroop computarizada. Resulta...

  6. Seguimiento posterior a la cirugía curativa para el cáncer colorrectal: impacto de la tomografía por emisión de positrones - tomografía computarizada (PET/TC)

    OpenAIRE

    Kishimoto, Gustavo; Murakami, Koji; Con, Sergio A.; Yamasaki, Erena; Domeki, Yasushi; Tsubaki, Masahiro; Sakamoto, Setsu

    2010-01-01

    El seguimiento postoperatorio tiene un rol importante para la sobrevida del paciente después de la resección curativa del cáncer colorrectal. OBJETIVOS: Describir las características del seguimiento con tomografía por emisión de positrones (PET) integrado a tomografía axial computarizada (CT) (PET/CT) y su impacto en los sobrevivientes de cáncer colorrectal (CCR) posterior a la resección con intención curativa en un hospital universitario en la prefectura de Tochigi, Japón. MATERIAL Y MÉTODOS...

  7. Paciente con tumor de cuerpo carotideo

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    Mariuska Forteza Sáez

    Full Text Available Los tumores de cuerpo carotideo (paragangliomas son neoplasias altamente vascularizadas, muy poco frecuentes y generalmente benignas, originadas en los quimiorreceptores del cuerpo carotideo. Se presenta el caso de un paciente de 54 años, con aumento de volumen cervical derecho, asintomático, con estudio preoperatorio y angiografía realizados por tomografía axial computarizada, que resultan compatibles con tumor de cuerpo carotideo. Se realiza disección subadventicial, informando la biopsia paraganglioma. El tumor fue completamente resecado, sin evidencia de recurrencia y sin complicaciones.

  8. Analysis of the results of CAT of thorax with bronchiectasis protocol, period 2000-2001 Hospital Calderon Guardia; Analisis de los resultados de TAC de torax con protocolo de bonquiectasias, periodo 2000-2001 Hospital Calderon Guardia

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    Pacheco Segura, Maureen [Costa Rica

    2003-07-01

    This investigation analyses the computerized axial tomography (CAT) of thorax with protocol of bronchiectasis. It was carried out in the Servicio de Radiologia e Imagenes Medicas of the Hospital Calderon Guardia, Costa Rica. The bronchiectasis is the abnormal permanent expansion of the bronchial tuber and is important to diagnose it because the patient can suffer of pulmonary infections, these can be accompanied by bronchial blood flow and hemoptysis. When they are disseminated can be associated with significant obstruction of the aerial tract. When they are gotten into focus can be confused with neoplasia and other diseases. From the bronchiectasis diagnosis it is used methods of image such as x-ray of thorax, bronchography and computerized axial tomography (CAT) of thorax, usually the diagnosis is confirmed by means of a computerized axial tomography (CAT); which is the image of election to establish the presence and extension of the bronchiectasis. In addition, this study analyzes the radiological clinical relation in the patients which were performed the computerized axial tomography (CAT) of thorax with protocol of bronchiectasis and it identifies the most suitable radiological technique to obtain a satisfactory result in the computerized axial tomography with protocol of bronchiectasis. [Spanish] En esta investigacion se analiza la tomografia axial computarizada (TAC) de torax con protocolo de bronquiectasis realizada en el Servicio de Radiologia e Imagenes Medicas del Hospital Calderon Guardia, Costa Rica. Las bronquiectasias se definen como la dilatacion permanente anormal de los bronquios y es importante diagnosticarlas porque el paciente puede sufrir de infecciones pulmonares. Ademas, estas pueden acompanarse de flujo sanguineo bronquial y hemoptisis. Cuando estan diseminadas se pueden asociar con obstruccion significativa de la via aerea. Si estan focalizadas se pueden confundir con neoplasias u otras enfermedades. Para el diagnostico de bronquiectasias

  9. Estudio de un vórtice de Rankine con velocidad axial discontinua en un tubo infinito

    OpenAIRE

    Gonzalez, R; Vigh, C.D

    2016-01-01

    En este trabajo se muestra que un vórtice de Rankine confinado con flujo axial uniforme, posee sólo modos neutros aun cuando la velocidad axial sea discontinua en la interfase rotacional-irrotacional. Esta discontinuidad produce un curvamiento de las ramas inferiores de la relación de dispersión de tal forma que cortan al eje del número de onda con pendiente negativa, es decir velocidad de grupo negativa. Este resultado apoya la idea original de que el fenómeno de Vortex Breakdown se podría e...

  10. REVISIÓN DE LAS EVALUACIONES ADAPTATIVAS COMPUTARIZADAS (CAT

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    Ruber López

    2015-06-01

    Full Text Available En este artículo presentamos una revisión de las Evaluaciones Adaptativas Computarizadas. A diferencia de los test convencionales, estas evaluaciones plantean un examen adaptado a las necesidades y capacidades de cada uno de los evaluados, lo cual redunda en una mejor experiencia para el evaluado y en una mayor precisión del resultado. Las evaluaciones adaptativas se fundamentan en la teoría de respuesta a ítems, que define las directrices y condiciones para que este tipo de pruebas sea posible. A partir de esta teoría, surgen distintos modelos que permiten modelar diferentes rasgos de los evaluados y la relación de estos con la probabilidad de acertar un ítem dado. Para llevar a cabo el proceso de evaluación, un test adaptativo debe estar conformado de un banco de ítems, un método que permita la selección de estos y un criterio de terminación. Todos estos componentes articulan la prueba y la ayudan a concretarse adecuadamente. AbstractThis paper is a review of the Computerized Adaptive Testing Process. Unlike conventional tests, these assessments propose a test adapted to every examinee’s needs and capabilities, which results in a better experience for those assessed and a more accurate score. Adaptive assessments are based on item response theory, which defines the guidelines and conditions for such tests to be carried out. From this theory, different models that allow the repositioning of different traits of the examinees and their relationship with the probability to succeed in a given item, arise. To complete the assessment process, an adaptive test should consist of a set of items, a method which allows the selection of these and a termination criterion. All the aforementioned components articulate the test and help to properly materialize it.

  11. Fabricación de biomodelos tridimensionales odontológicos a partir de tomografías computarizadas

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    Fabián Villena

    2017-10-01

    Full Text Available Este manuscrito tiene por objetivo establecer un flujo de trabajo para la construcción de biomodelos tridimensionales mediante la técnica de fabricación con filamento fundido. Se describen las características de tomografías computarizadas en formato DICOM, la generación de un modelo tridimensional desde los archivos DICOM y finalmente la manufactura (impresión, por medio de la tecnología de fabricación con filamento fundido. A través de este protocolo de trabajo es posible generar biomodelos tridimensionales paciente-específicos a bajo costo, donde la precisión de la tecnología con filamento fundido es confrontable con otros sistemas más costosos.

  12. Costo-efectividad de la tomografía computarizada y la ecografía en el diagnóstico de apendicitis

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    Álvaro Sanabria

    2008-03-01

    Conclusiones. Los métodos diagnósticos por imágenes en los casos de duda diagnóstica de apendicitis, son más costo-efectivos que el examen clínico para definir la conducta terapéutica. La tomografía axial computarizada ofrece una mejor relación costo-efectividad en el sistema de salud prepagada y es casi equiparable a la ecografía para el plan obligatorio de salud.

  13. Distorsión en imágenes obtenidas mediante tomografía computarizada de cono Distortion in cone-beam computed tomography images

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    Gloria Baena

    2013-06-01

    Full Text Available Objetivo: Cuantificar la distorsión presente en imágenes de diferentes regiones del cráneo y la mandíbula humanos obtenidas mediante tomografía computarizada de cono. Metodología: Mediante el trazo de 3 planos horizontales y 4 verticales se delimitaron 15 cuadrantes en 30 cráneos secos humanos con las mandíbulas articuladas y se colocaron en cada cuadrante alambres de acero inoxidable en los planos sagital, coronal y axial (transversal. A cada espécimen debidamente posicionado se le tomó una tomografía computarizada de cono (CBCT. Se midió la longitud de los alambres, tanto en los especímenes óseos (medida real, como en las imágenes (medida tomográfica, para compararlas entre sí. Como pruebas estadísticas se utilizaron el Coeficiente de Correlación de Concordancia (CCC y la Media de las Diferencias. Resultados: Dado que el CCC encontrado en todos los cuadrantes fue siempre mayor de 0,80, las medidas tomográficas que se hagan en estos cuadrantes pueden ser consideradas estadísticamente confiables. Sin embargo, los valores obtenidos en todas las medidas espaciales revelan que en todos los cuadrantes se presenta algún porcentaje de distorsión, siendo este de magnificación para algunos o de minimización para otros. La mayor distorsión se presentó en las medidas verticales de los cuadrantes situados en la línea mediana o próximos a ella, y el menor porcentaje en las medidas horizontales. Conclusión: La distorsión presente en las diferentes regiones del cráneo y la mandíbula no es estadísticamente significativa, pero es aconsejable tenerla en cuenta para minimizar los errores que puedan presentarse en la práctica clínica.Objective: To quantify the distortion in Cone-Beam Computed Tomography images of different regions of the human skull and mandible. Methods: With the tracing of three horizontal and four vertical planes, fifteen quadrants were delimited in thirty dry human skulls with their articulated jaws

  14. Obliteración de fracturas de seno frontal con colgajos pediculados

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    J. Pefaure

    2014-03-01

    Full Text Available El compromiso del seno frontal con fractura de sus paredes es un tipo de lesión infrecuente, en torno al 5-12% de todas las fracturas faciales. Suele asociarse a lesiones intracraneales, oftalmológicas y a otras fracturas máxilofaciales y cuando conlleva fractura de la pared posterior de seno frontal requiere tratamiento inmediato, siendo necesaria la obliteración del seno frontal debido a la comunicación con meninges y lóbulo frontal, con el riesgo infeccioso que ello representa. Tratamos 18 pacientes con traumatismos craneofaciales y fracturas del seno frontal con compromiso de su pared posterior en el periodo comprendido entre 2007 y 2011; 8 mujeres y 10 varones con edades comprendidas entre los 15 y los 64 años. Todos los casos fueron tratados con reducción y osteosíntesis por vía abierta con distintos abordajes y realizamos en todos colgajos pediculados de vecindad. La vitalidad de los colgajos fue del 100% . Certificamos el posicionamiento correcto mediante tomografía axial computarizada. El tratamiento de las fracturas del seno frontal con compromiso de su pared posterior o del conducto nasofrontal requiere obliteración con tejido vascularizado para evitar comunicaciones con la cavidad nasal.

  15. Determinación del color en epicarpios de mango (Mangifera sp. y plátano (Musa AAB en maduración mediante sistema de visión computarizada

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    Carlos Alberto Padrón Pereira

    2012-01-01

    Full Text Available En investigación agraria y alimentaria, el procesamiento y análisis de imágenes en color se ha convertido en un área importante de estudio. En este contexto, el sistema de visión computarizada ha demostrado ser un procedimiento útil. Los propósitos de este trabajo fueron determinar el color en epicarpios de frutos de mango y plátano durante la maduración con sistema de visión computarizada. El sistema lo constituyó un escenario iluminado, una cámara digital CCD y un computador (desktop, ambos calibrados. El procesamiento digital de las imágenes se llevó a cabo con el software Adobe® Photoshop®, con el cual se generaron imágenes promediadas en coordenadas rectangulares L*, a*, b*. Las coordenadas polares (C*, hº fueron calculadas, y para todos los casos, los resultados fueron descritos. Los resultados permitieron describir adecuadamente las variaciones de color en epicarpios de ambos frutos durante la maduración, mediante coordenadas colorimétricas de los espacios de color CIE-L*a*b* y CIE-L*C*hº, a través de imágenes digitales obtenidas con sistema de visión computarizada.

  16. Determinación del color en epicarpios de mango (Mangifera sp. y plátano (Musa AAB en maduración mediante sistema de visión computarizada

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    Carlos Alberto Padrón Pereira

    2012-12-01

    Full Text Available En investigación agraria y alimentaria, el procesamiento y análisis de imágenes en color se ha convertido en un área importante de estudio. En este contexto, el sistema de visión computarizada ha demostrado ser un procedimiento útil. Los propósitos de este trabajo fueron determinar el color en epicarpios de frutos de mango y plátano durante la maduración con sistema de visión computarizada. El sistema lo constituyó un escenario iluminado, una cámara digital CCD y un computador (desktop, ambos calibrados. El procesamiento digital de las imágenes se llevó a cabo con el software Adobe® Photoshop®, con el cual se generaron imágenes promediadas en coordenadas rectangulares L*, a*, b*. Las coordenadas polares (C*, hº fueron calculadas, y para todos los casos, los resultados fueron descritos. Los resultados permitieron describir adecuadamente las variaciones de color en epicarpios de ambos frutos durante la maduración, mediante coordenadas colorimétricas de los espacios de color CIE-L*a*b* y CIE-L*C*hº, a través de imágenes digitales obtenidas con sistema de visión computarizada.

  17. Etmoiditis complicada con celulitis orbitaria en un lactante

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    Odette Pantoja Pereda

    Full Text Available Se define la etmoiditis como la inflamación e infección de la mucosa de las celdas etmoidales. Se diagnostica clínicamente con la presencia de edema en el ángulo medial del ojo, que se extiende a las estructuras adyacentes. Estudios imagenológicos son necesarios para verificar la presencia de complicaciones, entre las que se citan el absceso orbitario, subperióstico, epidural, subdural, cerebral, tromboflebitis del seno cavernoso, meningoencefalitis y la muerte del paciente. Streptococcus pneumoniae, Staphylococcus aureus y Haemophilus influenzae son microorganismos frecuentemente responsables de este cuadro. Las complicaciones orbitarias en las etmoiditis, necesitan el diagnóstico y tratamiento precoz para evitar secuelas irreversibles. Se presenta el caso de un lactante masculino, de 1 mes y 26 días de nacido, que ingresa con fiebre, rinorrea serosa y rechazo al alimento. Evolutivamente se constata marcada obstrucción nasal, edema periorbitario izquierdo, rubor, calor, protrusión del globo ocular e irritabilidad, y se diagnostica etmoiditis complicada con celulitis orbitaria. Se realiza tomografía axial computarizada que informa seno etmoidal izquierdo ocupado por contenido de densidad líquida con celularidad (15-25 UH, engrosamiento de partes blandas de la pared interna de la órbita que abomba, comprime y desplaza la musculatura orbitaria, y se extiende al párpado y al ala izquierda de la nariz desviando tabique blando; así como ligera proptosis, y disminución de la densidad ósea de la pared interna de la cavidad orbitaria. Se toma muestra para cultivo y se aísla Staphylococcus aureus meticillin resistente. Se comentan los elementos diagnósticos y su tratamiento, con el objetivo de llamar la atención de los pediatras para lograr el diagnóstico y tratamiento oportuno.

  18. Primeros pasos en la posturografía dinámica computarizada

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    Cristina CORDERO-CIVANTOS

    2018-01-01

    Full Text Available Introducción y objetivo: La posturografía dinámica computarizada (CDP es una técnica que nos va a permitir cuantificar de forma objetiva, como las diferentes patologías afectan la estabilidad postural de los pacientes y su evolución. Metodología: revisión narrativa. Resultados: En este trabajo vamos a repasar como se realizan y analizan las diferentes pruebas de la CDP; y su utilidad diagnóstica y terapéutica en la práctica otorrinolaringológica. Discusión y conclusiones: La posturografía dinámica computarizada es una prueba diagnóstico-terapéutica que permite cuantificar de forma objetiva y reproducible la estabilidad del paciente. Y aporta información relevante para planificar el tratamiento rehabilitador, así como para monitorizar su evolución.

  19. Evaluación de la disponibilidad, utilización y costos de la tomografía computarizada en el estado de Morelos, México

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    Pérez-Rodríguez John

    2002-01-01

    Full Text Available Objetivo. Evaluar la disponibilidad, utilización y costos económicos de la tomografía computarizada (TC en hospitales públicos y privados en el estado de Morelos, México. Material y métodos. Mediante un estudio transversal efectuado entre enero y abril de 1999, se evaluaron cuatro hospitales en el estado de Morelos, dos públicos y dos privados. Se llevaron a cabo entrevistas individuales con los directores, administradores, médicos radiólogos y jefes de mantenimiento. Se realizó un análisis estadístico descriptivo de las variables, disponibilidad, utilización y costos, así como una evaluación integral de la tomografía, haciendo énfasis en la variabilidad de los patrones observados en los hospitales participantes en el estudio. Resultados. La TC es una tecnología utilizada en los hospitales del estado de Morelos desde hace más de 10 años. Aun cuando existen programas de mantenimiento preventivo y correctivo a los equipos de tomografía, sus costos son muy elevados. Además se carece de estrategias que permitan evaluar la tecnología antes de su adquisición y durante su utilización. El estudio no incluyó aspectos relativos a la correcta indicación clínica de la TC, ni a sus posibles efectos secundarios. Conclusiones. Los hallazgos obtenidos a partir de la presente investigación fueron los siguientes: a existe una carencia de procesos de evaluación y gestión tecnológica, que permita a las unidades hospitalarias un manejo eficiente de la tomografía computarizada, y b también se carece de mecanismos para regular la adquisición, evaluar la tecnología y seleccionar las mejores alternativas en función de su efectividad, eficacia, seguridad y accesibilidad.

  20. Ependimoma celular parcialmente resecado complicado con meningoependimocoroiditis bacteriana por Pseudomonas aeruginosa e infección sistémica por citomegalovirus

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    Francisco Javier Otero-Mendoza

    2017-06-01

    Full Text Available Niño de 1 año 10 meses de edad, originario de Irapuato, Guanajuato, sin antecedentes de importancia para el padecimiento actual. Inició dos meses previos a su ingreso con crisis convulsivas tónico-clónicas generalizadas de 15 segundos de duración durante el sueño. Se realizó electroencefalograma que reportó actividad epileptiforme, por lo que se dio tratamiento con ácido valproico. Una semana previa al ingreso se agregó ataxia troncal impidiendo la marcha, por lo que se realizó una tomografía axial computarizada de cráneo en la que se observó un tumor en fosa posterior con densidad heterogénea y áreas de necrosis central que obliteraba el cuarto ventrículo, ocasionando efecto de masa y desplazamiento ventral del tallo cerebral. Por tal motivo, fue referido a nuestra institución.

  1. Axial myopathy

    DEFF Research Database (Denmark)

    Witting, Nanna; Andersen, Linda K; Vissing, John

    2016-01-01

    Classically, myopathies are categorized according to limb or cranial nerve muscle affection, but with the growing use of magnetic resonance imaging it has become evident that many well-known myopathies have significant involvement of the axial musculature. New disease entities with selective axial...

  2. La tomografía computarizada en cardiopatía isquémica: de la calcificación coronaria a la caracterización tisular miocárdica

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    Jordi Estornell Erill

    2015-03-01

    Full Text Available Durante las últimas 2 décadas las técnicas de imagen han alcanzado un papel indispensable en prácticamente todas las enfermedades cardiovasculares. La tomografía computarizada cardiaca, en el campo de la cardiopatía isquémica, proporciona información irreemplazable para la investigación clínica y básica, y se ha convertido también en imprescindible para guiar la actitud terapéutica de los pacientes con enfermedad coronaria en la práctica diaria. Revisamos su estado actual desde la mirada de su utilidad quirúrgica.

  3. Hallazgos endoscópicos en pacientes con bronquiectasias de una zona endémica de tuberculosis

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    Alfonzo Uribe-Barreto

    2008-04-01

    Full Text Available Las bronquiectasias son una entidad frecuente en el Perú debido a su presencia como secuela de la tuberculosis. Se describe los hallazgos más frecuentes en la broncoscopía flexible en 101 pacientes previamente diagnosticados de bronquiectasias mediante radiografía de tórax y tomografía axial computarizada en un hospital general de Lima. La mayoría de los pacientes tenía como antecedente tuberculosis pulmonar (80% y presentó hemoptisis (67% como motivo de consulta. Los hallazgos más frecuentes en la broncofibroscopía fueron la deformación de la luz bronquial con dilataciones y constricciones (100%, el acceso del broncofibroscopio (de 6,0 mm de diámetro más allá de los bronquios segmentarios (98%, la coalescencia de los anillos traqueales (97% y las estrías longitudinales (13,9%. Los tres primeros hallazgos deben ser considerados como propuesta para determinar los criterios de diagnóstico endoscópico de esta entidad.

  4. Integración de los aloinjertos óseos impregnados con alendronato: Estudio experimental. [Alendronate-impregnated­ bone­ allograft­ integration: Experimental­ study

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    Luis S. Ruchelli

    2014-10-01

    Full Text Available In­tro­duc­ción: el propósito de este estudio experimental es investigar la variabilidad en la reabsorción ósea de aloinjertos impregnados con alendronato respecto a aloinjertos sin impregnación con alendronato. Materiales­ y ­Métodos:­ se utilizaron 18 conejos neozelandeses, divididos en dos grupos de 9 animales cada uno. Se trabajó sobre el fémur derecho, se realizó una ventana ósea y se colocó aloinjerto con alendronato local en el grupo I y aloinjerto sin alendronato en el grupo II.­ Todos fueron sacrificados a las 10 semanas del procedimiento inicial, y se valoró el fémur operado con anatomía patológica, radiografías de frente y de perfil, y tomografía axial computarizada.­ Se evaluaron la osteointegración, la vascularización y la calidad ósea. Resultados: el estudio histológico demostró mayor osteointegración en el grupo I que en el grupo II (p = 0,003, y fenómenos bien definidos de “acoplamiento” entre el tejido óseo receptor e injertado, leve actividad osteoclástica. En el grupo II, se observó menor acoplamiento óseo (osteointegración. La evaluación de la reabsorción ósea con radiografía y tomografía computarizada no reveló una diferencia estadísticamente significativa entre ambos grupos. En el grupo I, se observó mayor osteointegración del aloinjerto (p = 0,577; no significativo. Conclusión:­ los resultados obtenidos en este trabajo experimental muestran que el alendronato local asociado a aloinjertos ayuda a mejorar la osteointegración de los aloinjertos, que es un método seguro, y que no se asocia a riesgos locales o sistémicos en conejos, aun en dosis elevadas.

  5. CT Assessment of the axial deviation of the femoral and tibial prosthetic components in total knee arthroplasty; Valutazione con Tomografia Computerizzata della rotazione delle componenti femorale e tibiale nell'artroprotesi totale del ginocchio

    Energy Technology Data Exchange (ETDEWEB)

    Rimondi, E.; Molinari, M.; Moio, A.; Busacca, M. [Istituto Ortopedico Rizzoli, Bologna (Italy). Servizio di Diagnostica per Immagini; Trentani, F.; Trentani, P.; Tigani, D. [Istituto Ortopedico Rizzoli, Bologna (Italy). VII Div.; Nigrosoli, M. [Istituto Ortopedico Rizzoli, Bologna (Italy). IV Div.

    2000-06-01

    components on frontal and axial planes. It was measured the orientation of the prosthetic components introducing a CT procedure which modifies the uniarticular with four scans introduced by Berger. The new method uses Berger's parameters and the CT study of both joints by means of Helical CT. With a single examination lasting less than 4 minutes and with the patient in a more confortable position, it can be obtained: (1) comparative and simultaneous assessment of the contralateral joint; (2) several scans to better define Berger's parameters and to accomplish measurement of the rotational deviation with higher precision and markedly decreasing the error margin. The analysis of the results confirms the international literature findings and especially the fundamental importance in positioning both prosthetic components within normal values, as emphasized by the relationship between the clinical symptoms and the rotational degree of the femoral and tibial prosthetic components. [Italian] Scopo di questo lavoro e' valutare mediante TC la rotazione delle componenti protesiche femorale e tibiale nella protesi del ginocchio. Da gennaio a luglio 1999 sono stati esaminati 17 pazienti, 10 maschi e 7 femmine, eta' media 66 anni (deviazione standard plus minus 4) operati di protesi totale del ginocchio. Sono stati esclusi tutti i soggetti con mobilizzazione delle componenti protesiche e con deviazioni gravi (uguali o superiore a 7) nel varismo o nel valgismo. Ogni paziente e' stato studiato con radiogrammi del ginocchio nell'ortostasi in due proiezioni completate da assiali della rotula e mediante TC. Rispetto alla metodica descritta da Berger la TC e' stata efettuata comparativamente con arti inferiori estesi scansioni perpendicolari all'asse meccanico del ginocchio, condotte dalla regione sovracondiloidea femorale al piano passante al di sotto delle estremita' distale della componente protesica tibiale. Su piani di scansione predefiniti

  6. Memoria de trabajo en niños escolarizados: efecto de intervalos de presentación y distractores en la prueba computarizada Memonum

    Directory of Open Access Journals (Sweden)

    Carlos Arturo Conde Cotes

    2013-06-01

    Full Text Available La presente investigación evaluó la memoria de trabajo visual a través de la prueba computarizada Memonum en niños escolarizados. Se evaluaron los efectos de tres tiempos de exposición (1, 4 y 8 segundos y de la presentación de un distractor sobre el desempeño mnemónico en la prueba Memonum en 72 niños pertenecientes a un colegio del área metropolitana de Bucaramanga, Colombia, con edades entre 8 y 11 años de los grados tercero, cuarto y quinto de primaria. Se encontró una diferencia significativa entre los tiempos de exposición en las variables número de aciertos y aciertos acumulados, demostrandoun mejor desempeño mnemónico en los participantes que presentaron la prueba en el tiempo de 8 segundos en comparación con los niños pertenecientes al grupo de 1 segundo; además, la presencia del distractor demostró una diferencia significativa en los aciertos y aciertos acumulados, considerándose como un estímulo generador de interferencia que perturba la capacidad de almacenamiento de la memoria de trabajo en niños. Adicionalmente, se halló una diferencia significativa en cuanto al uso de la estrategia de repetición mental, indicando que los participantes de los grupos de 4 y 8 segundos leasignaron mayor puntaje que los niños del grupo de 1 segundo. Un amplio tiempo de exposición de estímulos en la prueba Memonum aumenta la capacidad de retención; asimismo, el empleo de un distractor afecta en los participantes la capacidad de almacenamiento y esta, a suvez, aumenta de acuerdo a la progresión escolar, debidoal uso de las estrategias mnemónicas que los niños utilizan para garantizar el recuerdo de las series numéricas.

  7. Avaliação eletromiográfica de músculos da cintura escapular e braço durante exercícios com carga axial e rotacional Evaluación electromiográfica de músculos de la cintura escapular y brazos durante ejercicios con cargas axial y rotacional Electromyographic assessment of the shoulder girdle and arm muscles during exercises with axial and rotational loads

    Directory of Open Access Journals (Sweden)

    Anamaria Siriani de Oliveira

    2006-02-01

    Full Text Available O conhecimento da atividade eletromiográfica produzida durante a realização de exercícios para o ombro pode auxiliar na determinação de sua aplicabilidade clínica. O objetivo desta pesquisa foi avaliar a influência da direção da carga e condição da extremidade na atividade elétrica de músculos da cintura escapular e membro superior durante a realização de exercícios com a extremidade distal fixa e carga externa axial (EFCA e extremidade livre com carga externa rotacional (ELCR. Foram selecionadas 20 voluntárias (23,2 anos ± 0,9 sedentárias. Foram avaliados os mm. tríceps do braço, bíceps do braço, peitoral maior, trapézio e deltóide. Foi realizado o registro eletromiográfico de superfície, durante a realização de dois exercícios com EFCA e dois com ELCR, utilizando 100% da resistência máxima previamente estabelecida. Os valores de RMS normalizados pela contração voluntária máxima foram comparados por meio de um modelo de efeitos mistos com nível de significância de 5%. Nessas condições experimentais, os resultados do presente estudo mostraram que exercícios semelhantes, classificados pela condição da extremidade e a direção da carga aplicada ao membro superior, promovem níveis semelhantes de atividade eletromiográfica em apenas parte dos músculos estudados. Esses achados questionam a capacidade do sistema de classificação utilizado neste estudo de predizer o tipo de resposta muscular esperada na realização de diferentes tarefas de mesma classificação.El conocimiento de la actividad electromiográfica producida durante los ejercicios para el hombro puede ayudar en la determinación de la pertinencia clínica. El objetivo de esta investigación era evaluar sus influencias de la dirección de la carga y condición de la extremidad en la actividad eléctrica de músculos de la cintura escapular y miembro superior durante ejercicios con la extremidad distal fija y carga externa axial (EFCA y

  8. Tumor de Pindborg relacionado con trauma facial Pindborg's tumor in relationship with facial traumata

    Directory of Open Access Journals (Sweden)

    Niorgy Rodríguez Rodríguez

    2011-12-01

    Full Text Available El tumor de Pindborg es una neoplasia benigna, rara, con carácter invasivo local y tendencia a la recidiva, que representa entre el 0,17 y el 1,8 % de todos los tumores odontogénicos, del cual tan solo se han publicado unos 200 casos, con una media de 4 casos nuevos por año en el mundo. Se presentó el caso de un hombre de 39 años de edad que acudió a la consulta de cirugía maxilofacial remitido de neurocirugía postraumatismo craneofacial, por presentar un aumento de volumen en el ángulo mandibular derecho. Se tuvo como objetivo publicar la existencia de esta infrecuente neoplasia por lo interesantes que resultan estos tumores por su evolución, dificultad en el diagnóstico, variantes de tratamiento y tendencia a la recidiva. Después de realizar exámenes de laboratorio, radiografías, tomografía axial computarizada y biopsia de fragmento óseo, se obtuvo extensión y diagnóstico de tumor de Pindborg en hemimandíbula derecha. Se realizó la técnica quirúrgica de hemimandibulectomía derecha y reconstrucción con injerto óseo de cresta ilíaca. La evolución del paciente fue satisfactoria.The Pindborg's tumor is a benign and uncommon neoplasm with a local invasive character and a trend to relapse accounting for the 0.17 and the 1.8 % of all odontogenic tumors with only 200 cases published in the literature and a mean of four cases per year at world scale. This is the case of a man aged 39 came our consultation of Maxillofacial Surgery referred from Neurosurgery Service after a craniofacial trauma and an increase of volume in right mandibular angle with the aim to publish the existence of this uncommon neoplasm due to the interesting of this type of tumor by its evolution, difficulty for diagnosis, variants of treatment and trend to relapse. After carry out laboratory examinations, X-rays, axial tomography computerize and biopsy of bone fragment, it was possible the extension and diagnosis of Pindbog's tumor in right hemi

  9. Axial tomography

    International Nuclear Information System (INIS)

    Brueckner, K.A.; Lewis, J.H.

    1979-01-01

    The invention relates to axial tomography, sometimes referred to as cross-sectional x-ray. The apparatus described may utilize the conventional x-ray or ultrasonic source and detector and scanning mechanism for producing the plurality of sets of radiation detector output signals. It has the means for storing the detector output signals in analog form with the signals of one set overlying the signals of another set so that signals resulting from radiation through a zone of the object being examined are summed at a corresponding zone in the storage device, typically an electronic storage tube. The summed signals are read from the storage device with a radially inversely proportional reader producing a second signal for storage, again typically in an electronic storage tube. These signals stored in the second storage device are read with Laplacian relation, with the resultant sigal being a video signal that may be connected to a TV monitor for display of the sectional image. In alternative embodiments, optical film systems and electrostatic systems are utilized. (JTA)

  10. Analysis of fetal dose in CT procedures; Analisis de dosis fetal en procedimientos de tomografia computarizada

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz Torres, A.; Plazas, M. C.

    2006-07-01

    It is the miracle of the life, that sublime formation, the given more beautiful gift for heaven's sake to our to exist, and it is consequently our responsibility to look after their protection and care. Today in day the quantity of radiation absorbed by the fetus in the treatments for radiodiagnostic, mainly in the procedures of on-line axial tomography, the fetus absorbs a considerable dose of radiation and the questions generated regarding if these doses, bear to a risk of malformations or if it is necessary the interruption of the pregnancy is very frequent. In most of the cases, the treatment with ionizing radiations that it is beneficial for the mother, is only indirectly it for the fetus that is exposed to a risk. The possibility that a fetus or a small boy contract cancer caused by the radiation it can be three times superior to that of the population in general, of there the importance of analyzing the goods of the prenatal irradiation and the main agents to consider for the estimate of the magnitude of the risk of the exhibitions in uterus. In the different circumstances in that these can happen in treatments of on-line axial tomography computerized. (Author)

  11. Aplicación de metodología de modelado 3D utilizando Tomografías Computarizadas para su análisis numérico

    Directory of Open Access Journals (Sweden)

    Ariel Fuerte Hernández

    2014-01-01

    Full Text Available Este trabajo presenta una metodología para la generación de un modelo del segmento lumbar porcino y humano L4-L5 a partir de Tomografías Computarizadas (TC. El uso de la TC como herramienta de biomodelado es una técnica que actualmente es muy usada en el desarrollo de análisis numéricos computacionales mediante programas de Análisis de Elemento Finito (AEF, lo que permite visualizar y analizar estructuras anatómicas simples y/o complejas. Por lo que, la relevancia de este trabajo radica en el hecho de la generación de análisis numéricos biomecánicos con resultados muy cercanos a los análisis experimentales, creando soluciones médicas en el diseño de dispositivos protésicos. Los resultados numéricos muestran una concentración de esfuerzos en el disco intervertebral justo en la zona de las placas terminales, tanto en el caso humano como en el porcino, lo que concuerda con análisis experimentales previos. De este modo, se concluye que los resultados obtenidos mediante esta técnica validan análisis experimentales previos, sin embargo, es necesario tomar en cuenta las características del comportamiento mecánico de los diferentes tejidos biológicos que componen la columna lumbar.

  12. Evaluación de Lesiones Periapicales en Pacientes Derivados a Cirugía Periapical Mediante Tomografía Computarizada de Haz Cónico

    OpenAIRE

    Hernández Vigueras, Scarlette; Donoso Zúñiga, Manuel; Sanhueza Tobar, Claudio; Linco Olave, Jared; Riquelme Carrasco, Sebastián

    2017-01-01

    El uso de la tomografía computarizada de haz cónico (CBCT) en endodoncia ha ido en aumento, justificando su uso en casos más complejos, como cirugías periapicales. El objetivo fue evaluar las características imagenológicas encontradas en un grupo de pacientes derivados a cirugía periapical, mediante el uso de CBCT. Se realizó un estudio observacional descriptivo, en un grupo de pacientes, derivados a cirugía periapical, a los cuales se realizó un examen de CBCT, evaluación clínica y radiograf...

  13. Análisis de la cuantifiación tridimensional de las vías lagrimales en tomografía computarizada

    OpenAIRE

    Jáñez García, Lucía

    2016-01-01

    La descripción de la anatomía del sistema de drenaje lagrimal en la literatura es poco precisa. Se han realizado mediciones del canal nasolagrimal óseo (CNLO) en cadáver, radiografía y tomografía computarizada (TC). JUSTIFICACIÓN, HIPÓTESIS DE TRABAJO Y OBJETIVOS Hasta ahora, todas las mediciones realizadas sobre imágenes tienen al menos un paso manual, lo que inevitablemente degrada la fiabilidad de los datos obtenidos. La mayoría de las mediciones realizadas en TC son bidimensionales y únic...

  14. Adenocarcinoma mucoproductor de colon con infiltración de estómago y metástasis ováricas (tumor de Krukenberg Colon mucoproducing adenocarcinoma with stomach infiltration and ovarian metastases (Krukenberg's tumor

    Directory of Open Access Journals (Sweden)

    Orestes Noel Mederos Curbelo

    2011-12-01

    Full Text Available Se presenta una paciente femenina de 29 años, operada de urgencia por presentar un gran tumor que incluía cuerpo gástrico y colon trasverso, con una perforación gástrica. Se realizó una gastrectomía subtotal con colectomía trasversa en bloque que incluyó el epiplón mayor. El diagnóstico histológico fue adenocarcinoma túbulo papilar mucoproductor de origen colónico, que infiltra hasta la serosa y pared gástrica. Se realizó tratamiento adyuvante con poliquimioterapia. Diez meses después presenta un tumor en hipogastrio, que al tacto vaginal, correspondía a los órganos genitales, sospecha clínica que confirman el ultrasonido abdominal y la tomografía axial computarizada. El hallazgo transoperatorio fueron tumores voluminosos de ambos ovarios, y otro tumor que afectaba la unión rectosigmoide. Se realizó una histerectomía radical con ooforectomía bilateral y sigmoidectomía, se reseca la porción proximal del recto, y se cierra tipo Hartman. El diagnóstico histológico final fue metástasis en serosa uterina e intestinal, y en ambos ovarios de adenocarcinoma mucoproductor, túbulo papilar de intestino previamente diagnosticado (tumor de Krukenberg. Se complementó el tratamiento con poliquimioterapia adyuvante.This is the case of a woman aged 29 operated on of emergency due to a tumor involving gastric body and transverse colon with gastric perforation. A subtotal gastrectomy with block transverse colectomy including the greater omentum was carried out. The histological diagnosis was a mucoproducing papillary tubular adenocarcinoma of colonic origin infiltrating to serosa and gastric wall. An adjuvant treatment was applied with poly-chemotherapy. Ten months later appears a hypogastric tumor which at vaginal manual examination corresponding to genital organs, clinical suspicion confirmed by abdominal ultrasound and computerized axial tomography. The transoperative findings were bulky tumors of both ovaries and another tumor

  15. Tumor filodes de mama con metástasis en pulmón Phyllodes tumor of the breast with lung metastasis

    Directory of Open Access Journals (Sweden)

    Ernesto Arias Beatón

    2012-04-01

    Full Text Available Se describe el caso clínico de una paciente de 63 años de edad, quien ingresó en el Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba por presentar tos seca persistente, expectoración escasa (en ocasiones amarillenta, astenia y pérdida de peso. En el examen físico se palpó un tumor en la mama derecha, confirmado a través de ecografía y mamografía. Los resultados de la biopsia por aspiración con aguja fina fueron positivos de células neoplásicas, compatibles con carcinoma. La radiografía de tórax y la tomografía axial computarizada revelaron la presencia de imágenes metastásicas pulmonares, por lo cual se realizó la exéresis del tumor con un margen de seguridad de 2 cm. Mediante el estudio histopatológico se confirmó la existencia de un tumor filodes, de manera que fue preciso indicar 3 ciclos de quimioterapia (esquema CISCYVADACT, del que solo se cumplieron 2, pues la anciana evolucionó desfavorablemente y falleció 3 meses después.The case report of a 63-year-old patient is described, who was admitted to "Dr. Juan Bruno Zayas Alfonso" Teaching General Hospital of Santiago de Cuba due to persistent dry cough, little expectoration (sometimes yellowish, asthenia and loss of weight. On physical examination a tumor was palpated in the right breast, which was confirmed through sonography and mammogram. The results of the fine-needle biopsy were positive for neoplastic cells, consistent with carcinoma. Chest radiography and computerized axial tomography revealed the presence of lung metastatic images, reason why tumor excision with a safety margin of 2 cm was performed. The presence of phyllodes tumor was confirmed by means of the histopathologic study, so that it was necessary to indicate 3 cycles of chemotherapy (CISCYVADACT scheme, of which only two were administered as the old woman had an unfavorable course and she died 3 months later.

  16. Correlación neuropsicológica y electrofisiológica en niños escolares con TCE

    OpenAIRE

    Abel Delgado; Luis Quintanar; Yulia Solovieva; Regina Machinskaya

    2011-01-01

    El traumatismo craneoencefálico (TCE) es una de las causas principales por la que se solicita atención médica en el servicio hospitalario de urgencias. El TCE frecuentemente produce daño cerebral o deterioro funcional del sistema nervioso en distintos niveles, que se refleja en las funciones cognitivas, tanto en niños como en adultos. El objetivo del presente estudio es correlacionar los resultados obtenidos a través de la Tomografía Axial Computarizada (TAC), el registro electroencefalográfi...

  17. Hematoma masivo esofágico con compromiso supraglótico: Reporte de un caso y revisión de la literatura

    OpenAIRE

    Pardo J,Javiera; Abarca A,Alfredo; Walker J,Katherine; Celedón L,Carlos

    2010-01-01

    Se presenta el caso de un paciente de 67 años de sexo masculino, hipertenso, diabético y usuario de aspirina en dosis anticoagulante, que consulta en el servicio de urgencia por un cuadro de inicio súbito de dolor retroesternal asociado a disnea severa y estridor. La evaluación mediante nasofibroscopfa muestra una gran masa supraglótica que obstruye el 80% del lumen, compatible con una masa esofágica. La tomograffa computarizada de tórax muestra una imagen compatible con un hematoma disecante...

  18. BWR AXIAL PROFILE

    International Nuclear Information System (INIS)

    Huffer, J.

    2004-01-01

    The purpose of this calculation is to develop axial profiles for estimating the axial variation in burnup of a boiling water reactor (BWR) assembly spent nuclear fuel (SNF) given the average burnup of an assembly. A discharged fuel assembly typically exhibits higher burnup in the center and lower burnup at the ends of the assembly. Criticality safety analyses taking credit for SNF burnup must account for axially varying burnup relative to calculations based on uniformly distributed assembly average burnup due to the under-burned tips. Thus, accounting for axially varying burnup in criticality analyses is also referred to as accounting for the ''end effect'' reactivity. The magnitude of the reactivity change due to ''end effect'' is dependent on the initial assembly enrichment, the assembly average burnup, and the particular axial profile characterizing the burnup distribution. The set of bounding axial profiles should incorporate multiple BWR core designs and provide statistical confidence (95 percent confidence that 95 percent of the population is bound by the profile) that end nodes are conservatively represented. The profiles should also conserve the overall burnup of the fuel assembly. More background on BWR axial profiles is provided in Attachment I

  19. Computerised Axial Tomography (CAT)

    Science.gov (United States)

    1990-06-01

    Ministry of’ Defence, Defence Research Information Centre, UK. Computerised Axial Tomography ( CAT ) Report Secufty C"uMiauion tide Onadtiicadon (U. R, Cor S...DRIC T 8485 COMPUTERISED AXIAL TOMOGRAPHY ( CAT ) F.P. GENTILE, F. SABETTA, V. TRO1* ISS R 78/4.Rome, 1.5 Mlarch 1978 (from Italian) B Distribution(f...dello Radiazioni ISSN 0390--6477 F.P. GENTILE, F. SABETTA. V. TROI Computerised Axial Tomography ( CAT ) March 15, 1978). This paper is a review of

  20. Estudio mediante tomografía computarizada de los criterios radiográficos aplicados al diagnóstico del síndrome navicular del caballo

    OpenAIRE

    Arias Sanz, Pablo

    2016-01-01

    El síndrome del navicular ha sido reconocido como una de las causas más importantes de claudicación en el caballo. En la radiografía, muchas de las lesiones del hueso navicular quedan mal definidas. Y entre ellas la pérdida de definición córtico-medular. La TC es la mejor modalidad de imagen para la valoración de las características del hueso. Pero además de la información morfológica, también proporciona información sobre la atenuación radiológica de los tejidos (tomografía computarizada cua...

  1. Signatures for axial chromodynamics

    International Nuclear Information System (INIS)

    Pati, J.C.

    1978-07-01

    Within the context of basic left-right symmetry and the hypothesis of unification of weak, electromagnetic and strong forces at a mass level approximately equal to 10 4 -10 6 GeV, relatively light ''mass'' axial gluons, confined or liberated, must be postulated. The authors remark that the existence of such ''light'' axial gluons supplementing the familiar vector octet preserves the successes of QCD, both for deep inelastic processes and charmonium physics. Through the characteristic spin-spin force, generated by their exchange, they may even help resolve some of the discrepancies between vector QCD predictions and charmonium physics. The main remark of this note is that if colour is liberated, not only vector but also axial-vector gluons are produced in high-energy e - e + experiments, e.g. at PETRA and PEP, with fairly large cross-section. Distinctive decay modes of such liberated axial gluons are noted

  2. Pulmonary artery aneurysm in Bechcet's disease: helical computed tomography study; Aneurisma de la arteria pulmonar en la enfermedad de Behcet. Estudio con tomografia computarizada helicoidal

    Energy Technology Data Exchange (ETDEWEB)

    Munoz, J.; Caballero, P.; Olivera, M. J.; Cajal, M. L.; Caniego, J. L. [Hospital de la Princesa. Iniversidad Autonoma. Madrid (Spain)

    2000-07-01

    Behcet's disease is a vasculitis of unknown etiology that affects arteries and veins of different sizes and can be associated with pulmonary artery aneurysms. We report the case of a patient with Behcet's disease and a pulmonary artery aneurysm who was studied by means of plain chest X ray, helical computed tomography and pulmonary arteriography. Helical computed tomography is a reliable technique for the diagnosis and follow-up of these patients. (Author) 9 refs.

  3. Rectal contrast-enhanced computed tomography in the diagnosis of acute appendicitis; Tomografia computarizada con contraste rectal en el diagnostico de la apendicitis aguda

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    To assess the efficacy and utility of computed tomography (CT) in the diagnosis of appendicitis, and to evaluate the reliability of CT findings in right iliac fossa in the confirmation or exclusion of this diagnosis. Over a one-year period, 152 patients presenting clinical signs of appendicitis underwent CT scans. The images were reviewed by two radiologists who considered whether the appendix was normal or enlarged and the existence of other signs of appendicitis for the purpose of determining whether or not the patient presented appendicitis. The definitive diagnoses were established by surgery or by clinical follow-up. The sensitivity of CT for the diagnosis of appendicitis was 81.8%, the specificity was 95.3%, the positive predictive value was 93.1%, the negative predictive value was 87.2% and the reliability was 89.9%. The signs of appendicitis observed were: appendicoliths (sensitivity 30.3% and specificity 98.8%), fluid collections (sensitivity 19.7%, specificity 96.5%), cecal enlargement (sensitivity 21.2%, specificity 97.7%), inflammation of pericecal fat (sensitivity 72.7%, specificity 90.7%), fascial thickening (sensitivity 48.5%, specificity 91.9%) and an appendix measuring more than 6 mm (sensitivity 78.8%, specificity 94.3%). Adenopathy and free peritoneal fluid were not significantly related to appendicitis. The presence of a normal appendix filled with air or contrast material had an elevated negative predictive value with respect to appendicitis. In 35 of the 94 cases with negative CT scans, the images suggested alternative diagnoses. CT is a highly reliable diagnostic method for appendicitis. The observation of an appendix filled with air or contrast material has an elevated negative predictive value. The presence of appendicoliths has an elevated positive predictive value. (Author) 29 refs.

  4. Immediate adverse reactions to intravenous iodinated contrast media in computed tomography Reacciones adversas inmediatas al contraste yodado intravenoso en tomografía computarizada Reações adversas imediatas ao contraste iodado intravenoso em tomografia computadorizada

    Directory of Open Access Journals (Sweden)

    Beatriz Cavalcanti Juchem

    2007-02-01

    Full Text Available This exploratory-descriptive, non-experimental quantitative research aimed to learn about immediate adverse reactions to intravenous iodinated contrast media in hospitalized patients submitted to computed tomography at a teaching hospital in the South of Brazil. During the study period, all adverse reactions showed mild intensity, at a frequency of 12.5% with ionic iodinated contrast media, and 1% with non-ionic contrast agent. The extravasation of contrast occurred in 2.2% of the injections in a peripheral vein without complications in any of the cases. The results are within the limits cited in international literature and suggest that tomography service professionals should know their own rates of adverse reactions to iodinated contrast agent, as well as the conditions in which they occur, in order to obtain evidence to evaluate the respective care delivery processes.Investigación cuantitativa del tipo exploratorio-descriptivo, de carácter no experimental. El objetivo consistía en conocer las reacciones adversas inmediatas al contraste yodado intravenoso en pacientes internados, sometidos a tomografía computarizada en un hospital escuela del sur de Brasil. Durante el período del estudio, todas las reacciones adversas tuvieron intensidad leve y una frecuencia del 12,5% con la utilización del contraste yodado iónico, y 1% con contraste no iónico. La extravasación del contraste ocurrió en un 2,2% de las inyecciones en vena periférica, no ocasionando complicaciones en ninguno de los casos. Los índices evidenciados en el presente estudio se mantuvieron dentro de los límites que constan en la revisión de literatura y, entre las recomendaciones, se sugiere que los servicios de tomografía conozcan los propios índices de reacciones adversas al contraste yodado y las condiciones en que ocurren, con la finalidad de obtener evidencias para evaluación de los respectivos procesos asistenciales.Pesquisa quantitativa, explorat

  5. On renormalization of axial anomaly

    International Nuclear Information System (INIS)

    Efremov, A.V.; Teryaev, O.V.

    1989-01-01

    It is shown that multiplicative renormalization of the axial singlet current results in renormalization of the axial anomaly in all orders of perturbation theory. It is a necessary condition for the Adler - Bardeen theorem being valid. 10 refs.; 2 figs

  6. Axial tomographic scanner

    International Nuclear Information System (INIS)

    1976-01-01

    An axial tomographic system is described comprising axial tomographic means for collecting sets of data corresponding to the transmission or absorption of a number of beams of penetrating radiation through a planar slice of an object. It includes means to locate an object to be analyzed, a source and detector for directing one or more beams of penetrating radiation through the object from the source to the detector, and means to rotate (and optionally translate) the source as well as means to process the collected sets of data. Data collection, data processing, and data display can each be conducted independently of each other. An additional advantage of the system described is that the raw data (i.e., the originally collected data) are not destroyed by the data processing but instead are retained intact for further reference or use, if needed

  7. Estudio de la energía y el medio ambiente: una propuesta didáctica computarizada

    Directory of Open Access Journals (Sweden)

    Edwin Francisco Bonza Camargo

    2009-09-01

    Full Text Available El objetivo de este proyecto es desarrollar un material educativo computarizado, MEC, para la enseñanza de la energía; contribuyendo de esta manera a solucionar una de las grandes falencias del sistema educativo colombiano: la falta de material didáctico en las aulas de las escuelas y colegios. Además, con la aplicación de este material se aporta a la creación de conciencia en la población escolar hacia un uso más racional de la energía en pro del medio ambiente. El software se diseñó con base en el manejo de lecturas, imágenes, sonidos, videos y animaciones que permiten al estudiante aprender y conceptuar con mayor facilidad sobre un tema tan importante como lo es el de los recursos energéticos renovables y no renovables, abarcando temas tan importantes como la energía solar térmica, que es una posible solución a la crisis energética que se avecina. También, resalta la importancia que tiene la búsqueda de nuevas fuentes de energía que no degraden el medio ambiente.

  8. Critical Axial Load

    Directory of Open Access Journals (Sweden)

    Walt Wells

    2008-01-01

    Full Text Available Our objective in this paper is to solve a second order differential equation for a long, simply supported column member subjected to a lateral axial load using Heun's numerical method. We will use the solution to find the critical load at which the column member will fail due to buckling. We will calculate this load using Euler's derived analytical approach for an exact solution, as well as Euler's Numerical Method. We will then compare the three calculated values to see how much they deviate from one another. During the critical load calculation, it will be necessary to calculate the moment of inertia for the column member.

  9. Validación de una prueba computarizada de lectura inicial en niños escolares colombianos

    Directory of Open Access Journals (Sweden)

    Natalia Cadavid-Ruiz

    2016-01-01

    Full Text Available Con el objetivo de validar la prueba de evaluación de competencia lectora ABCDeti en población infantil colombiana, se evalua - ron 265 niños, entre los 5 y 8 años de edad, que cursaban entre transición y segundo de primaria, residentes en la ciudad de Cali (Co - lombia. Todos los participantes del estudio fueron evaluados con las pruebas ABCDeti y las dimensiones de Habilidades Metalin - güísticas y Lectura de la batería Evaluación Neuropsicológica Infantil. Los resultados demuestran que esta prueba presenta una consistencia interna, para los diferentes gra - dos escolares evaluados, entre .68 y .74. Entre tanto, la validez convergente oscila entre α = .68 a .79 en los grados evaluados. El análisis factorial realizado a los datos recogidos, por grado escolar, explican entre un 45% y 54% la varianza de los datos. En conclusión, la prueba ABCDeti es un instrumento fiable para evaluar la lectura inicial de niños colombianos.

  10. Neuroimagen en niños con epilepsia de difícil control Children with epilepsy of difficult control: Neuroimaging

    Directory of Open Access Journals (Sweden)

    Ileana Valdivia Álvarez

    2009-09-01

    Full Text Available INTRODUCCIÓN. Los actuales estudios de neuroimagen representan un gran avance para el diagnóstico etiológico y pronóstico de la epilepsia infantil. El objetivo del presente estudio fue describir los hallazgos por tomografía axial y resonancia magnética en niños con epilepsias de difícil control y comparar los resultados de estas técnicas. MÉTODOS. Se realizó un estudio descriptivo, longitudinal prospectivo, de 108 niños con diagnóstico de epilepsia de difícil control, ingresados en el Servicio de Neuropediatría del Hospital Pediátrico Docente «Juan Manuel Márquez» entre enero de 2002 y junio de 2006. Se realizaron técnicas imagenológicas por tomografía computarizada (TC y resonancia magnética nuclear (RM. RESULTADOS. Se encontraron alteraciones estructurales del cerebro en el 88 % de los niños, y hubo predominio de lesiones prenatales en la fosa posterior, trastornos de la migración y atrofias secundarias a hipoxia perinatal. Se diagnosticó atrofia cortical localizada, mediante RM, hasta en el 28 % de los niños. CONCLUSIONES. La RM es la técnica de elección para el estudio de pacientes con epilepsia de difícil control, por su especificidad, mayor resolución y relativa inocuidad. Los pacientes con zonas localizadas de atrofia requieren estudios funcionales del cerebro para descartar displasias corticales focales.INTRODUCTION: Current studies of Neuroimaging are a great advance to etiologic and prognostic diagnosis of children epilepsy. The aim of present paper was to describe findings by axial tomography (AT and magnetic resonance (MR in children with epilepsy of difficult control, and to compare results of both techniques. METHODS: A descriptive, longitudinal and prospective study was made in 108 children diagnosed with epilepsy of difficult control, admitted in Neuropediatrics Service of "Juán Manual Márquez" Teaching Children Hospital from January, 2002 to June, 2006. The techniques used were: computed

  11. Axial skeletal CT densitometry

    International Nuclear Information System (INIS)

    Lampmann, L.E.H.

    1982-01-01

    Since the discovery of the Roentgen ray a precise and accurate assessment of bone mineral content has been a challenge to many investigators. A number of methods have been developed but no one satisfied. Considering its technical possibilities computed tomography is very promising in determination of bone mineral content (BMC). The new modality enables BMC estimations in the axial skeletal trabecular bone. CT densitometry can be performed on a normal commercially available third generation whole body CT scanner. No dedicated device in a special clinical set-up is necessary. In this study 106 patients, most of them clinically suspected of osteoporosis, were examined. The new method CT densitometry has been evaluated. The results have been correlated to alternative BMC determination methods. (Auth.)

  12. Dissipative Axial Inflation

    CERN Document Server

    Notari, Alessio

    2016-12-22

    We analyze in detail the background cosmological evolution of a scalar field coupled to a massless abelian gauge field through an axial term $\\frac{\\phi}{f_\\gamma} F \\tilde{F}$, such as in the case of an axion. Gauge fields in this case are known to experience tachyonic growth and therefore can backreact on the background as an effective dissipation into radiation energy density $\\rho_R$, which which can lead to inflation without the need of a flat potential. We analyze the system, for momenta $k$ smaller than the cutoff $f_\\gamma$, including numerically the backreaction. We consider the evolution from a given static initial condition and explicitly show that, if $f_\\gamma$ is smaller than the field excursion $\\phi_0$ by about a factor of at least ${\\cal O} (20)$, there is a friction effect which turns on before that the field can fall down and which can then lead to a very long stage of inflation with a generic potential. In addition we find superimposed oscillations, which would get imprinted on any kind of...

  13. Evaluación de la disponibilidad, utilización y costos de la tomografía computarizada en el estado de Morelos, México Assessment of the availability, utilization, and costs of computerized tomography in Morelos, Mexico

    Directory of Open Access Journals (Sweden)

    John Pérez-Rodríguez

    2002-09-01

    Full Text Available Objetivo. Evaluar la disponibilidad, utilización y costos económicos de la tomografía computarizada (TC en hospitales públicos y privados en el estado de Morelos, México. Material y métodos. Mediante un estudio transversal efectuado entre enero y abril de 1999, se evaluaron cuatro hospitales en el estado de Morelos, dos públicos y dos privados. Se llevaron a cabo entrevistas individuales con los directores, administradores, médicos radiólogos y jefes de mantenimiento. Se realizó un análisis estadístico descriptivo de las variables, disponibilidad, utilización y costos, así como una evaluación integral de la tomografía, haciendo énfasis en la variabilidad de los patrones observados en los hospitales participantes en el estudio. Resultados. La TC es una tecnología utilizada en los hospitales del estado de Morelos desde hace más de 10 años. Aun cuando existen programas de mantenimiento preventivo y correctivo a los equipos de tomografía, sus costos son muy elevados. Además se carece de estrategias que permitan evaluar la tecnología antes de su adquisición y durante su utilización. El estudio no incluyó aspectos relativos a la correcta indicación clínica de la TC, ni a sus posibles efectos secundarios. Conclusiones. Los hallazgos obtenidos a partir de la presente investigación fueron los siguientes: a existe una carencia de procesos de evaluación y gestión tecnológica, que permita a las unidades hospitalarias un manejo eficiente de la tomografía computarizada, y b también se carece de mecanismos para regular la adquisición, evaluar la tecnología y seleccionar las mejores alternativas en función de su efectividad, eficacia, seguridad y accesibilidad.Objective. To assess the availability, utilization, and costs of computerized tomography (CT scan in private and public hospitals in Morelos State, Mexico. Material and Methods. From January to April 1999, a cross-sectional study was carried out in two private and two

  14. Celulitis orbitaria bilateral con endoftalmitis en una paciente con reciente diagnóstico de diabetes mellitus tipo 2

    Directory of Open Access Journals (Sweden)

    Lesley Farrell González

    2014-07-01

    Full Text Available Se presentó una mujer de 74 años al servicio de urgencias del HRAEBI, ISSSTE, el día 2 de septiembre de 2010 con datos de desequilibrio hidroelectrolítico, hipotensión y conjuntivitis bilateral. Sus signos vitales durante su estancia en urgencias fueron: tensión arterial, 80/40 mmHg; temperatura, 38.5 °C; frecuencia respiratoria, 22 rpm; frecuencia cardíaca 89 lpm Se interconsulta al servicio de Oftalmología quienes diagnosticaron celulitis orbitaria bilateral, con no percepción de luz en ambos ojos e igualmente ausencia de reflejos pupilares. Se inició tratamiento con antibióticos intravenosos y se solicitó tomografía computarizada de órbitas y cerebro. Se internó para estabilizar su estado general; durante su estancia se diagnosticó diabetes mellitus y estado inmunosupresivo por datos de candidiasis oral y otros síntomas. La tomografía mostró celulitis orbitaria bilateral con formación de abscesos orbitarios, sin datos de proceso infeccioso a nivel bucal o de senos paranasales. La evolución de la celulitis fue tórpida a pesar de la terapia antibiótica cuádruple (cefotaxima, vancomicina, metronidazol y clindamicina; posteriormente imipenem, clindamicina y vancomicina con desarrollo de endoftalmitis bilateral por lo cual fue necesario eviscerar ambos ojos. Se tomó cultivo directo del vítreo y 3 días después se encontró como germen causal Klebsiella pneumoniae.

  15. Monitorización con potenciales evocados somatosensoriales durante la descompresión occipitocervical en un lactante con acondroplasia: reporte de un caso

    Directory of Open Access Journals (Sweden)

    Diva Paola Ospino Arévalo

    2005-02-01

    Full Text Available Se revisa el caso de un paciente de ocho meses de edad, con acondroplasia y síntomas sugestivos de compresión cervicomedular. Los síntomas incluían convulsiones tónico-clónicas generalizadas, irritabilidad, episodios frecuentes de apnea, control cefálico nulo, flacidez generalizada, reflejos osteotendinosos abolidos y fontanela abombada. Los estudios radiológicos incluyeron tomografía computarizada (TC y resonancia magnética (RM que mostraron la compresión, y signos de mielopatía cervical crónica, esto último fue confirmado con estudio de potenciales evocados somatosensoriales (PESS preoperatorios del nervio mediano. Al paciente se le hicieron descompresión de la fosa posterior y laminectomía de C-1. La monitorización con PESS intraoperatorios continuos se usó para observar los cambios electrofisiológicos que se pueden presentar con la descompresión medular, y además para ayudar a determinar la extensión de la descompresión requerida.

  16. Characterization of Multiflux Axial Compressors

    International Nuclear Information System (INIS)

    Brasnarof, Daniel; Kyung Kyu-Hyung; Rivarola, Martin; Gonzalez Jose; Florido, Pablo; Orellano, Pablo; Bergallo, Juan

    2003-01-01

    In the present work the results of analytical models of performance are compared with experimental data acquired in the multi flux axial compressor test facility, built in The Pilcaniyeu Technological Complex for the SIGMA project.We describe the experimental circuit and the data of the dispersion inside the axial compressor obtained using a tracer gas through one of the annular inlets.The attained results can be used to validate the design code for the multi flux axial compressors and SIGMA industrial plant

  17. Axial gap rotating electrical machine

    Science.gov (United States)

    None

    2016-02-23

    Direct drive rotating electrical machines with axial air gaps are disclosed. In these machines, a rotor ring and stator ring define an axial air gap between them. Sets of gap-maintaining rolling supports bear between the rotor ring and the stator ring at their peripheries to maintain the axial air gap. Also disclosed are wind turbines using these generators, and structures and methods for mounting direct drive rotating electrical generators to the hubs of wind turbines. In particular, the rotor ring of the generator may be carried directly by the hub of a wind turbine to rotate relative to a shaft without being mounted directly to the shaft.

  18. Study of axial magnetic effect

    Energy Technology Data Exchange (ETDEWEB)

    Braguta, Victor [IHEP, Protvino, Moscow region, 142284 Russia ITEP, B. Cheremushkinskaya street 25, Moscow, 117218 (Russian Federation); School of Biomedicine, Far Eastern Federal University, Ajax 10 Building 25, Russian island, Vladivostok, 690922 (Russian Federation); Chernodub, M. N. [CNRS, Laboratoire de Mathématiques et Physique Théorique, Université François-Rabelais Tours, Fédération Denis Poisson, Parc de Grandmont, 37200 Tours, France Department of Physics and Astronomy, University of Gent, Krijgslaan 281, S9, B-9000 Gent (Belgium); School of Biomedicine, Far Eastern Federal University, Ajax 10 Building 25, Russian island, Vladivostok, 690922 (Russian Federation); Goy, V. A. [School of Natural Sciences, Far Eastern Federal University, Sukhanova street 8, Vladivostok, 690950 (Russian Federation); Landsteiner, K. [Instituto de Física Teórica UAM/CSIC, C/ Nicolás Cabrera 13-15, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Molochkov, A. V. [School of Biomedicine, Far Eastern Federal University, Ajax 10 Building 25, Russian island, Vladivostok, 690922 (Russian Federation); Ulybyshev, M. [ITEP, B. Cheremushkinskaya street 25, Moscow, 117218 Russia Institute for Theoretical Problems of Microphysics, Moscow State University, Moscow, 119899 (Russian Federation)

    2016-01-22

    The Axial Magnetic Effect manifests itself as an equilibrium energy flow of massless fermions induced by the axial (chiral) magnetic field. Here we study the Axial Magnetic Effect in the quenched SU(2) lattice gauge theory with massless overlap fermions at finite temperature. We numerically observe that in the low-temperature hadron phase the effect is absent due to the quark confinement. In the high-temperature deconfinement phase the energy flow is an increasing function of the temperature which reaches the predicted asymptotic T{sup 2} behavior at high temperatures. We find, however, that energy flow is about one order of magnitude lower compared to a theoretical prediction.

  19. Dissipative axial inflation

    Energy Technology Data Exchange (ETDEWEB)

    Notari, Alessio [Departament de Física Fondamental i Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, Barcelona, 08028 Spain (Spain); Tywoniuk, Konrad, E-mail: notari@ffn.ub.es, E-mail: konrad.tywoniuk@cern.ch [Theoretical Physics Department, CERN, Geneva (Switzerland)

    2016-12-01

    We analyze in detail the background cosmological evolution of a scalar field coupled to a massless abelian gauge field through an axial term φ/ f {sub γ} F ∼ F , such as in the case of an axion. Gauge fields in this case are known to experience tachyonic growth and therefore can backreact on the background as an effective dissipation into radiation energy density ρ{sub R}, which can lead to inflation without the need of a flat potential. We analyze the system, for momenta k smaller than the cutoff f {sub γ}, including the backreaction numerically. We consider the evolution from a given static initial condition and explicitly show that, if f {sub γ} is smaller than the field excursion φ{sub 0} by about a factor of at least O (20), there is a friction effect which turns on before the field can fall down and which can then lead to a very long stage of inflation with a generic potential. In addition we find superimposed oscillations, which would get imprinted on any kind of perturbations, scalars and tensors. Such oscillations have a period of 4–5 efolds and an amplitude which is typically less than a few percent and decreases linearly with f {sub γ}. We also stress that the curvature perturbation on uniform density slices should be sensitive to slow-roll parameters related to ρ{sub R} rather than φ-dot {sup 2}/2 and we discuss the existence of friction terms acting on the perturbations, although we postpone a calculation of the power spectrum and of non-gaussianity to future work and we simply define and compute suitable slow roll parameters. Finally we stress that this scenario may be realized in the axion case, if the coupling 1/ f {sub γ} to U(1) (photons) is much larger than the coupling 1/ f {sub G} to non-abelian gauge fields (gluons), since the latter sets the range of the potential and therefore the maximal allowed φ{sub 0∼} f {sub G}.

  20. Auxílio da tomografia computadorizada no planejamento pré-operatório de pacientes portadores de escoliose idiopática do adolescente Auxilio de la tomografía computarizada en el plan preoperatorio de pacientes portadores de escoliosis idiopática del adolescente Computed tomography aid in preoperative planning of patients with adolescent idiopathic scoliosis

    Directory of Open Access Journals (Sweden)

    Rodrigo Rezende

    2010-03-01

    á libre de riesgos y complicaciones, necesitando de una mayor curva de aprendizaje por el médico cirujano, así como también de un adecuado plan preoperatorio. Hasta el momento, no hay en la literatura un relato sobre la utilización de la tomografía computarizada en el auxilio quirúrgico de los pacientes con escoliosis. Según lo expuesto, proponemos, en el presente estudio, describir una técnica para el plan preoperatorio con el auxilio de la tomografía computarizada para la fijación de la columna en pacientes con escoliosis idiopática del adolescente, especificando la angulación y el diámetro de los pedículos vertebrales, lo que podrá auxiliar al médico cirujano en el momento de la fijación.The adolescent idiopathic scoliosis is a diagnosed disease in the beginning of puberty, with unknown etiology, characterized by lateral deviation of the spine (above 10°, which is related to vertebral rotation. The form of surgical treatment by spinal fixation with pedicle screws showed better results when compared to other fastening systems, but there are still technical difficulties at the time of passage and the choice of pedicle screws because of vertebral pedicles angle and diameter. Despite its advantages, this technique presents risks and complications, requiring a greater learning curve for the surgeon, as well as an adequate preoperative planning. So far, there is no literature report about the use of computed tomography as an aid to surgical planning of patients with scoliosis. In this light, the present study aims to describe a preoperative planning technique with the aid of computed tomography for spinal fixation in patients with Adolescent Idiopathic Scoliosis, specifying the angle and diameter of the vertebral pedicles, which may help the surgeon in the fixation.

  1. A note on axial symmetries

    International Nuclear Information System (INIS)

    Beetle, Christopher; Wilder, Shawn

    2015-01-01

    This note describes how to characterize and normalize an axial Killing field on a general Riemannian geometry or four-dimensional Lorentzian geometry. No global assumptions are necessary, such as that the orbits of the Killing field all have period 2π. Rather, any Killing field that vanishes at at least one point necessarily has the expected global properties. (note)

  2. Axial structure of the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Veronique Bernard; Latifa Elouadrhiri; Ulf-G Meissner

    2002-01-01

    We review the current status of experimental and theoretical understanding of the axial nucleon structure at low and moderate energies. Topics considered include (quasi)elastic (anti)neutrino-nucleon scattering, charged pion electroproduction off nucleons and ordinary as well as radiative muon capture on the proton.

  3. Axial magnetic field produced by axially and radially magnetized permanent rings

    International Nuclear Information System (INIS)

    Peng, Q.L.; McMurry, S.M.; Coey, J.M.D.

    2004-01-01

    Axial magnetic fields produced by axially and radially magnetized permanent magnet rings were studied. First, the axial magnetic field produced by a current loop is introduced, from which the axial field generated by an infinitely thin solenoid and by an infinitely thin current disk can be derived. Then the axial fields produced by axially and by radially magnetized permanent magnet rings can be obtained. An analytic formula for the axial fields produced by two axially magnetized rings is given. A permanent magnet with a high axial gradient field is fabricated, the measured results agree with the theoretical calculation very well. As an example, the axial periodic field produced by an arrangement of alternating axially and radially magnetized rings has been discussed

  4. View of the Axial Field Spectrometer

    CERN Multimedia

    1980-01-01

    The Axial Field Spectrometer, with the vertical uranium/scintillator calorimeter and the central drift chamber retracted for service. One coil of the Open Axial Field Magnet is just visible to the right.

  5. Axial-Centrifugal Compressor Program

    Science.gov (United States)

    1975-10-01

    Assembly . .. . .... ..... 33 5 Tie Bolt...... .. .. .. .. . *.. .. .. .. .. .. ... 34 6 Axial Compressor Rotor Assembly Runouts . . .. . 34 7 CCV Blow...1.796 Impeller Slip Factor ’Ce2/U 2 ) .91 Impeller Wheel Speed ft/sec 1992.2 Impellet ’.ip Radius in. 3.780 Blade Tip Metal Angle- deg 0 Numbec of Blades...test item to the next Phase V component test. The test vehicle final balance levels and rotor runouts were normal at teardown, and no rubsI were

  6. Electron angular distribution axial channeling

    International Nuclear Information System (INIS)

    Khokonov, A.Kh.; Khokonov, M.Kh.

    1989-01-01

    Angular distributions of ultra-relativistic electrons are calculated in the assumption about presence of statistical equilibrium. Analysis is based on numerical solution of Fokker-Planck type kinetic equation. It is shown that in contrast to case of amorphous medium, the multiple scattering at axial channeling of negative particles results in self-focusing of the initial beam particles and due to it number of electrons moving at an angles to the chain, which are smaller, than critical angle of channeling, may increase by several times as compared to the initial one

  7. Axially alignable nuclear fuel pellets

    International Nuclear Information System (INIS)

    Johansson, E.B.; Klahn, D.H.; Marlowe, M.O.

    1978-01-01

    An axially alignable nuclear fuel pellet of the type stacked in end-to-end relationship within a tubular cladding is described. Fuel cladding failures can occur at pellet interface locations due to mechanical interaction between misaligned fuel pellets and the cladding. Mechanical interaction between the cladding and the fuel pellets loads the cladding and causes increased cladding stresses. Nuclear fuel pellets are provided with an end structure that increases plastic deformation of the pellets at the interface between pellets so that lower alignment forces are required to straighten axially misaligned pellets. Plastic deformation of the pellet ends results in less interactions beween the cladding and the fuel pellets and significantly lowers cladding stresses. The geometry of pellets constructed according to the invention also reduces alignment forces required to straighten fuel pellets that are tilted within the cladding. Plastic deformation of the pellets at the pellet interfaces is increased by providing pellets with at least one end face having a centrally-disposed raised area of convex shape so that the mean temperature and shear stress of the contact area is higher than that of prior art pellets

  8. PWR AXIAL BURNUP PROFILE ANALYSIS

    International Nuclear Information System (INIS)

    J.M. Acaglione

    2003-01-01

    The purpose of this activity is to develop a representative ''limiting'' axial burnup profile for pressurized water reactors (PWRs), which would encompass the isotopic axial variations caused by different assembly irradiation histories, and produce conservative isotopics with respect to criticality. The effect that the low burnup regions near the ends of spent fuel have on system reactivity is termed the ''end-effect''. This calculation will quantify the end-effects associated with Pressurized Water Reactor (PWR) fuel assemblies emplaced in a hypothetical 21 PWR waste package. The scope of this calculation covers an initial enrichment range of 3.0 through 5.0 wt% U-235 and a burnup range of 10 through 50 GWd/MTU. This activity supports the validation of the process for ensuring conservative generation of spent fuel isotopics with respect to criticality safety applications, and the use of burnup credit for commercial spent nuclear fuel. The intended use of these results will be in the development of PWR waste package loading curves, and applications involving burnup credit. Limitations of this evaluation are that the limiting profiles are only confirmed for use with the B andW 15 x 15 fuel assembly design. However, this assembly design is considered bounding of all other typical commercial PWR fuel assembly designs. This calculation is subject to the Quality Assurance Requirements and Description (QARD) because this activity supports investigations of items or barriers on the Q-list (YMP 2001)

  9. Exact axially symmetric galactic dynamos

    Science.gov (United States)

    Henriksen, R. N.; Woodfinden, A.; Irwin, J. A.

    2018-05-01

    We give a selection of exact dynamos in axial symmetry on a galactic scale. These include some steady examples, at least one of which is wholly analytic in terms of simple functions and has been discussed elsewhere. Most solutions are found in terms of special functions, such as associated Lagrange or hypergeometric functions. They may be considered exact in the sense that they are known to any desired accuracy in principle. The new aspect developed here is to present scale-invariant solutions with zero resistivity that are self-similar in time. The time dependence is either a power law or an exponential factor, but since the geometry of the solution is self-similar in time we do not need to fix a time to study it. Several examples are discussed. Our results demonstrate (without the need to invoke any other mechanisms) X-shaped magnetic fields and (axially symmetric) magnetic spiral arms (both of which are well observed and documented) and predict reversing rotation measures in galaxy haloes (now observed in the CHANG-ES sample) as well as the fact that planar magnetic spirals are lifted into the galactic halo.

  10. Measurement and analyses of spectral noise power in computed tomography; Medida y analisis del espectro de potencias del ruido en imagenes de tomografia computarizada

    Energy Technology Data Exchange (ETDEWEB)

    Castro Tejero, P.; Garayoa Roca, J.

    2014-07-01

    Noise is an important feature of image quality. The standard deviation of pixel value in a uniform region has been frequently used as a metric to characterize noise. However, this measure does not provide any information about the noise spatial distribution. A more complete description is given by the Noise Power Spectrum (NPS) which provides both the amount and the spatial correlation of noise. The objective of the present work is to present a methodology and a computing tool to obtain the NPS, in order to analyze its components and study their behaviour for computed tomography (TC) images. Our results show that the major contribution to NPS is a random source for all the explored working conditions. The structural component is constrained to the low frequency region, where it can be as important as the random component. Moreover, we observe that the reconstruction filter and the acquisition technique, axial or helical, have a clear impact on the image noise. (Author)

  11. Axial vector mass spectrum and mixing angles

    International Nuclear Information System (INIS)

    Caffarelli, R.V.; Kang, K.

    1976-01-01

    Spectral sum rules of the axial-vector current and axial-vector current-pseudoscalar field are used to study the axial-vector mass spectrum and mixing angles, as well as the decay constants and mixing angles of the pseudoscalar mesons. In general, the result is quite persuasive for the existence of the Jsup(PC) = 1 ++ multiplet in which one has a canonical D-E mixing. (Auth.)

  12. Electric machines with axial magnetic flux

    Science.gov (United States)

    Nuca, I.; Ambros, T.; Burduniuc, M.; Deaconu, S. I.; Turcanu, A.

    2018-01-01

    The paper contains information on the performance of axial machines compared to cylindrical ones. At the same time, various constructive schemes of synchronous electromechanical converters with permanent magnets and asynchronous with short-circuited rotor are presented. In the developed constructions, the aim is to maximize the usage of the material of the stator windings. The design elements of the axial machine magnetic system are presented. The FEMM application depicted the array of the magnetic field of an axial machine.

  13. Centrifugal and axial compressor control

    CERN Document Server

    McMillan, Gregory K

    2009-01-01

    Control engineers, mechanical engineers and mechanical technicians will learn how to select the proper control systems for axial and centrifugal compressors for proper throughput and surge control, with a particular emphasis on surge control. Readers will learn to understand the importance of transmitter speed, digital controller sample time, and control valve stroking time in helping to prevent surge. Engineers and technicians will find this book to be a highly valuable guide on compressor control schemes and the importance of mitigating costly and sometimes catastrophic surge problems. It can be used as a self-tutorial guide or in the classroom with the book's helpful end-of-chapter questions and exercises and sections for keeping notes.

  14. Axial channeling in electron diffraction

    International Nuclear Information System (INIS)

    Ichimiya, A.; Lehmpfuhl, G.

    1978-01-01

    Kossel patterns from Silicon and Niobium were obtained with a convergent electron beam. An intensity maximum in the direction of the zone axes [001] and [111] of Nb was interpreted as axial channeling. The intensity distribution in Kossel patterns was calculated by means of the Bloch wave picture of the dynamical theory of electron diffraction. Particularly zone axis patterns were calculated for different substance-energy combinations and they were compared with experimental observations. The intensity distribution in the calculated Kossel patterns was very sensitive to the model of absorption and it was found that a treatment of the absorption close to the model of Humphreys and Hirsch [Phil. Mag. 18, 115 (1968)] gave the best agreement with the experimental observations. Furthermore it is shown which Bloch waves are important for the intensity distribution in the Kossel patterns, how they are absorbed and how they change with energy. (orig.) [de

  15. Axial channeling of uttrarelativistic electrons

    Energy Technology Data Exchange (ETDEWEB)

    Telegin, V.I.; Khokonov, M.Kh. (Moskovskij Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Yadernoj Fiziki)

    1982-07-01

    The dynamics of motion of ultrarelativistic electrons under axial channeling conditions is investigated. The analysis is based on the solution of the kinetic equation obtained recently by Beloshitsky and Kumakhov. The particle dechanneling function is investigated as depending on the type of a crystal, particle energy and angle of entrance into the single crystal. It is found that for most of the beam the major diffusion mechanism is scattering by electrons. It is shown that an optimal depth range exists for which the fraction of channeled particles sharply increases at the expense of the quasi-channeled particles. In a number of cases the dechanneling length for crystals with high atomic numbers may be greater than that of light elements.

  16. Axial channeling of uttrarelativistic electrons

    International Nuclear Information System (INIS)

    Telegin, V.I.; Khokonov, M.Kh.

    1982-01-01

    The dynamics of motion of ultrarelativistic electrons under axial channeling conditions is investigated. The analysis is based on the solution of the kinetic equation obtained recently by Beloshitsky and Kumakhov. The particle dechanneling function is investigated as depending on the type of a crystal, particle energy and angle of entrance into the single crystal. It is found that for most of the beam the major diffusion mechanism is scattering by electrons. It is shown that an optimal depth range exists for which the fraction of channeled particles sharply increases at the expense of the quasi-channeled particles. In a number of cases the dechanneling length for crystals with high atomic numbers may be greater than that of light elements

  17. Bone Disease in Axial Spondyloarthritis.

    Science.gov (United States)

    Van Mechelen, Margot; Gulino, Giulia Rossana; de Vlam, Kurt; Lories, Rik

    2018-05-01

    Axial spondyloarthritis is a chronic inflammatory skeletal disorder with an important burden of disease, affecting the spine and sacroiliac joints and typically presenting in young adults. Ankylosing spondylitis, diagnosed by the presence of structural changes to the skeleton, is the prototype of this disease group. Bone disease in axial spondyloarthritis is a complex phenomenon with the coexistence of bone loss and new bone formation, both contributing to the morbidity of the disease, in addition to pain caused by inflammation. The skeletal structural changes respectively lead to increased fracture risk and to permanent disability caused by ankylosis of the sacroiliac joints and the spine. The mechanism of this new bone formation leading to ankylosis is insufficiently known. The process appears to originate from entheses, specialized structures that provide a transition zone in which tendon and ligaments insert into the underlying bone. Growth factor signaling pathways such as bone morphogenetic proteins, Wnts, and Hedgehogs have been identified as molecular drivers of new bone formation, but the relationship between inflammation and activation of these pathways remains debated. Long-standing control of inflammation appears necessary to avoid ankylosis. Recent evidence and concepts suggest an important role for biomechanical factors in both the onset and progression of the disease. With regard to new bone formation, these processes can be understood as ectopic repair responses secondary to inflammation-induced bone loss and instability. In this review, we discuss the clinical implications of the skeletal changes as well as the underlying molecular mechanisms, the relation between inflammation and new bone formation, and the potential role of biomechanical stress.

  18. Resolution of axial shear strain elastography

    International Nuclear Information System (INIS)

    Thitaikumar, Arun; Righetti, Raffaella; Krouskop, Thomas A; Ophir, Jonathan

    2006-01-01

    The technique of mapping the local axial component of the shear strain due to quasi-static axial compression is defined as axial shear strain elastography. In this paper, the spatial resolution of axial shear strain elastography is investigated through simulations, using an elastically stiff cylindrical lesion embedded in a homogeneously softer background. Resolution was defined as the smallest size of the inclusion for which the strain value at the inclusion/background interface was greater than the average of the axial shear strain values at the interface and inside the inclusion. The resolution was measured from the axial shear strain profile oriented at 45 0 to the axis of beam propagation, due to the absence of axial shear strain along the normal directions. The effects of the ultrasound system parameters such as bandwidth, beamwidth and transducer element pitch along with signal processing parameters such as correlation window length (W) and axial shift (ΔW) on the estimated resolution were investigated. The results show that the resolution (at 45 0 orientation) is determined by the bandwidth and the beamwidth. However, the upper bound on the resolution is limited by the larger of the beamwidth and the window length, which is scaled inversely to the bandwidth. The results also show that the resolution is proportional to the pitch and not significantly affected by the axial window shift

  19. Origin of axial current in scyllac

    International Nuclear Information System (INIS)

    Sugisaki, K.

    1975-12-01

    The origin of the axial current observed in Scyllac (a high beta stellarator experiment) is discussed. A shaped coil and/or helical winding produce rotational transform which links magnetic lines of force to the plasma column and the axial current is induced electromagnetically. This phenomenon is inherent in a pulsed high-beta stellarator. The rotational transform produced by the induced axial current is much smaller than that associated with the l = 1, 0 equilibrium fields. The effect of the axial current on the equilibrium and stability of the plasma column is thus small. It is also shown that the magnetic field shear near a plasma surface is very strong

  20. Radial and axial compression of pure electron

    International Nuclear Information System (INIS)

    Park, Y.; Soga, Y.; Mihara, Y.; Takeda, M.; Kamada, K.

    2013-01-01

    Experimental studies are carried out on compression of the density distribution of a pure electron plasma confined in a Malmberg-Penning Trap in Kanazawa University. More than six times increase of the on-axis density is observed under application of an external rotating electric field that couples to low-order Trivelpiece-Gould modes. Axial compression of the density distribution with the axial length of a factor of two is achieved by controlling the confining potential at both ends of the plasma. Substantial increase of the axial kinetic energy is observed during the axial compression. (author)

  1. Diagnóstico y tratamiento de pacientes con linfomas primarios del sistema nervioso central (LPSN y sindrome de inmunodeficiencia adquirida (SIDA

    Directory of Open Access Journals (Sweden)

    Luis E Raez

    1999-07-01

    Full Text Available La incidencia del linfoma primario del sistema nervioso central (LPSNC ha crecido rápidamente. El LPSNC as una complicación letal en pacientes con SIDA. Objetivo: Nuestro objetivo fue estudiar la historia natural, métodos diagnósticos, al tratamiento y los factores pronósticos para la sobrevida de 75 pacientes con LPSNC y SIDA seguidos en el Jackson Memorial Hospital/Universidad de Miami. Resultados: La edad media fue de 37 años. El 84% de los pacientes eran hombres y el 55% hispanos. Factores de riesgo más comunes para SIDA fueron homosexualidad y múltiples compañeros sexuales. La cuenta promedio de CD4 fue de 15/ul y al promedio de LDH fue 1.5 veces al normal. La tomografía computarizada del cerebro mostraba lesiones múltiples en el 44% de los pacientes. Gammagrafia computarizada de emisión de fotones con talio-201 (SPECT del cerebro se realizó en 2/3 de los pacientes. Las histologías más comunes en las biopsias fueron: linfoma inmunoblástico y linfoma de células grandes. La radiación craneana fue ineficiente en el 50% de los pacientes tratados. La sobrevida promedio del grupo fue de 2.2 meses. Análisis univariado y multivariado mostraron que la mayor sobrevida se asociaba con una buena capacidad funcional (ECOG=1-2 vs 3-4. La presencia previa de infecciones oportunistas, la presencia de factores de riesgo de SIDA, las cuentas de CD4, niveles de LDH y raza no mostraron influencia en la sobrevida. Conclusiones: LPSNC es una neoplasia con pronóstico muy pobre y corta sobrevida aun con radioterapia del SNC. La capacidad funcional parece ser al factor de sobrevida más importante. No se encontraron diferencias en la presentación clínica ni el resultado entre pacientes hispanos y no hispanos. ( Rev Med Hered 1999; 10:96-104 .

  2. LIPOMA CEREBRAL EN CUERPO CALLOSO: HALLAZGO INCIDENTAL EN PACIENTE CON EVENTO CEREBROVASCULAR

    Directory of Open Access Journals (Sweden)

    Gloria Cárcamo-Portillo

    2016-07-01

    Full Text Available Los lipomas intracraneales son lesiones infrecuentes y benignas que representan el 0,03 al 0,08% de todas las masas intracraneales. Estos se encuentran relacionados a un defecto de la línea media debido a un mal cierre del tubo neural; lo que conlleva a una mala diferenciación y una persistencia anormal de la meninge primitiva con posterior diferenciación al tejido adiposo. La mitad de los casos permanecen asintomáticos y son diagnosticados como un hallazgo incidental en los estudios imagenológicos. Sin embargo, otros casos se asocian a sintomatología neurológica como retraso psicomotor, cefalea, epilepsia y parálisis cerebral. Se presenta el caso de una paciente de 46 años de edad, con antecedentes de hipertensión arterial y diabetes mellitus tipo 2; que cursa con sintomatología de Evento Cerebrovascular Isquémico por lo que le realizan –una Tomografía Computarizada (TC y una Resonancia Magnética (RM. En el reporte se describen múltiples infartos a nivel del hemisferio cerebral izquierdo mientras que al nivel de la línea media se observó una imagen compatible con lipoma cerebral que afectaba el rostro, la rodilla y la porción anterior del cuerpo calloso. La identificación de este hallazgo fue incidental. Palabras claves: Lipoma Cerebral; Cuerpo Calloso; Resonancia Magnética; Accidente Cerebrovascular. (Fuente: DeCS BIREME.

  3. Stochastic quantization for the axial model

    International Nuclear Information System (INIS)

    Farina, C.; Montani, H.; Albuquerque, L.C.

    1991-01-01

    We use bosonization ideas to solve the axial model in the stochastic quantization framework. We obtain the fermion propagator of the theory decoupling directly the Langevin equation, instead of the Fokker-Planck equation. In the Appendix we calculate explicitly the anomalous divergence of the axial-vector current by using a regularization that does not break the Markovian character of the stochastic process

  4. Health and imaging outcomes in axial spondyloarthritis

    NARCIS (Netherlands)

    Machado, P.M.

    2016-01-01

    This thesis focuses on the assessment and monitoring of health and imaging outcomes in axial spondyloarthritis (SpA) and the relationship between these outcomes. Four major contributions to the understanding and management of axial SpA were made: 1) the improvement and facilitation of the assessment

  5. Axial anomalies of Lifshitz fermions

    CERN Document Server

    Bakas, Ioannis

    2011-01-01

    We compute the axial anomaly of a Lifshitz fermion theory with anisotropic scaling z=3 which is minimally coupled to geometry in 3+1 space-time dimensions. We find that the result is identical to the relativistic case using path integral methods. An independent verification is provided by showing with spectral methods that the eta-invariant of the Dirac and Lifshitz fermion operators in three dimensions are equal. Thus, by the integrated form of the anomaly, the index of the Dirac operator still accounts for the possible breakdown of chiral symmetry in non-relativistic theories of gravity. We apply this framework to the recently constructed gravitational instanton backgrounds of Horava-Lifshitz theory and find that the index is non-zero provided that the space-time foliation admits leaves with harmonic spinors. Using Hitchin's construction of harmonic spinors on Berger spheres, we obtain explicit results for the index of the fermion operator on all such gravitational instanton backgrounds with SU(2)xU(1) isom...

  6. Avaliação de seis anos de fraturas cervicais subaxiais Evaluación de seis años de fracturas cervicales subaxiales Evaluation of six years of cervical sub-axial fractures

    Directory of Open Access Journals (Sweden)

    Leonardo Franco Pinheiro Gaia

    2013-01-01

    ón (AO. Se utilizaron radiografías en las incidencias frontal y lateral y tomografía computarizada, para dividir las fracturas en A (compresión, B (distracción y C (rotación, de acuerdo con el patrón de presentación. Se analizaron los siguientes parámetros: sexo, edad, clasificación AO, mecanismo de trauma, presencia de déficit neurológico y tratamiento quirúrgico o conservador. RESULTADOS: Fueron analizadas 264 historias clínicas, siendo 216 pacientes hombres e 48 mujeres. La media de edad de éstos pacientes fue de 38,55 años. El mecanismo de trauma más común de las fracturas cervicales subaxiales fue el accidente automovilístico, con 84 casos. En cuanto al tipo de fractura según la clasificación AO, la más frecuente fue el tipo B. De los casos evaluados, 136 pacientes presentaron déficit neurológico parcial o completo. El tratamiento quirúrgico fue realizado en 166 casos. CONCLUSIÓN: Queda claro que las fracturas cervicales representan un importante problema para la salud pública y privada en Brasil. La prevención de fracturas cervicales presenta la mejor relación costo beneficio en el abordaje de éstas lesiones.OBJECTIVE: Retrospectively assess the factors related to cervical trauma, according to the type of fracture based on the AO classification, taking into account etiological and epidemiological aspects of the event. METHODS: Records of patients with cervical fractures were retrospectively reviewed, from 2004 to 2009. The sub-axial fractures (C3-C7 were studied because they fit into only one classification (AO. Frontal and lateral x-rays were used as well as CTs to divide the fractures into A (compression, B (distraction and C (rotation, in accordance with the presented pattern. The following parameters were assessed: gender, age, AO classification, trauma mechanism, presence of neurological deficit, and conservative or surgical treatment. RESULTS: The study included 264 records from the spine, where 216 patients were male and 48

  7. Evaluación computarizada del terreno para una finca en Tenjo-Colombia Computerized land evaluation to a farm in Tenjo-Colombia

    Directory of Open Access Journals (Sweden)

    Madero Morales Edgar Enrique

    1993-12-01

    Full Text Available

    Se empleó el sistema automatizado ALES, un programa de computador que permite al evaluador construir un sistema experto para evaluar terrenos. Para el caso las entidades evaluadas tuvieron en cuenta consociaciones con contenido pedológico de fases de serie de suelos y, el balance hídrico histórico de la zona. Para cada uso escogido (cebada, maíz y la asociación de pastos kikuyotetralite se construyó la lista de requerimientos y una lista de características del terreno, de acuerdo con las condiciones locales de la finca. El estudio tuvo cuatro componentes: un modelo para describir cada uso en términos físicos y económicos; un modelo para describir las unidades de terreno a ser evaluadas; un modelo para armonizar los anteriores componentes y determinar la aptitud de cada terreno para los usos propuestos; y la presentación de resultados desde los puntos de vista físico, agronómico y económico. Los suelos evaluados presentaron un patrón muy influenciado por la presencia de ceniza volcánica y con predominio de los grandes campos Hapludalf y Dystrandept. Los factores que afectan el rendimiento de la cosecha influyen en una mayor medida sobre la rentabilidad de los usos estudiados, que los factores que afectan los costos de producción. Ganadería para leche es el más rentable de los usos planteados pero requiere mayor infraestructura y acceso al crédito; cebada es ideal porque es relativamente más rústica, no necesita alta inversión de capital y difícilmente deja pérdidas. Maíz para grano no es recomendable debido al precio actual de sustentación.

    The cornputarized programme ALES (Automated Land Evaluation System was employed here, it permiting the user or evaluator to construct and expert system, based on established FAO (1976 methodology. This system can be employed in different scales of studies; for this case the entities were calculated in relation to the pedological content of soil phases series taking as base

  8. Modernity: A new axial (era culture?

    Directory of Open Access Journals (Sweden)

    Wolfgang Schluchter

    2017-10-01

    Full Text Available The proposition of an axial age, lasting roughly from 800 to 200 B.C. and occurring in major civilizations (China, India, Near East independent of each other, first introduced by Alfred Weber and Karl Jaspers, then further developed by Robert Bellah and S. N. Eisenstadt among others, implied from the outset the question whether there has been a second axial age, leading to modernity, and if so, whether this second axial age consists in a secularization of the achievements of the first axial age. In this article it is argued that the notion of a second axial age is meaningful, but that the emergence of modernity can›t be accounted for in terms of secularization of the achievements of the first axial age. Rather, a new axial principle was institutionalized which separates the modern from the premodern world. This new principle is spelled out with reference to Hans Blumenberg, Charles Taylor and especially Max Weber. The emphasis is on the dialectics of disenchantment and the place of religion in a secular age

  9. Development of submersible axial pump for wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Jeong Eui [Kangwon Nat' l Univ., Chuncheon (Korea, Republic of)

    2013-02-15

    This study was performed to develop a high efficiency submersible axial pump for concentration wastewater treatment. To do this, we simulated the effect of some parameters such as the axial twist angle of a blade({beta}), the radial twist angle of a blade({alpha}) and the length of a blade ({iota}) on pump efficiency using commercial code, ANSYS CFX and BladeGen. The results showed that the axial twist angle of a blade({beta}) was the most sensible parameter on the pump efficiency. And the pump efficiency had a maximum at {beta}=20.deg, {alpha}=110.deg and {iota}=240mm.

  10. sizing of wind powered axial flux permanent magnet alternator using

    African Journals Online (AJOL)

    user

    2016-10-04

    Oct 4, 2016 ... Keywords: Wind-Power, Axial flux, Axial Flux Permanent Machines (AFPM), Axial Flux Permanent Magnet ... energy for power generation, a high constraint is the .... arrangements as Single-Rotor Single-Stator Structure.

  11. VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR

    African Journals Online (AJOL)

    Dr Obe

    1984-09-01

    Sep 1, 1984 ... VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR by. L. A. Agu ... order as that of the screw-thread motor can be obtained. LIST OF .... The n stator have equal non- magnetic spacers .... induction motor. An.

  12. Precision axial translator with high stability.

    Science.gov (United States)

    Bösch, M A

    1979-08-01

    We describe a new type of translator which is inherently stable against torsion and twisting. This concentric translator is also ideally suited for precise axial motion with clearance of the center line.

  13. Axial force measurement for esophageal function testing

    DEFF Research Database (Denmark)

    Gravesen, Flemming Holbæk; Funch-Jensen, Peter; Gregersen, Hans

    2009-01-01

    force (force in radial direction) whereas the bolus moves along the length of esophagus in a distal direction. Force measurements in the longitudinal (axial) direction provide a more direct measure of esophageal transport function. The technique used to record axial force has developed from external...... force transducers over in-vivo strain gauges of various sizes to electrical impedance based measurements. The amplitude and duration of the axial force has been shown to be as reliable as manometry. Normal, as well as abnormal, manometric recordings occur with normal bolus transit, which have been...... documented using imaging modalities such as radiography and scintigraphy. This inconsistency using manometry has also been documented by axial force recordings. This underlines the lack of information when diagnostics are based on manometry alone. Increasing the volume of a bag mounted on a probe...

  14. Theorem on axially symmetric gravitational vacuum configurations

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulos, A; Le Denmat, G [Paris-6 Univ., 75 (France). Inst. Henri Poincare

    1977-01-24

    A theorem is proved which asserts the non-existence of axially symmetric gravitational vacuum configurations with non-stationary rotation only. The eventual consequences in black-hole physics are suggested.

  15. Buoyant Helical Twin-Axial Wire Antenna

    Science.gov (United States)

    2016-11-15

    February 2017 The below identified patent application is available for licensing. Requests for information should be addressed to...300169 1 of 9 BUOYANT HELICAL TWIN-AXIAL WIRE ANTENNA CROSS REFERENCE TO OTHER PATENT APPLICATIONS [0001] This application is a divisional...application and claims the benefit of the filing date of United States Patent Application No. 14/280,889; filed on May 19, 2014; and entitled “Twin-Axial

  16. Nonperturbative Aspects of Axial Vector Vertex

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; CHEN Xiang-Song; WANG Fan; CHANG Chao-Hsi; ZHAO En-Guang

    2002-01-01

    It is shown how the axial vector current of current quarks is related to that of constituent quarks within the framework of the global color symmetry model.Gluon dressing of the axial vector vertex and the quark self-energy functions are described by the inhomogeneous Bethe-Salpeter equation in the ladder approximation and the Schwinger Dyson equation in the rainbow approximation,respectively.

  17. High temperature co-axial winding transformers

    Science.gov (United States)

    Divan, Deepakraj M.; Novotny, Donald W.

    1993-01-01

    The analysis and design of co-axial winding transformers is presented. The design equations are derived and the different design approaches are discussed. One of the most important features of co-axial winding transformers is the fact that the leakage inductance is well controlled and can be made low. This is not the case in conventional winding transformers. In addition, the power density of co-axial winding transformers is higher than conventional ones. Hence, using co-axial winding transformers in a certain converter topology improves the power density of the converter. The design methodology used in meeting the proposed specifications of the co-axial winding transformer specifications are presented and discussed. The final transformer design was constructed in the lab. Co-axial winding transformers proved to be a good choice for high power density and high frequency applications. They have a more predictable performance compared with conventional transformers. In addition, the leakage inductance of the transformer can be controlled easily to suit a specific application. For space applications, one major concern is the extraction of heat from power apparatus to prevent excessive heating and hence damaging of these units. Because of the vacuum environment, the only way to extract heat is by using a cold plate. One advantage of co-axial winding transformers is that the surface area available to extract heat from is very large compared to conventional transformers. This stems from the unique structure of the co-axial transformer where the whole core surface area is exposed and can be utilized for cooling effectively. This is a crucial issue here since most of the losses are core losses.

  18. Dechanneling function for relativistic axially channeled electrons

    International Nuclear Information System (INIS)

    Muralev, V.A.; Telegin, V.I.

    1981-01-01

    Behaviour of the x(t) dechanneling function depending on the depth is theoretically studied. Theoretical consideration of x(t) for axial channeled relativistic electrons in anisotropic medium results in two-dimensional kinetic equation with mixed derivatives of the parabolic type. The kinetic equation in the approximation of the continuous Lindchard model for relativistic axial channeled electrons is numerically solved. The depth dependence of the x(t) dechanneling function is obtained [ru

  19. Axial forces in centrifugal compressor couplings

    Science.gov (United States)

    Ivanov, A. N.; Ivanov, N. M.; Yun, V. K.

    2017-08-01

    The article presents the results of the theoretical and experimental investigation of axial forces arising in the toothed and plate couplings of centrifugal compressor shaft lines. Additional loads on the thrust bearing are considered that can develop in the toothed couplings as a result of coupled rotors misalignment. Design relationships to evaluate the level of axial forces and recommendations for their reduction in the operating conditions are given.

  20. Singlet axial constant from QCD sum rules

    International Nuclear Information System (INIS)

    Belitskij, A.V.; Teryaev, O.V.

    1995-01-01

    We analyze the singlet axial form factor of the proton for small momentum transferred in the framework of QCD sum rules using the interpolating nucleon current which explicitly accounts for the gluonic degrees of freedom. As the result we come to the quantitative prediction of the singlet axial constant. It is shown that the bilocal power corrections play the most important role in the analysis. 21 refs., 3 figs

  1. Computer axial tomography in geosciences

    International Nuclear Information System (INIS)

    Duliu, Octavian G.

    2002-01-01

    Computer Axial Tomography (CAT) is one of the most adequate non-invasive techniques for the investigation of the internal structure of a large category of objects. Initially designed for medical investigations, this technique, based on the attenuation of X- or gamma-ray (and in some cases neutrons), generates digital images which map the numerical values of the linear attenuation coefficient of a section or of the entire volume of the investigated sample. Shortly after its application in medicine, CAT has been successfully used in archaeology, life sciences, and geosciences as well as for the industrial materials non-destructive testing. Depending on the energy of the utilized radiation as well as on the effective atomic number of the sample, CAT can provide with a spatial resolution of 0.01 - 0.5 mm, quantitative as well as qualitative information concerning local density, porosity or chemical composition of the sample. At present two types of axial Computer Tomographs (CT) are in use. One category, consisting of medical as well as industrial CT is equipped with X-ray tubes while the other uses isotopic gamma-ray sources. CT provided with intense X-ray sources (equivalent to 12-15 kCi or 450-550 TBq) has the advantage of an extremely short running time (a few seconds and even less) but presents some disadvantages known as beam hardening and absorption edge effects. These effects, intrinsically related to the polychromatic nature of the X-rays generated by classical tubes, need special mathematical or physical corrections. A polychromatic X-ray beam can be made almost monochromatic by means of crystal diffraction or by using adequate multicomponent filters, but these devices are costly and considerably diminish the output of X-ray generators. In the case of CT of the second type, monochromatic gamma-rays generated by radioisotopic sources, such as 169 Yb (50.4 keV), 241 Am (59 keV), 192 Ir (310.5 and 469.1 keV ) or 137 Cs (662.7 keV), are used in combination with

  2. Hyperquenched hyaloclastites from Axial Seamount

    Science.gov (United States)

    Zezin, D.; Helo, C.; Richard, D.; Clague, D. A.; Dingwell, D. B.; Stix, J.

    2009-12-01

    We determined apparent cooling rates for basaltic hyaloclastites from Axial caldera, Juan de Fuca Ridge. Samples originate from different stratigraphic layers within the unconsolidated volcaniclastic sequences, on flanks of the volcanic edifice. Water depth is ~1400 m below sea level. The hyaloclastite glass fragments comprise two principal morphologies: (1) angular fragments, and (2) thin glassy melt films interpreted as bubble walls, called deep-sea limu o Pele. A natural cooling rate was estimated for each sample of ~50 carefully selected glass shards. The heat capacity was first measured with a differential scanning calorimeter in two heating scans with heating rates of 20 K/min, and a matching cooling rate between those scans. The fictive temperatures Tf were then determined from both heating cycles, and the natural cooling rate derived by the non-Arrhenian relationship between Tf and cooling rate. All samples display hyperquenched states, manifested in a strong exothermic energy release during the initial heating cycle before reaching the glass transition. Cooling rates range from 10 6.73 K/s to 10 3.94 K/s for the limu, and 10 4.92 K/s to 10 2.34 K/s for the angular fragments. Almost all samples of limu shards show elevated cooling rates compared to their angular counterparts of comparable grain mass. In addition, the exothermic part of the enthalpy curves reveal two superimposed relaxation domains, the main broad exothermal peak, ranging from ~350 K to the onset of the glass transition, and a small subordinate peak/shoulder occurring between 550 K and 700 K. The magnitude of the latter varies from clearly identifiable to nearly absent, and tends to be more pronounced in curves obtained from angular fragments. The main exothermal peak is related to the frozen-in structure of the glass and consequently to its thermal history when passing through the glass transition. The subordinate peak may represent strain rate-induced and tensile stress accumulation

  3. Quiste sinovial en articulación interapofisaria lumbar. Una causa infrecuente de lumbociática

    OpenAIRE

    Villas, C. (Carlos); Leyes, M. (Manuel)

    1997-01-01

    Los quistes sinoviales de las articulaciones facetarias pueden ser asintomáticos o provocar dolor lumbar, con o sin clínica radicular. Se considera que son secundarios a traumatismos o a degeneración articular, y ocurren con mayor frecuencia en pacientes con espondi lolistesis. El diagnóstico se establece con la tomografía axial computarizada o la resonancia magnética, que mues tran una lesión quísti ca adyacente a la faceta articu lar. Realizamos una revis...

  4. Vector and axial constants of the baryon decuplet

    International Nuclear Information System (INIS)

    Belyaev, V.M.; Blok, B.Y.; Kogan, Y.I.

    1985-01-01

    On the basis of the QCD sum rules for the polarization operator in external axial and vector fields we determine the vector and axial transition constants in the 3/2 + baryon decuplet. We show that the renormalization of the axial constant is due to the interaction of the external axial field with the quark condensate

  5. Δ(1232) Axial Charge and Form Factors from Lattice QCD

    International Nuclear Information System (INIS)

    Alexandrou, Constantia; Gregory, Eric B.; Korzec, Tomasz; Koutsou, Giannis; Negele, John W.; Sato, Toru; Tsapalis, Antonios

    2011-01-01

    We present the first calculation on the Δ axial vector and pseudoscalar form factors using lattice QCD. Two Goldberger-Treiman relations are derived and examined. A combined chiral fit is performed to the nucleon axial charge, N to Δ axial transition coupling constant and Δ axial charge.

  6. Using axial magnetized permanent rings to build axial gradient magnetic field

    International Nuclear Information System (INIS)

    Peng Quanling

    2003-01-01

    Axial field produced by an axially magnetized permanent ring was studied. For two permanent magnet rings, if they are magnetized in the same direction, a nearly uniform axial field can be produced; if they are magnetized in opposite direction, an axial gradient field can be produced in the region between the two permanent rings, with the field strength changing from -B 0 to B 0 . A high gradient axial magnetic field has been built by using two axially magnetized permanent rings, the measured field results agree with the PANDIRA calculation very well. It is desirable that the field gradient can be varied to match various requirements. A method to produce the variable gradient field is presented. Axial gradient field can also be used as a beam focusing facility for linear accelerator if axial periodic field can be produced. Its magnetic field is similar to that of a solenoid, in which, large stray field will leak to the outside environment. A method for shielding the outside stray field is discussed

  7. Optimization of residual heat removal pump axial thrust and axial bearing

    International Nuclear Information System (INIS)

    Schubert, F.

    1996-01-01

    The residual heat removal (RHR) pumps of German 1300 megawatt pressurized-water reactor (PWR) power plants are of the single stage end suction type with volute casing or with diffuser and forged circular casing. Due to the service conditions the pumps have to cover the full capacity range as well as a big variation in suction static pressure. This results in a big difference in the axial thrust that has to be borne by the axial bearing. Because these pumps are designed to operate without auxiliary systems (things that do not exist can not fail), they are equipped with antifriction bearings and sump oil lubrication. To minimize the heat production within the bearing casing, a number of PWR plants have pumps with combined axial/radial bearings of the ball type. Due to the fact that the maximum axial thrust caused by static pressure and hydrodynamic forces on the impeller is too big to be borne by that type of axial bearing, the impellers were designed to produce a hydrodynamic axial force that counteracts the static axial force. Thus, the resulting axial thrust may change direction when the static pressure varies

  8. Optimization of residual heat removal pump axial thrust and axial bearing

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, F.

    1996-12-01

    The residual heat removal (RHR) pumps of German 1300 megawatt pressurized-water reactor (PWR) power plants are of the single stage end suction type with volute casing or with diffuser and forged circular casing. Due to the service conditions the pumps have to cover the full capacity range as well as a big variation in suction static pressure. This results in a big difference in the axial thrust that has to be borne by the axial bearing. Because these pumps are designed to operate without auxiliary systems (things that do not exist can not fail), they are equipped with antifriction bearings and sump oil lubrication. To minimize the heat production within the bearing casing, a number of PWR plants have pumps with combined axial/radial bearings of the ball type. Due to the fact that the maximum axial thrust caused by static pressure and hydrodynamic forces on the impeller is too big to be borne by that type of axial bearing, the impellers were designed to produce a hydrodynamic axial force that counteracts the static axial force. Thus, the resulting axial thrust may change direction when the static pressure varies.

  9. Valor de la resonancia magnética de imágenes en pacientes con enfermedad cerebrovascular isquémica Evaluation of the magnetic resonance imaging in patient with ischemic cerebrovascular disease

    Directory of Open Access Journals (Sweden)

    Laura María Pons Porrata

    2009-04-01

    Full Text Available La resonancia magnética de imágenes permite investigar aspectos morfológicos y funcionales del cerebro, lo cual es sumamente útil para diagnosticar enfermedades neurológicas, incluidas las cerebrovasculares y, por supuesto, la isquemia cerebral en las primeras horas de ocurrida, de modo que facilita seguir la evolución del ictus, reducir la zona de necrosis y garantizar una mejor calidad de vida de los pacientes. A diferencia de la tomografía y la angiografía no utiliza radiaciones ionizantes. En este artículo se concluye, entre otras inferencias, que su elevada sensibilidad supera el número de confirmaciones obtenidas a través de la tomografía axial computarizada.Magnetic resonance imaging allows to investigate morphological and functional aspects of the brain, something extremely useful to diagnose neurological diseases, including the cerebrovascular diseases and, of course, the cerebral ischemia in the first hours of its ocurrence, so it facilitates to follow the clinical course of ictus, to reduce the necrosis area and to guarantee a better life quality of patients. Contrary to tomography and angiography it doesn't use ionizing radiations. In this article it is concluded, among other things, that its high sensibility overcomes the number of confirmations obtained through computarized axial tomography.

  10. Improving the lattice axial vector current

    International Nuclear Information System (INIS)

    Horsley, R.; Perlt, H.; Schiller, A.; Zanotti, J.M.

    2015-11-01

    For Wilson and clover fermions traditional formulations of the axial vector current do not respect the continuum Ward identity which relates the divergence of that current to the pseudoscalar density. Here we propose to use a point-split or one-link axial vector current whose divergence exactly satisfies a lattice Ward identity, involving the pseudoscalar density and a number of irrelevant operators. We check in one-loop lattice perturbation theory with SLiNC fermion and gauge plaquette action that this is indeed the case including order O(a) effects. Including these operators the axial Ward identity remains renormalisation invariant. First preliminary results of a nonperturbative check of the Ward identity are also presented.

  11. Diagnostic value of axial CT scan

    International Nuclear Information System (INIS)

    Kiuchi, Sousuke

    1983-01-01

    Axial CT scan was used to investigate the radiological details of the temporal bone of 33 patients with chronic otitis media, secondary cholesteatoma, sensorineural hearing loss, Meniere disease, vertigo, facial spasm, and neoplasma. The axial scans showed anatomic details of the temporal bone, and at the same time clearly demonstrated the extent of the soft-tissue masses in the middle ears, as well as the destructions of the ossicles. Bone changes of the anterior walls of the epitympanum and external auditory meatus were more clearly demonstrated than by coronary CT scan. However, the axial scan had the disadvantages in demonstrating the stapes, crista transversa, and the mastoid portion of the facial canal. (author)

  12. Axial Vircator for Electronic Warfare Applications

    Directory of Open Access Journals (Sweden)

    L. Drazan

    2009-12-01

    Full Text Available This paper deals with a high power microwave generator with virtual cathode – vircator in axial release for electronic warfare applications. The classification of directed energy weapons microwave (DEWM is introduced together with basic block diagrams of a particular class of DEWM. In the paper, methods for designing vircator pulsed power supply, axial vircator structure, measurement methods and experimental results are presented. The vircator in electromagnetic ammunition is powered by magneto-cumulative generator and in weapons for defense of objects (WDO, it is powered by Marx generator. The possible applications of a vircator in the DEWM area are discussed.

  13. Axial loaded MRI of the lumbar spine

    Energy Technology Data Exchange (ETDEWEB)

    Saifuddin, A. E-mail: asaifuddin@aol.com; Blease, S.; MacSweeney, E

    2003-09-01

    Magnetic resonance imaging is established as the technique of choice for assessment of degenerative disorders of the lumbar spine. However, it is routinely performed with the patient supine and the hips and knees flexed. The absence of axial loading and lumbar extension results in a maximization of spinal canal dimensions, which may in some cases, result in failure to demonstrate nerve root compression. Attempts have been made to image the lumbar spine in a more physiological state, either by imaging with flexion-extension, in the erect position or by using axial loading. This article reviews the literature relating to the above techniques.

  14. Axial nucleon form factors from lattice QCD

    International Nuclear Information System (INIS)

    Alexandrou, C.; Brinet, M.; Carbonell, J.; Harraud, P. A.; Papinutto, M.; Constantinou, M.; Guichon, P.; Jansen, K.; Korzec, T.

    2011-01-01

    We present results on the nucleon axial form factors within lattice QCD using two flavors of degenerate twisted mass fermions. Volume effects are examined using simulations at two volumes of spatial length L=2.1 fm and L=2.8 fm. Cut-off effects are investigated using three different values of the lattice spacings, namely a=0.089 fm, a=0.070 fm and a=0.056 fm. The nucleon axial charge is obtained in the continuum limit and chirally extrapolated to the physical pion mass enabling comparison with experiment.

  15. The Axially Symmetric One-Monopole

    International Nuclear Information System (INIS)

    Wong, K.-M.; Teh, Rosy

    2009-01-01

    We present new classical generalized one-monopole solution of the SU(2) Yang-Mills-Higgs theory with the Higgs field in the adjoint representation. We show that this solution with θ-winding number m = 1 and φ-winding number n = 1 is an axially symmetric generalization of the 't Hooft-Polyakov one-monopole. We construct this axially symmetric one-monopole solution by generalizing the large distance asymptotic solutions of the 't Hooft-Polyakov one-monopole to the Jacobi elliptic functions and solving the second order equations of motion numerically when the Higgs potential is vanishing. This solution is a non-BPS solution.

  16. Axial injection in Orsay superconducting cyclotron

    International Nuclear Information System (INIS)

    Depauw, J.; Kugler, M.F.; Legoff, A.; Potier, J.C.; Richomme, A.; Skowron, R.; Mandrillon, P.; Schapira, J.P.

    1983-01-01

    The compact superconducting cyclotron currently planned at IPN at Orsay is designed for light ion acceleration together with heavy ion acceleration. From the beginning, for this reason, a central geometry able to receive an inflector (to 90deg C) allowing the axial injection of low energy ion beams given by an outer source. The present study is aimed at showing the technical feasibility of theoretical results obtained on axial injection. First experimental study has been made of spatial repartition in three dimensions of electric potential developed by a central geometry of 3 electrodes. Then, the electric study of an electrostatic mirror has been made [fr

  17. «FLARES» IN AXIAL SPONDYLOARTHRITIS

    Directory of Open Access Journals (Sweden)

    Sh. F. Erdes

    2016-01-01

    Full Text Available The clear definition of the concept of «flare in axial spondyloarthritis» is of paramount importance for clinical trials and routine practice in particular. It will be able to unify the characteristics of outcomes over a particular period of time on the one hand and to standardize therapeutic approaches on the other. On 4 February 2016, the journal Annals of Rheumatic Diseases published the on-line paper «Preliminary definitions of 'flare' in axial spondyloarthritis, based on pain, BASDAI and ASDAS-CRP: an ASAS initiative» by L. Gossec et al., which was devoted to this topic.

  18. Dynamic stability of slender columns with semi-rigid connections under periodic axial load: theory

    Directory of Open Access Journals (Sweden)

    Oliver Giraldo-Londoño

    2014-01-01

    Full Text Available La estabilidad dinámica de una columna elástica prismática esbelta con conexiones semirrígidas en ambos extremos de rigidez idéntica y con desplazamiento lateral entre los dos extremos totalmente inhibido sujetos a cargas axiales paramétricos incluyendo los efectos combinados de inercia rotacional y amortiguación externas se investiga de una manera clásica. Expresiones cerradas que se pueden utilizar para predecir las regiones de inestabilidad dinámica de columnas esbeltas son desarrolladas haciendo uso de la teoría de Floquet. La solución propuesta es capaz de capturar el fenómeno de estabilidad en columnas sometidas a cargas axiales periódicas utilizando un solo elemento de columna. El método propuesto y las ecuaciones correspondientes se pueden utilizar para investigar los efectos del amortiguamiento, la inercia rotacional de la columna, y las conexiones semirrígidas en el análisis de estabilidad de columnas esbeltas sometidas a cargas axiales periódicas. Los efectos producidos por las deformaciones por cizallamiento a lo largo de la columna, así como los producidos por la inercia axial, el acoplamiento entre las deflexiones longitudinales y transversales y la curvatura no se tienen en cuenta. Estudios de sensibilidad que muestran los efectos de la inercia rotacional, el amortiguamiento y las conexiones semi-rígidas en la estabilidad dinámica de columnas sometidas a cargas axiales paramétricas son presentados en una publicación adjunta.

  19. Avaliação tomográfica dos pedículos vertebrais no tratamento cirúrgico dos pacientes com escoliose idiopática do adolescente Evaluación de tomografía computarizada de pedículos vertebrales nel tratamiento quirúrgico de escoliosis idiopática del adolescente Computed tomography scan evaluation of vertebral pedicles for surgical treatment of adolescent idiopathic scoliosis

    Directory of Open Access Journals (Sweden)

    Alceu Gomes Chueire

    2012-12-01

    Full Text Available OBJETIVO: Determinar através de cortes tomográficos e reconstrução tridimensional a incidência de mal posicionamento de parafusos em pacientes submetidos ao tratamento cirúrgico da Escoliose idiopática do adolescente. MÉTODOS: Foram analisados exames tomográficos de 8 pacientes, tratados cirurgicamente no Hospital de Base de São José do Rio Preto-SP, realizada instrumentação posterior partindo de T2 /T4 a L4/L5 totalizando 164 parafusos. RESULTADOS: 32,9% (n=54 apresentavam posicionamento com risco potencial,ou seja desvio acima de 2 milímetros, sendo 20,1% (n=33 com invasão lateral, 9,1% (n=15 com invasão medial, 3,6 %(n=6 com invasão anterior. Dos parafusos que ofereciam risco potencial a relação com aspecto da curva foi de 46% (n=25 na concavidade, 35% (n=19 na convexidade e 19% (n=10 em vértebras adjacentes a curva. CONCLUSÃO: Os limites de penetração aceitáveis, assim como os métodos de mensuração ainda não foram padronizados, a técnica "free hand' mostrou-se segura, apesar da violação dos pedículos. A tomografia computadorizada pré-operatória, auxilia no planejamento cirúrgico e na redução das complicações.OBJETIVO: Evaluar mediante tomografía computarizada tridimensional de reconstrucción, una mala posición de los tornillos de pedículo en pacientes con escoliosis idiopática del adolescente. MÉTODOS: Se analizó cortes de tomografía computarizada de 8 pacientes sometidos a tratamiento quirúrgico en el Hospital de Base de São José do Rio Preto-SP, que se llevaron a cabo la fusión vertebral posterior de T2/T4 a L4/L5, 164 tornillos se insertaron. RESULTADOS: 32,9% (n = 54 fueron mal colocados que ofrecen riesgo potencial, que se consideraba una desviación de 2 mm, 20,1% (n = 33, la invasión lateral, el 9,1% (n = 15 invasión medial, 3,6 % (n = 6 la invasión anterior. De los tornillos mal colocados el 46% (n = 25 fueron en la concavidad, el 35% (n = 19 en la convexidad y el 19% (n = 10 se

  20. Optimización de Estatores para Motores Superconductores de Flujo Axial Optimización de Estatores para Motores Superconductores de Flujo Axial

    Directory of Open Access Journals (Sweden)

    Oscar Gerardo Ibarra-Manzano

    2012-02-01

    Full Text Available The development of superconducting electrical machines has been designed primarily to design and build engines with the superconducting magnetic field in radial configuration, as traditional engines, so the design and construction of rotating electrical machines in axial flow configuration has become an alternative for the design and construction of such engines. In this paper we present preliminary calculations for the optimization of the stator of a superconducting motor in axial flow confi guration, based on the equations of general power of the rotary axial flow configuration. It performs the construction, optimization and evaluation of models of stators in geometries of 4, 6 and 8 poles with high-temperature superconducting tapes of Bismuth. The results show the feasibility of the design implemented, which is verified by a significant decrease in the current of superconducting motor operation.El desarrollo de máquinas eléctricas superconductoras ha estado encaminado principalmentea diseñar y construir motores superconductores con el campo magnético en configuración radial, como los motores tradicionales, por lo que el diseño y construcción demáquinas eléctricas rotativas en configuración de flujo axial ha venido a ser una alternativa para el diseño y construcción de este tipo de motores. En el presente trabajo se presentan los cálculos preliminares para la optimización del estator de un motor superconductor en configuración de flujo axial, basados en las ecuaciones generales de potencia de las máquinas eléctricas rotativas en configuración flujo axial ha venido a ser una alternativa para el diseño y construcción, optimización y evaluación de modelos de estatores en geometrías de 4, 6 y 8 polos, con cintas superconductoras de alta temperatura de Bismuto. Los resultados obtenidos muestran la viabilidaddel diseño implementado, lo cual se comprueba por medio de una disminución significativa de la corriente de operaci

  1. Paciente con esquizofrenia tratado con ziprasidona + clozapina

    Directory of Open Access Journals (Sweden)

    Pol Yanguas E.

    2013-05-01

    Full Text Available P es un paciente diagnosticado de esquizofrenia, sigue en un piso tutelado un programa de rehabilitación, está medicado con clozapina 500 mg/día y ziprasidona 280 mg/ día. Padece hipercolesterolemia, tabaquismo y sus hábitos alimenticios no son buenos. La medicación que utiliza desde 2007 hasta ahora se refleja en la tabla 1. El último tratamiento se le introdujo el 7 de agosto de 2012, habiendo presentado un electro cardiograma (ECG normal, pero con ligera taquicardia ventricular y prolactinemia de 44,8 ng/ml (valores normales: 2-18 ng/ml.

  2. BPHZL-subtraction scheme and axial gauges

    Energy Technology Data Exchange (ETDEWEB)

    Kreuzer, M.; Rebhan, A.; Schweda, M.; Piguet, O.

    1986-03-27

    The application of the BPHZL subtraction scheme to Yang-Mills theories in axial gauges is presented. In the auxillary mass formulation we show the validity of the convergence theorems for subtracted momentum space integrals, and we give the integral formulae necessary for one-loop calculations. (orig.).

  3. Accessory caudal axial and pelvic ribs

    International Nuclear Information System (INIS)

    Bohutova, J.; Kolar, J.; Vitovec, J.; Vyhnanek, L.

    1980-01-01

    Accessory caudal ribs are reported as an extremely curious anomaly in five patients. Once the fracture of this rib was a source of pains after injury. The different shapes of the ribs are documented in this clinical survey which is the most extensive in the present literature. Anomalous ribs arise due to inappropriate segmentation during the embryonal development of the axial skeleton. (orig.) [de

  4. Aryabha~ and Axial Rotation of Earth

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 4. Aryabhata and Axial Rotation of Earth - Naksatra Dina (the Sidereal Day). Amartya Kumar Dutta. General Article Volume 11 Issue 4 April 2006 pp 56-74. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Aryabhala and Axial Rotation of Earth

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 3. Aryabhata and Axial Rotation of Earth - Khagola (The Celestial Sphere). Amartya Kumar Dutta. General Article Volume 11 Issue 3 March 2006 pp 51-68. Fulltext. Click here to view fulltext PDF. Permanent link:

  6. Helical axial injection concept for cyclotrons

    Energy Technology Data Exchange (ETDEWEB)

    Hudson, E.D.

    1981-01-01

    A concept for an external beam injection system using a helical beam path centered on the cyclotron axis is described. This system could be used to couple two accelerator stages, with or without intermediate stripping, in cases where conventional axial injection or radial injection are not practical.

  7. Helical axial injection concept for cyclotrons

    International Nuclear Information System (INIS)

    Hudson, E.D.

    1981-01-01

    A concept for an external beam injection system using a helical beam path centered on the cyclotron axis is described. This system could be used to couple two accelerator stages, with or without intermediate stripping, in cases where conventional axial injection or radial injection are not practical

  8. The axial polarizability of nucleons and nuclei

    International Nuclear Information System (INIS)

    Ericson, M.; Figureau, A.

    1981-02-01

    The part of the static nuclear axial polarizability arising from the nucleonic excitations is derived from the low energy expansion of the πN amplitude. It is shown that the contribution of the Δ intermediate state, though dominant, does not saturate the nucleonic response. A similar effect, though more pronounced, is known to occur for the magnetic susceptibility

  9. Optimisation of efficiency of axial fans

    NARCIS (Netherlands)

    Kruyt, Nicolaas P.; Pennings, P.C.; Faasen, R.

    2014-01-01

    A three-stage research project has been executed to develop ducted axial-fans with increased efficiency. In the first stage a design method has been developed in which various conflicting design criteria can be incorporated. Based on this design method, an optimised design has been determined

  10. Axial crystals macroscopic symmetry and tensor properties

    Czech Academy of Sciences Publication Activity Database

    Janovec, Václav

    2017-01-01

    Roč. 90, č. 1 (2017), s. 1-10 ISSN 0141-1594 Institutional support: RVO:68378271 Keywords : axial * polar * pseudopolar * chiral * enantiomorphism * optical activity Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.060, year: 2016

  11. Review of Axial Burnup Distribution Considerations for Burnup Credit Calculations

    International Nuclear Information System (INIS)

    Wagner, J.C.; DeHart, M.D.

    2000-01-01

    This report attempts to summarize and consolidate the existing knowledge on axial burnup distribution issues that are important to burnup credit criticality safety calculations. Recently released Nuclear Regulatory Commission (NRC) staff guidance permits limited burnup credit, and thus, has prompted resolution of the axial burnup distribution issue. The reactivity difference between the neutron multiplication factor (keff) calculated with explicit representation of the axial burnup distribution and keff calculated assuming a uniform axial burnup is referred to as the ''end effect.'' This end effect is shown to be dependent on many factors, including the axial-burnup profile, total accumulated burnup, cooling time, initial enrichment, assembly design, and the isotopics considered (i.e., actinide-only or actinides plus fission products). Axial modeling studies, efforts related to the development of axial-profile databases, and the determination of bounding axial profiles are also discussed. Finally, areas that could benefit from further efforts are identified

  12. On the problem of axial anomaly in supersymmetric gauge theories

    International Nuclear Information System (INIS)

    Kazakov, D.I.

    1984-01-01

    The explicit relation is found between the axial current obeying the Adler-Bardeen theorem and the supersymmetric one belonging to a supermultiplet. It is shown that the axial and superconformal anomalies are consistent in all orders of perturbation theory

  13. Cross-flow filtration and axial filtration

    International Nuclear Information System (INIS)

    Kraus, K.A.

    1974-01-01

    Two relatively novel alternative solid-liquid-separation techniques of filtration are discussed. In cross-flow filtration, the feed is pumped past the filtering surface. While in axial filtration the filter, mounted on a rotor, is moved with respect to the feed. While large-scale application of the axial filter is still in doubt, it permits with little expenditure of time and money, duplication of many hydrodynamic aspects of cross-flow filtration for fine-particle handling problems. The technique has been applied to municipal wastes, low-level radioactive waste treatment plant, lead removal from industrial wastes, removal of pulp-mill contaminants, textile-mill wastes, and pretreatment of saline waters by lime-soda process in preparation for hyperfiltration. Economics and energy requirements are also discussed

  14. Computerized axial tomography in traumatic cervical lesions

    International Nuclear Information System (INIS)

    Koyama, Tsunemaro

    1982-01-01

    Although plain computerized axial tomography cannot routinely demonstrate the spinal cord, it does provide excellent visualization of the bony outline of the spinal canal and vertebral column. So it should be reasonable to use this technique in cases of cervical traumatic disorders. In this paper we presented 10 cases of cervical traumatic lesions; 3 atlanto-axial dislocation, 2 cervical canal stenosis, 3 OPLL, 1 intramedullary hematoma and 1 C 2 -neurinoma. In some patients neurologic deficits were induced by cervical trauma. Bony lesions appeared more adequately deliniated than intraspinal lesions, however, in some cases intramedullary changes could also be demonstrated. The use of metrizamide with high resolution CT-scanner could improve the usefullness of this technique. (author)

  15. Ventajas de los motores de flujo axial

    Directory of Open Access Journals (Sweden)

    Alberto M Basanta Otero

    2011-03-01

    Full Text Available Es importante conocer sobre una familia de motores que a diferencia de los convencionales o tradicionales no presentanun flujo rotatorio radial, denominados motores de flujo axial. Dichos motores presentan altos valores de par motriz abajas velocidades, una alta eficiencia y alta densidad de potencia. Este trabajo constituye un breve análisis dealgunos motores de la referencia bibliográfica.  Is important to know about a family of motors that at difference whit the traditional, don't have a rotator radial flux,called, axial flux motors. These motors have high torque for low speed, high efficiency and high power density. Thiswork is a brief analysis of several motors of the bibliographic references.

  16. Internal and external axial corner flows

    Science.gov (United States)

    Kutler, P.; Shankar, V.; Anderson, D. A.; Sorenson, R. L.

    1975-01-01

    The inviscid, internal, and external axial corner flows generated by two intersecting wedges traveling supersonically are obtained by use of a second-order shock-capturing, finite-difference approach. The governing equations are solved iteratively in conical coordinates to yield the complicated wave structure of the internal corner and the simple peripheral shock of the external corner. The numerical results for the internal flows compare favorably with existing experimental data.

  17. Axial flux permanent magnet brushless machines

    CERN Document Server

    Gieras, Jacek F; Kamper, Maarten J

    2008-01-01

    Axial Flux Permanent Magnet (AFPM) brushless machines are modern electrical machines with a lot of advantages over their conventional counterparts. They are being increasingly used in consumer electronics, public life, instrumentation and automation system, clinical engineering, industrial electromechanical drives, automobile manufacturing industry, electric and hybrid electric vehicles, marine vessels and toys. They are also used in more electric aircrafts and many other applications on larger scale. New applications have also emerged in distributed generation systems (wind turbine generators

  18. Axial gravity, massless fermions and trace anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Bonora, L. [International School for Advanced Studies (SISSA), Trieste (Italy); KEK, Tsukuba (Japan). KEK Theory Center; INFN, Sezione di Trieste (Italy); Cvitan, M.; Giaccari, S.; Stemberga, T. [Zagreb Univ. (Croatia). Dept. of Physics; Prester, P.D. [Rijeka Univ. (Croatia). Dept. of Physics; Pereira, A.D. [UERJ-Univ. Estadual do Rio de Janeiro (Brazil). Dept. de Fisica Teorica; UFF-Univ. Federal Fluminense, Niteroi (Brazil). Inst. de Fisica

    2017-08-15

    This article deals with two main topics. One is odd parity trace anomalies in Weyl fermion theories in a 4d curved background, the second is the introduction of axial gravity. The motivation for reconsidering the former is to clarify the theoretical background underlying the approach and complete the calculation of the anomaly. The reference is in particular to the difference between Weyl and massless Majorana fermions and to the possible contributions from tadpole and seagull terms in the Feynman diagram approach. A first, basic, result of this paper is that a more thorough treatment, taking account of such additional terms and using dimensional regularization, confirms the earlier result. The introduction of an axial symmetric tensor besides the usual gravitational metric is instrumental to a different derivation of the same result using Dirac fermions, which are coupled not only to the usual metric but also to the additional axial tensor. The action of Majorana and Weyl fermions can be obtained in two different limits of such a general configuration. The results obtained in this way confirm the previously obtained ones. (orig.)

  19. Axial gravity, massless fermions and trace anomalies

    International Nuclear Information System (INIS)

    Bonora, L.; Cvitan, M.; Giaccari, S.; Stemberga, T.; Prester, P.D.; Pereira, A.D.; UFF-Univ. Federal Fluminense, Niteroi

    2017-01-01

    This article deals with two main topics. One is odd parity trace anomalies in Weyl fermion theories in a 4d curved background, the second is the introduction of axial gravity. The motivation for reconsidering the former is to clarify the theoretical background underlying the approach and complete the calculation of the anomaly. The reference is in particular to the difference between Weyl and massless Majorana fermions and to the possible contributions from tadpole and seagull terms in the Feynman diagram approach. A first, basic, result of this paper is that a more thorough treatment, taking account of such additional terms and using dimensional regularization, confirms the earlier result. The introduction of an axial symmetric tensor besides the usual gravitational metric is instrumental to a different derivation of the same result using Dirac fermions, which are coupled not only to the usual metric but also to the additional axial tensor. The action of Majorana and Weyl fermions can be obtained in two different limits of such a general configuration. The results obtained in this way confirm the previously obtained ones. (orig.)

  20. Golimumab for the treatment of axial spondyloarthritis.

    Science.gov (United States)

    Palazzi, Carlo; D'angelo, Salvatore; Gilio, Michele; Leccese, Pietro; Padula, Angela; Olivieri, Ignazio

    2017-01-01

    Anti-TNF drugs have represented an epochal revolution in the treatment of rheumatoid arthritis and spondyloarthritis. In the field of axial spondyloarthritis, golimumab, a fully human monoclonal anti-TNFα administered subcutaneously every 4 weeks, has shown significant efficacy and good safety in patients with ankylosing spondylitis. More recently, it was also indicated as an effective treatment for patients suffering from non-radiographic axial spondyloarthitits. Areas covered: A systematic literature search was completed, using the largest electronic databases (Medline, Embase and Cochrane), with the aim to review all data concerning the administration of golimumab in patients suffering from axial spondyloartritis. Expert opinion: In the 16-week GO-AHEAD study, golimumab was effective in patients with non-radiographic spondyloarthritis with high levels of CRP and/or positive MRI findings, but not in subjects with both negative CRP and MRI. This finding allows for the addressing the of anti-TNF treatment more specifically. Preliminary data concerning an open-label extension of the GO-AHEAD study outlined the high retention-rate of the drug at 52 weeks. The production of antibodies against golimumab is rare and it seems to exert scarce influence on the drug performances. In conclusion, golimumab appears as a very useful and well tolerated anti-TNF agent.

  1. Computational analysis of a multistage axial compressor

    Science.gov (United States)

    Mamidoju, Chaithanya

    Turbomachines are used extensively in Aerospace, Power Generation, and Oil & Gas Industries. Efficiency of these machines is often an important factor and has led to the continuous effort to improve the design to achieve better efficiency. The axial flow compressor is a major component in a gas turbine with the turbine's overall performance depending strongly on compressor performance. Traditional analysis of axial compressors involves throughflow calculations, isolated blade passage analysis, Quasi-3D blade-to-blade analysis, single-stage (rotor-stator) analysis, and multi-stage analysis involving larger design cycles. In the current study, the detailed flow through a 15 stage axial compressor is analyzed using a 3-D Navier Stokes CFD solver in a parallel computing environment. Methodology is described for steady state (frozen rotor stator) analysis of one blade passage per component. Various effects such as mesh type and density, boundary conditions, tip clearance and numerical issues such as turbulence model choice, advection model choice, and parallel processing performance are analyzed. A high sensitivity of the predictions to the above was found. Physical explanation to the flow features observed in the computational study are given. The total pressure rise verses mass flow rate was computed.

  2. Axial Dispersion during Hanford Saltcake Washing

    International Nuclear Information System (INIS)

    Josephson, Gary B.; Geeting, John GH; Lessor, Delbert L.; Barton, William B.

    2006-01-01

    Clean up of Hanford salt cake wastes begins with dissolution retrieval of the sodium rich salts that make up the dominant majority of mass in the tanks. Water moving through the porous salt cake dissolves the soluble components and also displaces the soluble radionuclides (e.g. 137Cs and 99TcO4- ). The separation that occurs from this displacement, known as Selective dissolution, is an important component in Hanford?s pretreatment of low activity wastes for subsequent Supplemental treatment. This paper describes lab scale testing conducted to evaluate Selective dissolution of cesium from non-radioactive Hanford tank 241-S-112 salt cake simulant containing the primary chemicals found the actual tank. An modified axial dispersion model with increasing axial dispersion was developed to predict cesium removal. The model recognizes that water dissolves the salt cake during washing, which causes an increase in the axial dispersion during the wash. This model was subsequently compared with on-line cesium measurements from the retrieval of tank 241-S-112. The model had remarkably good agreement with both the lab scale and full scale data

  3. Bessel beam CARS of axially structured samples

    Science.gov (United States)

    Heuke, Sandro; Zheng, Juanjuan; Akimov, Denis; Heintzmann, Rainer; Schmitt, Michael; Popp, Jürgen

    2015-06-01

    We report about a Bessel beam CARS approach for axial profiling of multi-layer structures. This study presents an experimental implementation for the generation of CARS by Bessel beam excitation using only passive optical elements. Furthermore, an analytical expression is provided describing the generated anti-Stokes field by a homogeneous sample. Based on the concept of coherent transfer functions, the underling resolving power of axially structured geometries is investigated. It is found that through the non-linearity of the CARS process in combination with the folded illumination geometry continuous phase-matching is achieved starting from homogeneous samples up to spatial sample frequencies at twice of the pumping electric field wave. The experimental and analytical findings are modeled by the implementation of the Debye Integral and scalar Green function approach. Finally, the goal of reconstructing an axially layered sample is demonstrated on the basis of the numerically simulated modulus and phase of the anti-Stokes far-field radiation pattern.

  4. Dynamic control of knee axial deformities

    Directory of Open Access Journals (Sweden)

    E. E. Malyshev

    2013-01-01

    Full Text Available The authors have evaluated the clinical examination of the patients with axial malalignments in the knee by the original method and device which was named varovalgometer. The measurements were conducted by tension of the cord through the spina iliaca anterior superior and the middle of the lower pole of patella. The deviation of the center of the ankle estimated by metal ruler which was positioned perpendicular to the lower leg axis on the level of the ankle joint line. The results of comparison of our method and computer navigation in 53 patients during the TKA show no statistically significant varieties but they differ by average 5° of valgus in clinical examination in comparison with mechanical axis which was identified by computer navigation. The dynamic control of axial malalignment can be used in clinical practice for estimation of the results of treatment of pathology with axial deformities in the knee; for the control of reduction and secondary displacement of the fractures around the knee; for assessment of instability; in planning of correctional osteotomies and intraoperative control of deformity correction; for estimation of Q angle in subluxation and recurrent dislocation of patella; in planning of TKA; during the growth of child it allows to assess the progression of deformity.

  5. Axial anomaly at finite temperature and finite density

    International Nuclear Information System (INIS)

    Qian Zhixin; Su Rukeng; Yu, P.K.N.

    1994-01-01

    The U(1) axial anomaly in a hot fermion medium is investigated by using the real time Green's function method. After calculating the lowest order triangle diagrams, we find that finite temperature as well as finite fermion density does not affect the axial anomaly. The higher order corrections for the axial anomaly are discussed. (orig.)

  6. The deep structure of Axial Volcano

    Science.gov (United States)

    West, Michael Edwin

    The subsurface structure of Axial Volcano, near the intersection of the Juan de Fuca Ridge and the Cobb-Eickelberg seamount chain in the northeast Pacific, is imaged from an active source seismic experiment. At a depth of 2.25 to 3.5 km beneath Axial lies an 8 km x 12 km region of very low seismic velocities that can only be explained by the presence of magma. In the center of this magma storage chamber at 2--3.5 km below sea floor, the crust is at least 10--20% melt. At depths of 4--5 km there is evidence of additional low concentrations of magma (a few percent) over a larger area. In total, 5--11 km3 of magma are stored in the mid-crust beneath Axial. This is more melt than has been positively identified under any basaltic volcano on Earth. It is also far more than the 0.1--0.2 km3 emplaced during the 1998 eruption. The implied residence time in the magma reservoir of a few hundred to a few thousand years agrees with geochemical trends which suggest prolonged storage and mixing of magmas. The large volume of melt bolsters previous observations that Axial provides much of the material to create crust along its 50 km rift zones. A high velocity ring-shaped feature sits above the magma chamber just outside the caldera walls. This feature is believed to be the result of repeated dike injections from the magma body to the surface during the construction of the volcanic edifice. A rapid change in crustal thickness from 8 to 11 km within 15 km of the caldera implies focused delivery of melt from the mantle. The high flux of magma suggests that melting occurs deeper in the mantle than along the nearby ridge. Melt supply to the volcano is not connected to any plumbing system associated with the adjacent segments of the Juan de Fuca Ridge. This suggests that, despite Axial's proximity to the ridge, the Cobb hot spot currently drives the supply of melt to the volcano.

  7. Videojuego con Realidad Virtual

    OpenAIRE

    González Mora, César

    2017-01-01

    El objetivo del proyecto es el desarrollo de un videojuego deportivo que utilice realidad mixta. El videojuego se podrá utilizar con dispositivos de tipo cardboard, y utilizará realidad aumentada para la interacción del jugador con el videojuego. En el desarrollo se utilizará el motor Unity para conseguir una aplicación multiplataforma, y la librería Vuforia para implementar realidad mixta.

  8. Sistemas integrados con Arduino

    OpenAIRE

    EL YAKOUTI, MOHAMMED

    2017-01-01

    Design of a robot prototype remotely controllable from Bluetooth using Arduino. Control and testing of sensors and events interacting with Arduino and Bluetooth. Diseño de un prototipo de robot controlable remotamente con Bluetooth utilizando Arduino. Control y verificación de los sensores y eventos que interactúan mediante el Arduino y el Bluetooth. El Yakouti, M. (2017). Sistemas integrados con Arduino. http://hdl.handle.net/10251/89274. TFGM

  9. A new strategy of axial power distribution control based on three axial offsets concept

    International Nuclear Information System (INIS)

    Shimazu, Yoichiro

    2009-01-01

    We have proposed a very simple control procedure for axial xenon oscillation control based on a characteristic trajectory. The trajectory is drawn by three offsets of power distributions, namely, AOp, AOi and AOx. They are defined as the offset of axial power distribution, the offset of the power distribution under which the current iodine distribution is obtained as the equilibrium and that for xenon distribution, respectively. When these offsets are plotted on X-Y plane for (AOp-AOx, AOi-AOx) the trajectory draws a quite characteristic ellipse (or an elliptic spiral). On the other hands, Constant Axial Offset Control (CAOC) procedure is adopted as axial power distribution control strategy during both base load and load following operations in domestic PWRs. In the previous paper, we have presented an innovative procedure of axial power distribution control during load following in PWRs based on this trajectory such that the AOp-AOx is to be controlled to zero when the value deviates the pre-determined limiting values. In this paper we propose a modified control strategy to get more stability of axial power distributions. In this strategy, we control the trajectory to be close to the major axis of the ellipse when the power distribution reaches the limiting values. In other words, the plot is not controlled only to reduce AOp-AOx but also AOi-AOx is taken into account at the same time. It is known that when the plot is controlled to the major axis, it means that the point gives the peak position of axial xenon oscillation. Therefore xenon oscillation will not increase its amplitude any more. Thus more stable axial power distribution control is attained. This kind of design concept is quite important especially for the future PWRs with elongated fuel length and longer core life. Because in a longer effective core and also the longer core life, it has been known that the stability of axial xenon oscillation becomes more unstable. In this paper, some simulation

  10. Intrinsic carpal ligaments on MR and multidetector CT arthrography: comparison of axial and axial oblique planes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ryan K.L.; Griffith, James F.; Ng, Alex W.H.; Law, Eric K.C. [The Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Prince Of Wales Hospital, Hong Kong (China); Tse, W.L.; Wong, Clara W.Y.; Ho, P.C. [The Chinese University of Hong Kong, Department of Orthopedics and Traumatology, Prince Of Wales Hospital, Hong Kong (China)

    2017-03-15

    To compare axial and oblique axial planes on MR arthrography (MRA) and multidetector CT arthrography (CTA) to evaluate dorsal and volar parts of scapholunate (SLIL) and lunotriquetral interosseous (LTIL) ligaments. Nine cadaveric wrists of five male subjects were studied. The visibility of dorsal and volar parts of the SLIL and LTIL was graded semi-quantitatively (good, intermediate, poor) on MRA and CTA. The presence of a ligament tear was determined on arthrosocopy and sensitivity, specificity and accuracy of tear detection were calculated. Oblique axial imaging was particularly useful for delineating dorsal and volar parts of the LTIL on MRA with overall 'good' visibility increased from 11 % to 78 %. The accuracy of MRA and CTA in revealing SLIL and LTIL tear was higher using the oblique axial plane. The overall accuracy for detecting SLIL tear on CTA improved from 94 % to 100 % and from 89 % to 94 % on MRA; the overall accuracy of detecting LTIL tear on CTA improved from 89 % to 100 % and from 72 % to 89 % on MRA Oblique axial imaging during CT and MR arthrography improves detection of tears in the dorsal and volar parts of both SLIL and LTIL. (orig.)

  11. Investigando con personas con dificultades de aprendizaje

    Directory of Open Access Journals (Sweden)

    Borja González Luna

    2013-12-01

    Full Text Available El artículo muestra los orígenes de lo que Walmsley (2008 denomina «investigación inclusiva». Para comprender qué se entiende por investigación inclusiva tenemos que remontarnos a los debates epistemológicos sobre las metodologías cuantitativas y cualitativas, acontecidos en la década de los 90, en torno a la revista Disability & Society. A partir de una síntesis de dichos debates, focalizados en el ámbito de la «discapacidad intelectual y del desarrollo», se exponen dos estrategias de colaboración con dicha población: a una aproximación etnográfica (de trabajo grupal, y b una aproximación biográfica (de trabajo individual. A continuación se esboza un posible diseño de trabajo de campo que intenta superar el paradigma cualitativo «clásico» con el objetivo de incluir a dicho colectivo más allá del rol de «sujetos de la investigación». Para finalizar se recoge el debate sobre la accesibilidad de los resultados de la investigación a los participantes en dichas investigaciones, y con ello la necesaria innovación en el ámbito de las «devoluciones» de los resultados, cuando se trata de incluir a personas que presentan limitaciones para la comprensión del lenguaje abstracto oral y/o escrito.

  12. Axial flow heat exchanger devices and methods for heat transfer using axial flow devices

    Science.gov (United States)

    Koplow, Jeffrey P.

    2016-02-16

    Systems and methods described herein are directed to rotary heat exchangers configured to transfer heat to a heat transfer medium flowing in substantially axial direction within the heat exchangers. Exemplary heat exchangers include a heat conducting structure which is configured to be in thermal contact with a thermal load or a thermal sink, and a heat transfer structure rotatably coupled to the heat conducting structure to form a gap region between the heat conducting structure and the heat transfer structure, the heat transfer structure being configured to rotate during operation of the device. In example devices heat may be transferred across the gap region from a heated axial flow of the heat transfer medium to a cool stationary heat conducting structure, or from a heated stationary conducting structure to a cool axial flow of the heat transfer medium.

  13. Inverse axial mounting stiffness design for lithographic projection lenses.

    Science.gov (United States)

    Wen-quan, Yuan; Hong-bo, Shang; Wei, Zhang

    2014-09-01

    In order to balance axial mounting stiffness of lithographic projection lenses and the image quality under dynamic working conditions, an easy inverse axial mounting stiffness design method is developed in this article. Imaging quality deterioration at the wafer under different axial vibration levels is analyzed. The desired image quality can be determined according to practical requirements, and axial vibrational tolerance of each lens is solved with the damped least-squares method. Based on adaptive interval adjustment, a binary search algorithm, and the finite element method, the axial mounting stiffness of each lens can be traveled in a large interval, and converges to a moderate numerical solution which makes the axial vibrational amplitude of the lens converge to its axial vibrational tolerance. Model simulation is carried out to validate the effectiveness of the method.

  14. Axial sesamoiditis in the horse: A review

    Directory of Open Access Journals (Sweden)

    Christelle Le Roux

    2018-03-01

    Full Text Available Axial sesamoiditis or osteitis of the proximal sesamoid bones (PSBs in the horse is described as a rare condition. The cause remains unknown and speculative, with vascular, infectious, and traumatic aetiologies implicated. It is specifically associated with injury of the palmar or plantar ligament (PL, also known as the intersesamoidean ligament. Imaging findings are generally rewarding and radiological changes are typical, if not pathognomonic, for the condition. Lesions consist of bone lysis at the apical to mid-body axial margins of the PSBs, with variable degrees of joint effusion. Radiographic technique warrants careful attention to make a diagnosis, and exposure factors may need to be adjusted. Perineural, intra-articular and intra-thecal anaesthesia does not seem to provide consistent improvement of lameness in these cases, with literature reporting inconsistent findings. Ultrasonographic findings include digital flexor sheath effusion, loss of the normal fibre structure of the PL at its attachment to the PSBs, abnormal echogenicity or change in thickness of the PL, and irregular hyperechoic cortical margins of the axial margins of the PSBs. Scintigraphy, computed tomography and magnetic resonance imaging, although not necessary to make a diagnosis, may add valuable information regarding the location and extent of lesions. The prognosis remains guarded to poor for return to athletic function. The focus of this paper is a comprehensive review of the proposed aetiopathogenesis of the condition, the prognosis, and a summary of the literature findings with focus on the notable diagnostic imaging features, including radiography, ultrasonography, scintigraphy, computed tomography and magnetic resonance imaging.

  15. Axial Tomography from Digitized Real Time Radiography

    Science.gov (United States)

    Zolnay, A. S.; McDonald, W. M.; Doupont, P. A.; McKinney, R. L.; Lee, M. M.

    1985-01-18

    Axial tomography from digitized real time radiographs provides a useful tool for industrial radiography and tomography. The components of this system are: x-ray source, image intensifier, video camera, video line extractor and digitizer, data storage and reconstruction computers. With this system it is possible to view a two dimensional x-ray image in real time at each angle of rotation and select the tomography plane of interest by choosing which video line to digitize. The digitization of a video line requires less than a second making data acquisition relatively short. Further improvements on this system are planned and initial results are reported.

  16. Disordered axial movement in Parkinson's disease.

    OpenAIRE

    Steiger, M J; Thompson, P D; Marsden, C D

    1996-01-01

    Axial motor impairments are a common cause of disability in patients with Parkinson's disease, become more prominent with longer disease duration, and have been said to be less responsive to levodopa replacement therapy. The ability to turn in bed while lying supine before and after dopaminergic stimulation was studied in a group of 36 patients with Parkinson's disease; 23 were in Hoehn and Yahr stages 3-5 when "off", and 13 were in stages 1-2. Turning was also compared with postural stabilit...

  17. Digital enhancement of computerized axial tomograms

    Science.gov (United States)

    Roberts, E., Jr.

    1978-01-01

    A systematic evaluation has been conducted of certain digital image enhancement techniques performed in image space. Three types of images have been used, computer generated phantoms, tomograms of a synthetic phantom, and axial tomograms of human anatomy containing images of lesions, artificially introduced into the tomograms. Several types of smoothing, sharpening, and histogram modification have been explored. It has been concluded that the most useful enhancement techniques are a selective smoothing of singular picture elements, combined with contrast manipulation. The most useful tool in applying these techniques is the gray-scale histogram.

  18. Axial tomography in live cell laser microscopy

    Science.gov (United States)

    Richter, Verena; Bruns, Sarah; Bruns, Thomas; Weber, Petra; Wagner, Michael; Cremer, Christoph; Schneckenburger, Herbert

    2017-09-01

    Single cell microscopy in a three-dimensional (3-D) environment is reported. Cells are grown in an agarose culture gel, located within microcapillaries and observed from different sides after adaptation of an innovative device for sample rotation. Thus, z-stacks can be recorded by confocal microscopy in different directions and used for illustration in 3-D. This gives additional information, since cells or organelles that appear superimposed in one direction, may be well resolved in another one. The method is tested and validated with single cells expressing a membrane or a mitochondrially associated green fluorescent protein, or cells accumulating fluorescent quantum dots. In addition, axial tomography supports measurements of cellular uptake and distribution of the anticancer drug doxorubicin in the nucleus (2 to 6 h after incubation) or the cytoplasm (24 h). This paper discusses that upon cell rotation an enhanced optical resolution in lateral direction compared to axial direction can be utilized to obtain an improved effective 3-D resolution, which represents an important step toward super-resolution microscopy of living cells.

  19. Axial vessel widening in arborescent monocots.

    Science.gov (United States)

    Petit, Giai; DeClerck, Fabrice A J; Carrer, Marco; Anfodillo, Tommaso

    2014-02-01

    Dicotyledons have evolved a strategy to compensate for the increase in hydraulic resistance to water transport with height growth by widening xylem conduits downwards. In monocots, the accumulation of hydraulic resistance with height should be similar, but the absence of secondary growth represents a strong limitation for the maintenance of xylem hydraulic efficiency during ontogeny. The hydraulic architecture of monocots has been studied but it is unclear how monocots arrange their axial vascular structure during ontogeny to compensate for increases in height. We measured the vessel lumina and estimated the hydraulic diameter (Dh) at different heights along the stem of two arborescent monocots, Bactris gasipaes (Kunth) and Guadua angustifolia (Kunth). For the former, we also estimated the variation in Dh along the leaf rachis. Hydraulic diameter increased basally from the stem apex to the base with a scaling exponent (b) in the range of those reported for dicot trees (b = 0.22 in B. gasipaes; b = 0.31 and 0.23 in G. angustifolia). In B. gasipaes, vessels decrease in Dh from the stem's centre towards the periphery, an opposite pattern compared with dicot trees. Along the leaf rachis, a pattern of increasing Dh basally was also found (b = 0.13). The hydraulic design of the monocots studied revealed an axial pattern of xylem conduits similar to those evolved by dicots to compensate and minimize the negative effect of root-to-leaf length on hydrodynamic resistance to water flow.

  20. Anion-π Catalysts with Axial Chirality.

    Science.gov (United States)

    Wang, Chao; Matile, Stefan

    2017-09-04

    The idea of anion-π catalysis is to stabilize anionic transition states by anion-π interactions on aromatic surfaces. For asymmetric anion-π catalysis, π-acidic surfaces have been surrounded with stereogenic centers. This manuscript introduces the first anion-π catalysts that operate with axial chirality. Bifunctional catalysts with tertiary amine bases next to π-acidic naphthalenediimide planes are equipped with a bulky aromatic substituent in the imide position to produce separable atropisomers. The addition of malonic acid half thioesters to enolate acceptors is used for evaluation. In the presence of a chiral axis, the selective acceleration of the disfavored but relevant enolate addition was much better than with point chirality, and enantioselectivity could be observed for the first time for this reaction with small-molecule anion-π catalysts. Enantioselectivity increased with the π acidity of the π surface, whereas the addition of stereogenic centers around the aromatic plane did not cause further improvements. These results identify axial chirality of the active aromatic plane generated by atropisomerism as an attractive strategy for asymmetric anion-π catalysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Medullary sponge kidney on axial computed tomography

    International Nuclear Information System (INIS)

    Ginalski, J.-M.; Schnyder, Pierre; Portmann, Luc; Jaeger, Philippe

    1991-01-01

    To evaluate features of medullary sponge kidney (MSK) on computed tomography (CT), 4-mm-thick axial slices without intravenous contrast material were 1st made in 13 patients through 24 kidneys which showed images of MSK on excretory urograms. On CT, papillary calcifications were found in 11 kidneys. In 5 of these, the calcifications were not detectable on plain films. Some hyperdense papillae (attenuation value 55-70 Hounsfield units) without calcification were found in 4 other kidneys. 9 kidneys appeared normal. 10 of the 14 kidneys were reexamined by a 2nd series of 4-mm-thick axial slices, 5 min after intravenous injection of 50 ml of Urografin. Images suggesting possible ectasia of precaliceal tubules were found in only 4 kidneys. These images appear much less obvious and characteristic on CT than on excretory urogram and do nothing more than suggest the possibility of MSK. In conclusion, the sensitivity of CT in the detection of MSK is markedly lower than that of excretory urography. In the most florid cases of the disease, CT can only show images suggesting the possibility of MSK. On the other hand, CT appears much more sensitive than plain films and tomograms of excretory in the detection of papillary calcifications, the most frequent complication of MSK. (author). 13 refs.; 3 figs

  2. Canonical quantization of the generalized axial gauge

    International Nuclear Information System (INIS)

    Haller, K.

    1990-01-01

    The incompatibility of the constraint A 3 =0 with canonical commutation rules is discussed. A canonical formulation is given of QED and QCD in the axial gauge with n 1 =n 2 =0, n 3 =α and n 0 =β, where α and β are arbitrary real numbers. A Hilbert space is established for the perturbative theory, and a propagator is derived by obtaining an expression for the interaction picture gauge fields, and evaluating the vacuum expectation value of its time-ordered products in the perturbative vacuum. The propagator is expressed in terms of the parameter γ=α/β and is shown to reproduce the light cone gauge propagator when γ=1, and the temporal gauge propagator when γ=0, accommodating various prescriptions for the spurious propagator pole, including the Mandelstam-Leibbrandt and principal value prescriptions. When γ→∞, the generalized axial gauge propagator leads to an expression for the propagator in the A 3 =0 gauge, though in that case the order in which the integration over k 0 is performed, and the limit γ→∞ is taken, affects the resulting expression. Another Hilbert space is established, in which the constraints that include all interactions are implemented in a time independent fashion. It is pointed out that this Hilbert space, and the Hilbert space of the perturbative theory are unitarily equivalent in QED, but that they cannot be unitarily equivalent in QCD. Implications of this fact for the nonperturbative states of QCD are discussed. (orig.)

  3. The Modelling of Axially Translating Flexible Beams

    Science.gov (United States)

    Theodore, R. J.; Arakeri, J. H.; Ghosal, A.

    1996-04-01

    The axially translating flexible beam with a prismatic joint can be modelled by using the Euler-Bernoulli beam equation together with the convective terms. In general, the method of separation of variables cannot be applied to solve this partial differential equation. In this paper, a non-dimensional form of the Euler Bernoulli beam equation is presented, obtained by using the concept of group velocity, and also the conditions under which separation of variables and assumed modes method can be used. The use of clamped-mass boundary conditions leads to a time-dependent frequency equation for the translating flexible beam. A novel method is presented for solving this time dependent frequency equation by using a differential form of the frequency equation. The assume mode/Lagrangian formulation of dynamics is employed to derive closed form equations of motion. It is shown by using Lyapunov's first method that the dynamic responses of flexural modal variables become unstable during retraction of the flexible beam, which the dynamic response during extension of the beam is stable. Numerical simulation results are presented for the uniform axial motion induced transverse vibration for a typical flexible beam.

  4. Multi-axial response of idealized cermets

    International Nuclear Information System (INIS)

    Pickering, E.G.; Bele, E.; Deshpande, V.S.

    2016-01-01

    The yield response of two idealized cermets comprising mono and bi-disperse steel spheres in a Sn/Pb solder matrix has been investigated for a range of axisymmetric stress states. Proportional stress path experiments are reported, from which are extracted the initial yield surfaces and their evolution with increasing plastic strain. The initial yield strength is nearly independent of the hydrostatic pressure but the strain hardening rate increases with stress triaxiality up to a critical value. For higher triaxialities, the responses are independent of hydrostatic pressure. Multi-axial measurements along with X-ray tomography were used to demonstrate that the deformation of these idealized cermets occurs by two competing mechanisms: (i) a granular flow mechanism that operates at low levels of triaxiality, where volumetric dilation occurs under compressive stress states, and (ii) a plastically incompressible mechanism that operates at high stress triaxialities. A phenomenological viscoplastic constitutive model that incorporates both deformation mechanisms is presented. While such multi-axial measurements are difficult for commercial cermets with yield strengths on the order of a few GPa, the form of their constitutive relation is expected to be similar to that of the idealized cermets presented here.

  5. Endocarditis aórtica y pulmonar complicada con ictus hemorrágico: ¿cuál es el tiempo quirúrgico ideal?

    Directory of Open Access Journals (Sweden)

    Adrián Fernando Narvaez Muñoz

    2016-09-01

    Full Text Available Hombre de 77 años que presenta de forma súbita alteración del lenguaje y cambios de conducta; se realiza tomografía computarizada cerebral, en donde se observa hemorragia intraparenquimatosa frontal izquierda; su cuadro es acompañado de fiebre y hemocultivos positivos para Streptococcus bovis tipo i (gallolyticus. Se realiza un ecocardiograma transesofágico en donde se identifican vegetaciones a nivel de la válvula aortica y pulmonar; debido al contexto de su ictus hemorrágico, decidimos esperar al menos 4 semanas con tratamiento antibiótico antes de realizar cirugía. En la cirugía se resecó vegetación pulmonar y aórtica, realizándose recambio valvular aórtico metálico; la válvula pulmonar fue conservada. En el postoperatorio inmediato y mediato, el paciente presenta evolución favorable. El tratamiento antibiótico se continuó hasta la confirmación de los cultivos negativos de las válvulas extraídas. El ecocardiograma de control no mostró vegetaciones y el paciente fue dado de alta a su domicilio unos días después de su cirugía.

  6. Giochiamo con i robot

    Directory of Open Access Journals (Sweden)

    Andrea Bonarini

    2009-01-01

    Full Text Available "Giochiamo con i robot" e' un laboratorio interattivo per grandi e piccini realizzato per l'edizione 2007 del Festival della Scienza di Genova. Lungo un percorso che va dalla telerobotica alla robotica evolutiva, il laboratorio sviluppa il tema di dare intelligenza ai robot. Questo percorso, le cui tappe sono le varie installazioni, si conclude nella "bottega" dove e' possibile costruire e programmare i propri robot o smontare e modificare quelli esposti durante il percorso didattico. I visitatori sono coinvolti in attivita' ludiche grazie alle quali possonoentrare in contatto con alcune delle idee potenti della robotica,

  7. disegnare con ... Alberto Pratelli

    Directory of Open Access Journals (Sweden)

    Roberto Mingucci

    2017-12-01

    Full Text Available Con questa breve intervista ad Alberto Pratelli, (non a caso scelto per aprire questa nuova rubrica intendia-mo inaugurare un dialogo con personalità significati-ve del Disegno di Architettura, che consenta riflessioni dedicate alle sue varie dimensioni, oggi più che mai da approfondire. La suggestione a farlo, viene da un’idea di Pablo Rodri-guez Navarro ed abbiamo quindi pensato di avviarla proprio in questo numero, che Pablo ha accettato di curare su un tema a lui particolarmente caro.

  8. Mixoma ventricular izquierdo

    Directory of Open Access Journals (Sweden)

    Camilo Alvarado-Castro

    2017-05-01

    Conclusión: Las neoplasias cardiacas son infrecuentes siendo el mixoma, el tumor benigno más común del corazón. El diagnóstico puede ser sugerido por los síntomas, aunque es usual encontrar un examen físico normal. Se diagnóstica con el ecocardiograma transtorácico, la tomografía axial computarizada y la resonancia nuclear magnética. El tratamiento es quirúrgico, siendo seguro, efectivo y considerado curativo en la mayoría de las resecciones, con una tasa de supervivencia a 5 años del 83%.

  9. Comparison of femoropopliteal artery stents under axial and radial compression, axial tension, bending, and torsion deformations.

    Science.gov (United States)

    Maleckis, Kaspars; Deegan, Paul; Poulson, William; Sievers, Cole; Desyatova, Anastasia; MacTaggart, Jason; Kamenskiy, Alexey

    2017-11-01

    High failure rates of Peripheral Arterial Disease (PAD) stenting appear to be associated with the inability of certain stent designs to accommodate severe biomechanical environment of the femoropopliteal artery (FPA) that bends, twists, and axially compresses during limb flexion. Twelve Nitinol stents (Absolute Pro, Supera, Lifestent, Innova, Zilver, Smart Control, Smart Flex, EverFlex, Viabahn, Tigris, Misago, and Complete SE) were quasi-statically tested under bench-top axial and radial compression, axial tension, bending, and torsional deformations. Stents were compared in terms of force-strain behavior, stiffness, and geometrical shape under each deformation mode. Tigris was the least stiff stent under axial compression (6.6N/m axial stiffness) and bending (0.1N/m) deformations, while Smart Control was the stiffest (575.3N/m and 105.4N/m, respectively). Under radial compression Complete SE was the stiffest (892.8N/m), while Smart Control had the lowest radial stiffness (211.0N/m). Viabahn and Supera had the lowest and highest torsional stiffness (2.2μNm/° and 959.2μNm/°), respectively. None of the 12 PAD stents demonstrated superior characteristics under all deformation modes and many experienced global buckling and diameter pinching. Though it is yet to be determined which of these deformation modes might have greater clinical impact, results of the current analysis may help guide development of new stents with improved mechanical characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Análisis de percepción de riesgos laborales de tipo biológico con la utilización de un sistema informático especializado

    Directory of Open Access Journals (Sweden)

    Ana Teresa Carbonell Siam

    Full Text Available Introducción: la no disponibilidad e insuficiente flexibilidad de las herramientas de estudio de percepción de riesgo es limitante para alcanzar su generalización en diferentes ámbitos. Objetivo: diseñar un sistema informático para evaluación de percepción de riesgo flexible y demostrar su capacidad a través de aplicaciones a varios casos de estudio. Métodos: a partir del método de evaluación de percepción de riesgo ocupacional (EPRO, se elaboró el algoritmo base del código RISKPERCEP. Resultados: el método EPRO, informatizado a través de RISKPERCEP, se aplicó a escenarios diversos con peligro biológico asociado, como una empresa de producción de productos biológicos, un banco de sangre y las labores de las brigadas de vigilancia y lucha antivectorial. Se obtuvo en general, un perfil de subestimación de los peligros entre el personal ocupacionalmente expuesto. Conclusiones: la herramienta computarizada identificada como RISKPERCEP facilita la evaluación de percepción de riesgo, de manera que flexibiliza el análisis y permite su extensión a diferentes escenarios con riesgo biológico.

  11. Conversando con Oriol Bohigas

    OpenAIRE

    Redondo Domínguez, Ernesto; Moya Sala, Joaquim

    2015-01-01

    [EN] Interview with Oriol Bohigas [ES] Entrevista con Oriol Bohigas Redondo Domínguez, E.; Moya Sala, J. (2015). Conversando con… Oriol Bohigas. EGA. Revista de Expresión Gráfica Arquitectónica. 20(26):22-35. doi:10.4995/ega.2015.4061 22 35 20 26

  12. DR Con o:

    African Journals Online (AJOL)

    which could fall under the Ugandan influence. The con-. flict in the ..... The Congolese people and international community within SADC, the AU ..... ments and make peace among themselves. However, one ... friends overnight.There is a great ...

  13. fertilizada con diferentes abonos

    Directory of Open Access Journals (Sweden)

    Jorge Alberto Elizondo-Salazar

    2007-01-01

    Full Text Available Producción y calidad de la biomasa de morera (Morus alba fertilizada con diferentes abonos. Se llevó a cabo un experimento en la Estación Experimental “Alfredo Volio Mata” de la Universidad de Costa Rica con el fi n de evaluar la aplicación de 150 kg de N/ha/año proveniente de dos abonos orgánicos: lombriabono y compostaje; y de un fertilizante químico, sobre la producción y calidad de la biomasa de morera. El periodo experimental comprendió un ciclo de 12 meses, iniciando en julio del 2003 y fi nalizando en julio del 2004. Se utilizó una plantación de morera de 12 años de establecida con una densidad de siembra de 27.777 plantas/ ha. Se empleó un diseño de bloques completos al azar con cuatro tratamientos: dos abonos orgánicos, nitrato de amonio (33,5% N y un control. Las plantas se podaron a 0,6 m sobre el nivel del suelo al inicio del ensayo. Durante el periodo experimental, las plantas fueron podadas consecutivamente cada 90 días. Las hojas y los tallos fueron separados y analizados para determinar el contenido de materia seca y proteína cruda. La producción de materia seca fue 23% superior y el contenido de proteína cruda fue signifi cativamente mayor con el nitrógeno químico, mientras que el contenido de materia seca fue menor. No se encontraron diferencias signifi cativas entre el tratamiento control y los tratamientos orgánicos.

  14. Chiral filter, axial charges and Gamow-Teller strengths

    International Nuclear Information System (INIS)

    Rho, M.

    1983-09-01

    The different ways that nuclear matter responds to the weak axial-vector current are interpreted in terms of modification of the ''vacuum'' in baryon-rich environments. The notion of ''chiral filter'' is introduced. Use of a ward identity is suggested. The Gamow-Teller quenching and the enhanced axial charge in O + O - transitions follow from this. I also discuss briefly possible relevance of the nucleon as a topological soliton configuration to the global property of nuclear axial response functions

  15. Geometric inequalities for axially symmetric black holes

    International Nuclear Information System (INIS)

    Dain, Sergio

    2012-01-01

    A geometric inequality in general relativity relates quantities that have both a physical interpretation and a geometrical definition. It is well known that the parameters that characterize the Kerr-Newman black hole satisfy several important geometric inequalities. Remarkably enough, some of these inequalities also hold for dynamical black holes. This kind of inequalities play an important role in the characterization of the gravitational collapse; they are closely related with the cosmic censorship conjecture. Axially symmetric black holes are the natural candidates to study these inequalities because the quasi-local angular momentum is well defined for them. We review recent results in this subject and we also describe the main ideas behind the proofs. Finally, a list of relevant open problems is presented. (topical review)

  16. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The objects of this invention are first to reduce the time required to obtain statistically significant data in trans-axial tomographic radioisotope scanning using a scintillation camera. Secondly, to provide a scintillation camera system to increase the rate of acceptance of radioactive events to contribute to the positional information obtainable from a known radiation source without sacrificing spatial resolution. Thirdly to reduce the scanning time without loss of image clarity. The system described comprises a scintillation camera detector, means for moving this in orbit about a cranial-caudal axis relative to a patient and a collimator having septa defining apertures such that gamma rays perpendicular to the axis are admitted with high spatial resolution, parallel to the axis with low resolution. The septa may be made of strips of lead. Detailed descriptions are given. (U.K.)

  17. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The principal problem in trans-axial tomographic radioisotope scanning is the length of time required to obtain meaningful data. Patient movement and radioisotope migration during the scanning period can cause distortion of the image. The object of this invention is to reduce the scanning time without degrading the images obtained. A system is described in which a scintillation camera detector is moved to an orbit about the cranial-caudal axis relative to the patient. A collimator is used in which lead septa are arranged so as to admit gamma rays travelling perpendicular to this axis with high spatial resolution and those travelling in the direction of the axis with low spatial resolution, thus increasing the rate of acceptance of radioactive events to contribute to the positional information obtainable without sacrificing spatial resolution. (author)

  18. Axial tomographic system for radiation diagnoses

    International Nuclear Information System (INIS)

    Crowther, T.J.

    1977-01-01

    The axial tomographic scanner consists of a source of hard radiation passing a fan shaped beam through a plane layer of the body under examination, a detector, and driving systems for the sequential displacement and rotation of the radiation source and the detector. The diagnosis is made by means of a data processing system offering extensive time overlap capability of the individual system functions. The data sets from transmission or absorption are processed in three independent subsystems, i.e., the scanning system, the processing system and the display system. The systems are made up of well-known modules, e.g., Nova 1200 or Eclipse 5200. Hence, as a result of the independent design of the data system, raw data will not be lost in case of faults in some subsystem. (DG) [de

  19. Axial grazing collisions with insulator surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gravielle, M.S. [Instituto de Astronomia y Fisica del Espacio (IAFE), Consejo Nacional de Investigaciones Cientificas y Tecnicas, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina) and Departamento de Fisica, FCEN, Universidad de Buenos Aires (Argentina)]. E-mail: msilvia@iafe.uba.ar; Miraglia, J.E. [Instituto de Astronomia y Fisica del Espacio (IAFE), Consejo Nacional de Investigaciones Cientificas y Tecnicas, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina); Departamento de Fisica, FCEN, Universidad de Buenos Aires (Argentina)

    2007-05-15

    Electron capture and emission processes from insulator surfaces produced by grazing impact of fast ions are investigated under axial incidence conditions. For crystal surfaces we develop a model based on distorted wave methods, which allows us to express the coherent transition amplitude along the projectile path as a sum of atomic amplitudes, each one associated with a different lattice site. The method is applied to 100 keV protons colliding with LiF surfaces. For electron transitions from a given initial crystal state, the probabilities display strong interference effects as a function of the crystal orientation. But the interference patterns disappear when these partial probabilities are added to derive the total probability from the surface band.

  20. Axial grazing collisions with insulator surfaces

    International Nuclear Information System (INIS)

    Gravielle, M.S.; Miraglia, J.E.

    2007-01-01

    Electron capture and emission processes from insulator surfaces produced by grazing impact of fast ions are investigated under axial incidence conditions. For crystal surfaces we develop a model based on distorted wave methods, which allows us to express the coherent transition amplitude along the projectile path as a sum of atomic amplitudes, each one associated with a different lattice site. The method is applied to 100 keV protons colliding with LiF surfaces. For electron transitions from a given initial crystal state, the probabilities display strong interference effects as a function of the crystal orientation. But the interference patterns disappear when these partial probabilities are added to derive the total probability from the surface band

  1. Axial nonimaging characteristics of imaging lenses: discussion.

    Science.gov (United States)

    Siew, Ronian

    2016-05-01

    At observation planes away from the image plane, an imaging lens is a nonimaging optic. We examine the variation of axial irradiance with distance in image space and highlight the following little-known observation for discussion: On a per-unit-area basis, the position of the highest concentration in image space is generally not at the focal plane. This characteristic is contrary to common experience, and it offers an additional degree of freedom for the design of detection systems. Additionally, it would also apply to lenses with negative refractive index. The position of peak concentration and its irradiance is dependent upon the location and irradiance of the image. As such, this discussion also includes a close examination of expressions for image irradiance and explains how they are related to irradiance calculations beyond the image plane. This study is restricted to rotationally symmetric refractive imaging systems with incoherent extended Lambertian sources.

  2. Aerodynamic Modelling and Optimization of Axial Fans

    DEFF Research Database (Denmark)

    Sørensen, Dan Nørtoft

    A numerically efficient mathematical model for the aerodynamics oflow speed axial fans of the arbitrary vortex flow type has been developed.The model is based on a blade-element principle, whereby therotor is divided into a number of annular streamtubes.For each of these streamtubes relations......-Raphson method, andsolutions converged to machine accuracy are found at small computing costs.The model has been validated against published measurementson various fan configurations,comprising two rotor-only fan stages, a counter-rotatingfan unit and a stator-rotor-stator stage.Comparisons of local...... and integrated propertiesshow that the computed results agree well with the measurements.Integrating a rotor-only version of the aerodynamic modelwith an algorithm for numerical designoptimization, enables the finding of an optimum fan rotor.The angular velocity of the rotor, the hub radius and the spanwise...

  3. Image reconstruction. Application to transverse axial tomography

    International Nuclear Information System (INIS)

    Aubry, Florent.

    1977-09-01

    A method of computerized tridimensional image reconstruction from their projection, especially in the computerized transverse axial tomography is suggested. First, the different techniques actually developped and presented in the literature are analyzed. Then, the equipment used is briefly described. The reconstruction algorithm developped is presented. This algorithm is based on the convolution method, well adapted to the real conditions of exploitation. It is an extension of SHEPP and LOGAN's algorithm. A correction of the self absorption and of the detector's response is proposed. Finally, the first results obtained which are satisfactory are given. The simplicity of the method which does not need a too long computation time makes possible the implementation of the algorithm on a mini-computer [fr

  4. Composite Axial Flow Propulsor for Small Aircraft

    Directory of Open Access Journals (Sweden)

    R. Poul

    2005-01-01

    Full Text Available This work focuses on the design of an axial flow ducted fan driven by a reciprocating engine. The solution minimizes the turbulization of the flow around the aircraft. The fan has a rotor - stator configuration. Due to the need for low weight of the fan, a carbon/epoxy composite material was chosen for the blades and the driving shaft.The fan is designed for optimal isentropic efficiency and free vortex flow. A stress analysis of the rotor blade was performed using the Finite Element  Method. The skin of the blade is calculated as a laminate and the foam core as a solid. A static and dynamic analysis were made. The RTM technology is compared with other technologies and is described in detail. 

  5. Estimation of ocular volume from axial length.

    Science.gov (United States)

    Nagra, Manbir; Gilmartin, Bernard; Logan, Nicola S

    2014-12-01

    To determine which biometric parameters provide optimum predictive power for ocular volume. Sixty-seven adult subjects were scanned with a Siemens 3-T MRI scanner. Mean spherical error (MSE) (D) was measured with a Shin-Nippon autorefractor and a Zeiss IOLMaster used to measure (mm) axial length (AL), anterior chamber depth (ACD) and corneal radius (CR). Total ocular volume (TOV) was calculated from T2-weighted MRIs (voxel size 1.0 mm(3)) using an automatic voxel counting and shading algorithm. Each MR slice was subsequently edited manually in the axial, sagittal and coronal plane, the latter enabling location of the posterior pole of the crystalline lens and partitioning of TOV into anterior (AV) and posterior volume (PV) regions. Mean values (±SD) for MSE (D), AL (mm), ACD (mm) and CR (mm) were -2.62±3.83, 24.51±1.47, 3.55±0.34 and 7.75±0.28, respectively. Mean values (±SD) for TOV, AV and PV (mm(3)) were 8168.21±1141.86, 1099.40±139.24 and 7068.82±1134.05, respectively. TOV showed significant correlation with MSE, AL, PV (all p<0.001), CR (p=0.043) and ACD (p=0.024). Bar CR, the correlations were shown to be wholly attributable to variation in PV. Multiple linear regression indicated that the combination of AL and CR provided optimum R(2) values of 79.4% for TOV. Clinically useful estimations of ocular volume can be obtained from measurement of AL and CR. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. Aerodynamic modelling and optimization of axial fans

    Energy Technology Data Exchange (ETDEWEB)

    Noertoft Soerensen, Dan

    1998-01-01

    A numerically efficient mathematical model for the aerodynamics of low speed axial fans of the arbitrary vortex flow type has been developed. The model is based on a blade-element principle, whereby the rotor is divided into a number of annular stream tubes. For each of these stream tubes relations for velocity, pressure and radial position are derived from the conservation laws for mass, tangential momentum and energy. The equations are solved using the Newton-Raphson methods, and solutions converged to machine accuracy are found at small computing costs. The model has been validated against published measurements on various fan configurations, comprising two rotor-only fan stages, a counter-rotating fan unit and a stator-rotor stator stage. Comparisons of local and integrated properties show that the computed results agree well with the measurements. Optimizations have been performed to maximize the mean value of fan efficiency in a design interval of flow rates, thus designing a fan which operates well over a range of different flow conditions. The optimization scheme was used to investigate the dependence of maximum efficiency on 1: the number of blades, 2: the width of the design interval and 3: the hub radius. The degree of freedom in the choice of design variable and constraints, combined with the design interval concept, provides a valuable design-tool for axial fans. To further investigate the use of design optimization, a model for the vortex shedding noise from the trailing edge of the blades has been incorporated into the optimization scheme. The noise emission from the blades was minimized in a flow rate design point. Optimizations were performed to investigate the dependence of the noise on 1: the number of blades, 2: a constraint imposed on efficiency and 3: the hub radius. The investigations showed, that a significant reduction of noise could be achieved, at the expense of a small reduction in fan efficiency. (EG) 66 refs.

  7. Axially symmetric Lorentzian wormholes in general relativity

    International Nuclear Information System (INIS)

    Schein, F.

    1997-11-01

    The field equations of Einstein's theory of general relativity, being local, do not fix the global structure of space-time. They admit topologically non-trivial solutions, including spatially closed universes and the amazing possibility of shortcuts for travel between distant regions in space and time - so-called Lorentzian wormholes. The aim of this thesis is to (mathematically) construct space-times which contain traversal wormholes connecting arbitrary distant regions of an asymptotically flat or asymptotically de Sitter universe. Since the wormhole mouths appear as two separate masses in the exterior space, space-time can at best be axially symmetric. We eliminate the non-staticity caused by the gravitational attraction of the mouths by anchoring them by strings held at infinity or, alternatively, by electric repulsion. The space-times are obtained by surgically grafting together well-known solutions of Einstein's equations along timelike hypersurfaces. This surgery naturally concentrates a non-zero stress-energy tensor on the boundary between the two space-times which can be investigated by using the standard thin shell formalism. It turns out that, when using charged black holes, the provided constructions are possible without violation of any of the energy conditions. In general, observers living in the axially symmetric, asymptotically flat (respectively asymptotically de Sitter) region axe able to send causal signals through the topologically non-trivial region. However, the wormhole space-times contain closed timelike curves. Because of this explicit violation of global hyperbolicity these models do not serve as counterexamples to known topological censorship theorems. (author)

  8. Energy Dissipation in Sandwich Structures During Axial Compression

    DEFF Research Database (Denmark)

    Urban, Jesper

    2002-01-01

    The purpose of this paper is to investigate the energy dissipation in sandwich structures during axial crushing. Axial crushing tests on six sandwich elements are described. The sandwich elements consist of a polyurethane core and E-glass/Polyester skin. The elements compare to full-scale structu......The purpose of this paper is to investigate the energy dissipation in sandwich structures during axial crushing. Axial crushing tests on six sandwich elements are described. The sandwich elements consist of a polyurethane core and E-glass/Polyester skin. The elements compare to full...

  9. Improved axial position detection in optical tweezers measurements

    DEFF Research Database (Denmark)

    Dreyer, Jakob Kisbye; Berg-Sørensen, Kirstine; Oddershede, Lene

    2004-01-01

    We investigate the axial position detection of a trapped microsphere in an optical trap by using a quadrant photodiode. By replacing the photodiode with a CCD camera, we obtain detailed information on the light scattered by the microsphere. The correlation of the interference pattern with the axial...... position displays complex behavior with regions of positive and negative interference. By analyzing the scattered light intensity as a function of the axial position of the trapped sphere, we propose a simple method to increase the sensitivity and control the linear range of axial position detection....

  10. Dynamic stability of slender columns with semi-rigid connections under periodic axial load: verification and examples

    Directory of Open Access Journals (Sweden)

    Oliver Giraldo-Londoño

    2014-01-01

    Full Text Available La estabilidad dinámica de una columna elástica prismática esbelta con conexiones semirrígidas en ambos extremos de rigidez idéntica y con desplazamiento lateral entre los dos extremos totalmente inhibido sujetos a cargas axiales paramétricas incluyendo los efectos combinados de inercia rotacional y amortiguación externas fue presentada en una publicación adjunta. Expresiones cerradas que se pueden utilizar para predecir las regiones inestabilidad dinámica de columnas esbeltas se desarrollan haciendo uso de la teoría de Floquet. Las ecuaciones propuestas son sencillas y fáciles de aplicar. La solución propuesta es capaz de capturar el fenómeno de estabilidad en columnas sometidas a cargas axiales periódicas utilizando un solo elemento de columna. El método propuesto y las ecuaciones correspondientes se pueden utilizar para investigar los efectos del amortiguamiento, la inercia rotacional de la columna, y las conexiones semirrígidas en el análisis de estabilidad de columnas esbeltas sometidas a cargas axiales periódicas. Estudios de sensibilidad presentados en esta publicación muestran los efectos de la inercia rotacional, el amortiguamiento y las conexiones semi-rígidas en la estabilidad dinámica de columnas sometidas a cargas axiales paramétricas. Los estudios analíticos indican que el comportamiento dinámico de columnas bajo carga periódica está fuertemente afectado por la rigidez a la flexión de las conexiones de los dos apoyos y por el amortiguamiento externo, pero no tanto por la inercia rotacional. Tres ejemplos se presentan en detalle y los resultados calculados se comparan con los reportados por otros investigadores.

  11. Morfología comparada del esqueleto axial en la familia de cangrejos de agua dulce Trichodactylidae (Crustacea: Decapoda: Brachyura

    Directory of Open Access Journals (Sweden)

    Manuel Pedraza

    2015-07-01

    Full Text Available El esqueleto axial es una estructura compleja de origen cuticular, formada a partir de las láminas esclerotizadas de los esternitos y pleuritos torácicos así como por sus invaginaciones internas. Los caracteres de la parte ventral del esqueleto axial, que se reflejan externamente en las líneas de sutura del esternón torácico, son criterios importantes en el actual sistema de supragenerico de Trichodactylidae: (Trichodactylinae y Dilocarcininae (Dilocarcinini + Valdiviini. Con el objetivo de probar esa hipótesis de clasificación fue realizado el estudio anatómico del esqueleto axial de 43 individuos adultos, tanto machos como hembras, pertenecientes a 17 especies de 10 géneros de Trichodactylidae. Para la preparación del material, los individuos fueron diseccionados y sus esqueletos sumergidos, por un periodo de 24 a 48 horas, en una solución caliente de Hidróxido de Potasio (KOH. El análisis anatómico permitió describir un grupo de variaciones en la forma, orientación y conformación del esternón torácico, techo pleural, fragmas ventrales y dorsales, así como de la lámina de unión. De acuerdo con esas características las especies estudiadas fueron reunidas en tres grupos, siendo esas agrupaciones consistentes con la actual propuesta de clasificación de Trichodactylidae en subfamilias y tribus. El presente trabajo resalta la importancia informativa de la morfología del esqueleto axial para la taxonomía de Trichodactylidae.

  12. Dual-detection confocal fluorescence microscopy: fluorescence axial imaging without axial scanning.

    Science.gov (United States)

    Lee, Dong-Ryoung; Kim, Young-Duk; Gweon, Dae-Gab; Yoo, Hongki

    2013-07-29

    We propose a new method for high-speed, three-dimensional (3-D) fluorescence imaging, which we refer to as dual-detection confocal fluorescence microscopy (DDCFM). In contrast to conventional beam-scanning confocal fluorescence microscopy, where the focal spot must be scanned either optically or mechanically over a sample volume to reconstruct a 3-D image, DDCFM can obtain the depth of a fluorescent emitter without depth scanning. DDCFM comprises two photodetectors, each with a pinhole of different size, in the confocal detection system. Axial information on fluorescent emitters can be measured by the axial response curve through the ratio of intensity signals. DDCFM can rapidly acquire a 3-D fluorescent image from a single two-dimensional scan with less phototoxicity and photobleaching than confocal fluorescence microscopy because no mechanical depth scans are needed. We demonstrated the feasibility of the proposed method by phantom studies.

  13. pacientes con falla cardiaca

    Directory of Open Access Journals (Sweden)

    Diana Marcela Achury Saldaña

    2007-01-01

    Full Text Available Objetivo: determinar la adherencia al tratamiento de pacientes con falla cardiaca hospitalizados, al aplicar un plan educativo quefomenta el autocuidado.Método: estudio cuasiexperimental (entrevistas enfermera-paciente realizado entre diciembre de 2004 y mayo de 2006, con unamuestra de 50 pacientes seleccionados por conveniencia. Se diseñó un instrumento para evaluar los comportamientos de los pacientes,con base en algunos resultados de la adherencia y sus respectivos indicadores de la taxonomía NOC (Nursing out comes classification. Laadherencia al tratamiento fue medida en dos momentos: el primero durante la hospitalización, seguido de la aplicación del plan educativoantes del alta, que proporcionaba información en el manejo de su enfermedad desde una dimensión física, psicológica y social quepromueve el autocuidado; y el segundo un mes después del alta en su domicilio.Resultados: diferencias estadísticamente significativas (P=0,0001 que demuestran cómo mediante la capacitación al paciente enel manejo de su tratamiento farmacológico y no farmacológico, el establecimiento de una sana relación entre el profesional de enfermeríay el paciente, y la participación de la familia, se logra una total adherencia al tratamiento.Conclusiones: para lograr una adherencia total del paciente con falla cardiaca al tratamiento es necesario un proceso educativo y unseguimiento continuo y personalizado que motive permanentemente al paciente y se le reconozca el papel protagónico en su cuidado y manejo de la enfermedad.

  14. Bifunctional organocatalysts for the asymmetric synthesis of axially chiral benzamides

    Directory of Open Access Journals (Sweden)

    Ryota Miyaji

    2017-08-01

    Full Text Available Bifunctional organocatalysts bearing amino and urea functional groups in a chiral molecular skeleton were applied to the enantioselective synthesis of axially chiral benzamides via aromatic electrophilic bromination. The results demonstrate the versatility of bifunctional organocatalysts for the enantioselective construction of axially chiral compounds. Moderate to good enantioselectivities were afforded with a range of benzamide substrates. Mechanistic investigations were also carried out.

  15. Test Setup for Axially Loaded Piles in Sand

    DEFF Research Database (Denmark)

    Thomassen, Kristina

    The test setup for testing axially static and cyclic loaded piles in sand is described in the following. The purpose for the tests is to examine the tensile capacity of axially loaded piles in dense fully saturated sand. The pile dimensions are chosen to resemble full scale dimension of piles used...... in offshore pile foundations today....

  16. Characterisation of plasmas produced by the "Torche a Injection Axiale"

    NARCIS (Netherlands)

    Jonkers, J.; Selen, L.J.M.; Mullen, van der J.J.A.M.; Regt, de J.M.; Timmermans, E.A.H.; Schram, D.C.

    1996-01-01

    Summary form only given. The Torche a Injection Axiale (TIA), i.e. torch with axial gas injection, was developed by the group of Moisan in 1993. We report on the investigations on two different kind of plasmas created by the TIA: one with helium and the other with argon as main gas. Using absolute

  17. Equation of motion for the axial gravitational superfield

    International Nuclear Information System (INIS)

    Ogievetsky, V.; Sokatchev, E.

    1980-01-01

    Transformation properties of the axial supergravitational field variants are investigated. The equation of motion for the axial gravitational superfield is derived by direct variation of the N = 1 supergravity action. The left-hand side of this equation is a component of the torsion tensor, and the right-hand side is the supercurrent. The question about the cosmological term in supergravity is discussed

  18. Original paper Cytokine profiles in axial spondyloarthritis

    Directory of Open Access Journals (Sweden)

    Marta Madej

    2015-04-01

    Full Text Available Objectives: Current studies concentrate on the cytokine network and its role in the pathogenesis of spondyloarthritis (SpA. In this study, we analyzed whether the serum cytokine profile (interleukins: IL-10, IL-11, IL-12, IL-15, IL-17, IL-23 and IL-33 correlates with demographic data, clinical manifestations, disease activity and treatment outcome in a group of patients with axial spondyloarthritis. Material and methods: Forty-nine patients with an established diagnosis of axial spondyloarthritis (aSpA and 19 healthy volunteers as controls were enrolled in the study. Clinical evaluation included patient’s medical history, 44 joint count, back pain intensity and global disease activity in the preceding week (VAS, the duration of morning stiffness and blood tests. Disease activity was assessed using BASDAI and ASDAS-CRP. Serum concentration of IL-10, IL-11, IL-12, IL-15, IL-17, IL-23 and IL-33 was determined. Results : In patients with aSpA, elevated serum concentration of IL-10, IL-15, IL-17 and IL-23 was detected. In the aSpA group we detected higher values of serum concentration of IL-23 and IL-33 in the subgroup with anterior uveitis (83.1 ±184.0 pg/ml vs. 14.0 ±17.1 pg/ml, p < 0.0001 and 45.5 ±71.9 pg/ml vs. 18.4 ±14.3 pg/ml, p < 0.0001, respectively. Additionally, in the subgroup with peripheral arthritis, elevation of serum concentration of IL-12 (249.3 ±246.9 pg/ml vs. 99.9 ±105.9 pg/ml, p = 0.0001 was detected. Patients with preradiological SpA had higher serum concentration of IL-17 than patients with established diagnosis of AS (6.37 ±8.50 pg/ml vs. 2.04 ±2.98 pg/ml, p = 0.0295. No differences in serum concentration of analyzed cytokines were found between the subgroup with low to moderate disease activity and the subgroup with high to very high disease activity. Conclusions : We report that in aSpA patients, compared to controls, elevated serum concentrations of IL-10, IL-15, IL-17 and IL-23 were observed. Some cytokines may

  19. Evaluación de imágenes de tomografía computarizada cone beam, para el análisis y diagnóstico de las asimetrías faciales

    OpenAIRE

    Jaramillo Salazar, Luisa Fernanda

    2016-01-01

    INTRODUCCIÓN: El CBCT proporciona imágenes con excelente calidad diagnóstica. Además, realiza cortes tomográficos en cortos intervalos de tiempo y baja dosis de radiación, lo que aumenta la capacidad de evaluación en la clínica odontológica, con menor distorsión de las imágenes provenientes en 3D. Por otro lado, las asimetrías faciales han sido objeto de estudio por los ortodoncistas por su implicación en la cirugía ortognática, por lo que la visualización de estructuras 3D aporta una mej...

  20. Cementos con cenizas volantes

    Directory of Open Access Journals (Sweden)

    Ossa M., Mauricio

    1984-03-01

    additions of 20 and 30% .

    Casi la generalidad de los estudios realizados sobre cementos con adición de cenizas volantes se refieren a sus características y comportamiento en pastas, morteros y hormigones, siempre en relación con aquéllos del cemento portland. Esta vez, se desarrolló un trabajo experimental orientado a relacionar entre sí los cementos con adiciones de cenizas volantes y de puzolana natural. Para ello se fabricaron a escala de laboratorio cementos de ambos tipos, empleando como materias primas comunes clinker y yeso y, como variables, diferentes porcentajes de las dos adiciones, que cumplieron previamente los requisitos normalizados en cuanto a sus actividades puzolánicas. La calidad de los cementos fabricados resultó adecuada y concordante con la del cemento portland-puzolánico obtenido a escala industrial con los mismos clinker, yeso y puzolana natural de este estudio. Posteriormente, se determinaron las características de los cementos experimentales y se confeccionaron morteros normales para la realización de ensayos físicos y mecánicos. Los resultados de ensayos indicaron que los cementos con adición de cenizas volantes (CCV requieren menos agua para consistencia normal, presentan tiempos de fraguado mayores y expansiones en autoclave menores que los cementos con adición de puzolana (CP. Los calores de hidratación a 7 y 28 días de edad fueron aproximadamente similares para ambos tipos de cemento. En morteros normales, los cementos CCV mostraron menor retracción de secado, mayor retentividad y mayor fluidez (para igual cantidad de agua que los cementos CP. En los ensayos de exudación se observó que ésta depende más de la finura que el tipo de adición. Finalmente, los ensayos mecánicos señalaron que las resistencias a compresión y flexotracción de los morteros con cementos CCV son menores a edades inferiores que 14 días (del orden de 5 a 10% a un día de edad, pero que a partir de entonces pasan a ser mayores que las de

  1. The Klinger hot gas double axial valve

    International Nuclear Information System (INIS)

    Kruschik, J.; Hiltgen, H.

    1984-01-01

    The Klinger hot gas valve is a medium controlled double axial valve with advanced design features and safety function. It was first proposed by Klinger early in 1976 for the PNP-Project as a containment shut-off for hot helium (918 deg. C and 42 bar), because a market research has shown that such a valve is not state of present techniques. In the first stage of development a feasibility study had to be made by detailed design, calculation and by basic experiments for key components in close collaboration with Interatom/GHT. This was the basis for further design, calculation, construction and experimental work for such a valve prototype within the new development contract. The stage of knowledge to that time revealed the following key priority development areas: Finite element stress analysis for the highly stressed high temperature main components; development of an insulation layout; Detailed experimental tests of functionally important structural components or units of the valve, partly at Klingers (gasstatic bearings, flexible metallic sealing element, aerodynamic and thermohydraulic tests), partly at Interatom (actuator unit and also gasstatic bearings), partly at HRB in Juelich (flexible metallic sealing system, aerodynamic and thermohydraulic tests); Design of a test valve for experimental work in the KVK (test circuit at Interatom) for evaluation of temperature distribution and reliability of operation; Design of a prototype and extensive testing in the KVK

  2. Small axial compressor technology, volume 1

    Science.gov (United States)

    Holman, F. F.; Kidwell, J. R.; Ware, T. C.

    1976-01-01

    A scaled single-stage, highly-loaded, axial-flow transonic compressor was tested at speeds from 70 to 110% design equivalent speed to evaluate the effects of scaling compromises and the individual and combined effects of rotor tip running clearance and rotor shroud casing treatment on the overall and blade element performance. At design speed and 1% tip clearance the stage demonstrated an efficiency of 83.2% at 96.4% design flow and a pressure ratio of 1.865. Casing treatment increased design speed surge margin 2.0 points to 12.8%. Overall performance was essentially unchanged. An increase in rotor running clearance to 2.2%, with smooth casing, reduced design speed peak efficiency 5.7 points, flow by 7.4%, pressure ratio to 1.740, and surge margin to 5.4%. Reinstalling casing treatment regained 3.5 points in design speed peak efficiency, 4.7% flow, increased pressure ratio to 1.800 and surge margin to 8.7%.

  3. Giant Cell Tumors of the Axial Skeleton

    Directory of Open Access Journals (Sweden)

    Maurice Balke

    2012-01-01

    Full Text Available Background. We report on 19 cases of giant cell tumor of bone (GCT affecting the spine or sacrum and evaluate the outcome of different treatment modalities. Methods. Nineteen patients with GCT of the spine (=6 or sacrum (=13 have been included in this study. The mean followup was 51.6 months. Ten sacral GCT were treated by intralesional procedures of which 4 also received embolization, and 3 with irradiation only. All spinal GCT were surgically treated. Results. Two (15.4% patients with sacral and 4 (66.7% with spinal tumors had a local recurrence, two of the letter developed pulmonary metastases. One local recurrence of the spine was successfully treated by serial arterial embolization, a procedure previously described only for sacral tumors. At last followup, 9 patients had no evidence of disease, 8 had stable disease, 1 had progressive disease, 1 died due to disease. Six patients had neurological deficits. Conclusions. GCT of the axial skeleton have a high local recurrence rate. Neurological deficits are common. En-bloc spondylectomy combined with embolization is the treatment of choice. In case of inoperability, serial arterial embolization seems to be an alternative not only for sacral but also for spinal tumors.

  4. Axial channeling of boron ions into silicon

    International Nuclear Information System (INIS)

    La Ferla, A.; Galvagno, G.; Raineri, V.; Setola, R.; Rimini, E.; Carnera, A.; Gasparotto, A.

    1992-01-01

    Channeling boron implants were performed into (100) and (110) silicon substrates in the energy range 80-700 keV. The dose ranged between 3.5x10 11 and 1x10 15 atoms/cm 2 . The axial channeling concentration profiles of implanted B + were compared with that obtained for incidence along the random direction of the crystal and with that obtained by implantation in amorphous silicon. The electrical and chemical boron distributions were obtained by spreading resistance and secondary ion mass spectrometry measurements, respectively. The inelastic stopping power, S c , was extracted from the experimental maximum ranges for the [100] and [110] axis. The energy dependence of the electronic stopping power is given by S e = KE p with p [100] = 0.469±0.010 and p [110] = 0.554±0.004. Simulations obtained by the MARLOWE code, using the Oen-Robinson impact parameter dependent formula, for the electronic energy loss reproduce quite well the experimental depth profiles. (orig.)

  5. Axial sheath dynamics in a plasma focus

    International Nuclear Information System (INIS)

    Soliman, H.M.; El-Khalafawy, T.A.; Masoud, M.M.

    1990-01-01

    This paper presents the result of investigation with a 10 kJ Mather type plasma focus. It is operated in hydrogen gas at ambient pressure of 0.15--1 torr and charging voltage of 8--11 kV. Radial distribution of the current sheath density with axial distance has been estimated. Plasma rotation in the expansion chamber in the absence of external magnetic field has been detected. A plasma flare from the plasma focus region propagating in the radial direction has been observed. Streak photography shows two plasma streams flowing simultaneously out of the muzzle. The mean energy of the electron beam ejected from the pinch region of the focused plasma, was measured by retarding field analyzer to be 0.32 keV. The electron temperature of the plasma focus at peak compression was determined by measuring the X-ray intensity as a function of absorber thickness at a distance of 62 cm from the focus. The electron temperature has been found to 3 keV

  6. Relation between axial length and ocular parameters

    Directory of Open Access Journals (Sweden)

    Xue-Qiu Yang

    2013-09-01

    Full Text Available AIM: To investigatethe relation between axial length(AL, age and ocular parameters.METHODS: A total of 360 subjects(360 eyeswith emmetropia or myopia were recruited. Refraction, center corneal thickness(CCT, AL, intraocular pressure(IOPwere measured by automatic-refractor, Pachymeter, A-mode ultrasound and non-contact tonometer, respectively. Corneal curvature(CC, anterior chamber depth(ACDand white-to-white distance(WWDwere measured by Orbscan II. Three dimensional frequency domain coherent optical tomography(3D-OCTwas used to examine the retinal nerve fiber layer thickness(RNFLT. The Pearson correlation coefficient(rand multiple regression analysis were performed to evaluate the relationship between AL, age and ocular parameters.RESULTS: The average AL was 24.15±1.26mm. With elongation of the AL, spherical equivalent(SE(r=-0.742,Pr=-0.395, Pr=-0.374, Pr=0.411, Pr=0.099, P=0.060and WWD(r=0.061, P=0.252. There was also a significant correlation between AL and age(P=0.001, SE(PPPCONCLUSION: In longer eyes, there is a tendency toward myopia, a flatter cornea, a deeper ACD and a thinner RNFLT. Age is an influencing factor for the AL as well.

  7. Analysis of SONACO axial cooling experiments

    International Nuclear Information System (INIS)

    Sigg, B.; Dury, T.V.; Hudina, M.

    1994-01-01

    The SONACO test rig contained a sodium-cooled, electrically heated 37-pin bundle. On this rig, a series of forced, mixed and natural convection experiments have been performed with the aim of contributing to the understanding of thermal-hydraulic phenomena and providing data for code validation for a subassembly at decay heat power level with low flow or stagnant coolant. The test section and especially the heater pins were equipped with an extensive number of chromel-alumel thermocouples. In addition, special permanent-magnet probes were used for measuring local velocities. In this paper we give a survey of results from axial cooling experiments, where heat was removed by natural convection to a cooling coil situated in the coolant channel (plenum) above the bundle. The experimental conditions led to turbulent convection with a slowly varying, large scale flow pattern. It is shown that a power tilt in the bundle reduces these fluctuations but does not eliminate them. For the uniformly heated bundle, aglebraic expressions for the average turbulent heat flux as well as for temperature and velocity fluctuations are derived from a second-moments model and compared with experimental data. Furthermore, heat transfer in the plenum and the consequences of the SONACO experiments for the coolability of reactor fuel elements under loss-of-flow conditions are discussed. ((orig.))

  8. Nucleon axial coupling from Lattice QCD

    Science.gov (United States)

    Cheng Chang, Chia; Nicholson, Amy; Rinaldi, Enrico; Berkowitz, Evan; Garron, Nicolas; Brantley, David; Monge-Camacho, Henry; Monahan, Chris; Bouchard, Chris; Clark, M. A.; Joó, Bálint; Kurth, Thorsten; Orginos, Kostas; Vranas, Pavlos; Walker-Loud, André

    2018-03-01

    We present state-of-the-art results from a lattice QCD calculation of the nucleon axial coupling, gA, using Möbius Domain-Wall fermions solved on the dynamical Nf = 2 + 1 + 1 HISQ ensembles after they are smeared using the gradient-flow algorithm. Relevant three-point correlation functions are calculated using a method inspired by the Feynman-Hellmann theorem, and demonstrate significant improvement in signal for fixed stochastic samples. The calculation is performed at five pion masses of mπ {400, 350, 310, 220, 130} MeV, three lattice spacings of a {0.15, 0.12, 0.09} fm, and we do a dedicated volume study with mπL {3.22, 4.29, 5.36}. Control over all relevant sources of systematic uncertainty are demonstrated and quantified. We achieve a preliminary value of gA = 1.285(17), with a relative uncertainty of 1.33%.

  9. Multimode interaction in axially excited cylindrical shells

    Directory of Open Access Journals (Sweden)

    Silva F. M. A.

    2014-01-01

    Full Text Available Cylindrical shells exhibit a dense frequency spectrum, especially near the lowest frequency range. In addition, due to the circumferential symmetry, frequencies occur in pairs. So, in the vicinity of the lowest natural frequencies, several equal or nearly equal frequencies may occur, leading to a complex dynamic behavior. So, the aim of the present work is to investigate the dynamic behavior and stability of cylindrical shells under axial forcing with multiple equal or nearly equal natural frequencies. The shell is modelled using the Donnell nonlinear shallow shell theory and the discretized equations of motion are obtained by applying the Galerkin method. For this, a modal solution that takes into account the modal interaction among the relevant modes and the influence of their companion modes (modes with rotational symmetry, which satisfies the boundary and continuity conditions of the shell, is derived. Special attention is given to the 1:1:1:1 internal resonance (four interacting modes. Solving numerically the governing equations of motion and using several tools of nonlinear dynamics, a detailed parametric analysis is conducted to clarify the influence of the internal resonances on the bifurcations, stability boundaries, nonlinear vibration modes and basins of attraction of the structure.

  10. competencia con China

    Directory of Open Access Journals (Sweden)

    Elena de la Paz Hernández Águila

    2007-01-01

    Full Text Available El artículo ofrece un diagnóstico del desempeño de la industria mexicana del calzado desde la década de los ochenta hasta la actualidad. Analiza la problemática que ha enfrentado esta rama industrial a partir del proceso de apertura comercial y de la competencia en su mercado interno con productos provenientes de países asiáticos, particularmente China. Problematiza al respecto los retos y las perspectivas que a mediano plazo enfrentará este sector empresarial y sobre las posibilidades de competir en el mercado globalizado.

  11. Construir con Madera

    OpenAIRE

    Olabe-Velasco, F. (Fermín); Val-Hernández, Y. (Yolanda); Varela-de-la-Cruz, P. (Perla); Cabrero-Ballarín, J.M. (José Manuel)

    2010-01-01

    Guía divulgativa ‘Construir con madera’, elaborada por la Cátedra Madera de la Universidad de Navarra y el Gobierno de Navarra. La publicación pretende explicar de forma sencilla los beneficios y posibilidades de este material en la construcción, tanto en lo que respecta a su resistencia, comportamiento frente al fuego, durabilidad, capacidad de aislamiento, propiedades acústicas, estética, respeto al medio ambiente y sostenibilidad como fuente de energía. A modo de ejemplo, en la ...

  12. Stall inception and warning in a single-stage transonic axial compressor with axial skewed slot casing treatment

    International Nuclear Information System (INIS)

    Lim, Byeung Jun; Kwon, Se Jin; Park, Tae Choon

    2014-01-01

    Characteristic changes in the stall inception in a single-stage transonic axial compressor with an axial skewed slot casing treatment were investigated experimentally. A rotating stall occurred intermittently in a compressor with an axial skewed slot, whereas spike-type rotating stalls occurred in the case of smooth casing. The axial skewed slot suppressed stall cell growth and increased the operating range. A mild surge, the frequency of which is the Helmholtz frequency of the compressor system, occurred with the rotating stall. The irregularity in the pressure signals at the slot bottom increased decreasing flow rate. An autocorrelation-based stall warning method was applied to the measured pressure signals. Results estimate and warn against the stall margin in a compressor with an axial skewed slot.

  13. Entrevista con Giovanni Levi

    Directory of Open Access Journals (Sweden)

    Monica Oliveira

    2017-06-01

    Full Text Available En esta entrevista, Giovanni Levi - como un conocedor del tema de Familia - realiza una importante evaluación sobre el actual estado de las investigaciones realizadas en el Brasil y em el exterior. Con estilo franco, agudo y lucido critica las visiones tradicionales y sus ilusiones ypropone nuevos conceptos y métodos. La historia de la familia debería ceder espacio para el estudio de las redes relacionales o de los mundos relacionales. De la misma forma, la historia cuantitativa debería abrir espacio para el estudio de las cualidades. Ya con relación a la historia de las elites, tan estudiada y reproducida en una diversidad de trabajos, que deberíase mirar en otra perspectiva. Es decir, no mirar a las reglas sociales predeterminadas, sino a los desvíos y a las variaciones. Levi defiende que los historiadores deben trascender a los documentos que se encuentran fácilmente y que pueden fortalecer perspectivas deformadas y esequilibradas de la sociedad. Para él, los historiadores deben esforzarse por estudiar a aquellos grupos que dejaron pocos rastros documentales. En ese esfuerzo existiría una nueva mirada sobre la historia de la familia.

  14. Entrevista con Patricia Ariza

    Directory of Open Access Journals (Sweden)

    Esperanza Londoño La Rotta

    2017-01-01

    Full Text Available Pensamiento, Palabra y Obra entrevista a una artista, feminista y activista política, quien como mujer y artista ha permitido pensar el arte más allá de un simple espectáculo. Toda una vida dedicada al teatro y a darle voz, a través de sus obras, a víctimas del conflicto colombiano, defensora de derechos humanos; además de hacer evidente en su vida y a través de la plataforma “Artistas por la paz”, las múltiples relaciones que se pueden establecer entre el arte, la construcción de paz y la resolución de conflictos. Hablamos en su casa, en medio del calor de la bienvenida con Patricia Ariza, directora del festival alternativo de teatro, de Mujeres en Escena y de la Corporación Colombiana de Teatro, entre otras muchas actividades que voluntariamente su espíritu libertario ha asumido. Esta entrevista se realizó antes del 2 de octubre, pero con la revisión de los acuerdos que propició el plebiscito ganado por una ínfima minoría por el no, sigue siendo vigente este planteamiento.

  15. Conservative axial burnup distributions for actinide-only burnup credit

    International Nuclear Information System (INIS)

    Kang, C.; Lancaster, D.

    1997-11-01

    Unlike the fresh fuel approach, which assumes the initial isotopic compositions for criticality analyses, any burnup credit methodology must address the proper treatment of axial burnup distributions. A straightforward way of treating a given axial burnup distribution is to segment the fuel assembly into multiple meshes and to model each burnup mesh with the corresponding isotopic compositions. Although this approach represents a significant increase in modeling efforts compared to the uniform average burnup approach, it can adequately determine the reactivity effect of the axial burnup distribution. A major consideration is what axial burnup distributions are appropriate for use in light of many possible distributions depending on core operating conditions and histories. This paper summarizes criticality analyses performed to determine conservative axial burnup distributions. The conservative axial burnup distributions presented in this paper are included in the Topical Report on Actinide-Only Burnup Credit for Pressurized Water Reactor Spent Nuclear Fuel Packages, Revision 1 submitted in May 1997 by the US Department of Energy (DOE) to the US Nuclear Regulatory Commission (NRC). When approved by NRC, the conservative axial burnup distributions may be used to model PWR spent nuclear fuel for the purpose of gaining actinide only burnup credit

  16. Axial currents and nuclear spin orientation

    International Nuclear Information System (INIS)

    Minamisono, T.; Nojiri, Y.; Matsuta, K.

    1984-01-01

    This paper discusses the symmetries in the phenomena in which weak interaction is involved are largely violated, and it is still the up-to-date fore-front to study the structure of the nuclear weak currents and to learn the limitations on the applicabilities of the various relevant conservation laws as well as the nuclear structures studied by the β-decay. In this meeting, research works on the β-decay processes for the past 10 years have focused on the recoil order experiments designed to determine the limits of validity of the conserved vector current (CVC) theory and to test the G parity conservation i.e. the search for the second class currents (SCC), as well as to study the structure of the axial currents. Concerning the SCC, after intensive studies, but with not conclusive results, on the ft values of mirror β-decays in the early seventies, the correlation-type measurements on mass A=8, 12, 19 and 20 systems have been also carried out in various laboratories from 1975. Among those, concerns have been with the mass A=12 nuclear triad, /sup 12/B-/sup 12/C-/sup 12/N, the energy diagram of which is well known. The choice of this triad is because of the test done for the strong CVC predictions using the spectrum shapes of β-rays combined with the experimental analogue γ-width in /sup 12/C as well as those relevant nuclear structures. Thus, this A=12 system provides the best testing ground for the research described above

  17. Axial displacements in external and internal implant-abutment connection.

    Science.gov (United States)

    Lee, Ji-Hye; Kim, Dae-Gon; Park, Chan-Jin; Cho, Lee-Ra

    2014-02-01

    The purpose of this study was to evaluate the axial displacement of the abutments during clinical procedures by the tightening torque and cyclic loading. Two different implant-abutment connection systems were used (external butt joint connection [EXT]; internal tapered conical connection [INT]). The master casts with two implant replicas, angulated 10° from each other, were fabricated for each implant connection system. Four types of impression copings were assembled and tightened with the corresponding implants (hex transfer impression coping, non-hex transfer impression coping, hex pick-up impression coping, non-hex pick-up impression coping). Resin splinted abutments and final prosthesis were assembled. The axial displacement was measured from the length of each assembly, which was evaluated repeatedly, after 30 Ncm torque tightening. After 250 N cyclic loading of final prosthesis for 1,000,000 cycles, additional axial displacement was recorded. The mean axial displacement was statistically analyzed (repeated measured ANOVA). There was more axial displacement in the INT group than that of the EXT group in impression copings, resin splinted abutments, and final prosthesis. Less axial displacement was found at 1-piece non-hex transfer type impression coping than other type of impression copings in the INT group. There was more axial displacement at the final prosthesis than resin splinted abutments in the INT and the EXT groups. After 250 N cyclic loading of final prosthesis, the INT group showed more axial displacement than that of the EXT group. Internal tapered conical connection demonstrated a varying amount of axial displacement with tightening torque and cyclic loading. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  18. Radial loads and axial thrusts on centrifugal pumps

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The proceedings of a seminar organised by the Power Industries Division of the IMechE are presented in this text. Complete contents: Review of parameters influencing hydraulic forces on centrifugal impellers; The effect of fluid forces at various operation conditions on the vibrations of vertical turbine pumps; A review of the pump rotor axial equilibrium problem - some case studies; Dynamic hydraulic loading on a centrifugal pump impeller; Experimental research on axial thrust loads of double suction centrifugal pumps; A comparison of pressure distribution and radial loads on centrifugal pumps; A theoretical and experimental investigation of axial thrusts within a multi-stage centrifugal pump

  19. Measurement for cobalt target activity and its axial distribution

    International Nuclear Information System (INIS)

    Li Xingyuan; Chen Zigen.

    1985-01-01

    Cobalt target activity and its axial distribution are measured in process of producing radioactive isotopes 60 Co by irradiation in HFETR. Cobalt target activity is obtained with measured data at 3.60 m and 4.60 m, relative axial distribution of cobalt target activity is obtained with one at 30 cm, and axial distribution of cobalt target activity(or specific activity) is obtained with both of data. The difference between this specific activity and measured result for 60 Co teletherapy sources in the end is less than +- 5%

  20. Gravitational waves from the axial perturbations of hyperon stars

    International Nuclear Information System (INIS)

    Wen De-Hua; Yan Jing; Liu Xue-Mei

    2012-01-01

    The eigen-frequencies of the axial w-mode oscillations of hyperon stars are examined. It is shown that as the appearance of hyperons softens the equation of state of the super-density matter, the frequency of gravitational waves from the axial w-mode of hyperon star becomes smaller than that of a traditional neutron star at the same stellar mass. Moreover, the eigenfrequencies of hyperon stars also have scaling universality. It is shown that the EURO third-generation gravitational-wave detector has the potential to detect the gravitational-wave signal emitted from the axial w-mode oscillations of a hyperon star. (general)

  1. Axial weak currents in the Wess-Zumino term

    International Nuclear Information System (INIS)

    Fujikawa, Kazuo.

    1985-03-01

    The conventional axial gauging of the Wess-Zumino term leads to the results which do not necessarily agree with the expectations on the basis of quark level Ward-Takahashi identities. This discrepancy arises from the fact that the quark level anomalous identities reflect the short distance structure of QCD, whereas the gauging of the Wess-Zumino term reflects the axial symmetry in the spontaneously broken chiral phase. The low energy theorem for axial weak fields is not sharply defined, in contrast to the case of vector fields where no such complications arise. (author)

  2. Pion Photo- and Electroproduction and the Partially Conserved Axial Current

    International Nuclear Information System (INIS)

    Haberzettl, Helmut

    2000-01-01

    The relevance of the axial current for pion production processes off the nucleon with real or virtual photons is revisited. Employing the hypothesis of a partially conserved axial current (PCAC), it is shown that, when all of the relevant contributions are taken into account, PCAC does not provide any additional constraint for threshold production processes that goes beyond the Goldberger-Treiman relation. In particular, it is shown that pion electroproduction processes at threshold cannot be used to extract any information regarding the weak axial form factor. The relationships found in previous investigations are seen to be an accident of the approximations usually made in this context

  3. The spin of the proton and the axial anomaly

    International Nuclear Information System (INIS)

    Hatsuda, T.; Zahed, I.

    1989-01-01

    We show that a consistent treatment of the abelian axial anomaly in a two-phase model of the proton yields a flavor singlet axial current that is saturated by the anomaly at Q 2 =0 in the chiral limit. This result suggests that at Q 2 =0 the matrix element of the flavor singlet axial current in a polarized proton state is small while the proton spin is still one-half. Modulo the QCD evolution equation, this result is in fair agreement with the recent EMC data. (orig.)

  4. The Design Method of Axial Flow Runners Focusing on Axial Flow Velocity Uniformization and Its Application to an Ultra-Small Axial Flow Hydraulic Turbine

    Directory of Open Access Journals (Sweden)

    Yasuyuki Nishi

    2016-01-01

    Full Text Available We proposed a portable and ultra-small axial flow hydraulic turbine that can generate electric power comparatively easily using the low head of open channels such as existing pipe conduits or small rivers. In addition, we proposed a simple design method for axial flow runners in combination with the conventional one-dimensional design method and the design method of axial flow velocity uniformization, with the support of three-dimensional flow analysis. Applying our design method to the runner of an ultra-small axial flow hydraulic turbine, the performance and internal flow of the designed runner were investigated using CFD analysis and experiment (performance test and PIV measurement. As a result, the runners designed with our design method were significantly improved in turbine efficiency compared to the original runner. Specifically, in the experiment, a new design of the runner achieved a turbine efficiency of 0.768. This reason was that the axial component of absolute velocity of the new design of the runner was relatively uniform at the runner outlet in comparison with that of the original runner, and as a result, the negative rotational flow was improved. Thus, the validity of our design method has been verified.

  5. Transitions in axial morphology along the Southeast Indian Ridge

    Science.gov (United States)

    Ma, Ying; Cochran, James R.

    1996-07-01

    Shipboard bathymetric and magnetic profiles across the Southeast Indian Ridge (SEIR) were analyzed in order to examine the nature of along-axis variations in axial morphology at this intermediate spreading rate ridge. Three types of axial morphology are observed along the SEIR: an axial high, a shallow (200-700 m deep) axial valley and a deep (>1000 m deep) axial valley. An axial high is found to the east of the Australian-Antarctic Discordance (AAD) (east of 128°E) and between 82°E and 104°E. A shallow rift valley is found from 104°E to 114°E and from 82°E westward past the Amerstdam/St. Paul hotspot (ASP) to about 30°S, 75°E. Deep rift valleys are found from 114°E to 128°E in the vicinity of the AAD and from the Indian Ocean Triple Junction (IOTJ) at 25°S, 70°E to about 30°S, 75°E. The transition near 30°S occurs in an area of constant zero-age depth and does not appear to result from an increase in mantle temperature. It could be the result of the rapid increase in spreading rate along that portion of the SEIR. The most likely cause of the other transitions in axial morphology is variations in mantle temperature. The transitions between the different types of axial morphology are well defined and occur over a limited distance. Transitions in axial morphology are accompanied by significant changes in ridge flank topographic roughness. The transitions from axial valleys to axial highs are also accompanied by changes in the amplitude of the seafloor magnetic anomalies. Our observations suggest that there are distinct modes rather than a continuum of axial morphology on the SEIR and that there appears to be a "threshold" mechanism for a rapid change between different states of axial morphology. The ASP has only a limited influence on the SEIR. The ridge axis is marked by an axial valley for the entire distance from the IOTJ up to and past the ASP. The ridge axis becomes shallower as the ASP is approached from the northwest but only by about 300 m over

  6. NORMAL AXIAL ANGLES OF THE KNEE JOINT IN ADULT ...

    African Journals Online (AJOL)

    hi-tech

    2003-08-01

    Aug 1, 2003 ... Conclusion: Our study has demonstrated comparative variations in means and ranges of normal axial angles .... population was significantly different from the mean ... case, however, the angle also exhibits racial variations.

  7. Three-dimensional magnetotelluric axial anisotropic forward modeling and inversion

    Science.gov (United States)

    Cao, Hui; Wang, Kunpeng; Wang, Tao; Hua, Boguang

    2018-06-01

    Magnetotelluric (MT) data has been widely used to image underground electrical structural. However, when the significant axial resistivity anisotropy presents, how this influences three-dimensional MT data has not been resolved clearly yet. We here propose a scheme for three-dimensional modeling of MT data in presence of axial anisotropic resistivity, where the electromagnetic fields are decomposed into primary and secondary components. A 3D staggered-grid finite difference method is then used to resolve the resulting 3D governing equations. Numerical tests have completed to validate the correctness and accuracy of the present algorithm. A limited-memory Broyden-Fletcher-Goldfarb-Shanno method is then utilized to realize the 3D MT axial anisotropic inversion. The testing results show that, compared to the results of isotropic resistivity inversion, taking account the axial anisotropy can much improve the inverted results.

  8. The geometrical theory of diffraction for axially symmetric reflectors

    DEFF Research Database (Denmark)

    Rusch, W.; Sørensen, O.

    1975-01-01

    The geometrical theory of diffraction (GTD) (cf. [1], for example) may be applied advantageously to many axially symmetric reflector antenna geometries. The material in this communication presents analytical, computational, and experimental results for commonly encountered reflector geometries...

  9. Effect of axial heat flux distribution on CHF

    Energy Technology Data Exchange (ETDEWEB)

    Park, Cheol

    2000-10-01

    Previous investigations for the effect of axial heat flux distributions on CHF and the prediction methods are reviewed and summarized. A total of 856 CHF data in a tube with a non-uniform axial heat flux distribution has been compiled from the articles and analyzed using the 1995 Groeneveld look-up table. The results showed that two representative correction factors, K5 of the look-up table and Tongs F factor, can be applied to describe the axial heat flux distribution effect on CHF. However, they overpredict slightly the measured CHF, depending on the quality and flux peak shape. Hence, a corrected K5 factor, which accounts for the axial heat flux distribution effect is suggested to correct these trends. It predicted the CHF power for the compiled data with an average error of 1.5% and a standard deviation of 10.3%, and also provides a reasonable prediction of CHF locations.

  10. The relation between anomalous magnetic moment and axial anomaly

    International Nuclear Information System (INIS)

    Teryaev, O.V.

    1990-12-01

    The conservation of total angular momentum of spinor particle leads to a simple relation between the famous Schwinger and Adler coefficients determining axial anomaly and anomalous magnetic moment, respectively. (author). 8 refs, 1 fig

  11. Report on the Dynamical Evolution of an Axially Symmetric Quasar ...

    Indian Academy of Sciences (India)

    retical arguments together with some numerical evidence. The evolution of the orbits is studied, as mass is transported from the disk to the nucleus. ... galaxies and non-axially symmetric quasar models (see Papadopoulos & Caranicolas.

  12. Axial clamp for nuclear reactor head penetration conoseal joints

    International Nuclear Information System (INIS)

    Hackley, T.A.

    1986-01-01

    A method for forming a sealed coupling between two bodies each body presenting an abutment surface, the bodies being arranged so that their respective abutment surfaces are axially adjacent one another and define a space therebetween in which a deformable gasket is disposed. An axial external force is applied to the bodies for compressing the abutment surfaces together against the gasket to form a seal between the bodies and the bodies are immobilized relative to one another while the external force is being applied to the bodies so that sufficient compression will be maintained by the abutment surfaces to preserve the integrity of the seal when the external axial force is withdrawn. The external axial force is then withdrawn, leaving the two bodies coupled together via the seal. (author)

  13. first principles derivation of a stress function for axially symmetric

    African Journals Online (AJOL)

    HOD

    governing partial differential equations of linear isotropic elasticity were reduced to the solution of the biharmonic ... The stress function was then applied to solve the axially symmetric ..... [1] Borg S.K.: Fundamentals of Engineering Elasticity,.

  14. Cladding axial elongation models for FRAP-T6

    International Nuclear Information System (INIS)

    Shah, V.N.; Carlson, E.R.; Berna, G.A.

    1983-01-01

    This paper presents a description of the cladding axial elongation models developed at the Idaho National Engineering Laboratory (INEL) for use by the FRAP-T6 computer code in analyzing the response of fuel rods during reactor transients in light water reactors (LWR). The FRAP-T6 code contains models (FRACAS-II subcode) that analyze the structural response of a fuel rod including pellet-cladding-mechanical-interaction (PCMI). Recently, four models were incorporated into FRACAS-II to calculate cladding axial deformation: (a) axial PCMI, (b) trapped fuel stack, (c) fuel relocation, and (d) effective fuel thermal expansion. Comparisons of cladding axial elongation measurements from two experiments with the corresponding FRAP-T6 calculations are presented

  15. Uniform Decay for Solutions of an Axially Moving Viscoelastic Beam

    Energy Technology Data Exchange (ETDEWEB)

    Kelleche, Abdelkarim, E-mail: kellecheabdelkarim@gmail.com [Université des Sciences et de la Technologie Houari Boumediene, Faculté des Mathématiques (Algeria); Tatar, Nasser-eddine, E-mail: tatarn@Kfupm.edu.sa [King Fahd University of Petroleum and Minerals, Department of Mathematics and Statistics (Saudi Arabia)

    2017-06-15

    The paper deals with an axially moving viscoelastic structure modeled as an Euler–Bernoulli beam. The aim is to suppress the transversal displacement (transversal vibrations) that occur during the axial motion of the beam. It is assumed that the beam is moving with a constant axial speed and it is subject to a nonlinear force at the right boundary. We prove that when the axial speed of the beam is smaller than a critical value, the dissipation produced by the viscoelastic material is sufficient to suppress the transversal vibrations. It is shown that the rate of decay of the energy depends on the kernel which arise in the viscoelastic term. We consider a general kernel and notice that solutions cannot decay faster than the kernel.

  16. Axially modulated arch resonator for logic and memory applications

    KAUST Repository

    Hafiz, Md Abdullah Al; Tella, Sherif Adekunle; Alcheikh, Nouha; Fariborzi, Hossein; Younis, Mohammad I.

    2018-01-01

    We demonstrate reconfigurable logic and random access memory devices based on an axially modulated clamped-guided arch resonator. The device is electrostatically actuated and the motional signal is capacitively sensed, while the resonance frequency

  17. preescolares desnutridos con madres con obesidad y sin obesidad

    Directory of Open Access Journals (Sweden)

    Viridiana Vanessa Conzuelo-González

    2009-01-01

    Full Text Available El primer objetivo fue conocer cuántos menores de cinco años con diferentes grados de desnutrición tienen una madre con sobrepeso/obesidad/ en una comunidad indígena que vive en extrema pobreza y bajo condiciones de migración masculina internacional. El segundo fue comparar tres variables socionutricionales (ingreso familiar, educación de la madre y adecuación nutrimental de la dieta diaria entre estos hogares y los hogares con desnutrición infantil y madres sin obesidad. Se realizó un estudio transversal (2006-2007, en la comunidad mazahua de San Francisco Tepeolulco, Municipio de Temascalcingo; que incluyó a 85 hogares integrados por preescolares con desnutrición inscritos al programa Oportunidades. Se determinó el estado nutrición de los preescolares con indicadores antropométricos y se obtuvo el IMC de las madres de estos infantes. Se aplicó una encuesta socionutricional, incluida el recordatorio de 24 horas, y complementado con la observación participante (cualitativa. Se encontró que 83% de las madres mazahuas presentaron sobrepeso u obesidad. El estado de nutrición de los preescolares con madres con obesidad presentó un porcentaje mayor de desnutrición (76%. En la variable género, se encontró que 54% de los niños con madres con obesidad tenía baja talla. Al relacionar el nivel educativo de la madre, esta variable resultó ser estadísticamente significativa (p=0.015, donde el analfabetismo está más relacionado con la desnutrición infantil que tienen madres de bajo y/o peso normal. La elevada prevalencia de hogares conformados con preescolares con desnutrición y madres con obesidad, es un síntoma más de la pobreza en zonas indígenas en México, con bajo índice de desarrollo humano.

  18. Quasi-renormalization of the axial vector model

    International Nuclear Information System (INIS)

    Schweda, M.

    1979-01-01

    Using the regulator-free BPHZL renormalization scheme the problem of anomalies in a massive axial vector meson model is reinvestigated. The Adler-Bardeen-Bell-Jackiw anomaly introduces some impressive modifications: the nontrivial self-energy and the counterterm of the longitudinal part of the axial vector field depend on the anomaly via the anomalous Ward identity. The investigations are based on a Fermi-type gauge. (author)

  19. ABOUT MODELING COMPLEX ASSEMBLIES IN SOLIDWORKS – LARGE AXIAL BEARING

    Directory of Open Access Journals (Sweden)

    Cătălin IANCU

    2017-12-01

    Full Text Available In this paperwork is presented the modeling strategy used in SOLIDWORKS for modeling special items as large axial bearing and the steps to be taken in order to obtain a better design. In the paper are presented the features that are used for modeling parts, and then the steps that must be taken in order to obtain the 3D model of a large axial bearing used for bucket-wheel equipment for charcoal moving.

  20. The research on flow pulsation characteristics of axial piston pump

    Science.gov (United States)

    Wang, Bingchao; Wang, Yulin

    2017-01-01

    The flow pulsation is an important factor influencing the axial piston pump performance. In this paper we implement modeling and simulation of the axial piston pump with AMESim software to explore the flow pulsation characteristics under various factors . Theory analysis shows the loading pressure, angular speed, piston numbers and the accumulator impose evident influence on the flow pulsation characteristics. This simulation and analysis can be used for reducing the flow pulsation rate via properly setting the related factors.

  1. Experimental investigation of an annular diffuser for axial fans at different inflow profiles

    Directory of Open Access Journals (Sweden)

    Walter Johannes

    2017-01-01

    Full Text Available Axial fans are used in power plants for fresh air supply and flue gas transport. A typical configuration consists of an axial fan and annular diffuser which connects the fan to the following piping. In order to achieve a high efficiency of the con-figuration, not only the components have to be optimized but also their interaction. The present study focuses on the diffuser of the configuration. Experiments are performed on a diffuser-piping configuration to investigate the influence of the velocity profile at the fan outlet on the pressure recovery of the configuration. Two different diffuser inlet profiles are generated, an undisturbed profile and a profile with the typical outlet characteristics of a fan. The latter is generated by the superposition of screens in the inlet zone. The tests are conducted at a high Reynolds number (Re ≈ 4∙105. Mean velocity profiles and wall shear stresses are measured with hydraulic methods (Prandtl and Preston tubes. The results show that there is a lack of momentum at the outer wall of the diffuser and high shear stresses at the inner wall in case of the undisturbed inflow profile. For the typical fan outlet profile it is vice versa. There are high wall shear stresses at the outer wall while the boundary layer of the inner wall lacks momentum. The pressure recovery of the undisturbed inflow configuration is in good agreement with other studies.

  2. Development of vortex model with realistic axial velocity distribution

    International Nuclear Information System (INIS)

    Ito, Kei; Ezure, Toshiki; Ohshima, Hiroyuki

    2014-01-01

    A vortex is considered as one of significant phenomena which may cause gas entrainment (GE) and/or vortex cavitation in sodium-cooled fast reactors. In our past studies, the vortex is assumed to be approximated by the well-known Burgers vortex model. However, the Burgers vortex model has a simple but unreal assumption that the axial velocity component is horizontally constant, while in real the free surface vortex has the axial velocity distribution which shows large gradient in radial direction near the vortex center. In this study, a new vortex model with realistic axial velocity distribution is proposed. This model is derived from the steady axisymmetric Navier-Stokes equation as well as the Burgers vortex model, but the realistic axial velocity distribution in radial direction is considered, which is defined to be zero at the vortex center and to approach asymptotically to zero at infinity. As the verification, the new vortex model is applied to the evaluation of a simple vortex experiment, and shows good agreements with the experimental data in terms of the circumferential velocity distribution and the free surface shape. In addition, it is confirmed that the Burgers vortex model fails to calculate accurate velocity distribution with the assumption of uniform axial velocity. However, the calculation accuracy of the Burgers vortex model can be enhanced close to that of the new vortex model in consideration of the effective axial velocity which is calculated as the average value only in the vicinity of the vortex center. (author)

  3. Reactive control of subsonic axial fan noise in a duct.

    Science.gov (United States)

    Liu, Y; Choy, Y S; Huang, L; Cheng, L

    2014-10-01

    Suppressing the ducted fan noise at low frequencies without varying the flow capacity is still a technical challenge. This study examines a conceived device consisting of two tensioned membranes backed with cavities housing the axial fan for suppression of the sound radiation from the axial fan directly. The noise suppression is achieved by destructive interference between the sound fields from the axial fan of a dipole nature and sound radiation from the membrane via vibroacoustics coupling. A two-dimensional model with the flow effect is presented which allows the performance of the device to be explored analytically. The air flow influences the symmetrical behavior and excites the odd in vacuo mode response of the membrane due to kinematic coupling. Such an asymmetrical effect can be compromised with off-center alignment of the axial fan. Tension plays an important role to sustain the performance to revoke the deformation of the membrane during the axial fan operation. With the design of four appropriately tensioned membranes covered by a cylindrical cavity, the first and second blade passage frequencies of the axial fan can be reduced by at least 20 dB. The satisfactory agreement between experiment and theory demonstrates that its feasibility is practical.

  4. Investigation of angular and axial smoothing of PET data

    International Nuclear Information System (INIS)

    Daube-Witherspoon, M.E.; Carson, R.E.

    1996-01-01

    Radial filtering of emission and transmission data is routinely performed in PET during reconstruction in order to reduce image noise. Angular smoothing is not typically done, due to the introduction of a non-uniform resolution loss; axial filtering is also not usually performed on data acquired in 2D mode. The goal of this paper was to assess the effects of angular and axial smoothing on noise and resolution. Angular and axial smoothing was incorporated into the reconstruction process on the Scanditronix PC2048-15B brain PET scanner. In-plane spatial resolution and noise reduction were measured for different amounts of radial and angular smoothing. For radial positions away from the center of the scanner, noise reduction and degraded tangential resolution with no loss of radial resolution were seen. Near the center, no resolution loss was observed, but there was also no reduction in noise for angular filters up to a 7 degrees FWHM. These results can be understood by considering the combined effects of smoothing projections across rows (angles) and then summing (backprojecting). Thus, angular smoothing is not optimal due to its anisotropic noise reduction and resolution degradation properties. However, uniform noise reduction comparable to that seen with radial filtering can be achieved with axial smoothing of transmission data. The axial results suggest that combined radial and axial transmission smoothing could lead to improved noise characteristics with more isotropic resolution degradation

  5. Chiral lattice fermions, minimal doubling, and the axial anomaly

    International Nuclear Information System (INIS)

    Tiburzi, B. C.

    2010-01-01

    Exact chiral symmetry at finite lattice spacing would preclude the axial anomaly. In order to describe a continuum quantum field theory of Dirac fermions, lattice actions with purported exact chiral symmetry must break the flavor-singlet axial symmetry. We demonstrate that this is indeed the case by using a minimally doubled fermion action. For simplicity, we consider the Abelian axial anomaly in two dimensions. At finite lattice spacing and with gauge interactions, the axial anomaly arises from nonconservation of the flavor-singlet current. Similar nonconservation also leads to the axial anomaly in the case of the naieve lattice action. For minimally doubled actions, however, fine-tuning of the action and axial current is necessary to arrive at the anomaly. Conservation of the flavor nonsinglet vector current additionally requires the current to be fine-tuned. Finally, we determine that the chiral projection of a minimally doubled fermion action can be used to arrive at a lattice theory with an undoubled Dirac fermion possessing the correct anomaly in the continuum limit.

  6. Axial Myopia and its Influence on Diabetic Retinopathy

    International Nuclear Information System (INIS)

    Tayyab, H.; Haider, M. A.; Bukhari, S. A. H.

    2014-01-01

    Objective: To evaluate the correlation between axial myopia and diabetic retinopathy. Study Design: Cross-sectional study. Place and Duration of Study: Eye Department of Postgraduate Medical Institute, Lahore General Hospital, from August 2012 to February 2013. Methodology: A total of 258 participants suffering from type-2 diabetic retinopathy were included. Axial length was measured by two optometrists using contact type ultrasound biometer. Colored retinal photographs, red free retinal photographs and Fundus Fluorescein Angiography (FFA) were performed on all patients using standard fundus camera. All fundus photographs and angiograms were independently reviewed and graded by two qualified vitreoretinal fellows. Results: Out of 258 patients, 163 were males (63.2%) and 95 (36.8%) were females. Average age of patients was 56.30 +- 7.57 years. Average axial length of right and left eyes were 23.16 mm and 23.15 mm respectively. There was statistically significant negative correlation between axial length and severity of diabetic retinopathy in the right eye, (Spearman correlation = -0.511, p = 0.0001) as well as the left eye (Spearman correlation = -0.522, p = 0.0001). Conclusion: There is a protective influence of longer axial length of globe on the stage and severity of diabetic retinopathy. This study may help in modifying the screening protocol for diabetic retinopathy amongst patients of differing axial lengths. (author)

  7. High Precision Axial Coordinate Readout for an Axial 3-D PET Detector Module using a Wave Length Shifter Strip Matrix

    CERN Document Server

    Braem, André; Joram, C; Séguinot, Jacques; Weilhammer, P; De Leo, R; Nappi, E; Lustermann, W; Schinzel, D; Johnson, I; Renker, D; Albrecht, S

    2007-01-01

    We describe a novel method to extract the axial coordinate from a matrix of long axially oriented crystals, which is based on wavelength shifting plastic strips. The method allows building compact 3-D axial gamma detector modules for PET scanners with excellent 3-dimensional spatial, timing and energy resolution while keeping the number of readout channels reasonably low. A voxel resolution of about 10 mm3 is expected. We assess the performance of the method in two independent ways, using classical PMTs and G-APDs to read out the LYSO (LSO) scintillation crystals and the wavelength shifting strips. We observe yields in excess of 35 photoelectrons from the strips for a 511 keV gamma and reconstruct the axial coordinate with a precision of about 2.5 mm (FWHM).

  8. [Axial lumbar interbody fusion: prospective monocentric study].

    Science.gov (United States)

    Stulík, J; Adámek, S; Barna, M; Kaspříková, N; Polanecký, O; Kryl, J

    2014-01-01

    .6%), In one patient the finding was not clear. Also, posterolateral fusion was achieved in all but one patients (95.6%). A stable L5-S1 segment was found in all patients at all follow-up intervals. The improvement in both VAS and ODI values was statistically significant. In addition to indications usual in degenerative disc disease, overweight patients, those who had repeated trans- or retroperitoneal surgery in the L5-S1 region or who underwent long posterior fixation to stabilise the caudal margin of instrumentation are indicated for the AxiaLIF procedure. The clinical results of our study are in agreement with the conclusions of other studies and are similar to the outcomes of surgery using other types of fusion or dynamic stabilisation for this diagnosis. The high rate of fusion in our group is affected by use of a rigid transpedicular fixator together with posterolateral arthrodesis. On the other hand, no negative effects of only synthetic bone applied to interbody space were recorded. The percutaneous axial pre-sacral approach to the L5-S1 interbody space with application of a double-treaded screw is another option for the management of this much strained segment. The technique is useful particularly when contraindications for conventional surgical procedures are present in patients with anatomical anomalies, in overweight patients or in those who have had repeated surgery in the region. Clinical outcomes and the success rate for L5-S1 bone fusion are comparable with conventional techniques. Complications are rare but their treatment is difficult.

  9. Stability management of high speed axial flow compressor stage through axial extensions of bend skewed casing treatment

    Directory of Open Access Journals (Sweden)

    DilipkumarBhanudasji Alone

    2016-09-01

    Full Text Available This paper presents the experimental results to understand the performance of moderately loaded high speed single stage transonic axial flow compressor subjected to various configurations of axial extensions of bend skewed casing treatment with moderate porosity. The bend skewed casing treatment of 33% porosity was coupled with rectangular plenum chamber of depth equal to the slots depth. The five axial extensions of 20%, 40%, 60%, 80% and 100% were used for the experimental evaluations of compressor performance. The main objective was to identify the optimum extension of the casing treatment with reference to rotor leading edge which results in maximum stall margin improvements with minimum loss in the stage efficiency. At each axial extension the compressor performance is distinctive. The improvement in the stall margin was very significant at some axial extensions with 4%–5% penalty in the stage efficiency. The compressors stage shows recovery in terms of efficiency at lower axial extensions of 20% and 40% with increase in the peak stage efficiency. Measurements of flow parameters showed the typical behaviors at near stall flow conditions. Hot wire sensor was placed at the rotor upstream in the tip region to capture the oscillations in the inlet axial and tangential velocities at stall conditions. In the absence of casing treatment the compressor exhibit abrupt stall with very high oscillations in the inlet axial and tangential velocity of the flow. The extents of oscillations reduce with bend skewed casing treatment. Few measurements were also performed in the plenum chamber and salient results are presented in this paper.

  10. autorregulado con estudiantes universitarios

    Directory of Open Access Journals (Sweden)

    Jairo Andrés Montes

    2005-01-01

    Full Text Available El propósito del presente estudio es describir la forma en la que se presentan los procesos de aprendizaje autorregulado con un grupo de estudiantes (22 estudiantes de tercer semestre de Psicología de la PUJ, Cali, en el evento de preparación para la presentación un examen. Asimismo se describen las correlaciones que ocurren entre las distintas fases de dicho proceso de autorregulación del aprendizaje. Para conseguir los objetivos propuestos se ha hecho uso de una observación de desempeño en tiempo real, es decir, de la observación durante una sesión de preparación de examen de los estudiantes, en la cual se emplearon protocolos verbales para dar cuenta de lo que «pasaba por su mente» mientras estudiaban. Una entrevista semi-estructurada y una prueba objetiva. Los resultados fueron analizados a la luz del modelo mixto de procesamiento de información y constructivismo abordado por Winne(1998. Como resultado se encontró una relación significativa entre los niveles de desempeño en el proceso de ARR y el resultado del examen. Igualmente se encontraron bajos niveles de regulación en una parte importante de la muestra y un desfase significativo entre conocimiento declarativo de ARR y desempeño en el mismo

  11. Análisis de la dispersión axial de masa y calor en reactores de lecho fijo

    Directory of Open Access Journals (Sweden)

    Rangel Jara Hermes Augusto

    1997-01-01

    Full Text Available Dentro del espíritu investigativo a nivel teórico del estudio de los reactores químicos, el presente trabajo desarrolla e implementa un análisis conceptual y numérico de los fenómenos de dispersión axial de calor y masa en reactores de lecho fijo. Se pretende disponer de una alternativa numérica que permita en una forma rápida y precisa la solución de las ecuaciones diferenciales junto con las respectivas condiciones de frontera del modelo matemático. Para la simulación del reactor de lecho fijo se empleó un modelo unidimensional pseudohomogeneo con parámetros aglomerados.

  12. SCLERAL AND CHOROIDAL THICKNESS IN SECONDARY HIGH AXIAL MYOPIA.

    Science.gov (United States)

    Shen, Ling; You, Qi Sheng; Xu, Xiaolin; Gao, Fei; Zhang, Zhibao; Li, Bin; Jonas, Jost B

    2016-08-01

    To assess differences in scleral and choroidal thickness between eyes with secondary high axial myopia caused by congenital glaucoma, eyes with primary high axial myopia, and nonhighly myopic eyes. The study consisted of 301 Chinese individuals with a mean age of 23.9 ± 22.6 years and mean axial length of 24.8 ± 4.2 mm. It included the "secondary highly myopic group" (SHMG) because of congenital glaucoma (n = 20 eyes; axial length >26.0 mm), the "primary highly myopic group" (PHMG) (n = 73; axial length >26.0 mm), and the remaining nonhighly myopic group (NHMG). The secondary highly myopic group versus the primary highly myopic group had significantly thinner sclera in the pars plana region (343 ± 71 μm versus 398 ± 83 μm; P = 0.006), whereas scleral thickness in other regions did not differ significantly between both highly myopic groups and was significantly thinner in both highly myopic groups than in the NHMG. Mean total scleral volume did not differ significantly (P > 0.20) between any group (SHMG: 659 ± 106 μm; PHMG: 667 ± 128 μm; NHMG: 626 ± 135 μm). Choroidal thickness was significantly thinner in both highly myopic groups than in the NHMG, with no significant differences between both highly myopic groups. Choroidal volume did not differ significantly (P > 0.40) between any of the groups (SHMG: 43 ± 12 μm; PHMG: 43 ± 13 μm; NHMG: 46 ± 17 μm). In secondary high axial myopia, the sclera gets thinner anterior and posterior to the equator; whereas in primary high axial myopia, scleral thinning is predominantly found posterior to the equator. Because volume of sclera and choroid did not differ between any group, scleral and choroidal thinning in myopia may be due to a rearrangement of tissue and not due to the new formation of tissue.

  13. Investigation of axial power gradients near a control rod tip

    Energy Technology Data Exchange (ETDEWEB)

    Loberg, John, E-mail: John.Loberg@fysast.uu.se [Uppsala University, Department of Physics and Astronomy, Division of Applied Nuclear Physics, Box 525, SE-75120 Uppsala (Sweden); Osterlund, Michael, E-mail: Michael.Osterlund@fysast.uu.se [Uppsala University, Department of Physics and Astronomy, Division of Applied Nuclear Physics, Box 525, SE-75120 Uppsala (Sweden); Bejmer, Klaes-Hakan, E-mail: Klaes-Hakan.Bejmer@vattenfall.com [Vattenfall Nuclear Fuel AB, Jaemtlandsgatan 99, 162 60 Vaellingby, Stockholm (Sweden); Blomgren, Jan, E-mail: Jan.Blomgren@vattenfall.com [Vattenfall Nuclear Fuel AB, Jaemtlandsgatan 99, 162 60 Vaellingby, Stockholm (Sweden); Kierkegaard, Jesper, E-mail: Jesper.Kierkegaar@vattenfall.com [Vattenfall Nuclear Fuel AB, Jaemtlandsgatan 99, 162 60 Vaellingby, Stockholm (Sweden)

    2011-07-15

    Highlights: > Pin power gradients near BWR control rod tips have been investigated. > A control rod tip is modeled in MCNP and compared to simplified 2D/3D geometry. > Small nodes increases pin power gradients; standard nodes underestimates gradients. > The MCNP results are validated against axial gamma scan of a controlled fuel pin. - Abstract: Control rod withdrawal in BWRs induces large power steps in the adjacent fuel assemblies. This paper investigates how well a 2D/3D method, e.g., CASMO5/SIMULATE5 computes axial pin power gradients adjacent to an asymmetrical control-rod tip in a BWR. The ability to predict pin power gradients accurately is important for safety considerations whereas large powers steps induced by control rod withdrawal can cause Pellet Cladding Interaction. The computation of axial pin power gradients axially around a control rod tip is a challenging task for any nodal code. On top of that, asymmetrical control rod handles are present in some BWR designs. The lattice code CASMO requires diagonal symmetry of all control rod parts. This introduces an error in computed pin power gradients that has been evaluated by Monte Carlo calculations. The results show that CASMO5/SIMULATE5, despite the asymmetrical control rod handle, is able to predict the axial pin power gradient within 1%/cm for axial nodal sizes of 15-3.68 cm. However, a nodal size of 3.68 cm still causes underestimations of pin power gradients compared with 1 cm nodes. Furthermore, if conventional node sizes are used, {approx}15 cm, pin power gradients can be underestimated by over 50% compared with 1 cm nodes. The detailed axial pin power profiles from MCNP are corroborated by measured gamma scan data on fuel rods irradiated adjacent to control rods.

  14. Investigation of axial power gradients near a control rod tip

    International Nuclear Information System (INIS)

    Loberg, John; Osterlund, Michael; Bejmer, Klaes-Hakan; Blomgren, Jan; Kierkegaard, Jesper

    2011-01-01

    Highlights: → Pin power gradients near BWR control rod tips have been investigated. → A control rod tip is modeled in MCNP and compared to simplified 2D/3D geometry. → Small nodes increases pin power gradients; standard nodes underestimates gradients. → The MCNP results are validated against axial gamma scan of a controlled fuel pin. - Abstract: Control rod withdrawal in BWRs induces large power steps in the adjacent fuel assemblies. This paper investigates how well a 2D/3D method, e.g., CASMO5/SIMULATE5 computes axial pin power gradients adjacent to an asymmetrical control-rod tip in a BWR. The ability to predict pin power gradients accurately is important for safety considerations whereas large powers steps induced by control rod withdrawal can cause Pellet Cladding Interaction. The computation of axial pin power gradients axially around a control rod tip is a challenging task for any nodal code. On top of that, asymmetrical control rod handles are present in some BWR designs. The lattice code CASMO requires diagonal symmetry of all control rod parts. This introduces an error in computed pin power gradients that has been evaluated by Monte Carlo calculations. The results show that CASMO5/SIMULATE5, despite the asymmetrical control rod handle, is able to predict the axial pin power gradient within 1%/cm for axial nodal sizes of 15-3.68 cm. However, a nodal size of 3.68 cm still causes underestimations of pin power gradients compared with 1 cm nodes. Furthermore, if conventional node sizes are used, ∼15 cm, pin power gradients can be underestimated by over 50% compared with 1 cm nodes. The detailed axial pin power profiles from MCNP are corroborated by measured gamma scan data on fuel rods irradiated adjacent to control rods.

  15. Puentes con vigas pretensadas

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1965-07-01

    Full Text Available This paper describes one of the three bridges which Hidrocivil, S. A., has built in Catalonia (northern Spain, over the river Ripoll. The other two bridges are very similar to this one, both in construction and design, and show only minor adjustments to the local topography. The contracting firm proposed several alterations in the prefabrication and constructional procedure, in relation to the initial project, and these changes were accepted. The main feature of these projects is the use of prestressed beams, built at the workshop in sections, and joined together by means of sixty 7 mm cables in each beam. As the shear forces are more acute at the joints, the end of each section has a kind of diaphragm, to provide a large contact area, and hence greater surface to transmit the shear forces. The methods of construction are also of interest. Briefly, they involve building the bridge piles, and use these to support a provisional structure with transversal movement. This provisional structure, in turn, served as platform for two bridge cranes, which lifted the girders to their final location. After the first span was completed, the deck was concreted and the auxiliary structure pushed forward to the next span, to repeat the same operations. This arrangement saved the use of provisional framework.En este trabajo se describe uno de los tres puentes que Hidrocivil, S. A., ha construido.—previo concurso— en la región catalana; concretamente, el que salva el río Ripoll. Los otros dos no han sido objeto de descripción general por ser muy similares, en lo que a ejecución y concepción se refiere, con la única variante que presentan las características topográficas locales. La empresa propuso ciertas variantes— que fueron aceptadas— en la prefabricación y métodos de construcción. El interés de estas obras se centra en el empleo de vigas pretensadas, prefabricadas en taller por trozos, y solidarizados en el mismo mediante las operaciones

  16. Violencia con el anciano

    Directory of Open Access Journals (Sweden)

    Rita Campillo Motilva

    2002-08-01

    Full Text Available La violencia doméstica es tan antigua como la humanidad misma y se reconocen la violencia infantil, contra la mujer y al anciano, fundamentalmente; siendo este último grupo una población en ascenso por las mayores expectativas de vida de los últimos años. Como resultado de ello, el número de casos de abuso en el anciano se incrementará y el impacto de este abuso sobre la salud debe ser considerado de forma adecuada. La gama de maltratos es variadísima e incluye el abuso físico, emocional, financiero, sexual, por negligencia, negación a brindarle ayuda y otras formas más. Los ancianos con deterioro cognitivo son los más vulnerables. El médico en la atención primaria de salud es un pilar importante en la prevención y educación de este problema.Domestic violence is as old as humanity itself. Child, women and elderly abuse are mainly recognized. The elderly group is increasing due to the higher life expectancy experimented during the last years. As a result, the number of battered elderly will grow and the impact of this abuse on health should be adequately considered. The range of abuse is very wide and it includes physical, emotional, financial and sexual abuse, negligence, rejection to give assistance and others. The elderly with cognitive deterioration are the most vulnerable. The physician at the primary health care level is an important milestone in the prevention and education of this problem.

  17. Analysis of axial compressive loaded beam under random support excitations

    Science.gov (United States)

    Xiao, Wensheng; Wang, Fengde; Liu, Jian

    2017-12-01

    An analytical procedure to investigate the response spectrum of a uniform Bernoulli-Euler beam with axial compressive load subjected to random support excitations is implemented based on the Mindlin-Goodman method and the mode superposition method in the frequency domain. The random response spectrum of the simply supported beam subjected to white noise excitation and to Pierson-Moskowitz spectrum excitation is investigated, and the characteristics of the response spectrum are further explored. Moreover, the effect of axial compressive load is studied and a method to determine the axial load is proposed. The research results show that the response spectrum mainly consists of the beam's additional displacement response spectrum when the excitation is white noise; however, the quasi-static displacement response spectrum is the main component when the excitation is the Pierson-Moskowitz spectrum. Under white noise excitation, the amplitude of the power spectral density function decreased as the axial compressive load increased, while the frequency band of the vibration response spectrum increased with the increase of axial compressive load.

  18. Continuous millennial decrease of the Earth's magnetic axial dipole

    Science.gov (United States)

    Poletti, Wilbor; Biggin, Andrew J.; Trindade, Ricardo I. F.; Hartmann, Gelvam A.; Terra-Nova, Filipe

    2018-01-01

    Since the establishment of direct estimations of the Earth's magnetic field intensity in the first half of the nineteenth century, a continuous decay of the axial dipole component has been observed and variously speculated to be linked to an imminent reversal of the geomagnetic field. Furthermore, indirect estimations from anthropologically made materials and volcanic derivatives suggest that this decrease began significantly earlier than direct measurements have been available. Here, we carefully reassess the available archaeointensity dataset for the last two millennia, and show a good correspondence between direct (observatory/satellite) and indirect (archaeomagnetic) estimates of the axial dipole moment creating, in effect, a proxy to expand our analysis back in time. Our results suggest a continuous linear decay as the most parsimonious long-term description of the axial dipole variation for the last millennium. We thus suggest that a break in the symmetry of axial dipole moment advective sources occurred approximately 1100 years earlier than previously described. In addition, based on the observed dipole secular variation timescale, we speculate that the weakening of the axial dipole may end soon.

  19. Axial clamp for nuclear reactor head penetration conoseal joints

    International Nuclear Information System (INIS)

    Hackley, T.A.

    1987-01-01

    A method is described for forming a sealed coupling between two bodies, each body presenting an annular abutment surface. The respective bodies are arranged so that their respective annular abutment surfaces are axially adjacent one another, defining a space therebetween, wherein a deformable gasket is disposed within the space. The method comprises: providing one of the bodies with an annular projection; providing the other body with threads for receiving an annular locknut which can be tightened to bear against the annular projection of the one body; applying an external axial forced to the bodies for compressing the abutment surfaces together against the gasket to form a seal between the bodies; immobilizing the bodies relative to one another while the external force is being applied to the bodies by hand-tightening an annular locknut via the threads of the other body until the locknut abuts the annular projection of the one body, substantially preventing relative axial movement between the bodies when the external axial force is withdrawn; and withdrawing the external axial force applied to the bodies, leaving the two bodies coupled together via the seal

  20. Method to Measure Tone of Axial and Proximal Muscle

    Science.gov (United States)

    Gurfinkel, Victor S.; Cacciatore, Timothy W.; Cordo, Paul J.; Horak, Fay B.

    2011-01-01

    The control of tonic muscular activity remains poorly understood. While abnormal tone is commonly assessed clinically by measuring the passive resistance of relaxed limbs1, no systems are available to study tonic muscle control in a natural, active state of antigravity support. We have developed a device (Twister) to study tonic regulation of axial and proximal muscles during active postural maintenance (i.e. postural tone). Twister rotates axial body regions relative to each other about the vertical axis during stance, so as to twist the neck, trunk or hip regions. This twisting imposes length changes on axial muscles without changing the body's relationship to gravity. Because Twister does not provide postural support, tone must be regulated to counteract gravitational torques. We quantify this tonic regulation by the restive torque to twisting, which reflects the state of all muscles undergoing length changes, as well as by electromyography of relevant muscles. Because tone is characterized by long-lasting low-level muscle activity, tonic control is studied with slow movements that produce "tonic" changes in muscle length, without evoking fast "phasic" responses. Twister can be reconfigured to study various aspects of muscle tone, such as co-contraction, tonic modulation to postural changes, tonic interactions across body segments, as well as perceptual thresholds to slow axial rotation. Twister can also be used to provide a quantitative measurement of the effects of disease on axial and proximal postural tone and assess the efficacy of intervention. PMID:22214974

  1. Amphiregulin Antibody and Reduction of Axial Elongation in Experimental Myopia

    Directory of Open Access Journals (Sweden)

    Wen Jun Jiang

    2017-03-01

    Full Text Available To examine the mechanism of ocular axial elongation in myopia, guinea pigs (age: 2–3 weeks which either underwent unilateral or bilateral lens-induced myopization (group 1 or which were primarily myopic at baseline (group 2 received unilateral intraocular injections of amphiregulin antibody (doses: 5, 10, or 15 μg three times in intervals of 9 days. A third group of emmetropic guinea pigs got intraocular unilateral injections of amphiregulin (doses: 0.25, 0.50 or 1.00 ng, respectively. In each group, the contralateral eyes received intraocular injections of Ringer's solution. In intra-animal inter-eye comparison and intra-eye follow-up comparison in groups 1 and 2, the study eyes as compared to the contralateral eyes showed a dose-dependent reduction in axial elongation. In group 3, study eyes and control eyes did not differ significantly in axial elongation. Immunohistochemistry revealed amphiregulin labelling at the retinal pigment epithelium in eyes with lens-induced myopization and Ringer's solution injection, but not in eyes with amphiregulin antibody injection. Intraocular injections of amphiregulin-antibody led to a reduction of lens-induced axial myopic elongation and of the physiological eye enlargement in young guinea pigs. In contrast, intraocularly injected amphiregulin in a dose of ≤1 ng did not show a significant effect. Amphiregulin may be one of several essential molecular factors for axial elongation.

  2. Neumomediastino espontáneo recidivante

    Directory of Open Access Journals (Sweden)

    Damaris Reyes Hernández

    2017-12-01

    Full Text Available El neumomediastino espontáneo se caracteriza por la presencia de aire en el mediastino. Es una enfermedad generalmente benigna y autolimitada, no asociada a causa directa conocida. Es de infrecuente ocurrencia. Se presenta principalmente con dolor torácico, disnea y enfisema subcutáneo. El diagnóstico se realiza sobre la base del cuadro clínico y radiografía o tomografía axial computarizada de tórax. Se presenta el caso de un paciente masculino de 17 años de edad, atleta de alto rendimiento, que comienza de forma súbita con dolor torácico, disnea y enfisema subcutáneo. Se le realizó radiografía de tórax en la que se observa la presencia de aire en el mediastino, y se corrobora el diagnóstico de neumomediastino mediante tomografía axial computarizada de tórax. Recibió tratamiento conservador con mejoría evidente. Aunque la literatura reporta que no es habitual la recurrencia, en el paciente que se presenta hubo recidiva del neumomediastino a los tres meses del primer evento. Se presenta este caso por lo infrecuente de esta enfermedad y su recurrencia.

  3. Bifurcation and chaos of an axially accelerating viscoelastic beam

    International Nuclear Information System (INIS)

    Yang Xiaodong; Chen Liqun

    2005-01-01

    This paper investigates bifurcation and chaos of an axially accelerating viscoelastic beam. The Kelvin-Voigt model is adopted to constitute the material of the beam. Lagrangian strain is used to account for the beam's geometric nonlinearity. The nonlinear partial-differential equation governing transverse motion of the beam is derived from the Newton second law. The Galerkin method is applied to truncate the governing equation into a set of ordinary differential equations. By use of the Poincare map, the dynamical behavior is identified based on the numerical solutions of the ordinary differential equations. The bifurcation diagrams are presented in the case that the mean axial speed, the amplitude of speed fluctuation and the dynamic viscoelasticity is respectively varied while other parameters are fixed. The Lyapunov exponent is calculated to identify chaos. From numerical simulations, it is indicated that the periodic, quasi-periodic and chaotic motions occur in the transverse vibrations of the axially accelerating viscoelastic beam

  4. Plasma sheath axial phase dynamics in coaxial device

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, H.M. (Plasma Physics Dept., NRC, Atomic Energy Authority, Cairo (Egypt)); Masoud, M.M. (Plasma Physics Dept., NRC, Atomic Energy Authority, Cairo (Egypt))

    1994-10-01

    The study of the plasma sheath dynamics in the axial phase has been carried out in a 3 kJ coaxial system of Mather type for two different inner electrode (IE) lengths, 20 cm and 31.5 cm. For both lengths, measurements showed that the plasma sheath is splitted into two layers at the breech, which is referred to as a shock front and its magnetic piston. It has been found that the two layers of the plasma current sheath rotate around the inner electrode. At the muzzle the back layer reverse its rotation direction due to the magnetic field structure of the system. Results showed that the axial velocity of the first layer is greater than the second one all over the axial phase within the range between 1.4 and 1.7. (orig.).

  5. Plasma sheath axial phase dynamics in coaxial device

    International Nuclear Information System (INIS)

    Soliman, H.M.; Masoud, M.M.

    1994-01-01

    The study of the plasma sheath dynamics in the axial phase has been carried out in a 3 kJ coaxial system of Mather type for two different inner electrode (IE) lengths, 20 cm and 31.5 cm. For both lengths, measurements showed that the plasma sheath is splitted into two layers at the breech, which is referred to as a shock front and its magnetic piston. It has been found that the two layers of the plasma current sheath rotate around the inner electrode. At the muzzle the back layer reverse its rotation direction due to the magnetic field structure of the system. Results showed that the axial velocity of the first layer is greater than the second one all over the axial phase within the range between 1.4 and 1.7. (orig.)

  6. Thermocapillary Convection in Floating Zone with Axial Magnetic Fields

    Science.gov (United States)

    Liang, Ruquan; Yang, Shuo; Li, Jizhao

    2014-02-01

    Numerical simulations on the effects of axial magnetic fields on the thermocapillary convection in a liquid bridge of silicone-oil-based ferrofluid under zero gravity have been conducted. The Navier-Stokes equations coupled with the energy conservation equation are solved on a staggered grid, and the mass conserving level set approach is used to capture the free surface deformation of the liquid bridge. The obvious effects of the magnetic fields on the flow pattern as well as the velocity and temperature distributions in the liquid bridge can be detected. The axial magnetic fields suppress the thermocapillary convection and a stagnant flow zone is formed between the circulating flow and the symmetric axis as the magnetic fields increase. The axial magnetic fields affect not only the velocity level inside the liquid bridge but also the velocity level on the free surface. The temperature contours near the free surface illustrates conduction-type temperature profiles at moderate strength fields.

  7. Anisotropic yield surfaces in bi-axial cyclic plasticity

    International Nuclear Information System (INIS)

    Rider, R.J.; Harvey, S.J.; Breckell, T.H.

    1985-01-01

    Some aspects of the behaviour of yield surfaces and work-hardening surfaces occurring in biaxial cyclic plasticity have been studied experimentally and theoretically. The experimental work consisted of subjecting thin-walled tubular steel specimens to cyclic plastic torsion in the presence of sustained axial loads of various magnitudes. The experimental results show that considerable anisotropy is induced when the cyclic shear strains are dominant. Although the true shapes of yield and work-hardening surfaces can be very complex, a mathematical model is presented which includes both anisotropy and Bauschinger effects. The model is able to qualitatively predict the deformation patterns during a cycle of applied plastic shear strain for a range of sustained axial stresses and also indicate the material response to changes in axial stress. (orig.)

  8. Axial blanket enrichment optimization of the NPP Krsko fuel

    International Nuclear Information System (INIS)

    Kromar, M.; Kurincic, B.

    2001-01-01

    In this paper optimal axial blanket enrichment of the NPP Krsko fuel is investigated. Since the optimization is dictated by economic categories that can significantly vary in time, two step approach is applied. In the first step simple relationship between the equivalent change in enrichment of axial blankets and central fuel region is established. The relationship is afterwards processed with economic criteria and constraints to obtain optimal axial blanket enrichment. In the analysis realistic NPP Krsko conditions are considered. Except for the fuel enrichment all other fuel characteristics are the same as in the fuel used in the few most recent cycles. A typical reload cycle after the plant power uprate is examined. Analysis has shown that the current blanket enrichment is close to the optimal. Blanket enrichment reduction results in an approximately 100 000 US$ savings per fuel cycle.(author)

  9. Improvement of axial power distribution synthesis methodology in CPC

    International Nuclear Information System (INIS)

    Kim, H. H.; Gee, S. G.;; Kim, Y. B.; In, W. K.

    2003-01-01

    The capability of axial power distribution synthesis in CPC plays an important role in determining the DNBR and LPD trip caused by CPC. The axial power distribution is synthesized using the cubic spline function based on the three excore detector signals. The axial power distributions are categorized into 8 function sets and each sets are stored as pre-calculated values in CPC to save the calculation time. In this study, the additional function sets, the real break-point function sets and the polynomial function are suggested to evaluate the possibility of improving the synthesis capability in CPC. In addition, RMS errors are compared and evaluated for each synthesis method. As a result, it was confirmed that the function sets stored in CPC were not optimal. The analysis result showed that RMS error could be reduced by selecting the proper function sets suggested in this study

  10. Ball Screw Actuator Including an Axial Soft Stop

    Science.gov (United States)

    Wingett, Paul T. (Inventor); Forrest, Steven Talbert (Inventor); Abel, Steve (Inventor); Woessner, George (Inventor); Hanlon, Casey (Inventor)

    2016-01-01

    An actuator includes an actuator housing, a ball screw, and an axial soft stop assembly. The ball screw extends through the actuator housing and has a first end and a second end. The ball screw is coupled to receive a drive force and is configured, upon receipt of the drive force, to selectively move in a retract direction and an extend direction. The axial soft stop assembly is disposed within the actuator housing. The axial soft stop assembly is configured to be selectively engaged by the ball screw and, upon being engaged thereby, to translate, with compliance, a predetermined distance in the extend direction, and to prevent further movement of the ball screw upon translating the predetermined distance.

  11. Axially modulated arch resonator for logic and memory applications

    KAUST Repository

    Hafiz, Md Abdullah Al

    2018-01-17

    We demonstrate reconfigurable logic and random access memory devices based on an axially modulated clamped-guided arch resonator. The device is electrostatically actuated and the motional signal is capacitively sensed, while the resonance frequency is modulated through an axial electrostatic force from the guided side of the microbeam. A multi-physics finite element model is used to verify the effectiveness of the axial modulation. We present two case studies: first, a reconfigurable two-input logic gate based on the linear resonance frequency modulation, and second, a memory element based on the hysteretic frequency response of the resonator working in the nonlinear regime. The energy consumptions of the device for both logic and memory operations are in the range of picojoules, promising for energy efficient alternative computing paradigm.

  12. Linear optical response of carbon nanotubes under axial magnetic field

    Science.gov (United States)

    Moradian, Rostam; Chegel, Raad; Behzad, Somayeh

    2010-04-01

    We considered single walled carbon naotubes (SWCNTs) as real three dimensional (3D) systems in a cylindrical coordinate. The optical matrix elements and linear susceptibility, χ(ω), in the tight binding approximation in terms of one-dimensional wave vector, kz and subband index, l are calculated. In an external axial magnetic field optical frequency dependence of linear susceptibility are investigated. We found that axial magnetic field has two effects on the imaginary part of the linear susceptibility spectrum, in agreement with experimental results. The first effect is broadening and the second, splitting. Also we found that for all metallic zigzag and armchair SWCNTs, the axial magnetic field leads to the creation of a peak with energy less than 1.5 eV, contrary to what is observed in the absence of a magnetic field.

  13. Temporal and Spatial Variability in the Geochemistry of Axial and CoAxial Segment Lavas and their Mantle Sources

    Science.gov (United States)

    Smith, M. C.; Perfit, M. R.; Davis, C.; Kamenov, G. D.

    2011-12-01

    Three spatially related volcanic eruptions along the CoAxial Segment of the Juan de Fuca Ridge (JdFR) have documented emplacements between 1981 and 1993. Two of the historic flows outcrop at the "Flow Site" and were emplaced within less than 12 years and 500 m from one another. The third was emplaced at the "Floc Site" to the south in the 1980s. Previous studies have documented that CoAxial lavas are among the most incompatible element and isotopically depleted lavas along the entire JdFR, whereas the Axial Seamount segment immediately south of CoAxial has erupted the most chemically enriched lavas south of the Endeavor Segment. Geochemical studies have shown little temporal change in the chemistry of recent Axial Seamount eruptives, whereas CoAxial lavas exhibit distinct chemical differences over short time periods. Significant chemical differences observed among depleted CoAxial lavas emplaced close to one another in space and time are in marked contrast to the relatively constant chemical characteristics of enriched lavas erupted at the magmatically more robust Axial segment only 10's of kilometers to the south and west. New trace element and isotopic (Sr, Nd, Pb) geochemical analyses of historic and older CoAxial lavas have resulted in better documentation of interflow and intraflow chemical variation providing an improved understanding of spatial/temporal chemical variability in lavas, and further insight into JdFR magmatic processes. Modeling of major and trace element abundances suggest that the observed intraflow chemical variation within CoAxial lavas is largely due to shallow-level fractional crystallization but that a single fractional crystallization model cannot account for all interflow chemical variation. In fact, elemental and isotopic data require different parental magmas for each of the three recent CoAxial Segment lava flows suggesting very short-term differences or changes in the chemical character of the mantle source region. In particular

  14. [Myopia: frequency of lattice degeneration and axial length].

    Science.gov (United States)

    Martín Sánchez, M D; Roldán Pallarés, M

    2001-05-01

    To evaluate the relationship between lattice retinal degeneration and axial length of the eye in different grades of myopia. A sample of 200 eyes from 124 myopic patients was collected by chance. The average age was 34.8 years (20-50 years) and the myopia was between 0.5 and 20 diopters (D). The eyes were grouped according to the degree of refraction defect, the mean axial length of each group (Scan A) and the frequency of lattice retinal degeneration and the relationship between these variables was studied. The possible influence of age on our results was also considered. For the statistical analysis, the SAS 6.07 program with the variance analysis for quantitative variables, and chi(2) test for qualitative variables with a 5% significance were used. A multivariable linear regression model was also adjusted. The highest frequency of lattice retinal degeneration occurred in those myopia patients having more than 15 D, and also in the group of myopia patients between 3 and 6 D, but this did not show statistical significance when compared with the other myopic groups. If the axial length is assessed, a greater frequency of lattice retinal degeneration is also found when the axial length is 25-27 mm and 29-30 mm, which correspond, respectively, to myopias between 3-10 D and more than 15 D. When the multivariable linear regression model was adjusted, the axial length showed the existence of lattice retinal degeneration (beta 0.41 mm; p=0.08) adjusted by the number of diopters (beta 0.38 mm; plattice retinal degeneration was found for myopias with axial eye length between 29-30 mm (more than 15 D), and 25-27 mm (between 3-10 D).

  15. Spectral analysis in thin tubes with axial heterogeneities

    KAUST Repository

    Ferreira, Rita; Mascarenhas, M. Luí sa; Piatnitski, Andrey

    2015-01-01

    In this paper, we present the 3D-1D asymptotic analysis of the Dirichlet spectral problem associated with an elliptic operator with axial periodic heterogeneities. We extend to the 3D-1D case previous 3D-2D results (see [10]) and we analyze the special case where the scale of thickness is much smaller than the scale of the heterogeneities and the planar coefficient has a unique global minimum in the periodic cell. These results are of great relevance in the comprehension of the wave propagation in nanowires showing axial heterogeneities (see [17]).

  16. Manufacture of axially insulated large-area diodes

    International Nuclear Information System (INIS)

    Ma Weiyi; Zhou Kungang; Wang Youtian; Zhang Dong; Shan Yusheng; Wang Naiyan

    1999-01-01

    The author describes the design and construction of the axially insulated large-area diodes used in the 'Heaven-1'. The four axially insulated large-area diodes are connected to the 10 ohm pulse transmission lines via the vacuum feed through tubes. The experimental results with the diodes are given. The diodes can steadily work at the voltage of 650 kV, and the diode current density is about 80 A per cm 2 with a pulse width of 220 ns. The electron beams with a total energy of 25 kJ are obtained

  17. Study on Predicting Axial Load Capacity of CFST Columns

    Science.gov (United States)

    Ravi Kumar, H.; Muthu, K. U.; Kumar, N. S.

    2017-11-01

    This work presents an analytical study and experimental study on the behaviour and ultimate load carrying capacity of axially compressed self-compacting concrete-filled steel tubular columns. Results of tests conducted by various researchers on 213 samples concrete-filled steel tubular columns are reported and present authors experimental data are reported. Two theoretical equations were derived for the prediction of the ultimate axial load strength of concrete-filled steel tubular columns. The results from prediction were compared with the experimental data. Validation to the experimental results was made.

  18. Light-front view of the axial anomaly

    International Nuclear Information System (INIS)

    Ji, C.; Rey, S.

    1996-01-01

    Motivated by an apparent puzzle of the light-front vacua incompatible with the axial anomaly, we have considered the two-dimensional massless Schwinger model for an arbitrary interpolating angle of Hornbostel close-quote s interpolating quantization surface. By examining spectral deformation of the Dirac sea under an external electric field semiclassically, we have found that the axial anomaly is quantization angle independent. This indicates an intricate nontrivial vacuum structure present even in the light-front limit. copyright 1996 The American Physical Society

  19. Study of different aerodynamics modifications for small axial flow fan

    OpenAIRE

    Bin Abdul Jalil, Anas

    2017-01-01

    En este proyecto, se investigaron los efectos de los álabes en el comportamiento aerodinámico de pequeños ventiladores axiales para disminuir la turbulencia del flujo en su superficie y generalmente para mejorar el rendimiento aerodinámico. Se estudiaron mediante simulación dos modificaciones en la superficie de los alabes de un pequeño ventilador axial (modelo 1, prototipo): la situación de un “winglet” en el extremo del álabe (modelo 2) y el diseño denominado de “aleta de tiburón” (modelo 3...

  20. Dispersive approach to the axial anomaly and nonrenormalization theorem

    International Nuclear Information System (INIS)

    Pasechnik, R.S.; Teryaev, O.V.

    2006-01-01

    Anomalous triangle graphs for the divergence of the axial-vector current are studied using the dispersive approach generalized for the case of higher orders of perturbation theory. The validity of this procedure is proved up to the two-loop level. By direct calculation in the framework of dispersive approach we have obtained that the two-loop axial-vector-vector (AVV) amplitude is equal to zero. According to the Vainshtein's theorem, the transversal part of the anomalous triangle is not renormalized in the chiral limit. We generalize this theorem for the case of finite fermion mass in the triangle loop

  1. Asymptotic freedom in the axial and Coulomb gauges

    International Nuclear Information System (INIS)

    Frenkel, J.; Taylor, J.C.

    1976-01-01

    The sources of the negative contribution to the charge renormalization factor gsup(B)/g-1 in Yang-Mills theories are investigated in the axial and Coulomb gauges. In the axial gauge, a Kaellen dispersion relation exists but the spectral function is not positive definite because of the prescription that is used to integrate the singular polarization vectors. In the Coulomb gauge, the negative contributions are (to the lowest order) isolated in the Coulomb self-energy corrections to the Coulomb field. (Auth.)

  2. Rotating stall simulation for axial and centrifugal compressors

    Science.gov (United States)

    Halawa, Taher; Gadala, Mohamed S.

    2017-05-01

    This study presents a numerical simulation of the rotating stall phenomenon in axial and centrifugal compressors with detailed descriptions of stall precursors and its development with time. Results showed that the vaneless region of the centrifugal compressor is the most critical location affected by stall. It was found that the tip leakage flow and the back flow impingement are the main cause of the stall development at the impeller exit area for centrifugal compressors. The results of the axial compressor simulations indicated that the early separated flow combined with the tip leakage flow can block the impeller passages during stall.

  3. Acne polimorfo: tratamiento con Implacen

    Directory of Open Access Journals (Sweden)

    Rubén Pérez Armas

    1995-06-01

    Full Text Available Se realiza el estudio de 40 pacientes con acné polimorfo, los que fueron atendidos en la Consulta de Dermatología del Hospital Provincial Clinicoquirúrgico Docente "Celia Sánchez Manduley", en el período comprendido de enero de 1988 a diciembre de 1989. Se revisa la literatura médica sobre los diversos métodos y medicamentos utilizados en la terapéutica de esta dermatosis. Se describe el esquema de tratamiento empleado con implacén en 30 pacientes; los 10 restantes se trataron con placebo; se compara dicho esquema con los tradicionales y se observan mejores resultados con nuestro estudio. Se destaca la ausencia de recaídas, así como el resultado del tratamiento de acuerdo con el sexo.A study was performed in 40 patients presenting with polymorphic acne who were attended in the Dermatology Department of "Celia Sánchez Manduley" Clinicosurgical and Teaching Hospital from January, 1988 to December, 1989. A review of the literature was made seeking for the different methods and drugs used for the treatment of this dermatosis. The treatment schedule with the use of implacen in 30 patients is described. Such therapeutic schedule was compared with traditional ones and better results were observed with the use of implacen. The fact that there were no relapses is highlighted, as well as the result of treatment according to sex.

  4. Redesigning axial-axial (biaxial) cruciform specimens for very high cycle fatigue ultrasonic testing machines.

    Science.gov (United States)

    Montalvão, Diogo; Wren, Andrew

    2017-11-01

    The necessity to increase performances in terms of lifetime and security in mechanical components or structures is the motivation for intense research in fatigue. Applications range from aeronautics to medical devices. With the development of new materials, there is no longer a fatigue limit in the classical sense, where it was accepted that the fatigue limit is the stress level such that there is no fracture up to 1E7 cycles. The recent development of ultrasonic testing machines where frequencies can go as high as 20 kHz or over enabled tests to be extended to ranges larger than 1E9 in just a few days. This area of studies is now known as Very High Cycle Fatigue (VHCF). On the other hand, most of the existing test equipment in the market for both classical and VHCF are uniaxial test machines. However, critical components used in Engineering applications are usually subjected to complex multi-axial loading conditions. In this paper, it is presented the methodology to redesigning existing cruciform test specimens that can be used to create an in-plane biaxial state of stress when used in 'uniaxial' VHCF ultrasonic testing machines (in this case, the term 'uniaxial' is used not because of the state of stress created at the centre of the specimen, but because of the direction at which the load is applied). The methodology is explained in such a way that it can be expanded to other existing designs, namely cruciform designs, that are not yet used in VHCF. Also, although the approach is presented in simple and logical terms, it may not be that obvious for those who have a more focused approach on fatigue rather than on modal analysis. It is expected that by contributing to bridging the gap between the sciences of modal analysis and fatigue, this research will help and encourage others exploiting new capabilities in VHCF.

  5. Osteoesclerosant axial. Proposal for a new diagnostic approach

    International Nuclear Information System (INIS)

    Toro, Carlos Enrique; Quintana Duque, Mario Andres; Restrepo, Jose Felix; Quintana, Gerardo; Rondon, Federico; Sanchez, Alvaro; Cons Molina, Fidencio; Gamarra, Antonio Iglesias

    2007-01-01

    Osteosclerosant diseases with axial involvement are a rare group of disorders characterized by a high bone mineral density secondary to impairment in the endochondral and membranous bone formation process. In this article we analyzed the current classification of these diseases and propose a new and simple approach. In addition, we describe the main radiologic, laboratory and clinical keys to arrive to the differential diagnosis

  6. On aspects of vibration of axially moving continua

    NARCIS (Netherlands)

    Hageraats-Ponomareva, S.

    2009-01-01

    In axially moving structures like conveyor belt systems, magnetic tapes, and so on, vibrations occur due to the presence of different kinds of imperfections in the systems. For these structures internal resonances can lead to severe vibrations. Resonance free conveyor belt systems can be constructed

  7. Nonsteroidal Antiinflammatory Drugs for Axial Spondyloarthritis: A Cochrane Review

    NARCIS (Netherlands)

    Kroon, Féline P. B.; van der Burg, Lennart R. A.; Ramiro, Sofia; Landewé, Robert B. M.; Buchbinder, Rachelle; Falzon, Louise; van der Heijde, Désirée

    2016-01-01

    To determine the benefits and harms of nonsteroidal antiinflammatory drugs (NSAID) in axial spondyloarthritis (axSpA). Systematic review using Cochrane Collaboration methodology. randomized controlled trials (RCT) and quasi-RCT (to June 2014), investigating NSAID versus any control for axSpA, and

  8. View of the Axial Field Spectrometer (R807)

    CERN Multimedia

    1980-01-01

    In this view of the Axial Field Spectrometer at I8, the vertical uranium/scintillator hadron calorimeter (just left of centre) is retracted to give access to the cylindrical central drift chamber. The yellow iron structure served as a filter to identify muons, with MWPCs and the array of Cherenkov counters to the right.

  9. Supersymmetric axial anomalies and the Wess-Zumino action

    International Nuclear Information System (INIS)

    Harada, K.; Shizuya, K.

    1988-01-01

    We derive, by an algebraic method, a manifestly supersymmetric extension of Bardeen's minimal form of axial anomalies, which obeys the Wess-Zumino consistency condition. The left-right symmetric form of the anomalies is also obtained by a reduction procedure. We construct the supersymmetric Wess-Zumino effective action and study its low-energy features. (orig.)

  10. Whole-body magnetic resonance imaging in axial spondyloarthritis

    DEFF Research Database (Denmark)

    Krabbe, Simon; Østergaard, Mikkel; Eshed, Iris

    2018-01-01

    Objective. To investigate whether adalimumab (ADA) reduces whole-body (WB-) magnetic resonance imaging (MRI) indices for inflammation in the entheses, peripheral joints, sacroiliac joints, spine, and the entire body in patients with axial spondyloarthritis (axSpA). Methods. An investigator-initia...

  11. Axial tomography in 3D live cell microscopy

    Science.gov (United States)

    Richter, Verena; Bruns, Sarah; Bruns, Thomas; Piper, Mathis; Weber, Petra; Wagner, Michael; Cremer, Christoph; Schneckenburger, Herbert

    2017-07-01

    A miniaturized setup for sample rotation on a microscope stage has been developed, combined with light sheet, confocal or structured illumination microscopy and applied to living cells as well as to small organisms. This setup permits axial tomography with improved visualization of single cells or small cell clusters as well as an enhanced effective 3D resolution upon sample rotation.

  12. Fission gas retention and axial expansion of irradiated metallic fuel

    International Nuclear Information System (INIS)

    Fenske, G.R.; Emerson, J.E.; Savoie, F.E.; Johanson, E.W.

    1986-05-01

    Out-of-reactor experiments utilizing direct electrical heating and infrared heating techniques were performed on irradiated metallic fuel. The results indicate accelerated expansion can occur during thermal transients and that the accelerated expansion is driven by retained fission gases. The results also demonstrate gas retention and, hence, expansion behavior is a function of axial position within the pin

  13. Elevated temperature axial and torsional fatigue behavior of Haynes 188

    Science.gov (United States)

    Bonacuse, Peter J.; Kalluri, Sreeramesh

    1992-06-01

    The results of high-temperature axial and torsional low-cycle fatigue experiments performed on Haynes 188, a wrought cobalt-base superalloy, are reported. Fatigue tests were performed at 760 C in air on thin-walled tubular specimens at various ranges under strain control. Data are also presented for coefficient of thermal expansion, elastic modulus, and shear modulus at various temperatures from room to 1000 C, and monotonic and cyclic stress-strain curves in tension and in shear at 760 C. The data set is used to evaluate several multiaxial fatigue life models (most were originally developed for room temperature multiaxial life prediction) including von Mises equivalent strain range (ASME boiler and pressure vessel code), Manson-Halford, Modified Multiaxiality Factor (proposed here), Modified Smith-Watson-Topper, and Fatemi-Socie-Kurath. At von Mises equivalent strain ranges (the torsional strain range divided by the square root of 3, taking the Poisson's ratio to be 0.5), torsionally strained specimens lasted, on average, factors of 2 to 3 times longer than axially strained specimens. The Modified Multiaxiality Factor approach shows promise as a useful method of estimating torsional fatigue life from axial fatigue data at high temperatures. Several difficulties arose with the specimen geometry and extensometry used in these experiments. Cracking at extensometer probe indentations was a problem at smaller strain ranges. Also, as the largest axial and torsional strain range fatigue tests neared completion, a small amount of specimen buckling was observed.

  14. Axial and focal-plane diffraction catastrophe integrals

    International Nuclear Information System (INIS)

    Berry, M V; Howls, C J

    2010-01-01

    Exact expressions in terms of Bessel functions are found for some of the diffraction catastrophe integrals that decorate caustics in optics and mechanics. These are the axial and focal-plane sections of the elliptic and hyperbolic umbilic diffraction catastrophes, and symmetric elliptic and hyperbolic unfoldings of the X 9 diffraction catastrophes. These representations reveal unexpected relations between the integrals.

  15. Evaluation of electromagnetic shielding effectiveness of multi-axial ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... ... Lecture Workshops · Refresher Courses · Symposia. Home; Journals; Bulletin of Materials Science; Volume 39; Issue 4. Evaluation of electromagnetic shielding effectiveness of multi-axial fabrics and their reinforced PES composites. RAMAZAN ERDEM. Volume 39 Issue 4 August 2016 pp 963-970 ...

  16. Employing a tri-axial accelerometer for estimating energy ...

    African Journals Online (AJOL)

    The Tritrac-R3D, a portable tri-axial accelerometer, was assessed for its ability to estimate energy expenditure during simulated load carrying activities. The Tritrac data were compared to metabolic data collected simultaneously by a MetaMax ergospirometry system while ten, healthy male subjects (aged 20.7 ±1.4 years) ...

  17. On the axially symmetric equilibrium of a magnetically confined plasma

    International Nuclear Information System (INIS)

    Lehnert, B.

    1975-01-01

    The axially symmetric equilibrium of a magnetically confined plasma is reconsidered, with the special purpose of studying high-beta schemes with a purely poloidal magnetic field. A number of special solutions of the pressure and magnetic flux functions are shown to exist, the obtained results may form starting-points in a further analysis of physically relevant configurations. (Auth.)

  18. Developmental ossification sequences of the appendicular and axial ...

    African Journals Online (AJOL)

    A pre-hatch developmental study on ossification sequences of axial and appendicular skeletal system in Kuttanad duck embryos was undertaken using 78 viable embryos. From day 3 to day 7 of incubation no ossification densities were seen both by alizarin red staining and computerized radiography. The first indication of ...

  19. Is a charmed axial-vector meson already found

    International Nuclear Information System (INIS)

    Matsuda, S.

    1976-12-01

    A calculation is presented of the production rate via e + e - annihilation for a charmed p-wave meson of Jsup(P) = 1 + , based on a non-relativistic quark model of charmed hadrons. The results strongly suggest that the charmed axial-vector meson should be found copiously in association with a ground-state charmed meson. (author)

  20. Radiographic analysis of body composition by computerized axial tomography

    International Nuclear Information System (INIS)

    Heymsfield, S.B.

    1986-01-01

    Radiographic methods of evaluating body composition have been applied for over five decades. A marked improvement in this approach occurred in the mid-nineteen-seventies with the introduction of computerized axial tomography. High image contrast, cross-sectional imaging and rapid computerized data processing make this technique a sophisticated clinically applicable tool. (author)

  1. Solution of the gauge identities in the axial gauge

    International Nuclear Information System (INIS)

    Delbourgo, R.

    1981-01-01

    Starting from the spectral representation of the two-point functions in the axial gauge, the gauge identities are solved so as to express the higher-point Green functions linearly in terms of the two-point spectral function. The four-point functions are an important input for investigations of scalar electrodynamics and vector chromodynamics based on the gauge technique. (author)

  2. A cylindrical drift chamber with azimuthal and axial position readout

    International Nuclear Information System (INIS)

    Bar-Yam, Z.; Cummings, J.P.; Dowd, J.P.; Eugenio, P.; Hayek, M.; Kern, W.; King, E.; Shenhav, N.; Chung, S.U.; Hackenburg, R.W.; Olchanski, C.; Weygand, D.P.; Willutzki, H.J.; Brabson, B.B.; Crittenden, R.R.; Dzierba, A.R.; Gunter, J.; Lindenbusch, R.; Rust, D.R.; Scott, E.; Smith, P.T.; Sulanke, T.; Teige, S.; Denisov, S.; Dushkin, A.; Kochetkov, V.; Lipaev, V.; Popov, A.; Shein, I.; Soldatov, A.; Anoshina, E.V.; Bodyagin, V.A.; Demianov, A.I.; Gribushin, A.M.; Kodolova, O.L.; Korotkikh, V.L.; Kostin, M.A.; Ostrovidov, A.I.; Sarycheva, L.I.; Sinev, N.B.; Vardanyan, I.N.; Yershov, A.A.; Adams, T.; Bishop, J.M.; Cason, N.M.; Sanjari, A.H.; LoSecco, J.M.; Manak, J.J.; Shephard, W.D.; Stienike, D.L.; Taegar, S.A.; Thompson, D.R.; Brown, D.S.; Pedlar, T.; Seth, K.K.; Wise, J.; Zhao, D.; Adams, G.S.; Napolitano, J.; Nozar, M.; Smith, J.A.; Witkowski, M.

    1997-01-01

    A cylindrical multiwire drift chamber with axial charge-division has been constructed and used in experiment E852 at Brookhaven National Laboratory. It serves as a trigger element and as a tracking device for recoil protons in π - p interactions. We describe the chamber's design considerations, details of its construction, electronics, and performance characteristics. (orig.)

  3. Axial Length/Corneal Radius of Curvature Ratio and Refractive ...

    African Journals Online (AJOL)

    2017-12-05

    Dec 5, 2017 ... variously described as determined by the ocular biometric variables. There have been many studies on the relationship between refractive error and ocular axial length (AL), anterior chamber depth, corneal radius of curvature (CR), keratometric readings as well as other ocular biometric variables such as ...

  4. Effects of axial coordination on immobilized Mn(salen) catalysts.

    Science.gov (United States)

    Teixeira, Filipe; Mosquera, Ricardo A; Melo, André; Freire, Cristina; Cordeiro, M Natália D S

    2014-11-13

    The consequences of anchoring Mn(salen) catalysts onto a supporting material using one of the vacant positions of the metal center are tackled by studying several Mn(salen) complexes with different axial ligands attached. This is accomplished using Density Functional Theory at the X3LYP/Triple-ζ level of theory and the Atom In Molecules formalism. The results suggest that both Mn(salen) complexes and their oxo derivatives should lie in a triplet ground state. Also, the choice of the axial ligand bears a moderate effect on the energy involved in the oxidation of the former to oxo-Mn(salen) complexes, as well as in the stability of such complexes toward ligand removal by HCl. AIM analysis further suggests that the salen ligand acts as a "charge reservoir" for the metal center, with strong correlations being obtained between the charge of salen and the electron population donated by the axial ligand to the metal center. Moreover, the results suggest that the Mn atom in Mn(salen) complexes holds different hybridization of its valence orbitals depending on the type of axial ligand present in the system.

  5. Evaluation of electromagnetic shielding effectiveness of multi-axial ...

    Indian Academy of Sciences (India)

    The usage of electrical and electronic equipments has been increasing in daily life, which has a potential hazardous impact on humans and other living organisms. In this paper, multi-axial fabrics containing steel yarns and carbon filaments, and their polyester (PES) resin-reinforced composites have been prepared for ...

  6. Probability analysis of dynamical effects of axial piston hydraulic motor

    OpenAIRE

    Sapietova Alzbeta; Dekys Vladimír; Sapieta Milan; Sulka Peter; Gajdos Lukas; Rojek Izabela

    2018-01-01

    The paper presents an analysis of impact force on stopper screw in axial piston hydraulic motor. The solution contains probabilistic description of input variables. If the output parameters of probabilistic solution are compared with arbitrary values and values acquired by analytical solution, the probability of proper operation of the device can be evaluated.

  7. Characterisation of plasmas produced by the "torche à injection axiale"

    NARCIS (Netherlands)

    Jonkers, J.; Selen, L.J.M.; Mullen, van der J.J.A.M.; Timmermans, E.A.H.; Schram, D.C.; Fauchais, P.

    1997-01-01

    Two different kinds of plasmas created by the microwave driven Torche a' Injection Axiale (TIA) are investigated: one with helium and the other with argon as the main gas. By using abs. line intensity measurements, the densities of the excited states are detd. Applying the ideal gas law gives the

  8. Multi-axial mechanical stimulation of tissue engineered cartilage: Review

    Directory of Open Access Journals (Sweden)

    S D Waldman

    2007-04-01

    Full Text Available The development of tissue engineered cartilage is a promising new approach for the repair of damaged or diseased tissue. Since it has proven difficult to generate cartilaginous tissue with properties similar to that of native articular cartilage, several studies have used mechanical stimuli as a means to improve the quantity and quality of the developed tissue. In this study, we have investigated the effect of multi-axial loading applied during in vitro tissue formation to better reflect the physiological forces that chondrocytes are subjected to in vivo. Dynamic combined compression-shear stimulation (5% compression and 5% shear strain amplitudes increased both collagen and proteoglycan synthesis (76 ± 8% and 73 ± 5%, respectively over the static (unstimulated controls. When this multi-axial loading condition was applied to the chondrocyte cultures over a four week period, there were significant improvements in both extracellular matrix (ECM accumulation and the mechanical properties of the in vitro-formed tissue (3-fold increase in compressive modulus and 1.75-fold increase in shear modulus. Stimulated tissues were also significantly thinner than the static controls (19% reduction suggesting that there was a degree of ECM consolidation as a result of long-term multi-axial loading. This study demonstrated that stimulation by multi-axial forces can improve the quality of the in vitro-formed tissue, but additional studies are required to further optimize the conditions to favour improved biochemical and mechanical properties of the developed tissue.

  9. Axial Torsion of Gangrenous Meckel's Diverticulum Causing Small ...

    African Journals Online (AJOL)

    dividing the band. Resection and anastomosis of the small bowel including the MD was performed. We hereby report a rare and unusual complication of a MD. Although treatment outcome is generally good, pre-operative diagnosis is often difficult. Key words: Axial torsion, Meckel's diverticulum, small bowel obstruction.

  10. Axial anomaly and index theorem for Dirac-Kaehler fermions

    International Nuclear Information System (INIS)

    Linhares, C.A.; Mignaco, J.A.; Monteiro, M.A.R.

    1985-01-01

    We present the calculation of the axial anomaly for Dirac-Kaehler fermions in two and four dimensions applying the procedure developed by Seeley to the signature operator in the twisted complex. The result is equal to the one for the twisted spin complex times 2 n/2 (n:number of dimensions) and agrees with the expressions from the index theorem. (author) [pt

  11. Axial anomaly and index theorem for Dirac-Kaehler fermions

    International Nuclear Information System (INIS)

    Linhares, C.A.; Mignaco, J.A.; Rego Monteiro, M.A.

    1985-01-01

    We present a calculation of the axial anomaly for Dirac-Kaehler fermions in two and four dimensions applying the procedure developed by Seeley to the signature operator in the twisted complex. The result is equal to the one for the twisted spin complex times 2sup(π/2) (n: number of dimensions) and agrees with the expressions from the index theorem. (orig.)

  12. Spin energy levels in axial symmetry: spin 4

    Energy Technology Data Exchange (ETDEWEB)

    de Biasi, R S; Portella, P D [Instituto Militar de Engenharia, Rio de Janeiro (Brazil). Secao de Engenharia e Ciencia dos Materiais

    1979-01-01

    The spin energy levels in axial symmetry are presented, in graphical and tabular form, for a spin 4. The levels are calculated for five different angles between the applied field and the symmetry axis 0/sup 0/, 30/sup 0/, 45/sup 0/, 60 and 90/sup 0/.

  13. Spin energy levels in axial symmetry: spin 3/2

    Energy Technology Data Exchange (ETDEWEB)

    de Biasi, R S; Portella, P D [Instituto Militar de Engenharia, Rio de Janeiro (Brazil). Secao de Engenharia e Ciencia dos Materiais

    1977-01-01

    The spin energy levels in axial symmetry are presented, in graphical and tabular form, for a spin 3/2. The levels are calculated for five different angles between the applied field and the symmetry axis: 0/sup 0/, 30/sup 0/, 45/sup 0/, 60/sup 0/ and 90/sup 0/.

  14. Baryon axial charges from chirally improved fermions - first results

    Science.gov (United States)

    Engel, G.; Gattringer, C.; Glozman, L. Y.; Lang, C. B.; Limmer, M.; Mohler, D.; Schäfer, A.

    We present first results from dynamical Chirally Improved (CI) fermion simulations for the axial charge $G_A$ of various hadrons. We work with 16^3x32 lattices of spatial extent 2.4 fm and use the variational method with a suitable basis of Jacobi-smeared interpolators to suppress contaminations from excited states.

  15. Axial heterogeneous core concept applied for super phoenix reactor

    International Nuclear Information System (INIS)

    Batista, J.L.; Renke, C.A.C.; Waintraub, M.; Santos Bastos, W. dos; Brito Aghina, L.O. de.

    1991-11-01

    Always maintaining the current design rules, this paper presents a parametric study on the type of axial heterogeneous core concept (CHA), utilizing a core of fast reactor Super Phenix type, reaching a maximum thermal burnup rate of 150000 M W d/t and being managed in single batch. (author)

  16. Boundary layer flow past a circular cylinder in axial flow

    International Nuclear Information System (INIS)

    Sawchuk, S.P.; Zamir, M.; Camiletti, S.E.

    1985-01-01

    This paper discusses a study of the laminar boundary layer on a semi-infinite circular cylinder in axial incompressible flow. Unlike previous studies, the present study investigates a full range of this boundary layer problem to determine skin friction, heat transfer and other integral properties of the boundary layer

  17. con mala calidad de vida

    Directory of Open Access Journals (Sweden)

    Agustín Martín-Rodríguez

    2007-01-01

    Full Text Available En este estudio ex post facto se ha analizado si los familiares de pacientes con mala calidad de vida presentan diferencias en las variables clínicas de personalidad y relaciones familiares en función de que el paciente haya estado o no ingresado en una Unidad de Cuidados Intensivos. Seleccionamos dos grupos: 29 familiares de pacientes traumatizados graves transcurridos cuatro años de su ingreso en una UCI de Traumatología y con mala calidad de vida (debido a secuelas físicas y/o psicológicas tras el ingreso, tales como traumatismos craneoencefálicos, politraumatismos y tetraplejias traumáticas y 32 familiares de pacientes con mala calidad de vida con cuatro años de evolución de su enfermedad física (hipertensión, diabetes, artritis reumatoide y síndrome de intestino irritable que no han estado ingresados en la UCI. Para alcanzar nuestro objetivo empleamos una Encuesta Psicosocial y los siguientes instrumentos: Cuestionario de Análisis Clínico, Escala de Clima Social en la Familia y Escala de Adaptación Psicosocial de la Enfermedad. Los resultados mostraron que los familiares de pacientes con mala calidad de vida que estuvieron ingresados en la UCI hace cuatro años, presentan diferencias significativas en las variables agitación y expresividad comparados con los familiares de pacientes con mala calidad de vida que no han estado ingresados en la UCI.

  18. Axial SPN and radial MOC coupled whole core transport calculation

    International Nuclear Information System (INIS)

    Cho, Jin-Young; Kim, Kang-Seog; Lee, Chung-Chan; Zee, Sung-Quun; Joo, Han-Gyu

    2007-01-01

    The Simplified P N (SP N ) method is applied to the axial solution of the two-dimensional (2-D) method of characteristics (MOC) solution based whole core transport calculation. A sub-plane scheme and the nodal expansion method (NEM) are employed for the solution of the one-dimensional (1-D) SP N equations involving a radial transverse leakage. The SP N solver replaces the axial diffusion solver of the DeCART direct whole core transport code to provide more accurate, transport theory based axial solutions. In the sub-plane scheme, the radial equivalent homogenization parameters generated by the local MOC for a thick plane are assigned to the multiple finer planes in the subsequent global three-dimensional (3-D) coarse mesh finite difference (CMFD) calculation in which the NEM is employed for the axial solution. The sub-plane scheme induces a much less nodal error while having little impact on the axial leakage representation of the radial MOC calculation. The performance of the sub-plane scheme and SP N nodal transport solver is examined by solving a set of demonstrative problems and the C5G7MOX 3-D extension benchmark problems. It is shown in the demonstrative problems that the nodal error reaching upto 1,400 pcm in a rodded case is reduced to 10 pcm by introducing 10 sub-planes per MOC plane and the transport error is reduced from about 150 pcm to 10 pcm by using SP 3 . Also it is observed, in the C5G7MOX rodded configuration B problem, that the eigenvalues and pin power errors of 180 pcm and 2.2% of the 10 sub-planes diffusion case are reduced to 40 pcm and 1.4%, respectively, for SP 3 with only about a 15% increase in the computing time. It is shown that the SP 5 case gives very similar results to the SP 3 case. (author)

  19. High-resolution axial MR imaging of tibial stress injuries

    Directory of Open Access Journals (Sweden)

    Mammoto Takeo

    2012-05-01

    Full Text Available Abstract Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries.

  20. The Nucleon Axial Form Factor and Staggered Lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Aaron Scott [Chicago U.

    2017-01-01

    The study of neutrino oscillation physics is a major research goal of the worldwide particle physics program over the upcoming decade. Many new experiments are being built to study the properties of neutrinos and to answer questions about the phenomenon of neutrino oscillation. These experiments need precise theoretical cross sections in order to access fundamental neutrino properties. Neutrino oscillation experiments often use large atomic nuclei as scattering targets, which are challenging for theorists to model. Nuclear models rely on free-nucleon amplitudes as inputs. These amplitudes are constrained by scattering experiments with large nuclear targets that rely on the very same nuclear models. The work in this dissertation is the rst step of a new initiative to isolate and compute elementary amplitudes with theoretical calculations to support the neutrino oscillation experimental program. Here, the eort focuses on computing the axial form factor, which is the largest contributor of systematic error in the primary signal measurement process for neutrino oscillation studies, quasielastic scattering. Two approaches are taken. First, neutrino scattering data on a deuterium target are reanalyzed with a model-independent parametrization of the axial form factor to quantify the present uncertainty in the free-nucleon amplitudes. The uncertainties on the free-nucleon cross section are found to be underestimated by about an order of magnitude compared to the ubiquitous dipole model parametrization. The second approach uses lattice QCD to perform a rst-principles computation of the nucleon axial form factor. The Highly Improved Staggered Quark (HISQ) action is employed for both valence and sea quarks. The results presented in this dissertation are computed at physical pion mass for one lattice spacing. This work presents a computation of the axial form factor at zero momentum transfer, and forms the basis for a computation of the axial form factor momentum dependence

  1. High-resolution axial MR imaging of tibial stress injuries

    Science.gov (United States)

    2012-01-01

    Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries. PMID:22574840

  2. Morteros Reforzados con Fibras de Bambú

    Directory of Open Access Journals (Sweden)

    Arbeláez Arce Anacilia

    1997-12-01

    Full Text Available El término fibras de bambú, hace referencia al material de desecho (aserrín, seleccionado por diferencia de peso, en inmersión en agua. Se atiene a la definición de fibras que presentan la Norma ASTM C-JI16-89 "Standard Specification for Fiber-Reinforced Concrete ". Se estudian las propiedades físico-mecánicas del mortero 1.3, reforzado con 15, 50 y 100 kg de fibras de bambú, por metro cúbico de mortero, con el objeto de determinar la factibilidad de uso de este material, como matriz para muros estructurales. En el caso de matrices de mortero reforzados para paneles, además de determinar el porcentaje de refuerzo, que permita mantener la resistencia mecánica dentro de los límites establecidos,éste debe lograr un control en el agrietamiento. De hecho en condiciones normales bajo carga, el agrietamiento es inevitable, sea cual fuere la cantidad y calidad de refuerzo usado: Sinembargo, las fibras tienen la propiedad de controlar la propagación del agrietamiento ypor ende transformaruna matrizfrágil, en un material con cierto grado de ductilidad. Los compuestos son probados a compresión axial, flexión e impacto. Las propiedades físicas de absorción de humedad ycontracciones por secado se miden en probetas con dosificación deporcentaje de refuerzo seleccionado de las pruebas mecánicas.

  3. Two-dimensional nonlinear dynamics of an axially moving viscoelastic beam with time-dependent axial speed

    International Nuclear Information System (INIS)

    Ghayesh, Mergen H.; Amabili, Marco; Farokhi, Hamed

    2013-01-01

    In the present study, the coupled nonlinear dynamics of an axially moving viscoelastic beam with time-dependent axial speed is investigated employing a numerical technique. The equations of motion for both the transverse and longitudinal motions are obtained using Newton’s second law of motion and the constitutive relations. A two-parameter rheological model of the Kelvin–Voigt energy dissipation mechanism is employed in the modelling of the viscoelastic beam material, in which the material time derivative is used in the viscoelastic constitutive relation. The Galerkin method is then applied to the coupled nonlinear equations, which are in the form of partial differential equations, resulting in a set of nonlinear ordinary differential equations (ODEs) with time-dependent coefficients due to the axial acceleration. A change of variables is then introduced to this set of ODEs to transform them into a set of first-order ordinary differential equations. A variable step-size modified Rosenbrock method is used to conduct direct time integration upon this new set of first-order nonlinear ODEs. The mean axial speed and the amplitude of the speed variations, which are taken as bifurcation parameters, are varied, resulting in the bifurcation diagrams of Poincaré maps of the system. The dynamical characteristics of the system are examined more precisely via plotting time histories, phase-plane portraits, Poincaré sections, and fast Fourier transforms (FFTs)

  4. Non-steroidal anti-inflammatory drugs (NSAIDs) for axial spondyloarthritis (ankylosing spondylitis and non-radiographic axial spondyloarthritis)

    NARCIS (Netherlands)

    Kroon, Feline P. B.; van der Burg, Lennart R. A.; Ramiro, Sofia; Landewé, Robert B. M.; Buchbinder, Rachelle; Falzon, Louise; van der Heijde, Désirée

    2015-01-01

    Axial spondyloarthritis (axSpA) comprises ankylosing spondylitis (radiographic axSpA) and non-radiographic (nr-)axSpA and is associated with psoriasis, uveitis and inflammatory bowel disease. Non-steroidal anti-inflammatory drugs (NSAIDs) are recommended as first-line drug treatment. To determine

  5. Miasis orbital severa causada por Cochliomyia hominivorax en la región andina de Ecuador

    Directory of Open Access Journals (Sweden)

    Juan Dominguez Enríquez

    2016-01-01

    Full Text Available Presentamos el caso de una indígena kichwa de 91 años con miasis orbital destructiva que compromete globo ocular derecho con destrucción de tejido óseo orbital, nasal, etmoidal y del seno frontal, confirmado por tomografía axial computarizada y con reconstrucción ósea tridimensional. Infectada en una zona templada a 2,418 m de altitud en la provincia andina de Imbabura, Ecuador. La paciente se presentó en el Hospital de Cotacachi con una tumoración cavitaria en el globo ocular derecho acompañada de secreción maloliente, supurativa, observando y extrayéndose más de 100 larvas de moscas desde su interior. Estas fueron identificadas como Cochliomyia hominivorax, por la disposición de sus espiráculos respiratorios.

  6. Tratamiento con implantes Leader-Nano en paciente con oligodoncia

    Directory of Open Access Journals (Sweden)

    Salvador Javier Santos Medina

    2015-03-01

    Full Text Available Los implantes dentales de titanio han revolucionado el mundo de la rehabilitación desde su surgimiento. De manera particular, el empleo de implantes de carga inmediata acorta el tiempo quirúrgico y protésico, con el consiguiente bienestar estético. Se presenta el caso de una paciente femenina de 32 años de edad, con antecedentes de oligodoncia de ambos incisivos laterales superiores y portadora de prótesis parcial acrílica. Fue atendida por el equipo multidisciplinario de implantes en la Clínica Estomatológica Docente “3 de Octubre” y se le realizó tratamiento de rehabilitación integral con implantes Leader-Nano y prótesis fija con corona acrílica sobre dichos implantes. La implantología fue satisfactoria en la paciente; la mejoría estética y funcional, así como la satisfacción de la paciente, fueron los principales logros obtenidos

  7. Generation of parasitic axial flow by drift wave turbulence with broken symmetry: Theory and experiment

    Science.gov (United States)

    Hong, R.; Li, J. C.; Hajjar, R.; Chakraborty Thakur, S.; Diamond, P. H.; Tynan, G. R.

    2018-05-01

    Detailed measurements of intrinsic axial flow generation parallel to the magnetic field in the controlled shear decorrelation experiment linear plasma device with no axial momentum input are presented and compared to theory. The results show a causal link from the density gradient to drift-wave turbulence with broken spectral symmetry and development of the axial mean parallel flow. As the density gradient steepens, the axial and azimuthal Reynolds stresses increase and radially sheared azimuthal and axial mean flows develop. A turbulent axial momentum balance analysis shows that the axial Reynolds stress drives the radially sheared axial mean flow. The turbulent drive (Reynolds power) for the azimuthal flow is an order of magnitude greater than that for axial flow, suggesting that the turbulence fluctuation levels are set by azimuthal flow shear regulation. The direct energy exchange between axial and azimuthal mean flows is shown to be insignificant. Therefore, the axial flow is parasitic to the turbulence-zonal flow system and is driven primarily by the axial turbulent stress generated by that system. The non-diffusive, residual part of the axial Reynolds stress is found to be proportional to the density gradient and is formed due to dynamical asymmetry in the drift-wave turbulence.

  8. Modelling larval transport in a axial convergence front

    Science.gov (United States)

    Robins, P.

    2010-12-01

    Marine larvae exhibit different vertical swimming behaviours, synchronised by factors such as tidal currents and daylight, in order to aid retention near the parent populations and hence promote production, avoid predation, or to stimulate digestion. This paper explores two types of larval migration in an estuarine axial convergent front which is an important circulatory mechanism in many coastal regions where larvae are concentrated. A parallelised, three-dimensional, ocean model was applied to an idealised estuarine channel which was parameterised from observations of an axial convergent front which occurs in the Conwy Estuary, U.K. (Nunes and Simpson, 1985). The model successfully simulates the bilateral cross-sectional recirculation of an axial convergent front, which has been attributed to lateral density gradients established by the interaction of the lateral shear of the longitudinal currents with the axial salinity gradients. On the flood tide, there is surface axial convergence whereas on the ebb tide, there is (weaker) surface divergence. Further simulations with increased/decreased tidal velocities and with stronger/weaker axial salinity gradients are planned so that the effects of a changing climate on the secondary flow can be understood. Three-dimensional Lagrangian Particle Tracking Models (PTMs) have been developed which use the simulated velocity fields to track larvae in the estuarine channel. The PTMs take into account the vertical migrations of two shellfish species that are commonly found in the Conwy Estuary: (i) tidal migration of the common shore crab (Carcinus maenas) and (ii), diel (daily) migration of the Great scallop (Pecten maximus). These migration behaviours are perhaps the most widespread amongst shellfish larvae and have been compared with passive (drifting) particles in order to assess their relative importance in terms of larval transport. Preliminary results suggest that the net along-estuary dispersal over a typical larval

  9. con dietas suplementadas con Cromo-L-metionina

    Directory of Open Access Journals (Sweden)

    Ram\\u00F3n Garc\\u00EDa-Castillo

    2006-01-01

    Full Text Available Un total de 48 cerdos (Sus scrofa domesticus; 24 machos castrados y 24 hembras cruzados (Yorkshire, Hampshire, Duroc y Landrace de 3,5 a 4,0 meses de edad y 60,0 ± 5,0 kg PV en finalización. Se alimentaron con dietas isoproteícas (14,5 % PC e isoenergéticas (3.400 kcal EM/kg de MS, adicionadas con Cr-L-metionina (MiCroPlex® (0, 200, 400 y 600 ppb. El experimento tuvo una duración de 45 días y se realizó de agosto a noviembre del 2002 en las instalaciones de la Universidad Autónoma Agraria Antonio Narro, localizada en Saltillo, Coahuila, México. Al tener los animales aproximadamente 95 kg PV, se tomó muestra de 15 ml de sangre por cada animal para determinar la concentración de glucosa, ácido úrico, creatinina, urea, proteinas totales y colesterol. Se aplicó un diseño completamente al azar con arreglo factorial 2 x 4; dos para el factor sexo y cuatro para nivel de cromo. Los metabolitos en suero no fueron afectados (P>0,05 por el factor sexo. La glucosa en suero disminuyó (P<0,05 y el colesterol incrementó (P<0,05 con cromo en la dieta. Se concluye que el Cr incrementa el metabolismo de glucosa y disminuye el de colesterol, con lo cual puede haber energía disponible para síntesis de proteína la cual es necesaria para el crecimiento de los animales

  10. Plasticity around an Axial Surface Crack in a Cylindrical Shell

    DEFF Research Database (Denmark)

    Krenk, Steen

    1979-01-01

    of the yield zone. The model is used to analyse published test data on surface cracked pressurised pipes. The analysis consists in COD evaluation and estimate of failure as a consequence of plastic instability. A method is proposed which deals with the problem by simultaneous analysis of a number of cracks......This paper presents a plasticity model for deep axial surface cracks in pressurised pipes. The model is used in an investigation of the relative merits of fracture criteria based on COD and plastic instability. Recent investigations have shown that the inconsistency of the singular bending stress...... on the bending stresses is considerable. In the case of surface cracks moments are induced due to the eccentricity of the crack and transverse shear effects should therefore be included. A plasticity model for a rectangular axial surface crack is developed. Like a previous surface crack model by Erdogen...

  11. Axial offset anomalies and local pH

    International Nuclear Information System (INIS)

    Tarin, F.; Montes, M.; Izquierdo, J.; Garcia-Sanchez, J.

    2001-01-01

    Small radial and axial offset anomalies (AOA) in some Spanish PWR-type NPP's, in addition to the knowledge of the existence of similar anomalies in U.S. PWR's, led us in 1993 to study this problem. Important parameters were correlated for a database of plant operating data consisting of six cycles of five different PWR plants (all of them of the Westinghouse 3-loop, 12 ft., 17 x 17 fuel design). One of these cycles (the oldest one) followed the standard constant pH 308 = 7.0, and the remaining ones followed a modified elevated pH control strategy (the pH at EOC is typically 7.4). Only for the oldest cycle that used the standard pH control was the in-core and ex-core axial offset values found to be in good agreement with the predictions, and an anomalous soluble boron curve behavior not observed. (author)

  12. Axial Ge/Si nanowire heterostructure tunnel FETs

    Energy Technology Data Exchange (ETDEWEB)

    Picraux, Sanuel T [Los Alamos National Laboratory; Daych, Shadi A [Los Alamos National Laboratory

    2010-01-01

    The vapor-liquid-solid (VLS) growth of semiconductor nanowires allows doping and composition modulation along their axis and the realization of axial 1 D heterostructures. This provides additional flexibility in energy band-edge engineering along the transport direction which is difficult to attain by planar materials growth and processing techniques. We report here on the design, growth, fabrication, and characterization of asymmetric heterostructure tunnel field-effect transistors (HTFETs) based on 100% compositionally modulated Si/Ge axial NWs for high on-current operation and low ambipolar transport behavior. We discuss the optimization of band-offsets and Schottky barrier heights for high performance HTFETs and issues surrounding their experimental realization. Our HTFET devices with 10 nm PECVD SiN{sub x} gate dielectric resulted in a measured current drive exceeding 100 {mu}A/{mu}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios.

  13. Tests of a new axial sputtering technique in an ECRIS

    International Nuclear Information System (INIS)

    Scott, R.; Pardo, R.; Vondrasek, R.

    2012-01-01

    Axial and radial sputtering techniques have been used over the years to create beams from an ECRIS at multiple accelerator facilities. Operational experience has shown greater beam production when using the radial sputtering method versus axial sputtering. At Argonne National Laboratory, previous work with radial sputtering has demonstrated that the position of the sputter sample relative to the plasma chamber wall influences sample drain current, beam production and charge state distribution. The possibility of the chamber wall acting as a ground plane which influences the sputtering of material has been considered, and an attempt has been made to mimic this possible ground plane effect with a coaxial sample introduced from the injection end. Results of these tests will be shown as well as comparisons of outputs using the two methods. The paper is followed by the associated poster. (authors)

  14. Axial force in a superconductor magnet journal bearing

    Science.gov (United States)

    Postrekhin, E.; Chong, Wang; Ki Bui, Ma; Chen, Quark; Chu, Wei-Kan

    Using superconductors and magnets, a journal bearing could be made from a permanent magnet cylinder in a superconductor ring. We have assembled a prototype superconductor magnet journal bearing of this configuration, and investigated the behavior of the axial force that it can provide. We have put together a numerical model of the interaction between the permanent magnet and the superconductor that is capable of describing these experimental results semi-quantitatively. Combining direct experimental measurements and using the numerical models proposed, we have achieved a qualitative understanding of the behavior of the axial force and its relationship of to the dimensions of the magnet and material quality such as the homogeneity of the superconductor that constitute the bearing.

  15. An Axial Sliding Test for machine elements surfaces

    DEFF Research Database (Denmark)

    Godi, Alessandro; Grønbæk, J.; Mohaghegh, Kamran

    2012-01-01

    are necessary: a press to provide the normal pressure and a tensile machine to perform the axial movements. The test is calibrated so that the correspondence between the normal pressure and the container advancement is found. Finally, preliminary tests are carried out involving a multifunctional and a fine......Throughout the years, it has become more and more important to find new methods for reducing friction and wear occurrence in machine elements. A possible solution is found in texturing the surfaces under tribological contact, hence the development and spread of plateau-honed surface for cylinder...... liners. To prove the efficacy of a particular textured surface, it is paramount to perform experimental tests under controlled laboratory conditions. In this paper a new test rig simulating pure sliding conditions is presented, dubbed Axial Sliding Test. It presents four major components: a rod, a sleeve...

  16. Computerized axial tomography : the tool in osseointegrated dental implants

    International Nuclear Information System (INIS)

    Fernandez-Lopez, Otton

    2002-01-01

    Failure rates in rehabilitations with osseointegrated implants are handled through appropriate radiographic preoperative planning. The appropriate length of the implant without running the risk of a perforation of vital structures, has been determined by a radiographic diagnosis. Computerized and conventional axial tomography have proved to be invaluable elements for pre-surgical evaluation. A radiologic guidance is elaborated to perform a computerized axial tomography (CT) of maxillary bones in totally edentulous patients. Surgical guides are constructed from a wax-up emanated from the information of the CT. The CT has proven to be an radiographic indispensable element to achieve the surgical-prosthetic success in osseointegrated dental implants. The CT has allowed the realization of a precise wax-up for making of surgical guide and a precise temporary prostheses in positioning of osseointegrated implants, with the consequent saving time and money for the rehabilitator and patient [es

  17. Laboratory Test Setup for Cyclic Axially Loaded Piles in Sand

    DEFF Research Database (Denmark)

    Thomassen, Kristina; Ibsen, Lars Bo; Andersen, Lars Vabbersgaard

    2017-01-01

    This paper presents a comprehensive description and the considerations regarding the design of a new laboratory test setup for testing cyclic axially loaded piles in sand. The test setup aims at analysing the effect of axial one-way cyclic loading on pile capacity and accumulated displacements....... Another aim was to test a large diameter pile segment with dimensions resembling full-scale piles to model the interface properties between pile and sand correctly. The pile segment was an open-ended steel pipe pile with a diameter of 0.5 m and a length of 1 m. The sand conditions resembled the dense sand...... determined from the API RP 2GEO standard and from the test results indicated over consolidation of the sand. Two initial one-way cyclic loading tests provided results of effects on pile capacity and accumulated displacements in agreement with other researchers’ test results....

  18. Impaired bed mobility: quantitative torque analysis with axial inertial sensors.

    Science.gov (United States)

    Bhidayasiri, Roongroj; Sringean, Jirada; Thanawattano, Chusak

    2017-08-01

    Difficulty in turning in bed is rated as the most troublesome night-time symptom among Parkinson's disease (PD) patients. To develop a practical objective method for home assessment of a patient's ability to turn in bed. Nocturnal parameters and torque of self-turning in bed from 17 PD couples were assessed and compared using a wearable axial sensor for two nights in their homes. The torque of axial rotation which indicates the ability of PD patients to turn in bed was significantly less than their spouses (p turning in bed and total unified Parkinson's Disease Rating Scale score (r = 0.71; p = 0.001), and total Nocturnal Akinesia Dystonia and Cramp score (r = 0.634; p = 0.006). Our study confirms a decreased ability in turning in PD.

  19. Periodicity effects of axial waves in elastic compound rods

    DEFF Research Database (Denmark)

    Nielsen, R. B.; Sorokin, S. V.

    2015-01-01

    Floquet analysis is applied to the Bernoulli-Euler model for axial waves in a periodic rod. Explicit asymptotic formulae for the stop band borders are given and the topology of the stop band pattern is explained. Eigenfrequencies of the symmetric unit cell are determined by the Phase-closure Prin......Floquet analysis is applied to the Bernoulli-Euler model for axial waves in a periodic rod. Explicit asymptotic formulae for the stop band borders are given and the topology of the stop band pattern is explained. Eigenfrequencies of the symmetric unit cell are determined by the Phase......-closure Principle, and their correspondence with stop band formation is shown. Steady-state and transient dynamics of a periodic rod of finite length are analysed numerically and the difference in structural response when excitation is done in either stop- or pass bands is demonstrated. A physical interpretation...

  20. One-loop calculations in QED in axial gauge

    International Nuclear Information System (INIS)

    Boos, E.E.; Kurannoy, S.S.

    1983-01-01

    The present paper pursued the aim to test at the simple example of the calculation of the anomalous magnetic moment in quantum electrodynamics the methods of calculating one-loop integrals in the axial gauge, using the dimensional regularization, and to investigate the independence of the results on the choice of the recipe of how to treat the poles in the denominators (k eta) -1 . It is shown that the techniques developed in another paper, as well as in the present paper, can be successfully applied in such calculations, in spite of the peculiarities of the axial gauge that have been discussed previously. The results of the two different ways of treating singularities (k eta) -1 (the principal value and 't Hooft's prescription) turn out to be equal. At the same time it was verified that the Green functions obtained by these calculations near the mass shell in the one-loop approximation satisfy the ward identity

  1. Multichannel singular spectrum analysis of the axial atmospheric angular momentum

    Directory of Open Access Journals (Sweden)

    Leonid Zotov

    2017-11-01

    Full Text Available Earth's variable rotation is mainly produced by the variability of the AAM (atmospheric angular momentum. In particular, the axial AAM component χ3, which undergoes especially strong variations, induces changes in the Earth's rotation rate. In this study we analysed maps of regional input into the effective axial AAM from 1948 through 2011 from NCEP/NCAR reanalysis. Global zonal circulation patterns related to the LOD (length of day were described. We applied MSSA (Multichannel Singular Spectrum Analysis jointly to the mass and motion components of AAM, which allowed us to extract annual, semiannual, 4-month, quasi-biennial, 5-year, and low-frequency oscillations. PCs (Principal components strongly related to ENSO (El Nino southern oscillation were released. They can be used to study ENSO-induced changes in pressure and wind fields and their coupling to LOD. The PCs describing the trends have captured slow atmospheric circulation changes possibly related to climate variability.

  2. Ultraviolet and infrared aspects of the axial anomaly. I

    International Nuclear Information System (INIS)

    Horejsi, J.

    1992-01-01

    The paper is the first part of a brief review of some perturbative aspects of the Adler-Bell-Jackiw axial anomaly, described in terms of ultraviolet and infrared behavior of the famous VVA triangle graph. Apart from a general overview of the diversified role played by the anomaly in quantum field theory and particle physics, an elementary introduction is presented to the subject of the anomaly, comprehensible to an uninitiated reader with only a basic background in quantum field theory. The ultraviolet aspects of the anomaly are stressed and the topics covered are the following: vector and axial-vector Ward identities for the VVA triangle graph; the anomaly and several ways to derive it, namely the symmetric momentum cut-off and shifting the integration variables in linearly divergent integrals; the Adler-Rosenberg argument; the Pauli-Villars method; and dimensional regularization. (author) 2 figs., 34 refs

  3. Axial positrons emission tomography: from mouse to human brain imaging

    International Nuclear Information System (INIS)

    Brard, Emmanuel

    2013-01-01

    Positrons emission tomography is a nuclear imaging technics using nuclear decays. It is used both in clinical and preclinical studies. The later requires the use of small animals such as the mouse. The objective is to obtain the best signal with the best spatial resolution. Yet, a weight ratio between humans and mice indicates the need of a sub-millimeter resolution. A conventional scanner is based on detection modules surrounding the object to image and arranged perpendicularly. This implies a strong relationship between efficiency and spatial resolution. This work focuses on the axial geometry in which detection modules are arranged parallel to the object. This limits the relationship between the figures of merit, leading to both high spatial resolution and efficiency. The simulations of prototypes showed great perspectives in term of sub-millimeter resolution with efficiencies of 15 or 40% according to the scanner's axial extension. These results indicate great perspectives for both clinical and preclinical imaging. (author)

  4. [Inflammatory spinal diseases: axial spondyloarthritis : Central importance of imaging].

    Science.gov (United States)

    Baraliakos, X; Fruth, M; Kiltz, U; Braun, J

    2017-03-01

    The diagnosis of axial spondyloarthritis (axSpA) includes classical ankylosing spondylitis (AS) as well as earlier stages and abortive courses of the disease, in which structural alterations have not yet occurred. These are classified as non-radiographic axSpA (nr-axSpa). Inflammatory changes in the entire axial skeleton are characteristic for axSpA and can be visualized by magnetic resonance imaging (MRI), while in most patients structural alterations, such as new bone formation with syndesmophytes and ankylosis develop in the later course of the disease. These bony alterations can best be visualized by conventional radiography and by computed tomography. Certain MRI sequences are nowadays considered as the standard method for depiction of inflammatory changes in axSpA. The introduction of MRI has led to a paradigm shift for this disease because the inflammatory lesions characteristic for the disease can be visualized at an early stage using appropriate MRI sequences.

  5. Buckling localization in a cylindrical panel under axial compression

    DEFF Research Database (Denmark)

    Tvergaard, Viggo; Needleman, A.

    2000-01-01

    Localization of an initially periodic buckling pattern is investigated for an axially compressed elastic-plastic cylindrical panel of the type occurring between axial stiffeners on cylindrical shells. The phenomenon of buckling localization and its analogy with plastic flow localization in tensile...... test specimens is discussed in general. For the cylindrical panel, it is shown that buckling localization develops shortly after a maximum load has been attained, and this occurs for a purely elastic panel as well as for elastic-plastic panels. In a case where localization occurs after a load maximum......, but where subsequently the load starts to increase again, it is found that near the local load minimum, the buckling pattern switches back to a periodic type of pattern. The inelastic material behavior of the panel is described in terms of J(2) corner theory, which avoids the sometimes unrealistically high...

  6. Classical theory of the Kumakhov radiation in axial channeling

    International Nuclear Information System (INIS)

    Khokonov, M.K.; Komarov, F.F.; Telegin, V.I.

    1984-01-01

    The paper considers radiation of ultrarelativistic electrons in axial channeling initially predicted by Kumakhov. The consideration is based on the results of solution of the Fokker-Planck equation. The spectral-angular characteristics of the Kumakhov radiation in thick single crystals are calculated. It is shown that in heavy single crystals the energy losses on radiation can amount to a considerable portion of the initial beam energy. The possibility of a sharp increase of radiation due to a decrease of crystal temperature is discussed. It is shown that radiation intensity in axial channeling is weakly dependent on the initial angle of the electron entrance into the channel if this angle changes within the limits of a critical one. (author)

  7. High pressure axial flow fans for modern coal power stations

    Energy Technology Data Exchange (ETDEWEB)

    Cyrus, Vaclav [AHT Energetika s.r.o., Praha (Czech Republic); Koci, Petr [ZVVZ Milevsko a.s. (Czech Republic)

    2008-07-01

    Brown coal fired power stations, located in Northern Bohemia, have mostly older boiler blocks with an output of 110 and 200 MWe. Flue gases are cleaned by the desulphurization plants installed between 1993 and 1997. Usually, each boiler block has two air fans and one to three flue gas fans. Flue gas fans operate in severe conditions; fan blades should be resistant to the flue gases containing sulphur and acid drops with the operating temperature at 170 C to 190 C. Additionally, flue gas also often contains ash particles. Currently, some boiler blocks are gradually being refurbished. New blocks with an electrical power output of 600 to 700 MWe are at the design stage. Submitted paper shows our design study of one stage axial flow fan for the new blocks. Results from the new aerodynamic research of the axial flow stages were used in the fan design. (orig.)

  8. Axial weak currents in the Wess-Zumino term

    International Nuclear Information System (INIS)

    Fujikawa, Kazuo

    1986-01-01

    In a simplified model lagrangian of 3 quarks with an SU(2)sub(L) gauging of chiral SU(3)sub(L)xSU(3)sub(R) to introduce W-boson, we analyse certain complications associated with the low-energy theorem including axial weak fields. We first show that the low-energy amplitude is independent of the form of the quark-level anomalous identity, whether in the covariant form or the consistent form. However, the interplay of the short-distance dynamics (anomalous identity) and the long-distance dynamics (low-energy theorem) becomes involved in the presence of axial fields. We then discuss what kinds of conditions single out the gauged Wess-Zumino term as a low-energy effective action. The connection of the low-energy theorem with the 't Hooft anomaly matching condition is also discussed. (orig.)

  9. Recubrimiento de acero con polidopamina

    OpenAIRE

    Carrasco Rodríguez, Javier

    2013-01-01

    Se ha obtenido recubrimientos de polidopamina en acero mecánicamente resistentes y con tiempos de obtención relativamente pequeños a través de la polimerización de la dopamina bajo diferentes condiciones.

  10. Colonic surveillance by CT colonography using axial images only

    International Nuclear Information System (INIS)

    Bruzzi, John F.; Brennan, Darren D.; Fenlon, Helen M.; Moss, Alan C.; MacMathuna, Padraic

    2004-01-01

    Patients at increased risk of colon cancer require strict colon surveillance. Our objective was to establish the efficacy of 2D axial CT colonography as a surveillance test when performed in routine clinical practice. Eighty-two patients at increased risk of colon cancer underwent CT colonography followed by conventional colonoscopy on the same morning. CT colonography studies were performed on a four-ring multidetector CT scanner (100 mAs, 120 kVp, 4 x 2.5 collimation) and were interpreted by two radiologists using 2D axial images only. Results were correlated with findings at colonoscopy. Note was made of subsequent histology reports from polypectomy specimens. A total of 52 polyps were detected at colonoscopy. Using 2D axial images alone, with no recourse to 2D multiplanar or 3D views, the sensitivity of CT colonography was 100, 33 and 19% for polyps larger than 9, 6-9 and smaller than 6 mm, respectively. Per-patient specificities were 98.8, 96 and 81.5%, respectively. Twenty-nine percent of polyps smaller than 1 cm were adenomatous and there were no histological features of severe dysplasia. CT colonography is a useful colon surveillance tool for patients at increased risk of colon cancer. It has a high specificity for identifying patients who should proceed to colonoscopy and polypectomy, while allowing further colon examination to be deferred in patients with normal studies. Using 2D axial images only, CT colonography can be performed as part of the daily CT workload, with a very low rate of referral for unnecessary colonoscopy. (orig.)

  11. Overview of the Axial Field Spectrometer in the ISR tunnel

    CERN Multimedia

    1980-01-01

    A view of the Axial Field Spectrometer – the last large experiment at the ISR. The horizontal top and vertical outer arrays of the uranium-scintillator hadron calorimeter are clear to be seen, with the blue cylindrical pole piece of the magnet just visible. The pipes that are visible in front of the pole piece are cryogenic feed pipes for the superconducting low-beta quadrupoles.

  12. The nucleon axial charge in full lattice QCD

    International Nuclear Information System (INIS)

    Edwards, R.G.; Richards, D.G.; Fleming, G.T.; Haegler, P.; Technische Univ. Muenchen, Garching; Negele, J.W.; Pochinsky, A.V.; Orginos, K.; College of William and Mary, Williamsburg, VA; Renner, D.B.; Schroers, W.

    2005-10-01

    The nucleon axial charge is calculated as a function of the pion mass in full QCD. Using domain wall valence quarks and improved staggered sea quarks, we present the first calculation with pion masses as light as 354 MeV and volumes as large as (3.5 fm) 3 . We show that finite volume effects are small for our volumes and that a constrained fit based on finite volume chiral perturbation theory agrees with experiment within 7% statistical errors. (orig.)

  13. Axial anomaly and mixing: From real to highly virtual photons

    International Nuclear Information System (INIS)

    Klopot, Yaroslav N.; Teryaev, Oleg V.; Oganesian, Armen G.

    2011-01-01

    The relation for transition form factors of η and η ' is obtained by combining the exact nonperturbative QCD sum rule, following from the dispersive representation of axial anomaly, and quark-hadron duality. It is valid at all virtual photon momenta and allows one to express the transition form factors entirely in terms of meson decay constants. This relation is in a good agreement with experimental data.

  14. Channel of Axial Injection of DC-60 Cyclotron

    CERN Document Server

    Gikal, B N; Bogomolov, S L; Borisenko, A N; Borisov, O N; Gulbekyan, G G; Ivanenko, I A; Kalagin, I V; Kazacha, V I; Kazarinov, N Yu; Khabarov, M V; Lysukhin, S N; Melnikov, V N; Paschenko, S V; Tikhomirov, A V

    2006-01-01

    The design study and realization of the axial injection beam line of DC-60 cyclotron constructed at the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research are given. The channel allows one to transport and to inject into the cyclotron ions with mass-to-charge ratio $A/Z$ being within interval A/Z=6-12 and kinetic energy up to 17 $Z/A$ keV/m.u.

  15. Moving blade for steam turbines with axial flow

    International Nuclear Information System (INIS)

    Raschke, K.; Wehle, G.

    1976-01-01

    The invention concerns the improvement of the production of moving blades for steam turbines with axial flow, especially of multi-blades produced by welding of the top plates. It is proposed to weld the top plates before the moving blades are fitted into the rotor. Welding is this made much easier and can be carried out under protective gas and with better results. (UWI) [de

  16. Static axially symmetric gravitational fields with shell sources

    International Nuclear Information System (INIS)

    McCrea, J.D.

    1976-01-01

    Israel's (Israel, W., 1966, Nuovo Cim., vol.44, 1-14) method for treating surface layers in general relativity is applied to construct shell sources for exterior static axially symmetric gravitational fields. Consideration is restricted to cases in which the 3-cylinder representing the history of the shell is an equipotential surface of the exterior field and consequently the space-time inside this 3-cylinder is flat. (author)

  17. Radiation of electrons in an electromagnetic axial trap

    International Nuclear Information System (INIS)

    Toropova, A.I.

    1998-01-01

    The version of a trap. wherein particles move in a homogeneous constant magnetic field and electrostatic field, formed by two equipotential planes and rotation axial surface, is proposed. The solution of canonic equations is found. It is shown that interaction of electrons with the radiation field leads to damping parametric resonance. The trap model, accounting for the finite conductivity of the resonator walls and losses by collisions with gas, is studied

  18. Investigation on a procedure for optimal axial depth of cut accuracy in micromilling

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2005-01-01

    On the basis of a previously developed procedure for control of axial depth of cut in high accuracy micromilling operations, this paper presents an investigation on the estimation of the uncertainty of the set axial depth of cut.......On the basis of a previously developed procedure for control of axial depth of cut in high accuracy micromilling operations, this paper presents an investigation on the estimation of the uncertainty of the set axial depth of cut....

  19. Fundamental metallurgical aspects of axial splitting in zircaloy cladding

    International Nuclear Information System (INIS)

    Chung, H. M.

    2000-01-01

    Fundamental metallurgical aspects of axial splitting in irradiated Zircaloy cladding have been investigated by microstructural characterization and analytical modeling, with emphasis on application of the results to understand high-burnup fuel failure under RIA situations. Optical microscopy, SEM, and TEM were conducted on BWR and PWR fuel cladding tubes that were irradiated to fluence levels of 3.3 x 10 21 n cm -2 to 5.9 x 10 21 n cm -2 (E > 1 MeV) and tested in hot cell at 292--325 C in Ar. The morphology, distribution, and habit planes of macroscopic and microscopic hydrides in as-irradiated and posttest cladding were determined by stereo-TEM. The type and magnitude of the residual stress produced in association with oxide-layer growth and dense hydride precipitation, and several synergistic factors that strongly influence axial-splitting behavior were analyzed. The results of the microstructural characterization and stress analyses were then correlated with axial-splitting behavior of high-burnup PWR cladding reported for simulated-RIA conditions. The effects of key test procedures and their implications for the interpretation of RIA test results are discussed

  20. Accretion mode of oceanic ridges governed by axial mechanical strength

    Science.gov (United States)

    Sibrant, A. L. R.; Mittelstaedt, E.; Davaille, A.; Pauchard, L.; Aubertin, A.; Auffray, L.; Pidoux, R.

    2018-04-01

    Oceanic spreading ridges exhibit structural changes as a function of spreading rate, mantle temperature and the balance of tectonic and magmatic accretion. The role that these or other processes have in governing the overall shape of oceanic ridges is unclear. Here, we use laboratory experiments to simulate ridge spreading in colloidal aqueous dispersions whose rheology evolves from purely viscous to elastic and brittle when placed in contact with a saline water solution. We find that ridge shape becomes increasingly linear with spreading rate until reaching a minimum tortuosity. This behaviour is predicted by the axial failure parameter ΠF, a dimensionless number describing the balance of brittle and plastic failure of axial lithosphere. Slow-spreading, fault-dominated and fast-spreading, fluid intrusion-dominated ridges on Earth and in the laboratory are separated by the same critical ΠF value, suggesting that the axial failure mode governs ridge geometry. Values of ΠF can also be calculated for different mantle temperatures and applied to other planets or the early Earth. For higher mantle temperatures during the Archaean, our results preclude the predicted formation of large tectonic plates at high spreading velocity.

  1. Taming axial dispersion in hydrodynamic chromatography columns through wall patterning

    Science.gov (United States)

    Adrover, Alessandra; Cerbelli, Stefano; Giona, Massimiliano

    2018-04-01

    A well-known limitation of hydrodynamic chromatography arises from the synergistic interaction between transverse diffusion and streamwise convection, which enhances axial dispersion through the Taylor-Aris mechanism. We show that a periodic sequence of slip/no-slip conditions at the channel walls (e.g., representing wall indentations hosting stable air pockets) can significantly reduce axial dispersion, thus enhancing separation performance. The theoretical/numerical analysis is based on a generalization of Brenner's macrotransport approach to solute transport, here modified to account for the finite-size of the suspended particles. The most effective dispersion-taming outcome is observed when the alternating sequence of slip/no-slip conditions yields non-vanishing cross-sectional flow components. The combination of these components with the hindering interaction between the channel boundaries and the finite-sized particles gives rise to a non-trivial solution of Brenner's problem on the unit periodic cell, where the cross-sectional particle number density departs from the spatially homogeneous condition. In turn, this effect impacts upon the solution of the so-called b-field defining the large-scale dispersion tensor, with an overall decremental effect on the axial dispersion coefficient and on the Height Equivalent of a Theoretical Plate.

  2. Axial power monitoring uncertainty in the Savannah River Reactors

    International Nuclear Information System (INIS)

    Losey, D.C.; Revolinski, S.M.

    1990-01-01

    The results of this analysis quantified the uncertainty associated with monitoring the Axial Power Shape (APS) in the Savannah River Reactors. Thermocouples at each assembly flow exit map the radial power distribution and are the primary means of monitoring power in these reactors. The remaining uncertainty in power monitoring is associated with the relative axial power distribution. The APS is monitored by seven sensors that respond to power on each of nine vertical Axial Power Monitor (APM) rods. Computation of the APS uncertainty, for the reactor power limits analysis, started with a large database of APM rod measurements spanning several years of reactor operation. A computer algorithm was used to randomly select a sample of APSs which were input to a code. This code modeled the thermal-hydraulic performance of a single fuel assembly during a design basis Loss-of Coolant Accident. The assembly power limit at Onset of Significant Voiding was computed for each APS. The output was a distribution of expected assembly power limits that was adjusted to account for the biases caused by instrumentation error and by measuring 7 points rather than a continuous APS. Statistical analysis of the final assembly power limit distribution showed that reducing reactor power by approximately 3% was sufficient to account for APS variation. This data confirmed expectations that the assembly exit thermocouples provide all information needed for monitoring core power. The computational analysis results also quantified the contribution to power limits of the various uncertainties such as instrumentation error

  3. Imaging results and TOF studies with axial PET detectors

    CERN Document Server

    Joram, Christian

    2013-01-01

    We have developed a fully operational PET demonstrator setup which allows true 3D reconstruction of the 511 keV photons and therefore leads to practically parallax free images. The AX-PET concept is based on thin 100 mm long scintillation crystals (LYSO), axially oriented and arranged in layers around the held of view. Layers of wavelength shifting plastic strips mounted in between the crystal layers give the axial coordinate. Both crystals and WLS strips are individually read out by G-APD (SiPM) photodetectors. The Fully scalable concept overcomes the dilemma of sensitivity versus spatial resolution which is inherent to classical PET designs. A demonstrator set-up based on two axial modules was exhaustively characterized using point-like sources, phantoms filled with radiotracer and finally rats and a mouse. The results entirely meet the performance expectations ( <2 mm FWHM in all three coordinates over the complete held of view) and also demonstrated the ability to include Compton interactions (inter-cr...

  4. Imaging results and TOF studies with axial PET detectors

    Science.gov (United States)

    Joram, Christian

    2013-12-01

    We have developed a fully operational PET demonstrator setup which allows true 3D reconstruction of the 511 keV photons and therefore leads to practically parallax free images. The AX-PET concept is based on thin 100 mm long scintillation crystals (LYSO), axially oriented and arranged in layers around the field of view. Layers of wavelength shifting plastic strips mounted in between the crystal layers give the axial coordinate. Both crystals and WLS strips are individually read out by G-APD (SiPM) photodetectors. The fully scalable concept overcomes the dilemma of sensitivity versus spatial resolution which is inherent to classical PET designs. A demonstrator set-up based on two axial modules was exhaustively characterized using point-like sources, phantoms filled with radiotracer and finally rats and a mouse. The results entirely meet the performance expectations (PET concept making use of the novel digital SiPM detectors by Philips. After reproducing comparable energy and spatial resolution on a small digital AX-PET set-up with 100 mm long crystals, we demonstrated a coincidence resolving time of about 210 ps FWHM.

  5. Multi technical analysis of wear mechanisms in axial piston pumps

    Science.gov (United States)

    Schuhler, G.; Jourani, A.; Bouvier, S.; Perrochat, J.-M.

    2017-05-01

    Axial piston pumps convert a motor rotation motion into hydraulic or pneumatic power. Their compactness and efficiency of approximately 0.9 make them suitable for actuation applications especially in aeronautics. However, they suffer a limited life due to the wear of their components. In the literature, studies of axial piston pumps deal with contact between its different elements under lubrication conditions. Nevertheless, they are more focused on analytic or numerical approaches. This study consists in an experimental analysis of worn pump components to highlight and understand wear mechanisms. Piston shoes are central components in the axial piston pump since they are involved in three tribological contacts. These three contacts are thereby studied: piston shoes/swashplate, piston shoes/pistons and piston shoes/shoes hold down plate (SHDP). To perform this analysis, helicopter hydraulic pumps after different operating times have been studied. The wear damage mechanisms and wear debris are analysed using SEM observations. 3D surface roughness measurements are then used to characterize worn surfaces. The observations reveal that in the contact between shoes and swashplate, the main wear mechanism is three-body abrasive wear due to coarse carbides removal. Between shoes and pistons, wear occurs in a less severe way and is mainly due to the debris generated in the first contact and conveyed by the lubricating fluid. In the third contact, the debris are also the prime cause of the abrasive wear and the generation of deep craters in the piston shoes.

  6. HTS axial flux induction motor with analytic and FEA modeling

    Energy Technology Data Exchange (ETDEWEB)

    Li, S., E-mail: alexlee.zn@gmail.com; Fan, Y.; Fang, J.; Qin, W.; Lv, G.; Li, J.H.

    2013-11-15

    Highlights: •A high temperature superconductor axial flux induction motor and a novel maglev scheme are presented. •Analytic method and finite element method have been adopted to model the motor and to calculate the force. •Magnetic field distribution in HTS coil is calculated by analytic method. •An effective method to improve the critical current of HTS coil is presented. •AC losses of HTS coils in the HTS axial flux induction motor are estimated and tested. -- Abstract: This paper presents a high-temperature superconductor (HTS) axial-flux induction motor, which can output levitation force and torque simultaneously. In order to analyze the character of the force, analytic method and finite element method are adopted to model the motor. To make sure the HTS can carry sufficiently large current and work well, the magnetic field distribution in HTS coil is calculated. An effective method to improve the critical current of HTS coil is presented. Then, AC losses in HTS windings in the motor are estimated and tested.

  7. A mini axial and a permanent maglev radial heart pump.

    Science.gov (United States)

    Qian, Kun-Xi; Ru, Wei-Min; Wang, Hao; Jing, Teng

    2007-05-31

    The implantability and durability have been for decades the focus of artificial heart R&D. A mini axial and a maglev radial pump have been developed to meet with such requirements.The mini axial pump weighing 27g (incl.5g rotor) has an outer diameter of 21mm and a length of 10mm in its largest point, but can produce a maximal blood flow of 6l/min with 50mmHg pressure increase. Therefore, it is suitable for the patients of 40-60kg body weight. For other patients of 60-80kg or 80-100kg body weight, the mini axial pumps of 23mm and 25mm outer diameter had been developed before, these devices were acknowledged to be the world smallest LVADs by Guinness World Record Center in 2004.The permanent maglev radial pump weighing 150g is a shaft-less centrifugal pump with permanent magnetic bearings developed by the author. It needs no second coil for suspension of the rotor except the motor coil, different from all other maglev pumps developed in USA, Japan, European, etc. Thus no detecting and controlling systems as well as no additional power supply for maglev are necessary. The pump can produce a blood flow up to as large as 10l/min against 100mmHg pressure.An implantable and durable blood pump will be a viable alternative to natural donor heart for transplantation.

  8. Axial temperatures and fuel management models for a HTR system

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, U

    1971-11-12

    In the HTR system, there is a large difference in temperature between different parts of the reactor core. The softer neutron spectrum in the upper colder core regions tends to shift the power productions in the fresh fuel upwards. As uranium 235 depletes and plutonium with its higher cross sections in the lower hot regions is built-up, an axial power flattening takes place. These effects have been studied in detail for a single column in an equilibrium environment. The aim of this paper is to relate these findings to a whole reactor core and to investigate the influence of axial temperatures on the overall performance and in particular, the fuel management scheme chosen for the reference design. A further objective has been to calculate the reactivity requirements for different part load conditions and for various daily and weekly load diagrams. As the xenon cross section changes significantly with temperature these investigations are performed for an equilibrium core with due representation of axial temperature zones.

  9. The New Performance Calculation Method of Fouled Axial Flow Compressor

    Directory of Open Access Journals (Sweden)

    Huadong Yang

    2014-01-01

    Full Text Available Fouling is the most important performance degradation factor, so it is necessary to accurately predict the effect of fouling on engine performance. In the previous research, it is very difficult to accurately model the fouled axial flow compressor. This paper develops a new performance calculation method of fouled multistage axial flow compressor based on experiment result and operating data. For multistage compressor, the whole compressor is decomposed into two sections. The first section includes the first 50% stages which reflect the fouling level, and the second section includes the last 50% stages which are viewed as the clean stage because of less deposits. In this model, the performance of the first section is obtained by combining scaling law method and linear progression model with traditional stage stacking method; simultaneously ambient conditions and engine configurations are considered. On the other hand, the performance of the second section is calculated by averaged infinitesimal stage method which is based on Reynolds’ law of similarity. Finally, the model is successfully applied to predict the 8-stage axial flow compressor and 16-stage LM2500-30 compressor. The change of thermodynamic parameters such as pressure ratio, efficiency with the operating time, and stage number is analyzed in detail.

  10. HTS axial flux induction motor with analytic and FEA modeling

    International Nuclear Information System (INIS)

    Li, S.; Fan, Y.; Fang, J.; Qin, W.; Lv, G.; Li, J.H.

    2013-01-01

    Highlights: •A high temperature superconductor axial flux induction motor and a novel maglev scheme are presented. •Analytic method and finite element method have been adopted to model the motor and to calculate the force. •Magnetic field distribution in HTS coil is calculated by analytic method. •An effective method to improve the critical current of HTS coil is presented. •AC losses of HTS coils in the HTS axial flux induction motor are estimated and tested. -- Abstract: This paper presents a high-temperature superconductor (HTS) axial-flux induction motor, which can output levitation force and torque simultaneously. In order to analyze the character of the force, analytic method and finite element method are adopted to model the motor. To make sure the HTS can carry sufficiently large current and work well, the magnetic field distribution in HTS coil is calculated. An effective method to improve the critical current of HTS coil is presented. Then, AC losses in HTS windings in the motor are estimated and tested

  11. Axial and Centrifugal Compressor Mean Line Flow Analysis Method

    Science.gov (United States)

    Veres, Joseph P.

    2009-01-01

    This paper describes a method to estimate key aerodynamic parameters of single and multistage axial and centrifugal compressors. This mean-line compressor code COMDES provides the capability of sizing single and multistage compressors quickly during the conceptual design process. Based on the compressible fluid flow equations and the Euler equation, the code can estimate rotor inlet and exit blade angles when run in the design mode. The design point rotor efficiency and stator losses are inputs to the code, and are modeled at off design. When run in the off-design analysis mode, it can be used to generate performance maps based on simple models for losses due to rotor incidence and inlet guide vane reset angle. The code can provide an improved understanding of basic aerodynamic parameters such as diffusion factor, loading levels and incidence, when matching multistage compressor blade rows at design and at part-speed operation. Rotor loading levels and relative velocity ratio are correlated to the onset of compressor surge. NASA Stage 37 and the three-stage NASA 74-A axial compressors were analyzed and the results compared to test data. The code has been used to generate the performance map for the NASA 76-B three-stage axial compressor featuring variable geometry. The compressor stages were aerodynamically matched at off-design speeds by adjusting the variable inlet guide vane and variable stator geometry angles to control the rotor diffusion factor and incidence angles.

  12. Notchless is required for axial skeleton formation in mice.

    Directory of Open Access Journals (Sweden)

    Sarah Beck-Cormier

    Full Text Available Maintenance of cell survival is essential for proper embryonic development. In the mouse, Notchless homolog 1 (Drosophila (Nle1 is instrumental for survival of cells of the inner cell mass upon implantation. Here, we analyze the function of Nle1 after implantation using the Meox2(tm1(creSor mouse that expresses the Cre recombinase specifically in the epiblast at E5.5. First, we find that NLE1 function is required in epiblast cells, as Nle1-deficient cells are rapidly eliminated. In this report, we also show that the Meox2(Cre transgene is active in specific tissues during organogenesis. In particular, we detect high Cre expression in the vertebral column, ribs, limbs and tailbud. We took advantage of this dynamic expression profile to analyze the effects of inducing mosaic deletion of Nle1 in the embryo. We show that Nle1 deletion in this context, results in severe developmental anomalies leading to lethality at birth. Mutant embryos display multiple developmental defects in particular during axial skeletal formation. We also provide evidence that axial defects are due to an increase in apoptotic cell death in the somite at E9.5. These data demonstrate an essential role for Nle1 during organogenesis and in particular during axial development.

  13. Notchless is required for axial skeleton formation in mice.

    Science.gov (United States)

    Beck-Cormier, Sarah; Escande, Marie; Souilhol, Céline; Vandormael-Pournin, Sandrine; Sourice, Sophie; Pilet, Paul; Babinet, Charles; Cohen-Tannoudji, Michel

    2014-01-01

    Maintenance of cell survival is essential for proper embryonic development. In the mouse, Notchless homolog 1 (Drosophila) (Nle1) is instrumental for survival of cells of the inner cell mass upon implantation. Here, we analyze the function of Nle1 after implantation using the Meox2(tm1(cre)Sor) mouse that expresses the Cre recombinase specifically in the epiblast at E5.5. First, we find that NLE1 function is required in epiblast cells, as Nle1-deficient cells are rapidly eliminated. In this report, we also show that the Meox2(Cre) transgene is active in specific tissues during organogenesis. In particular, we detect high Cre expression in the vertebral column, ribs, limbs and tailbud. We took advantage of this dynamic expression profile to analyze the effects of inducing mosaic deletion of Nle1 in the embryo. We show that Nle1 deletion in this context, results in severe developmental anomalies leading to lethality at birth. Mutant embryos display multiple developmental defects in particular during axial skeletal formation. We also provide evidence that axial defects are due to an increase in apoptotic cell death in the somite at E9.5. These data demonstrate an essential role for Nle1 during organogenesis and in particular during axial development.

  14. Observed Incidence of Uveitis Following Certolizumab Pegol Treatment in Patients With Axial Spondyloarthritis

    NARCIS (Netherlands)

    Rudwaleit, M.; Rosenbaum, J. T.; Landewé, R.; Marzo-Ortega, H.; Sieper, J.; van der Heijde, D.; Davies, O.; Bartz, H.; Hoepken, B.; Nurminen, T.; Deodhar, A.

    2016-01-01

    Axial spondyloarthritis (axial SpA) is characterized by inflammation of the spine and sacroiliac joints and can also affect extraarticular sites, with the most common manifestation being uveitis. Here we report the incidence of uveitis flares in axial SpA patients from the RAPID-axSpA trial,

  15. Experimental Study of Axially Tension Cold Formed Steel Channel Members

    Science.gov (United States)

    Apriani, Widya; Lubis, Fadrizal; Angraini, Muthia

    2017-12-01

    Experimental testing is commonly used as one of the steps to determine the cause of the collapse of a building structure. The collapse of structures can be due to low quality materials. Although material samples have passed laboratory tests and the existing technical specifications have been met but there may be undetected defects and known material after failure. In this paper will be presented Experimental Testing of Axially Tension Cold Formed Steel Channel Members to determine the cause of the collapse of a building roof truss x in Pekanbaru. Test of tensile strength material cold formed channel sections was performed to obtain the main characteristics of Cold Formed steel material, namely ultimate tensile strength loads that can be held by members and the yield stress possessed by channel sections used in construction. Analysis of axially tension cold formed steel channel section presents in this paper was conducted through experimental study based on specificationsAnnualBook of ASTM Standards: Metal Test methods and Analitical Procedures, Section 3 (1991). The result of capacity loads experimental test was compared with design based on SNI 03-7971-2013standard of Indonesia for the design of cold formed steel structural members. The results of the yield stress of the material will be seen against the minimum allowable allowable stress range. After the test, the percentace of ultimate axial tension capacity theory has a result that is 16.46% larger than the ultimate axial tension capacity experimental. When compared with the load that must be borne 5.673 kN/m it can be concluded that 2 specimens do not meet. Yield stress of member has fulfilled requirement that wass bigger than 550 MPa. Based on the curve obtained ultimate axial tension capacity theory, results greater than experimental. The greatest voltage value (fu) is achieved under the same conditions as its yield stress. For this specimen with a melting voltage value fy = 571.5068 MPa has fulfilled the

  16. Design and axial optimization of nuclear fuel for BWR reactors

    International Nuclear Information System (INIS)

    Garcia V, M.A.

    2006-01-01

    In the present thesis, the modifications made to the axial optimization system based on Tabu Search (BT) for the axial design of BWR fuel type are presented, developed previously in the Nuclear Engineering Group of the UNAM Engineering Faculty. With the modifications what is mainly looked is to consider the particular characteristics of the mechanical design of the GE12 fuel type, used at the moment in the Laguna Verde Nucleo electric Central (CNLV) and that it considers the fuel bars of partial longitude. The information obtained in this thesis will allow to plan nuclear fuel reloads with the best conditions to operate in a certain cycle guaranteeing a better yield and use in the fuel burnt, additionally people in charge in the reload planning will be favored with the changes carried out to the system for the design and axial optimization of nuclear fuel, which facilitate their handling and it reduces their execution time. This thesis this developed in five chapters that are understood in the following way in general: Chapter 1: It approaches the basic concepts of the nuclear energy, it describes the physical and chemical composition of the atoms as well as that of the uranium isotopes, the handling of the uranium isotope by means of the nuclear fission until arriving to the operation of the nuclear reactors. Chapter 2: The nuclear fuel cycle is described, the methods for its extraction, its conversion and its enrichment to arrive to the stages of the nuclear fuel management used in the reactors are described. Beginning by the radial design, the axial design and the core design of the nuclear reactor related with the fuel assemblies design. Chapter 3: the optimization methods of nuclear fuel previously used are exposed among those that are: the genetic algorithms method, the search methods based on heuristic rules and the application of the tabu search method, which was used for the development of this thesis. Chapter 4: In this part the used methodology to the

  17. Experimental Studies on Strength Behaviour of Notched Glass/Epoxy Laminated Composites under Uni-axial and Bi-axial Loading

    Science.gov (United States)

    Guptha, V. L. Jagannatha; Sharma, Ramesh S.

    2017-11-01

    The use of FRP composite materials in aerospace, aviation, marine, automotive and civil engineering industry has increased rapidly in recent years due to their high specific strength and stiffness properties. The structural members contrived from such composite materials are generally subjected to complex loading conditions and leads to multi-axial stress conditions at critical surface localities. Presence of notches, much required for joining process of composites, makes it further significant. The current practice of using uni-axial test data alone to validate proposed material models is inadequate leading to evaluation and consideration of bi-axial test data. In order to correlate the bi-axial strengths with the uni-axial strengths of GFRP composite laminates in the presence of a circular notch, bi-axial tests using four servo-hydraulic actuators with four load cells were carried out. To determine the in-plane strength parameters, bi-axial cruciform test specimen model was considered. Three different fibre orientations, namely, 0°, 45°, and 90° are considered with a central circular notch of 10 mm diameter in the present investigation. From the results obtained, it is observed that there is a reduction in strength of 5.36, 2.41 and 13.92% in 0°, 45°, and 90° fibre orientation, respectively, under bi-axial loading condition as compared to that of uni-axial loading in laminated composite.

  18. Santiago, una ciudad con temor

    Directory of Open Access Journals (Sweden)

    Enrique Oviedo S.

    1999-04-01

    Full Text Available El objetivo general de este artículo es evaluar los efectos de la inseguridad ciudadana en el uso del espacio público. Dicha evaluación exige analizar dos relaciones que se establecen en el ámbito de la violencia: la relación entre victimización y percepción de inseguridad; y la que se establece entre actitudes sociales y resolución pacífica de conflictos nacionales. Para ello, se analizaron las variables victimización, percepción de inseguridad, uso del espacio físico, actitudes hacia el sistema institucional político y social y hacia la resolución de conflictos nacionales, y las posibles relaciones entre ellas. Los datos para realizar el estudio se obtuvieron por medio de una encuesta que se llevó a cabo con 1 200 personas de 18 y 70 años de edad residentes en la ciudad de Santiago. Los resultados indican que Santiago es una ciudad de habitantes con temor y que el aumento de la percepción de inseguridad de sus habitantes contrasta con el hecho de que las tasas de victimización se hayan mantenido, más o menos, constantes en los años que precedieron a la encuesta. El temor se relaciona con el abandono del espacio público físico y sociopolítico, así como con el refugio en los espacios y la vida privados. La actitud de resolver los conflictos por medios no pacíficos es frecuente y se asocia en mayor medida con la inseguridad, la actitud negativa hacia la democracia y la falta de expectativas sobre el futuro del país. Los resultados de este estudio respaldan la idea de que para superar el temor la gente tiende a adaptarse a la realidad adoptando una postura conformista, homogeneizando las creencias y los comportamientos, y sobreestimando la fuerza como medio para resolver las diferencias.

  19. Santiago, una ciudad con temor

    Directory of Open Access Journals (Sweden)

    Oviedo S. Enrique

    1999-01-01

    Full Text Available El objetivo general de este artículo es evaluar los efectos de la inseguridad ciudadana en el uso del espacio público. Dicha evaluación exige analizar dos relaciones que se establecen en el ámbito de la violencia: la relación entre victimización y percepción de inseguridad; y la que se establece entre actitudes sociales y resolución pacífica de conflictos nacionales. Para ello, se analizaron las variables victimización, percepción de inseguridad, uso del espacio físico, actitudes hacia el sistema institucional político y social y hacia la resolución de conflictos nacionales, y las posibles relaciones entre ellas. Los datos para realizar el estudio se obtuvieron por medio de una encuesta que se llevó a cabo con 1 200 personas de 18 y 70 años de edad residentes en la ciudad de Santiago. Los resultados indican que Santiago es una ciudad de habitantes con temor y que el aumento de la percepción de inseguridad de sus habitantes contrasta con el hecho de que las tasas de victimización se hayan mantenido, más o menos, constantes en los años que precedieron a la encuesta. El temor se relaciona con el abandono del espacio público físico y sociopolítico, así como con el refugio en los espacios y la vida privados. La actitud de resolver los conflictos por medios no pacíficos es frecuente y se asocia en mayor medida con la inseguridad, la actitud negativa hacia la democracia y la falta de expectativas sobre el futuro del país. Los resultados de este estudio respaldan la idea de que para superar el temor la gente tiende a adaptarse a la realidad adoptando una postura conformista, homogeneizando las creencias y los comportamientos, y sobreestimando la fuerza como medio para resolver las diferencias.

  20. Research on axial thrust of the waterjet pump based on CFD under cavitation conditions

    Science.gov (United States)

    Shen, Z. H.; Pan, Z. Y.

    2015-01-01

    Based on RANS equations, performance of a contra-rotating axial-flow waterjet pump without hydrodynamic cavitation state had been obtained combined with shear stress transport turbulence model. Its cavitation hydrodynamic performance was calculated and analysed with mixture homogeneous flow cavitation model based on Rayleigh-Plesset equations. The results shows that the cavitation causes axial thrust of waterjet pump to drop. Furthermore, axial thrust and head cavitation characteristic curve is similar. However, the drop point of the axial thrust is postponed by 5.1% comparing with one of head, and the critical point of the axial thrust is postponed by 2.6%.

  1. Research on axial thrust of the waterjet pump based on CFD under cavitation conditions

    International Nuclear Information System (INIS)

    Shen, Z H; Pan, Z Y

    2015-01-01

    Based on RANS equations, performance of a contra-rotating axial-flow waterjet pump without hydrodynamic cavitation state had been obtained combined with shear stress transport turbulence model. Its cavitation hydrodynamic performance was calculated and analysed with mixture homogeneous flow cavitation model based on Rayleigh-Plesset equations. The results shows that the cavitation causes axial thrust of waterjet pump to drop. Furthermore, axial thrust and head cavitation characteristic curve is similar. However, the drop point of the axial thrust is postponed by 5.1% comparing with one of head, and the critical point of the axial thrust is postponed by 2.6%

  2. pacientes con insuficiencia renal terminal

    Directory of Open Access Journals (Sweden)

    Karen Herrera Herrera

    2011-01-01

    Full Text Available La presente investigación fundamenta en la clínica psicoanalítica el estudio de dos casos de tres personas diagnosticadas con IRT que reciben tratamiento de hemodiálisis, en razón a que dadas las características y el aumento de los reportes que se presentan, ya esto se considera un problema de salud pública. El objetivo principal es describir las características dinámicas del proceso de duelo en pacientes con IRT en un centro de terapia renal de la ciudad de Cartagena. El procedimiento metodológico empleó un diseño de tipo cualitativo; la investigación se desarrolló con un diseño clínico mediante el estudio de casos, y fundamentada en la hermenéutica psicoanalítica. Todo esto respaldado en la historia clínica, la entrevista semiestructurada individual y familiar, los test proyectivos, test del dibujo de la figura humana Machover y TAT de Murray, para la debida integración de los análisis. Se concluye que predominan funciones fallidas de los progenitores y que son individuos provenientes de familias psicosomáticas, que utilizan la enfermedad para obtener un beneficio secundario.

  3. con bajo peso al nacer

    Directory of Open Access Journals (Sweden)

    Adriana Mora Antó

    2005-01-01

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

  4. Probing Framework-Restricted Metal Axial Ligation and Spin State Patterns in a Post-Synthetically Reduced Iron-Porphyrin-Based Metal–Organic Framework

    Energy Technology Data Exchange (ETDEWEB)

    Kucheryavy, Pavel; Lahanas, Nicole; Velasco, Ever; Sun, Cheng-Jun; Lockard, Jenny V.

    2016-04-07

    An iron porphyrin-based metal organic framework, PCN-222(Fe) is investigated upon post-synthetic reduction with piperidine. Fe K-edge X-ray absorption and Kβ mainline emission spectroscopy measurements reveal the local coor-dination geometry, oxidation and spin state changes experi-enced by the Fe sites upon reaction with this axially coordi-nating reducing agent. Analysis and fitting of these data con-firm the binding pattern predicted by a space filling model of the structurally constrained pore environments. These results are further support by UV-vis diffuse reflectance, IR and Raman spectroscopy data.

  5. Neumonía organizada como forma de presentación de una artritis reumatoide

    Directory of Open Access Journals (Sweden)

    Verónica Temprado

    2015-09-01

    Full Text Available La neumonía organizada (NO es una enfermedad pulmonar intersticial que puede asociarse a la artritis reumatoide (AR. Normalmente, la afectación pulmonar se presenta tras años de evolución de las manifestaciones articulares, siendo menos frecuente la aparición concomitante de ambos procesos. Se expone el caso de una paciente de 79 años que presentó tos y disnea junto con inflamación articular y criterios serológicos de AR. La radiografía de tórax (Rx y la tomografía axial computarizada (TAC objetivaron un infiltrado alveolar bibasal con broncograma aéreo. Las manifestaciones pulmonares de una NO motivaron el ingreso y fueron la clave para el diagnóstico final de una AR. La paciente recibió tratamiento corticoideo con excelente respuesta.

  6. Renormalization of the axial-vector current in QCD

    International Nuclear Information System (INIS)

    Chiu, C.B.; Pasupathy, J.; Wilson, S.L.

    1985-01-01

    Following the method of Ioffe and Smilga, the propagation of the baryon current in an external constant axial-vector field is considered. The close similarity of the operator-product expansion with and without an external field is shown to arise from the chiral invariance of gauge interactions in perturbation theory. Several sum rules corresponding to various invariants both for the nucleon and the hyperons are derived. The analysis of the sum rules is carried out by two independent methods, one called the ratio method and the other called the continuum method, paying special attention to the nondiagonal transitions induced by the external field between the ground state and excited states. Up to operators of dimension six, two new external-field-induced vacuum expectation values enter the calculations. Previous work determining these expectation values from PCAC (partial conservation of axial-vector current) are utilized. Our determination from the sum rules of the nucleon axial-vector renormalization constant G/sub A/, as well as the Cabibbo coupling constants in the SU 3 -symmetric limit (m/sub s/ = 0), is in reasonable accord with the experimental values. Uncertainties in the analysis are pointed out. The case of broken flavor SU 3 symmetry is also considered. While in the ratio method, the results are stable for variation of the fiducial interval of the Borel mass parameter over which the left-hand side and the right-hand side of the sum rules are matched, in the continuum method the results are less stable. Another set of sum rules determines the value of the linear combination 7F-5D to be roughly-equal0, or D/(F+D)roughly-equal(7/12). .AE

  7. Predictors of Persistent Axial Neck Pain After Cervical Laminoplasty.

    Science.gov (United States)

    Kimura, Atsushi; Shiraishi, Yasuyuki; Inoue, Hirokazu; Endo, Teruaki; Takeshita, Katsushi

    2018-01-01

    Retrospective analysis of prospective data. The aim of this study was to reveal baseline predictors of persistent postlaminoplasty neck pain. Axial neck pain is one of the most common complications after cervical laminoplasty; however, baseline predictors of persistent postlaminoplasty neck pain are unclear. We analyzed data from 156 patients who completed a 2-year follow-up after double-door laminoplasty for degenerative cervical myelopathy. Patients rated the average intensity of axial neck pain in the last month using an 11-point numerical rating scale preoperatively and at the 2-year follow-up. The dependent variable was the presence of moderate-to-severe neck pain (numerical rating scale ≥4) at the 2-year follow-up. The independent variables included patient characteristics, baseline radiological parameters, surgical variables, baseline axial neck pain intensity, and baseline functions, which were measured by the Japanese Orthopaedic Association score and the Short Form-36 survey (SF-36). Logistic regression analysis was performed to identify independent predictors of moderate-to-severe neck pain after laminoplasty. At the 2-year follow-up, 51 patients (32%) had moderate-to-severe neck pain, and 106 patients (68%) had no or mild pain. Univariate analysis revealed that the ratio of cervical anterolisthesis, ratio of current smoking, baseline neck pain intensity, and baseline SF-36 Mental Component Summary differed significantly between the groups. Multivariate logistic regression analysis showed that independent predictors of moderate-to-severe neck pain at the 2-year follow-up include the presence of anterolisthesis, current smoking, moderate-to-severe baseline neck pain, and lower SF-36 Mental Component Summary. The presence of anterolisthesis and moderate-to-severe baseline neck pain were also associated with significantly poorer physical function after surgery. The presence of anterolisthesis was associated not only with the highest odds ratio of

  8. Test Procedure for Axially Loaded Piles in Sand

    DEFF Research Database (Denmark)

    Thomassen, Kristina

    The test procedure described in the following is used when examining the effects of static or cyclic loading on the skin friction of an axially loaded pile in dense sand. The pile specimen is only loaded in tension to avoid any contribution from the base resistance. The pile dimensions are chosen...... to resemble full scale dimension of piles used in offshore pile foundations today. In this report is given a detailed description of the soil preparation and pile installation procedures as well data acquisition methods....

  9. Bone mineral density in patients with early axial spondyloarthritis

    Directory of Open Access Journals (Sweden)

    E. E. Gubar

    2015-01-01

    Full Text Available Objective: to study bone mineral density (BMD of the lumbar spine (LS and femoral neck (FN in patients with early axial spondyloarthritis (SpA and to reveal its association with inflammatory disease activity.Subjects and methods. Seventy-three patients aged 18–45 years with inflammatory back pain lasting at least 3 months and not more than 5 years were examined. Axial SpA was diagnosed according to the 2009 ASAS criteria. BASDAI and ASDAS C-reactive protein (CRP values were used to estimate disease activity; BASFI was employed to evaluate functional status. The examination encompassed determination of HLA-B27, X-ray of the pelvis and LS, magnetic resonance imaging (MRI of sacroiliac joints, LS, and hip joints (in the presence of clinical signs of their injuries, densitometry of LS (LI-IV and FN. By taking into account the young age of patients, the Z-score was applied to measure BMD. The latter is considered lower if the Z-score is 1–2 standard deviations (SD in at least one of the segments under study.Results. The median Z-score was -0.7 (-1.3; -0.3 SD for FN and 0.9 (-1.6; -0.5 SD for LS. Reduced BMD in at least one of the segments under study was detected in 13 (17.8% patients: that in LS and FN in 11 (15.1% and 5 (6.8% patients, respectively. Lower BMD was observed in two segments in 3 (4.1% patients. No association was found between lower BMD and age, gender, disease activity (BASDAI, ASDAS, and laboratory inflammatory markers (erythrocyte sedimentation rate (ESR and CRP. A relationship was established between inflammatory changes according to the data of MRI of LS (MRI spondylitis and reduced BMD in the same segment. MRI spondylitis was detected in 8 patients. Five and 3 patients with spondylitis of LS were found to have lower and normal BMD in this segment, respectively. Six out of 65 patients without MRI spondylitis in LS had its reduced BMD and the remaining (n=59 patients had its normal BMD (p=0.0014.Conclusion. There was an

  10. Axial gap formation in P.W.R. fuel pins

    International Nuclear Information System (INIS)

    Roberts, G.; Jones, K.W.

    1978-07-01

    The potential mechanisms of axial gap formation in PWR fuel pins are examined analytically and also using evidence from post-irradiation examination (p.i.e.) investigation. It is concluded that fuel and cladding cannot remain in contact during densification and so the settling of of the fuel stack, which forms the gaps, must be prevented by such things as asperities in the cladding, fuel chips or tilted pellets. Examples from the p.i.e. examination programme are used to support this conclusion. (author)

  11. Momentum distribution at great depths when electron axial channeling

    International Nuclear Information System (INIS)

    Khokonov, M.Kh.; Tuguz, F.K.

    1989-01-01

    The electron distribution in momenta during axial channeling in thick monocrystals in great depths is estimated. The estimate was carried out with respect to the fact that due to diffusion the angular momentum of the electron can change only in a limited region of phase space and that multiple scattering only takes place on thermal oscillations of nuclei of the crystal lattice. It is shown that in thick monocrystals the distribution in momenta can be considered uniform on the greater part of the way of channeled electrons which can simplity the qualitative consideration of spectral-angular characteristics forming during this radiation

  12. Evaluation of axial fission gas transport in power ramping experiments

    International Nuclear Information System (INIS)

    Kinoshita, Motoyasu

    1986-01-01

    The LINUS code calculates advective and diffusional transport of fission gas towards an upper plenum through the pellet-cladding gap. The basic equations were modified for analyzing a multi-component gas mixture in the gap and also for dealing with opening and/or closing of the gap, which induces additional axial gas flow. Analysis of the Petten ramp experiment shows that helium pressurization is effective in suppressing an ascending rate of fission gas concentration. After the maximum concentration is achieved through power ramping, the gas concentration could be described by a steady state analytical solution which does not depend on the filling gas pressure. (author)

  13. Axial Permanent Magnet Generator for Wearable Energy Harvesting

    DEFF Research Database (Denmark)

    Högberg, Stig; Sødahl, Jakob Wagner; Mijatovic, Nenad

    2016-01-01

    An increasing demand for battery-free electronics is evident by the rapid increase of wearable devices, and the design of wearable energy harvesters follows accordingly. An axial permanent magnet generator was designed to harvest energy from human body motion and supplying it to a wearable......W, respectively) with an iron yoke is subject to losses that exceed the realistic input power, and was therefore deemed infeasible. A generator without the iron yoke was concluded to perform well as a wearable energy harvester. An experimental investigation of a prototype revealed an output power of almost 1 m...

  14. Time Dependent and Steady Uni-axial Elongational Viscosity

    DEFF Research Database (Denmark)

    Nielsen, Jens K.; Rasmussen, Henrik Koblitz; Hassager, Ole

    2005-01-01

    Here we present measurements of transient and steady uni-axial elongational viscosity, using the Filament Stretching Rheometer1 or FSR1 (see Fig. 1) of the following melts: Four narrow MMD polystyrene (PS) samples with weight-average molar mass Mw in the range of 50k to 390k. Three different bi......-disperse samples, mixed from the narrow MMD PS. Two low-density polyethylene (LDPE) melts (Lupolen 1840D and 3020D). A steady-state viscosity was kept for 1-2.5 Hencky strain units in all measurements....

  15. Axial gravitational waves in FLRW cosmology and memory effects

    Science.gov (United States)

    Kulczycki, Wojciech; Malec, Edward

    2017-09-01

    We show initial data for gravitational axial waves that are twice differentiable but that are not C2. They generate wave pulses that interact with matter in the radiation cosmological era. This forces the radiation matter to rotate. This rotation is permanent—it persists after the passage of the gravitational pulse. The observed inhomogeneities of the cosmic microwave background radiation put a bound onto discontinuities of superhorizon metric perturbations. We explicitly show that a class of smooth initial metrics that are at least C2 gives rise to gravitational wave pulses that do not interact with the background during the radiation epoch.

  16. Axially symmetric reconstruction of plasma emission and absorption coefficients

    International Nuclear Information System (INIS)

    Yang Lixin; Jia Hui; Yang Jiankun; Li Xiujian; Chen Shaorong; Liu Xishun

    2013-01-01

    A layered structure imaging model is developed in order to reconstruct emission coefficients and absorption coefficients simultaneously, in laser fusion core plasma diagnostics. A novel axially symmetric reconstruction method that utilizes the LM (Levenberg-Marquardt) nonlinear least squares minimization algorithm is proposed based on the layered structure. Numerical simulation results demonstrate that the proposed method is sufficiently accurate to reconstruct emission coefficients and absorption coefficients, and when the standard deviation of noise is 0.01, the errors of emission coefficients and absorption coefficients are 0.17, 0.22, respectively. Furthermore, this method could perform much better on reconstruction effect compared with traditional inverse Abel transform algorithms. (authors)

  17. On the equivalence between the Schwinger and axial models

    International Nuclear Information System (INIS)

    Souza Dutra, A. de.

    1991-01-01

    We show the equivalence between the Schwinger and axial models, in the sense that all Green's functions of one model can be obtained from those of the other, and that both models have the same effective Lagrangian density (and so they have equal partition functions associated with them). In particular, we show that the two models have the same chiral anomaly. Finally it is demonstrated that the Schwinger model can keep gauge invariance for an arbitrary mass, dispensing with an additional gauge group integration. (author)

  18. Axial and Radial Gas Holdup in Bubble Column Reactor

    International Nuclear Information System (INIS)

    Wagh, Sameer M.; Ansari, Mohashin E Alan; Kene, Pragati T.

    2014-01-01

    Bubble column reactors are considered the reactor of choice for numerous applications including oxidation, hydrogenation, waste water treatment, and Fischer-Tropsch (FT) synthesis. They are widely used in a variety of industrial applications for carrying out gas-liquid and gas-liquid-solid reactions. In this paper, the computational fluid dynamics (CFD) model is used for predicting the gas holdup and its distribution along radial and axial direction are presented. Gas holdup increases linearly with increase in gas velocity. Gas bubbles tends to concentrate more towards the center of the column and follows a wavy path

  19. Axial dispersion via shear-enhanced diffusion in colloidal suspensions

    KAUST Repository

    Griffiths, I. M.

    2012-03-01

    The familiar example of Taylor dispersion of molecular solutes is extended to describe colloidal suspensions, where the fluctuations that contribute to dispersion arise from hydrodynamic interactions. The generic scheme is illustrated for a suspension of particles in a pressure-driven pipe flow, with a concentration-dependent diffusivity that captures both the shear-induced and Brownian contributions. The effect of the cross-stream migration via shear-induced diffusion is shown to dramatically reduce the axial dispersion predicted by classical Taylor dispersion for a molecular solute. Analytic and numerical solutions are presented that illustrate the effect of the concentration dependence of this nonlinear hydrodynamic mechanism. Copyright © EPLA, 2012.

  20. Characteristics of axial splits in failed BWR fuel rods

    International Nuclear Information System (INIS)

    Lysell, G.; Grigoriev, V.

    2000-01-01

    Secondary cladding defects in BWR fuel sometimes have the shape of long axial cracks or ''splits''. Due to the large open UO 2 surfaces exposed to the water, fission product and UO 2 release to the coolant can reach excessive levels leading to forced shut downs to remove the failed fuel rods. A number of such fuel rods have been examined in Studsvik over the last 10 years. The paper describes observations from the PIE of long cracks and discusses the driving force of the cracks. Details such as starting cracks, macroscopic and microscopic fracture surface appearance, cross sections of cracks, hydride precipitates, location and degree of plastic deformation are given. (author)

  1. Research on a novel axial-flux magnetic-field-modulated brushless double-rotor machine with low axial force and high efficiency

    Directory of Open Access Journals (Sweden)

    Chengde Tong

    2017-05-01

    Full Text Available The axial-flux magnetic-field-modulated brushless double-rotor machine (MFM-BDRM is a possible alternative as a power-split device for hybrid electric vehicles (HEVs. However, the existence of large axial force may lead to assembly problems and rich inner air-gap harmonics could result in high PM loss and low efficiency. This paper proposes a novel axial-flux MFM-BDRM with improved PM rotor structure. 2-D analytical method to predict the magnetic-field distribution of the proposed MFM-BDRM is developed and the design procedure of the proposed machine is illustrated. The impact of key geometrical parameters on axial force and torque is investigated. To evaluate the advantage of the proposed machine, a comparison is made with a conventional one with respect to electromagnetic performances. Results show that the proposed machine is effective in reducing PM eddy loss and axial force by 60% and 35%, respectively.

  2. Numerical simulation of the tip clearance flow in axial turbomachinery; Numerische Simulation der Stroemung im radialen Schaufelspalt axialer Turbomaschinen

    Energy Technology Data Exchange (ETDEWEB)

    Melake, A [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Koeln (Germany). Inst. fuer Antriebstechnik

    1997-12-31

    A computer program has been developed to calculate the three-dimensional tip leakage flow in axial turbomachinery based on the Navier-Stokes equation. This program has been applied to investigate the leakage flow within the gap between the blade fip and casing in an annular compressor cascade. A block structured computational mesh has been used in order to resolve the flow details within the gap and the passage flow. Flow characteristics like boundary layer separation, vortex genesis and interaction of the leakage flow with the secondary flow have been investigated and compared with existing experimental data. By varying the incidence angle and the tip gap the above mentioned flow phenomena have been analysed in an annular compressor cascade and a shrouded propfan rotor respectively. Furthermore, the relationship between the total pressure loss, the axial velocity deficit and the divergence of the tip leakage vortex has been investigated. Streamlines, limited streamlines and the critical point theory have been used extensively to analyse the boundary layer separation on the casing and its roll up to form the tip clearance vortex. (orig.). 59 figs., 3 tabs., 110 refs. [Deutsch] Es wurde ein Rechenprogramm zur Berechnung der dreidimensionalen Spaltstroemung im radialen Schaufelspalt axialer Turbomaschinen auf der Basis der Navier-Stokes`schen Gleichungen entwickelt und angewendet. Um die Stroemung innerhalb des Spaltes und der Schaufelpassage besser aufloesen zu koennen, wurde eine blockstrukturierte Netztopologie verwendet. Stroemungseigenschaften wie Grenzschichtabloesung, Entstehung des Spaltwirbels, Interaktion der Spaltstroemung mit der Sekundaerstroemung werden untersucht und mit vorhandenen experimentellen Daten verglichen. Im weiteren werden durch Variation der Inzidenz und der Spaltweite die oben genannten Stroemungsphaenomene an einem axialen Verdichterringgitter und an einem ummantelten Propfan analysiert. Ferner werden die Korrelation zwischen

  3. Conversando con...Momoyo Kaijima

    OpenAIRE

    Gómez Alonso, Carlos; Álvarez Isidro, Eva; Torres Barchino, Ana

    2017-01-01

    [ES] Momoyo Kaijima es profesora en la Facultad de Arte y Diseño de la Universidad de Tsukuba en la Prefectura de Ibaraki y profesora visitante en la ETH de Zürich, en Royal Academy of Fine Arts, en Rice School of Architecture y en Harvard GSD. A lo largo de los años, Atelier Bow Wow ha colaborado con Krešimir Rogina, arquitecto de Zagreb y socio de la firma internacional Penezic&Rogina, en la realización del Grožnjan International Summer School of Architecture, siendo Rogina el nexo indispen...

  4. Flow measurements using noise signals of axially displaced thermocouples

    Energy Technology Data Exchange (ETDEWEB)

    Kozma, R.; Hoogenboom, J.E. (Interuniversitair Reactor Inst., Delft (Netherlands))

    1990-01-01

    Determination of the flow rate of the coolant in the cooling channels of nuclear reactors is an important aspect of core monitoring. It is usually impossible to measure the flow by flowmeters in the individual channels due to the lack of space and safety reasons. An alternative method is based on the analysis of noise signals of the available in-core detectors. In such a noise method, a transit time which characterises the propagation of thermohydraulic fluctuations (density or temperature fluctuations) in the coolant is determined from the correlation between the noise signals of axially displaced detectors. In this paper, the results of flow measurements using axially displaced thermocouples in the channel wall will be presented. The experiments have been performed in a simulated MRT-type fuel assembly located in the research reactor HOR of the Interfaculty Reactor Institute, Delft. It was found that the velocities obtained via temperature noise correlation methods are significantly larger than the area-averaged velocity in the single-phase coolant flow. Model calculations show that the observed phenomenon can be explained by effects due to the radial velocity distribution in the channel. (author).

  5. Axial design of fuel for BWRs using neural networks

    International Nuclear Information System (INIS)

    Ortiz, J.J.; Castillo, A.; Montes, J.L.; Perusquia, R.

    2007-01-01

    In this work a new system of axial optimization of fuel is presented based on a recurrent multi state neural net called RENODC. They are described with detail the main characteristics of this type of neural net (architecture, energy function and actualization of neural states) and like was adapted to the assemble design of nuclear fuel. The fuel design is proven by means of a fuel recharge and pre determined control rod patterns. By this way a good axial fuel design one has, when the thermal limits are fulfilled along the cycle, the reactor stays critic and at least the wanted longitude of the cycle is reached; also the margin of in cold turned off is verified. The assemble of fuel created with RENODC it is substituted by a recharge assemble and it is sought to verify that the energy requirements and aspects of safety are completed. The used cycle corresponds to a balance cycle of 18 months that it can be applied to the Laguna Verde Nucleo electric Central. The tests demonstrate the effectiveness of the system to reach satisfactory results in times of CPU of around 4 hours. This way, it could be proven that the design proposed with a lightly superior enrichment to that of the substituted design, fulfills the energy requirements. In later stages of this project this system will be coupled to the other optimization modules that are already had. (Author)

  6. Competition between modes with different axial structures in gyrotrons

    International Nuclear Information System (INIS)

    Khutoryan, Eduard M.; Nusinovich, Gregory S.; Sinitsyn, Oleksandr V.

    2014-01-01

    This study was motivated by some experiments in which it was found that during the voltage rise, instead of expected excitation of a high-frequency parasitic mode, the excitation of a lower-frequency parasitic mode takes place in a certain range of voltages. For explaining this fact, the dependence of start currents of possible competing modes on the beam voltage was carried out in the cold-cavity approximation and by using the self-consistent approach. It was found that in the case of cavities, which consist of the combination of a section of constant radius waveguide and a slightly uptapered waveguide, these two approaches yield completely different results. Thus, experimentally observed excitation of the low-frequency parasitic mode can be explained by the self-consistent modification of the axial profile of the excited field, which has strong influence on the diffractive quality factor of competing modes. This modification is especially pronounced in the case of excitation of modes with many axial variations which can be excited in the region of beam interaction with the backward-wave component of such modes

  7. Design and analysis of miniature tri-axial fluxgate magnetometer

    Science.gov (United States)

    Zhi, Menghui; Tang, Liang; Qiao, Donghai

    2017-02-01

    The detection technology of weak magnetic field is widely used in Earth resource survey and geomagnetic navigation. Useful magnetic field information can be obtained by processing and analyzing the measurement data from magnetic sensors. A miniature tri-axial fluxgate magnetometer is proposed in this paper. This miniature tri-axial fluxgate magnetometer with ring-core structure has a dynamic range of the Earth’s field ±65,000 nT, resolution of several nT. It has three independent parts placed in three perpendicular planes for measuring three orthogonal magnetic field components, respectively. A field-programmable gate array (FPGA) is used to generate stimulation signal, analog-to-digital (A/D) convertor control signal, and feedback digital-to-analog (D/A) control signal. Design and analysis details are given to improve the dynamic range, sensitivity, resolution, and linearity. Our prototype was measured and compared with a commercial standard Magson fluxgate magnetometer as a reference. The results show that our miniature fluxgate magnetometer can follow the Magson’s change trend well. When used as a magnetic compass, our prototype only has ± 0.3∘ deviation compared with standard magnetic compass.

  8. Axial and parity anomalies and vacuum charge: A direct approach

    International Nuclear Information System (INIS)

    Boyanovsky, D.; Blankenbecler, R.

    1985-01-01

    We study the axial and parity anomalies in Abelian gauge theories using the direct yet intuitive approach of counting the relative number of states of one chirality with respect to the other. A fundamental gauge-invariant quantity, the determinantal ratio, is introduced for this purpose. We find that the number of states is conserved and that the gauge fields differentially phase shift states of opposite chirality at infinite energies. This implies a relative flow of states at very large energies which must be compensated by a rearrangement of the density of states at finite energies. We then derive a sum rule which yields two alternative formulas for the index of a Dirac operator. One expresses the index in terms of its high-energy behavior, and the other in terms of the low-energy properties; these are the ''zero modes'' of definite chirality. Two examples are worked out in detail to clarify our general result. The physics of the axial anomaly is shown to translate into that of the parity anomaly in 2+1 dimensions, in which parity and chirality have interchanged roles. We also analyze the vacuum charge in regard to its high- and low-energy origin. The possibility of spectral flow is formulated and briefly discussed. In short, we provide a physical interpretation of certain mathematical indices, relate them to an extended version of Levinson's theorem of potential scattering, and simplify their evaluation

  9. Axial Ge/Si nanowire heterostructure tunnel FETs.

    Energy Technology Data Exchange (ETDEWEB)

    Dayeh, Shadi A. (Los Alamos National Laboratory); Gin, Aaron V.; Huang, Jian Yu; Picraux, Samuel Thomas (Los Alamos National Laboratory)

    2010-03-01

    Axial Ge/Si heterostructure nanowires (NWs) allow energy band-edge engineering along the axis of the NW, which is the charge transport direction, and the realization of asymmetric devices for novel device architectures. This work reports on two significant advances in the area of heterostructure NWs and tunnel FETs: (i) the realization of 100% compositionally modulated Si/Ge axial heterostructure NWs with lengths suitable for device fabrication and (ii) the design and implementation of Schottky barrier tunnel FETs on these NWs for high-on currents and suppressed ambipolar behavior. Initial prototype devices with 10 nm PECVD SiN{sub x} gate dielectric resulted in a very high current drive in excess of 100 {micro}A/{micro}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios. Prior work on the synthesis of Ge/Si axial NW heterostructures through the VLS mechanism have resulted in axial Si/Si{sub 1-x}Ge{sub x} NW heterostructures with x{sub max} {approx} 0.3, and more recently 100% composition modulation was achieved with a solid growth catalyst. In this latter case, the thickness of the heterostructure cannot exceed few atomic layers due to the slow axial growth rate and concurrent radial deposition on the NW sidewalls leading to a mixture of axial and radial deposition, which imposes a big challenge for fabricating useful devices form these NWs in the near future. Here, we report the VLS growth of 100% doping and composition modulated axial Ge/Si heterostructure NWs with lengths appropriate for device fabrication by devising a growth procedure that eliminates Au diffusion on the NW sidewalls and minimizes random kinking in the heterostructure NWs as deduced from detailed microscopy analysis. Fig. 1 a shows a cross-sectional SEM image of epitaxial Ge/Si axial NW heterostructures grown on a Ge(111) surface. The interface abruptness in these Ge/Si heterostructure NWs is of the order of the NW diameter. Some of these NWs develop a crystallographic kink that is {approx

  10. Axial U(1) current in Grabowska and Kaplan's formulation

    Science.gov (United States)

    Hamada, Yu; Kawai, Hikaru

    2017-06-01

    Recently, Grabowska and Kaplan [Phys. Rev. Lett. 116, 211602 (2016); Phys. Rev. D 94, 114504 (2016)] suggested a nonperturbative formulation of a chiral gauge theory, which consists of the conventional domain-wall fermion and a gauge field that evolves by gradient flow from one domain wall to the other. We introduce two sets of domain-wall fermions belonging to complex conjugate representations so that the effective theory is a 4D vector-like gauge theory. Then, as a natural definition of the axial-vector current, we consider a current that generates simultaneous phase transformations for the massless modes in 4 dimensions. However, this current is exactly conserved and does not reproduce the correct anomaly. In order to investigate this point precisely, we consider the mechanism of the conservation. We find that this current includes not only the axial current on the domain wall but also a contribution from the bulk, which is nonlocal in the sense of 4D fields. Therefore, the local current is obtained by subtracting the bulk contribution from it.

  11. Pit above the lesser tuberosity in axial view radiography.

    Science.gov (United States)

    Cho, Jae-Ho; Han, Kyeong-Jin; Lee, Doo-Hyung; Chung, Nam-Su; Park, Do Young

    2015-02-01

    This study examined the relationship between the presence of a pit above the lesser tuberosity on axial view radiographs and rotator cuff tears and compared the demographic data between groups according to the presence of a pit above the lesser tuberosity. The hypothesis of this study was that the radiographic finding of a pit above the lesser tuberosity is related to rotator cuff tears. For 112 patients with a symptomatic rotator cuff tear, plain radiographs of the symptomatic shoulder (tear side radiographs) and plain radiographs of the asymptomatic contralateral shoulder (no-tear side radiographs) were assessed. Seventeen radiological findings, including a pit above the lesser tuberosity, osteophytes, subchondral cysts, and sclerosis, were recorded by one blinded observer. Demographic data such as age, duration of symptoms, sex, arm dominance, smoking history, trauma history, American Shoulder and Elbow Surgeons score, Constant score, and involved tendon were collected. A pit above the lesser tuberosity was noted on tear side radiographs of 40 patients (35.7 %) and on the no-tear side radiographs of 27 patients (24.1 %), representing a significant difference (P = 0.040). A pit associated with a rotator cuff tear was observed more often in the dominant arm (P = 0.040) and more often in patients with less previous trauma (P = 0.024). A pit above the lesser tuberosity on axial view radiography was associated with a rotator cuff tear and occurred more often in the dominant arm of patients who had no trauma history. Prognostic study, Level III.

  12. Axial anomaly and index theorem for Dirac-Kaehler fermions

    International Nuclear Information System (INIS)

    Fonseca Junior, C.A.L. da.

    1985-02-01

    Some aspects of topological influence on gauge field theory are analysed, considering the geometry and differential topology methods. A review of concepts of differential forms, fibered spaces, connection and curvature, showing an interpretation of gauge theory in this context, is presented. The question of fermions, analysing in details the Dirac-Kaehler which fermionic particle is considered a general differential form, is studied. It is shown how the explicit expressions in function of the Dirac spinor components vary with the Dirac matrix representation. The Dirac-Kahler equation contains 4 times (in 4 dimensions) the Dirac equation, each particle being associated an ideal at left of the algebra of general differential forms. These ideals and the SU(4) symmetry among them are also studied on the point of view of spinors and, the group of reduction to one of the ideals is identified as the Cartan subalgebra of this SU(4). Finally, the axial anomaly is calculated through the functional determinant given by the Dirac-Kaehler operator. The regularization method is the Seeley's coefficients. From that results a comparison of the index theorems for the twisted complexes of signature and spin, which proportionality is given by the number of the algebra ideals contained in the Dirac-Kaehler equation and which also manifests in the respective axial anomaly equations. (L.C.) [pt

  13. Axial length of atomic bomb survivors in Nagasaki

    International Nuclear Information System (INIS)

    Wakiyama, Harumi; Kishikawa, Yasuhiro; Imamura, Naoki; Amemiya, Tsugio

    2002-01-01

    We reviewed a series of 778 patients who had cataract surgery during the past 4 years at the Nagasaki Atomic Bomb Memorial Hospital. We evaluated the history of exposure to radiation by atomic bomb in 1945, axial length and state of refraction. All were born before 1945. The series comprised 263 males and 515 females. Their ages averaged 76.5±8.6 years. History of exposure to radiation was present in 356 patients. The remaining 422 patients served as control. There was no difference in the type of cataract between the two groups. High myopia was present in 11 irradiated patients (3.2%) and in 24 patients in the control group (6.0%). The difference was not significant (p=0.083). There was no high myopia among 24 patients who were aged 18 years or less at the time of radiation and who were within 2 km from the epicenter. No difference was present regarding the axial length between the two groups or between both sexes. The present result is not definitive because ''irradiated group'' would include those with little or no exposure and because precise data has not been available about the dosis of radiation. (author)

  14. Vibration mechanism of fuel rod in axial flow

    International Nuclear Information System (INIS)

    Kang, Heung Seok; Yoon, Kyung Ho; Kim, Hyung Kyu; Song, Kee Nam

    1998-08-01

    This is a review on the previous researches for the vibration of fuel rod induced by axial flow. The analysis methods are classified into three categories accordingly as the researchers postulate the vibration to be self-excited, forced and parametric; the self-excited mechanism by Burgreen and Quinn, the forced one by Reavis, Gorman, kanazawa, and S. Chen, and the parametric one by Y. Chen. Quinn supposed that the centrifugal force by flow exaggerated the natural bow in the cylinder, and the flexural force by it diminished the bow by turns; this interactive motion leaded cylinder to vibration. The supporters to the forced mechanism considered the forces arising from pressure perturbation within the boundary layers as vibrating sources. Y. Chen insisted that the cylinder could only be excited to vibration in resonance by the small oscillation of mean flow velocity. The previous studies were based on the simple boundary conditions such as hinged-hinged or fixed-fixed single span. Therefore, for the more accurate prediction of the fuel rod vibration in reactor, the further studies need to reflect the actual boundary conditions of the fuel rod like axial force and continuous supports by grids. (author). 25 refs

  15. The effects of initial rise and axial loads on MEMS arches

    KAUST Repository

    Tella, Sherif Adekunle

    2017-04-07

    Arch microbeams have been utilized and proposed for many uses over the past few years due to their large tunability and bistability. However, recent experimental data have shown different mechanical behavior of arches when subjected to axial loads. This paper aims to investigate in depth the influence of the competing effects of initial rise and axial loads on the mechanical behavior of micromachined arches; mainly their static deflection and resonant frequencies. Based on analytical solutions, the static response and eigenvalue problems are analyzed for various values of initial rises and axial loads. Universal curves showing the variation of the first three resonance frequencies of the arch are generated for various values of initial rise under both tensile and compressive axial loads. This study shows that increasing the tensile or compressive axial loads for different values of initial rise may lead to either increase in the stiffness of the beam or initial decrease in the stiffness, which later increases as the axial load is increased depending on the dominant effect of the initial rise of the arch and the axial load. The obtained universal curves represent useful design tools to predict the tunability of arches under axial loads for various values of initial rises. The use of the universal curves is demonstrated with an experimental case study. Analytical formulation is developed to predict the point of minimum where the trend of the resonance frequency versus axial loads changes qualitatively due to the competing effects of axial loads and initial curvature.

  16. Food irradiation - pros and cons

    International Nuclear Information System (INIS)

    1983-01-01

    The use of ionising radiation for food preservation is a much-disputed topic, both among experts and among consumers. Pros and cons of this issue were discussed in detail at the consumers' forum. Professor Dr. Johannes Friedrich Diehl, Director of the Institute for Biochemistry of the Food Research Centre, Karlsruhe, is a well-known supporter of the new method of food preservation; he sees advantages in the radiopreservation of food because, for example, losses due to inedibility are reduced, the danger of salmonellosis is decreased, just as the use of chemicals. He thinks this method to be without danger to health, shown by many years of experience. Opponents to food irradiation like Prof. Dr. Konrad Pfeilsticker, Professor for food science and food chemistry at the Bonn University deem the method to be unnecessary and raise the problem of qualitative changes caused in the food. In the course of the discussions, the pros and cons seemed to balance each other out. (orig./AJ) [de

  17. De paseo con los Bourbaki

    Directory of Open Access Journals (Sweden)

    Miquel Escudero

    2012-04-01

    Full Text Available Setenta y siete años después de la fundación del grupo Bourbaki, procedemos a una reflexión que puede ser útil para los estudiantes que acaso no sepan de su existencia, ni tan siquiera los de matemáticas. Sería interesante conocer que a este grupo se le debe el signo del vacío como conjunto. Con todo lo discutible que sea el método Bourbaki en su reinterpretación de la matemática, no cabe duda de su importante repercusión hasta el punto de que ha marcado una época. Hay un antes y un después tras su irrupción, ningún matemático de primera fila de la segunda mitad del siglo XX fue ajeno a su influjo, para encabezarlo o para reprobarlo. Comenzaron como una juvenil extravagancia, pero repleta de conocimientos y con decidida voluntad de aprehender el rigor de forma exhaustiva.

  18. Tratamiento del paciente con artrosis

    Directory of Open Access Journals (Sweden)

    Francisco Vargas Negrín

    2014-01-01

    Full Text Available El manejo terapéutico del paciente con artrosis tiene como objetivo disminuir la sintomatología dolorosa e inflamatoria, mejorar la capacidad funcional del paciente y la aplicación de intervenciones terapéuticas eficaces y lo más seguras posibles. Un enfoque centrado en el paciente implica su participación activa en el diseño del plan terapéutico y en la toma de decisiones informadas oportunas en todas las etapas de la enfermedad. La educación terapéutica, la actividad física y el ejercicio terapéutico junto con el control de peso, en caso de sobrepeso u obesidad, constituyen el núcleo central del tratamiento. Los autocuidados individuales y por los familiares son fundamentales en el control del día a día del paciente. El uso de terapias físicas, ayudas técnicas (bastón, etc. y de fármacos tipo analgésicos simples, opioides y antiinflamatorios tiene evidencias demostradas en el control del dolor, mejora la funcionalidad y la calidad de vida del paciente y una clara recomendación de uso en el tratamiento de la artrosis. La cirugía conservadora y la de reemplazo articular se indican en los casos en los que no se logran los objetivos terapéuticos en casos concretos.

  19. Interconnection between several eye biomechanical and biometric parameters in children with axial and refractive mild myopia

    Directory of Open Access Journals (Sweden)

    T. Ye. Tsybulskaya

    2016-08-01

    Full Text Available Aim – to study the relationship of biometric and biomechanical indicators of corneoscleral capsule of the eye in children with axial and refractive mild myopia. Materials and methods. Axial myopia was diagnosed in 32 children (64 eyes, refractive myopia – 18 (36 eyes. The control group – 16 children without ophthalmic diseases (32 eyes. Eye examination: visometry, automated refractometry, biomicroscopy, ophthalmoscopy, determination of the axial length of the eyeball and corneal hysteresis. Results. Significant differences were determined in the indicators of dioptric power of the cornea: 42.2 dpt in patients with axial and 44.7 dpt with refractive myopia (p<0.05, and also difference between patients with refractive myopia and the control group, in which the diopter power of cornea was 42.6 (p<0.05. There are also significant differences in the indicators of the axial length of eyes between axial and refractive myopia – 24.5±0.64 mm and 23.1±0.43 mm (p<0.05. Significant difference with the control group in the axial length marked only in eyes with axial myopia 22.7±0.33 mm and 24.5±0.64 mm, respectively (p<0.05. Corneal hysteresis determined significantly reduced on eyes with both the axial and refractive myopia, which was significantly lower than in the indicators of emmetropic eyes of the control group 13.7 (p<0.05. Corneal hysteresis is inversely related to the axial length of the eyeball: in patients with axial myopia r -0.32, p<0.05; with refractive myopia r -0.36, p<0.05. Сorrelation between diopter power of cornea and axial length of the eyeball: r -0.53, р<0.05 in eyes with axial myopia and r -0.42, p<0.05 refractive myopia. Comparative analysis showed no significant differences between the corneal hysteresis, the axial length of the eye and the spherical component of myopia. Conclusions. In patients with axial and refractive mild myopia corneal hysteresis is reduced on average in 1.2 and 1.1 times, in comparison with

  20. Axial design of fuel for BWRs using neural networks; Diseno axial de combustible para BWRs usando redes neuronales

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, J.J.; Castillo, A.; Montes, J.L.; Perusquia, R. [ININ, Carretera Mexico-Toluca s/n, 52750 La Marquesa, Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: jjortiz@nuclear.inin.mx

    2007-07-01

    In this work a new system of axial optimization of fuel is presented based on a recurrent multi state neural net called RENODC. They are described with detail the main characteristics of this type of neural net (architecture, energy function and actualization of neural states) and like was adapted to the assemble design of nuclear fuel. The fuel design is proven by means of a fuel recharge and pre determined control rod patterns. By this way a good axial fuel design one has, when the thermal limits are fulfilled along the cycle, the reactor stays critic and at least the wanted longitude of the cycle is reached; also the margin of in cold turned off is verified. The assemble of fuel created with RENODC it is substituted by a recharge assemble and it is sought to verify that the energy requirements and aspects of safety are completed. The used cycle corresponds to a balance cycle of 18 months that it can be applied to the Laguna Verde Nucleo electric Central. The tests demonstrate the effectiveness of the system to reach satisfactory results in times of CPU of around 4 hours. This way, it could be proven that the design proposed with a lightly superior enrichment to that of the substituted design, fulfills the energy requirements. In later stages of this project this system will be coupled to the other optimization modules that are already had. (Author)

  1. Axial design of nuclear fuel using path relinking

    International Nuclear Information System (INIS)

    Castillo, A.; Torres, M.; Ortiz, J. J.; Perusquia, R.; Hernandez, J. L.; Montes, J. L.

    2008-01-01

    In the present work the preliminary results were obtained with the zoctli system whose purpose is the axial design of assembly of nuclear fuel under certain considerations. For the mentioned design well-know cells were already used and that they have been proven in diverse cycles of operation in the nuclear power plant of Laguna Verde. The design contemplates fuels assemblies of 10x10 and with 2 water channels. The assembly was distributed in 6 axial zones according to its structure. In order to take to end the optimization is was used the well-known technique like Path relinking and to find the group of previous solutions required by this technique uses the technical Taboo search. In order to work with Path relinking, 5 trajectories was taken in to account from a set of 5 previous solutions generated with theTaboo search, the update of the group of solutions is carried out in dynamic form. In the case of the Taboo search it was used a list of variable size, it was implement an aspiration approach, it was used the vector of frequencies and due to the cost of the evaluation of the objective function, only it was review 5% of the vicinity. For the objective function was considered the limit thermal, the axial profile of power, the effective multiplication factor and the margin of having turned off in cold. In order to prove the design system, it was used a balance cycle with a value of reference of 0.9928 for the effective multiplication factor that is equivalent to a produced energy of 10896 MWd/TU at the end of operation to full power. The designed assemblies were placed both in one of lots different from fresh assemblies on which it counts the referred cycle. At the end one a comparison with the results obtained with other techniques and under similar conditions is made. The results obtained until the moment show an appropriate performance of the system. It is possible to indicate that a small inconvenient is the amount of consumed resources of calculation during

  2. Three-dimensional S-wave tomography under Axial Seamount

    Science.gov (United States)

    Baillard, C.; Wilcock, W. S. D.; Arnulf, A. F.; Tolstoy, M.; Waldhauser, F.

    2017-12-01

    Axial Seamount is a submarine volcano located at the intersection of the Juande Fuca Ridge and the Cobb-Eickelberg hotspot 500 km off the coast of thenorthwestern United States. The seamount, which rises 1 km above the seafloor, ischaracterized by a shallow caldera that is elongated in the N-S direction, measure 8km by 3 km and sits on top of a 14 km by 3 km magma reservoir. Two eruptive eventsin 1998 and 2011 motivated the deployment in 2014 of a real time cabled observatorywithin the Axial caldera, as part of the Ocean Observatories Initiative (OOI).Theobservatory includes a network of seven seismometers that span the southern half ofthe caldera. Five months after the observatory came on-line in November 2014, thevolcano erupted on April 24, 2015. Well over 100,000 events were located in thevicinity of the caldera, delineating an outward dipping ring fault that extends fromnear the surface to the magma body at 2 km depth and which accommodatesinflation and deflation of the volcano.The initial earthquake locations have beenobtained with a one-dimensional velocity model but the travel time residuals suggeststrong heterogeneities. A three-dimensional P-wave velocity model, obtained bycombining multichannel and ocean bottom seismometer refraction data, is being usedto refine locations but the three-dimensional S-wave structure is presently unknown.In most mid-ocean ridge settings, the distribution of earthquakes is not conducive forjoint inversions for S-wave velocity and hypocentral parameters because there are fewcrossing ray paths but at Axial the presence of a ring fault that is seismically active atall depths on both the east and west side of the caldera, provides a reasonablegeometry for such efforts. We will present the results of joint inversions that assumethe existing three-dimensional P wave velocity model and solve for VP/VS structure andhypocentral parameters using LOTOS, an algorithm that solves the forward problemusing ray bending.The resulting model

  3. Axial to transverse energy mixing dynamics in octupole-based magnetostatic antihydrogen traps

    Science.gov (United States)

    Zhong, M.; Fajans, J.; Zukor, A. F.

    2018-05-01

    The nature of the trajectories of antihydrogen atoms confined in an octupole minimum-B trap is of great importance for upcoming spectroscopy, cooling, and gravity experiments. Of particular interest is the mixing time between the axial and transverse energies for the antiatoms. Here, using computer simulations, we establish that almost all trajectories are chaotic, and then quantify the characteristic mixing time between the axial and transverse energies. We find that there are two classes of trajectories: for trajectories whose axial energy is higher than about 20% of the total energy, the axial energy substantially mixes within about 10 s, whereas for trajectories whose axial energy is lower than about 10% of the total energy, the axial energy remains nearly constant for 1000 s or longer.

  4. Axial power deviation control strategy and computer simulation for Daya Bay Nuclear Power Station

    International Nuclear Information System (INIS)

    Liao Yehong; Zhou Xiaoling, Xiao Min

    2004-01-01

    Daya Bay Nuclear Power Station has very tight operation diagram especially at its right side. Therefore the successful control of axial power deviation for PWR is crucial to nuclear safety. After analyzing various core characters' effect on axial power distribution, several axial power deviation control strategies has been proposed to comply with different power varying operation scenario. Application and computer simulation of the strategies has shown that our prediction of axial power deviation evolution are comparable to the measurement values, and that our control strategies are effective. Engineering experience shows that the application of our methodology can predict accurately the transient of axial power deviation, and therefore has become a useful tool for reactor operation and safety control. This paper presents the axial power control characteristics, reactor operation strategy research, computer simulation, and comparison to measurement results in Daya Bay Nuclear Power Station. (author)

  5. Second harmonic generation of off axial vortex beam in the case of walk-off effect

    Science.gov (United States)

    Chen, Shunyi; Ding, Panfeng; Pu, Jixiong

    2016-07-01

    Process of off axial vortex beam propagating in negative uniaxial crystal is investigated in this work. Firstly, we get the formulae of the normalized electric field and calculate the location of vortices for second harmonic beam in two type of phase matching. Then, numerical analysis verifies that the intensity distribution and location of vortices of the first order original vortex beam depend on the walk-off angle and off axial magnitude. It is shown that, in type I phase matching, the distribution of vortices is symmetrical about the horizontal axis, the separation distance increases as the off axial magnitude increases or the off axial magnitude deceases. However, in type II phase matching, the vortices are symmetrical along with some vertical axis, and increase of the walk-off angle or off axial magnitude leads to larger separation distance. Finally, the case of high order original off axial vortex beam is also investigated.

  6. Study of Fuel Rods Axial Enrichment Distribution Effect on the Neutronic Parameters of the Reactor Core

    International Nuclear Information System (INIS)

    Pazirandeh, A.; Nasiri, S. H.

    2012-01-01

    Optimization of the fuel burn up is an important issue in nuclear reactor fuel management and technology. Radial enrichment distribution in the reactor core is a conventional method and axial enrichment is constant along the fuel rod. In this article, the effects of axial enrichment distribution variation on neutronic parameters of PWR core are studied. The axial length of the core is divided into ten sections, considering axial enrichment variation and leaving the existing radial enrichment distribution intact. This study shows that the radial and axial power peaking factors are decreased as compared with the typical conventional core. In addition, the first core lifetime lasts 30 days longer than normal PWR core. Moreover, at the same time boric acid density is 0.2 g/kg at the beginning of the cycle. The flux shape is also flat at the beginning of the cycle for the proposed configuration of the axially enrichment distribution.

  7. Launch Lock Assemblies Including Axial Gap Amplification Devices and Spacecraft Isolation Systems Including the Same

    Science.gov (United States)

    Barber, Tim Daniel (Inventor); Hindle, Timothy (Inventor); Young, Ken (Inventor); Davis, Torey (Inventor)

    2014-01-01

    Embodiments of a launch lock assembly are provided, as are embodiments of a spacecraft isolation system including one or more launch lock assemblies. In one embodiment, the launch lock assembly includes first and second mount pieces, a releasable clamp device, and an axial gap amplification device. The releasable clamp device normally maintains the first and second mount pieces in clamped engagement; and, when actuated, releases the first and second mount pieces from clamped engagement to allow relative axial motion there between. The axial gap amplification device normally residing in a blocking position wherein the gap amplification device obstructs relative axial motion between the first and second mount pieces. The axial gap amplification device moves into a non-blocking position when the first and second mount pieces are released from clamped engagement to increase the range of axial motion between the first and second mount pieces.

  8. Cons ICARUS, TIGER and Fascism

    Directory of Open Access Journals (Sweden)

    Janez Vrečko

    2010-12-01

    Full Text Available Like the scientists of their time, Russian artists in the 1920s considered gravity the central problem – a view which points to the close harmony between modern physics and the avant-garde. It was only with the constructivist movement that the Icarus revolution grasped the principles of the “mobile philosophy” (3.651 which was almost at the same time recognised by modern physics as well. The static view of the world became obsolete, space and time were no longer absolute values. It was necessary to transcend Euclidean geometry, shake off the political ʻshackles on one’s hands’ and surrender to Lisicki’s imaginary space, where “At 2000 metres in the air / there is no more perspective” (Integrals 276.  Kosovel’s Icarus project accorded with Tatlin’s, and both of them accorded with the quintessential aims of the constructivist movement. It is no accident that Kosovel wished to name one of his poetry collections The Dream of Icarus. Poems on the Icarus theme, such as “Cons Icarus”, “Evacuation of the Spirit”, “Eh, Hey”, “A Heart in Alcohol” etc. belong to the group of Kosovel’s conses which follow his “mobile philosophy” (3.650 and “letters growing into space” (Int. 282.  The question “Man, do you want up in the air?” (Int. 128 will remain a question until the moment when man is finally ready to transcend the existing boundary and dive “beyond”. Hence Kosovel’s clear-cut contrast between the “green windows of an illuminated / express on a viaduct”, which moves horizontally and is, like a water current, subject to the earth’s gravity, and “the spirit in space”, whose direction of motion is “the perpendicular of the spirit”, atectonicity. “The spirit burns in space”: fire is an element that knows vertical movement alone, the only one of the elements to outgrow and transcend the earth’s gravity, therefore it is associated with another mythological figure important for

  9. Design, Test, and Evaluation of a Transonic Axial Compressor Rotor with Splitter Blades

    Science.gov (United States)

    2013-09-01

    INTRODUCTION A. MOTIVATION Over the course of turbomachinery history splitter vanes have been used extensively in centrifugal compressors . Axial...TEST, AND EVALUATION OF A TRANSONIC AXIAL COMPRESSOR ROTOR WITH SPLITTER BLADES by Scott Drayton September 2013 Dissertation Co...AXIAL COMPRESSOR ROTOR WITH SPLITTER BLADES 5. FUNDING NUMBERS 6. AUTHOR(S) Scott Drayton 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES

  10. Metamorphosis of helical magnetorotational instability in the presence axial electric current

    OpenAIRE

    Priede, Jānis

    2014-01-01

    This paper presents numerical linear stability analysis of a cylindrical Taylor-Couette flow of liquid metal carrying axial electric current in a generally helical external magnetic field. Axially symmetric disturbances are considered in the inductionless approximation corresponding to zero magnetic Prandtl number. Axial symmetry allows us to reveal an entirely new electromagnetic instability. First, we show that the electric current passing through the liquid can extend the range of helical ...

  11. Precautions against axial fan stall in reactor building to Tianwan NPP

    International Nuclear Information System (INIS)

    Liu Chunlong; Pei Junmin

    2011-01-01

    The paper introduces the mechanism and harm of rotating stall of axial fans, analyzes the necessity for prevention against axial fan stall in reactor building of Tianwan NPP, introduces the precautions, and then makes an assessment on anti-stall effect of flow separators. It can provide reference for model-selection or reconstruction of similar fans in power stations, and for operation and maintenance of axial fans. (authors)

  12. Atlanto-axial Subluxation in rheumatoid arthritis: description of a case

    International Nuclear Information System (INIS)

    Medina, Yimy F; Martinez V, Jose B; Restrepo, Jose Felix; Rondon H, Federico; Iglesias G, Antonio

    2004-01-01

    The damage of the spine by rheumatoid arthritis is multiple and a variety of affectations have been described at cervical level, being the anterior atlanto-axial subluxation and vertical subluxation the more common. However the posterior atlanto-axial subluxation has been rarely described. In this paper, we describe the case of a patient with posterior atlanto-axial subluxaction in addition to its infrequent manifestation of alteration of the lower cranial nerves as a manifestation of myelopathy

  13. Endoscopic Transoral Resection of an Axial Chordoma: A Case Report

    Directory of Open Access Journals (Sweden)

    Taran S

    2015-11-01

    Full Text Available Upper cervical chordoma (UCC is rare condition and poses unique challenges to surgeons. Even though transoral approach is commonly employed, a minimally invasive technique has not been established. We report a 44-year old Malay lady who presented with a 1 month history of insidious onset of progressive neck pain without neurological symptoms. She was diagnosed to have an axial (C2 chordoma. Intralesional resection of the tumour was performed transorally using the Destandau endoscopic system (Storz, Germany. Satisfactory intralesional excision of the tumour was achieved. She had a posterior fixation of C1-C4 prior to that. Her symptoms improved postoperatively and there were no complications noted. She underwent adjuvant radiotherapy to minimize local recurrence. Endoscopic excision of UCC via the transoral approach is a safe option as it provides an excellent magnified view and ease of resection while minimizing the operative morbidity.

  14. On the mechanism of zircaloy cladding axial splits

    International Nuclear Information System (INIS)

    Grigoriev, V.; Josefsson, B.

    1998-01-01

    The macroscopically brittle axial splitting is treated as a process entirely accomplished by a plastic mechanism operating on a microscopic scale and is discussed in terms of the degree of plasticity and localisation of plasticity. The suggested mechanism involves hydrogen assisted localised shear (HALS) as a main factor of material deterioration. The reason and the driving force for the HALS is an in-plane shear (as for mode II loading) existing at the tip of a crack loaded in mode I (Opening). The HALS mechanism does not require brittle fracture of the hydrides and is only operable under certain combination of material strength, applied stresses, and temperature, needed for the local yielding at the crack tip. If the combination of those parameters results in the bulk yielding, the in-plane shear component is diminished and the delayed cracking is suppressed. (orig.)

  15. Stress Analysis of Fuel Rod under Axial Coolant Flow

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hai Lan; Lee, Young Shin; Lee, Hyun Seung [Chungnam National University, Daejeon (Korea, Republic of); Park, Num Kyu; Jeon, Kyung Rok [Kerea Nuclear Fuel., Daejeon (Korea, Republic of)

    2010-05-15

    A pressurized water reactor(PWR) fuel assembly, is a typical bundle structure, which uses light water as a coolant in most commercial nuclear power plants. Fuel rods that have a very slender and long clad are supported by fuel assembly which consists of several spacer grids. A coolant is a fluid which flows through device to prevent its overheating, transferring the heat produced by the device to other devices that use or dissipate it. But at the same time, the coolant flow will bring out the fluid induced vibration(FIV) of fuel rods and even damaged the fuel rod. This study has been conducted to investigate the flow characteristics and nuclear reactor fuel rod stress under effect of coolant. Fluid structure interaction(FSI) analysis on nuclear reactor fuel rod was performed. Fluid analysis of the coolant which flow along the axial direction and structural analysis under effect of flow velocity were carried out under different output flow velocity conditions

  16. Active surge control for variable speed axial compressors.

    Science.gov (United States)

    Lin, Shu; Yang, Chunjie; Wu, Ping; Song, Zhihuan

    2014-09-01

    This paper discusses active surge control in variable speed axial compressors. A compression system equipped with a variable area throttle is investigated. Based on a given compressor model, a fuzzy logic controller is designed for surge control and a proportional speed controller is used for speed control. The fuzzy controller uses measurements of the change of pressure rise as well as the change of mass flow to determine the throttle opening. The presented approach does not require the knowledge of system equilibrium or the surge line. Numerical simulations show promising results. The proposed fuzzy logic controller performs better than a backstepping controller and is capable to suppress surge at different operating points. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Computerized axial tomography and diagnosis of multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Paulo R.M. Bittencourt

    1983-06-01

    Full Text Available Computed axial tomography (C.T. findings are illustrated in 3 patients who presented with C.T. changes suggesting respectively chronic M.S., acute M.S., and an appearance simulating a malignant tumour. Review of the literature shows that the chronic form with cerebral atrophy and low density lesions in the hemispheres is common in patients with a long history and is unlikely to cause diagnostic difficulty. The acute presentation is less common and could be confused with a variety of causes of multiple low density enhancing lesions. The C.T. diagnosis of M.S. is more difficult in rare cases in which plaques cause mass effect and show ring enhancement; all 3 such cases in the literature were subjected to cerebral biopsy.

  18. Structures of water molecular nanotube induced by axial tensile strains

    Energy Technology Data Exchange (ETDEWEB)

    Li, H. [Key Laboratory of Liquid Structures and Heredity of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University (China)], E-mail: lihuilmy@hotmail.com; Zhang, X.Q. [Physics Department, Ocean University of China, Qingdao (China); Liew, K.M. [Department of Building and Constructions, City University of Hong Kong, Kowloon (Hong Kong); Liu, X.F. [Key Laboratory of Liquid Structures and Heredity of Materials, Ministry of Education, School of Materials Science and Engineering, Shandong University (China)

    2008-10-06

    Five well-ordered nano-ice structures embedded in carbon nanotubes are obtained in this study. These five nano-ice phases all exhibit single walled tubular morphologies, including the pentagon, hexagon ice nanotubes whose structures are quite different from bulk ice. Our simulation results indicate that water molecules tend to rearrange into surface ring structures to reduce the number of free OH groups. The structural behavior of these ice nanotubes inside CNTs subject to axial stress is also investigated. The ice nanotubes tend to be drawn to ice nanorings or ice nanospring during the mechanical stretching. The distribution function exhibits typical order-to-disorder transition of the water network confined in carbon nanotube during the stretching. By analysis, we suggest that it is unlikely that additional water molecules will enter the tubes because of the increased volume available if the tubes are stretched at contact with a water reservoir.

  19. Axial shape index calculation for the 3-level excore detector

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han Gon; Kim, Yong Hee; Kim, Byung Sop; Lee, Sang Hee; Cho, Sung Jae [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    A new method based on the alternating conditional expectation (ACE) algorithm is developed to calculate axial shape index (ASI) for the 3-level excore detector. The ACE algorithm, a type of nonparametric regression algorithms, yields an optimal relationship between a dependent variable and multiple independent variables. In this study, the simple correlation between ASI and excore detector signals is developed using the Younggwang nuclear power plant unit 3 (YGN-3) data without any preprocessing on the relationships between independent variables and dependent variable. The numerical results show that simple correlations exist between the three excore signals and ASI of the core. The accuracy of the new method is much better than those of the current CPC and COLSS algorithms. 5 refs., 2 figs., 2 tabs. (Author)

  20. A review of X-ray computed axial tomography

    International Nuclear Information System (INIS)

    Schmidt, M.

    1989-01-01

    A review of Computed axial tomography (CAT) scanning literature outlining the theoretical and practical aspects of this technique with application in both medical diagnosis and industrial non-destructive inspection (NDI) is presented. Practical aspects of CAT scanning discussed include : radiation sources, currently available spatial and contrast resolution limits and the evolution of the computerized tomography (CT) system. It was found that monochromatic gamma rays are preferred to X-rays, especially for very high density materials, and that in medical CAT scanning, the special resolution is only, 0.5 mm while spatial resolutions of less than 50μm have been achieved in NDI. An increased number of scientific and industrial applications are anticipated (e.g. for studying sintering reactions), as the capital cost of CAT scanning decreased. 13 refs., 9 figs., 2 tabs

  1. Development of throughflow calculation code for axial flow compressors

    International Nuclear Information System (INIS)

    Kim, Ji Hwan; Kim, Hyeun Min; No, Hee Cheon

    2005-01-01

    The power conversion systems of the current HTGRs are based on closed Brayton cycle and major concern is thermodynamic performance of the axial flow helium gas turbines. Particularly, the helium compressor has some unique design challenges compared to the air-breathing compressor such as high hub-to-tip ratios throughout the machine and a large number of stages due to the physical property of the helium and thermodynamic cycle. Therefore, it is necessary to develop a design and analysis code for helium compressor that can estimate the design point and off-design performance accurately. KAIST nuclear system laboratory has developed a compressor design and analysis code by means of throughflow calculation and several loss models. This paper presents the outline of the development of a throughflow calculation code and its verification results

  2. Predicting the Coupling Properties of Axially-Textured Materials

    Directory of Open Access Journals (Sweden)

    María E. Fuentes-Montero

    2013-10-01

    Full Text Available A description of methods and computer programs for the prediction of “coupling properties” in axially-textured polycrystals is presented. Starting data are the single-crystal properties, texture and stereography. The validity and proper protocols for applying the Voigt, Reuss and Hill approximations to estimate coupling properties effective values is analyzed. Working algorithms for predicting mentioned averages are given. Bunge’s symmetrized spherical harmonics expansion of orientation distribution functions, inverse pole figures and (single and polycrystals physical properties is applied in all stages of the proposed methodology. The established mathematical route has been systematized in a working computer program. The discussion of piezoelectricity in a representative textured ferro-piezoelectric ceramic illustrates the application of the proposed methodology. Polycrystal coupling properties, predicted by the suggested route, are fairly close to experimentally measured ones.

  3. Predicting the Coupling Properties of Axially-Textured Materials

    Science.gov (United States)

    Fuentes-Cobas, Luis E.; Muñoz-Romero, Alejandro; Montero-Cabrera, María E.; Fuentes-Montero, Luis; Fuentes-Montero, María E.

    2013-01-01

    A description of methods and computer programs for the prediction of “coupling properties” in axially-textured polycrystals is presented. Starting data are the single-crystal properties, texture and stereography. The validity and proper protocols for applying the Voigt, Reuss and Hill approximations to estimate coupling properties effective values is analyzed. Working algorithms for predicting mentioned averages are given. Bunge’s symmetrized spherical harmonics expansion of orientation distribution functions, inverse pole figures and (single and polycrystals) physical properties is applied in all stages of the proposed methodology. The established mathematical route has been systematized in a working computer program. The discussion of piezoelectricity in a representative textured ferro-piezoelectric ceramic illustrates the application of the proposed methodology. Polycrystal coupling properties, predicted by the suggested route, are fairly close to experimentally measured ones. PMID:28788370

  4. Static Tension Tests on Axially Loaded Pile Segments in Sand

    DEFF Research Database (Denmark)

    Thomassen, Kristina; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    This paper provides laboratory test results of static axially loaded piles in sand. With a newly developed test setup, the pile-soil interface friction was investigated by using an open-ended steel pile segment with a diameter of 0.5 m. Use of a pile length of 1 m enabled the pile-soil interface...... friction to be analyzed at a given soil horizon while increasing the vertical effective stress in the sand. Test results obtained by this approach can be analyzed as single t-z curves and compared to predictions of unit shaft friction from current design methods for offshore foundations. The test results...... showed best agreement with the traditional design method given in the American Petroleum Institute (API) design code. When t-z curves obtained from the test results were compared to t-z curve formulations found in the literature, the Zhang formulation gave good predictions of the initial and post...

  5. Axial shape index calculation for the 3-level excore detector

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han Gon; Kim, Yong Hee; Kim, Byung Sop; Lee, Sang Hee; Cho, Sung Jae [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    A new method based on the alternating conditional expectation (ACE) algorithm is developed to calculate axial shape index (ASI) for the 3-level excore detector. The ACE algorithm, a type of nonparametric regression algorithms, yields an optimal relationship between a dependent variable and multiple independent variables. In this study, the simple correlation between ASI and excore detector signals is developed using the Younggwang nuclear power plant unit 3 (YGN-3) data without any preprocessing on the relationships between independent variables and dependent variable. The numerical results show that simple correlations exist between the three excore signals and ASI of the core. The accuracy of the new method is much better than those of the current CPC and COLSS algorithms. 5 refs., 2 figs., 2 tabs. (Author)

  6. On the axial anomalies in external tensor fields

    International Nuclear Information System (INIS)

    Khudaverdyan, O.M.; Mkrtchyan, R.L.; Zurabyan, L.A.

    1985-01-01

    Computation of the axial anomaly for Dirac fermions in external tensor fields is studied. The sequence of the supersymmetric one-dimensional models is presented. Their supercharges are equal, after quantization, to Dirac operators in external tensor fields, and the density of Witten's partition function gives the anomaly. It is shown that action in the corresponding path integral differs from the classical one. Gaussian approximation gives the anomaly only in the case of third-rank tensor with zero exterior derivative and in that case anomaly is calculated in all dimensions. The interpretation of that field as the torsion of gravitational field and also connection with the results of Witten and Alvarez-Gaume and Atiyah-Singer index theorem are discussed

  7. Stress Analysis of Fuel Rod under Axial Coolant Flow

    International Nuclear Information System (INIS)

    Jin, Hai Lan; Lee, Young Shin; Lee, Hyun Seung; Park, Num Kyu; Jeon, Kyung Rok

    2010-01-01

    A pressurized water reactor(PWR) fuel assembly, is a typical bundle structure, which uses light water as a coolant in most commercial nuclear power plants. Fuel rods that have a very slender and long clad are supported by fuel assembly which consists of several spacer grids. A coolant is a fluid which flows through device to prevent its overheating, transferring the heat produced by the device to other devices that use or dissipate it. But at the same time, the coolant flow will bring out the fluid induced vibration(FIV) of fuel rods and even damaged the fuel rod. This study has been conducted to investigate the flow characteristics and nuclear reactor fuel rod stress under effect of coolant. Fluid structure interaction(FSI) analysis on nuclear reactor fuel rod was performed. Fluid analysis of the coolant which flow along the axial direction and structural analysis under effect of flow velocity were carried out under different output flow velocity conditions

  8. Study of axial protections of unloading machines of graphite piles

    International Nuclear Information System (INIS)

    Duco, Jacques; Pepin, Pierre; Cabaret, Guy; Dubor, Monique

    1969-10-01

    As previous studies resulted in the development of a simple calculation formula based on experimental results for the calculation of neutron protection thicknesses for loading machines, this study aimed at determining axial protections of these machines which represent a specific problem: scattering of delayed neutrons in the machine inner cavity may result in an important neutron leakage through the upper part, at the level of the winch enclosure. In an experimental part, this study comprises the measurement of the neutron dose in a 2.60 m long and 54 cm diameter cylindrical cavity, and in the thickness of the surrounding concrete protection. In the second part, the authors present a calculation method which uses the Zeus and Mercure codes to interpret the results [fr

  9. Treatment of the axial friction forces in the transuranus code

    International Nuclear Information System (INIS)

    Lassmann, K.

    1991-01-01

    The problems of calculating axial friction forces are discussed. It is found that for the majority of failure analyses or safety related analyses under normal, off-normal and accident conditions a detailed model which takes all different modes of interaction between fuel and cladding into account is indispensable. The URFRIC model described in this paper is such a model. It is formulated in an extremely efficient numerical algorithm which saves computational costs. The URFRIC model has been applied successfully for 2 years in the TRANSURANUS code, and may in principle also be used in other quasi two-dimensional fuel performance codes. Results of this model are compared with results from a simple slip and a simple noslip model. Recommendations are given for the use of each of these models

  10. Simple LMFBR axial-flow friction-factor correlation

    International Nuclear Information System (INIS)

    Chan, Y.N.; Todreas, N.E.

    1981-09-01

    Complicated LMFBR axial lead-length averaged friction factor correlations are reduced to an easy, ready-to-use function of bundle Reyonlds number for wire-wrapped bundles. The function together with the power curves to calculate the associated constants are incorporated in a computer pre-processor, EZFRIC. The constants required for the calculation of the subchannels and bundle friction factors are derived and correlated into power curves of geometrical parameters. A computer program, FRIC, which can alternatively be used to accurately calculate these constants is also included. The accuracte values of the constants and the corresponding values predicted by the power curves and percentage error of prediction are tabulated for a wide variety of geometries of interest

  11. Phenomenological model for coupled multi-axial piezoelectricity

    Science.gov (United States)

    Wei, Yuchen; Pellegrino, Sergio

    2018-03-01

    A quantitative calibration of an existing phenomenological model for polycrystalline ferroelectric ceramics is presented. The model relies on remnant strain and polarization as independent variables. Innovative experimental and numerical model identification procedures are developed for the characterization of the coupled electro-mechanical, multi-axial nonlinear constitutive law. Experiments were conducted on thin PZT-5A4E plates subjected to cross-thickness electric field. Unimorph structures with different thickness ratios between PZT-5A4E plate and substrate were tested, to subject the piezo plates to coupled electro-mechanical fields. Material state histories in electric field-strain-polarization space and stress-strain-polarization space were recorded. An optimization procedure is employed for the determination of the model parameters, and the calibrated constitutive law predicts both the uncoupled and coupled experimental observations accurately.

  12. Computer aided hydraulic design of axial flow pump impeller

    International Nuclear Information System (INIS)

    Sreedhar, B.K.; Rao, A.S.L.K.; Kumaraswamy, S.

    1994-01-01

    Pumps are the heart of any power plant and hence their design requires great attention. Computers with their potential for rapid computation can be successfully employed in the design and manufacture of these machines. The paper discusses a program developed for the hydraulic design of axial flow pump impeller. The program, written in FORTRAN 77, is interactive and performs the functions of design calculation, drafting and generation of numerical data for blade manufacture. The drafting function, which makes use of the software ACAD, is carried out automatically by means of suitable interface programs. In addition data for blade manufacture is also generated in either the x-y-z or r-θ-z system. (author). 4 refs., 3 figs

  13. Hamilton's equations for a fluid membrane: axial symmetry

    International Nuclear Information System (INIS)

    Capovilla, R; Guven, J; Rojas, E

    2005-01-01

    Consider a homogeneous fluid membrane, or vesicle, described by the Helfrich-Canham energy, quadratic in the mean curvature. When the membrane is axially symmetric, this energy can be viewed as an 'action' describing the motion of a particle; the contours of equilibrium geometries are identified with particle trajectories. A novel Hamiltonian formulation of the problem is presented which exhibits the following two features: (i) the second derivatives appearing in the action through the mean curvature are accommodated in a natural phase space and (ii) the intrinsic freedom associated with the choice of evolution parameter along the contour is preserved. As a result, the phase space involves momenta conjugate not only to the particle position but also to its velocity, and there are constraints on the phase space variables. This formulation provides the groundwork for a field theoretical generalization to arbitrary configurations, with the particle replaced by a loop in space

  14. Gearbox Instrumentation for the Investigation of Bearing Axial Cracking

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Jonathan A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lambert, Scott R [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-03-27

    Failures in gearbox bearings have been the primary source of reliability issues for wind turbine drivetrains, leading to costly downtime and unplanned maintenance. The most common failure mode is attributed to so-called axial cracks or white-etching cracks, which primarily affect the intermediate and high-speed-stage bearings. The high-speed-shaft and bearing loads and sliding will be measured with a specially instrumented gearbox installed in a 1.5-megawatt turbine at the National Wind Technology Center in an upcoming test campaign. Additional instrumentation will also measure the tribological environment of these bearings, including bearing temperatures, lubricant temperature and water content, air temperature and humidity, and stray electrical current across the bearings. This paper fully describes the instrumentation package and summarizes initial results.

  15. Control of hole localization in magnetic semiconductors by axial strain

    Science.gov (United States)

    Raebiger, Hannes; Bae, Soungmin; Echeverría-Arrondo, Carlos; Ayuela, Andrés

    2018-02-01

    Mn and Fe-doped GaN are widely studied prototype systems for hole-mediated magnetic semiconductors. The nature of the hole states around the Mn and Fe impurities, however, remains under debate. Our self-interaction corrected density-functional calculations show that the charge neutral Mn 0 and positively charged Fe+ impurities have symmetry-broken d5+h ground states, in which the hole is trapped by one of the surrounding N atoms in a small polaron state. We further show that both systems also have a variety of other d5+h configurations, including symmetric, delocalized states, which may be stabilized by axial strain. This finding opens a pathway to promote long-range hole-mediated magnetic interactions by strain engineering and clarifies why highly strained thin-films samples often exhibit anomalous magnetic properties.

  16. Computerized axial tomography in the detection of brain damage

    International Nuclear Information System (INIS)

    Cala, L.A.; Mastaglia, F.L.

    1980-01-01

    The cranial computerized axial tomography (CAT) findings in groups of patients with epilepsy, migraine, hypertension, and other general medical disorders have been reviewed to assess the frequency and patterns of focal and diffuse brain damage. In addition to demonstrating focal lesions in a proportion of patients with seizures and in patients presenting with a stroke, the CAT scan showed a premature degree of cerebral atrophy in an appreciable proportion of patients with long-standing epilepsy, hypertension and diabetes, and in some patients with migraine, valvular and ischaemic heart disease, chronic obstructive airways disease, and chronic renal failure. The value of CAT as a means of screening for brain damage in groups of individuals at risk is discussed

  17. A cryogenic axial-centrifugal compressor for superfluid helium refrigeration

    CERN Document Server

    Decker, L; Schustr, P; Vins, M; Brunovsky, I; Lebrun, P; Tavian, L

    1997-01-01

    CERN's new project, the Large Hadron Collider (LHC), will use superfluid helium as coolant for its high-field superconducting magnets and therefore require large capacity refrigeration at 1.8 K. This may only be achieved by subatmospheric compression of gaseous helium at cryogenic temperature. To stimulate development of this technology, CERN has procured from industry prototype Cold Compressor Units (CCU). This unit is based on a cryogenic axial-centrifugal compressor, running on ceramic ball bearings and driven by a variable-frequency electrical motor operating under low-pressure helium at ambient temperature. The machine has been commissioned and is now in operation. After describing basic constructional features of the compressor, we report on measured performance.

  18. Operational Experience with a Cryogenic Axial-Centrifugal Compressor

    CERN Document Server

    Decker, L; Löhlein, K; Purtschert, W; Ziegler, B L; Lebrun, P; Tavian, L; Brunovsky, I; Tucek, L

    1998-01-01

    The Large Hadron Collider (LHC), presently under construction at CERN, requires large refrigeration capacity at 1.8 K. Compression of gaseous helium at cryogenic temperatures is therefore inevitable. Together with subcontractors, Linde Kryotechnik has developed a prototype machine. This unit is based on a cryogenic axial-centrifugal compressor, running on ceramic ball bearings and driven by a variable-frequency electrical motor operating at ambient temperature. Integrated in a test facility for superconducting magnets the machine has been commissioned without major problems and successfully gone through the acceptance test in autumn 1995. Subsequent steps were initiated to improve efficiency of this prototype. This paper describes operating experience gained so far and reports on measured performance prior to and after constructional modifications.

  19. Fare astronomia con piccoli telescopi

    CERN Document Server

    Gainer, Michael K

    2007-01-01

    Non sono necessariamente richiesti strumenti mastodontici per produrre risultati scientificamente validi nel campo dell’astronomia. Anche l’astrofilo dotato di un piccolo telescopio, con un diametro di soli 8-9 cm, può contribuire alla scienza del cielo realizzando utili osservazioni del Sole, della Luna, dei pianeti, delle comete, degli asteroidi, delle stelle doppie o variabili, delle nebulose e degli ammassi stellari. Il manuale di M.K. Gainer spiega quale sia la dotazione minima (un piccolo telescopio, un computer, una semplice fotocamera digitale), come utilizzarla, e quali siano le tecniche appropriate da adottare nelle osservazioni. Offre inoltre schemi per interpretare e ridurre i dati raccolti, nonché schede da compilare e da spedire ai centri di raccolta internazionali. Questo libro è il passaporto grazie al quale l’astrofilo può entrare a pieno titolo nel mondo affascinante della scienza astronomica.

  20. Axial turbomachine modelling with a 1D axisymmetric approach

    International Nuclear Information System (INIS)

    Tauveron, Nicolas; Saez, Manuel; Ferrand, Pascal; Leboeuf, Francis

    2007-01-01

    This work concerns the design and safety analysis of direct cycle gas cooled reactor. The estimation of compressor and turbine performances in transient operations is of high importance for the designer. The first goal of this study is to provide a description of compressor behaviour in unstable conditions with a better understanding than the models based on performance maps ('traditional' 0D approach). A supplementary objective is to provide a coherent description of the turbine behaviour. The turbomachine modelling approach consists in the solution of 1D axisymmetric Navier-Stokes equations on an axial grid inside the turbomachine: mass, axial momentum, circumferential momentum and total-enthalpy balances are written. Blade forces are taken into account by using compressor or turbine blade cascade steady correlations. A particular effort has been developed to generate or test correlations in low mass flow and negative mass flow regimes, based on experimental data. The model is tested on open literature cases of the gas turbine aircraft community. For compressor and turbine, steady situations are fairly described, especially for medium and high mass flow rate. The dynamic behaviour of compressor is also quite well described, even in unstable operation (surge): qualitative tendencies (role of plenum volume and role of throttle) and some quantitative characteristics (frequency) are in a good agreement with experimental data. The application to transient simulations of gas cooled nuclear reactors is concentrated on the hypothetical 10 in. break accident. The results point out the importance of the location of the pipe rupture in a hypothetical break event. In some detailed cases, compressor surge and back flow through the circuit can occur. In order to be used in a design phase, a simplified model of surge has also been developed. This simplified model is applied to the gas fast reactor (GFR) and compared quite favourably with 1D axisymmetric simulation results

  1. A Novel Geometry for Shear Test Using Axial Tensile Setup

    Directory of Open Access Journals (Sweden)

    Sibo Yuan

    2018-05-01

    Full Text Available This paper studies a novel geometry for the in-plane shear test performed with an axial electromechanical testing machine. In order to investigate the influence of the triaxiality rate on the mechanical behavior, different tests will be performed on the studied material: simple tensile tests, large tensile tests and shear tests. For the whole campaign, a common equipment should be employed to minimize the impact of the testing device. As a consequence, for the shear tests, the geometry of the specimen must be carefully designed in order to adapt the force value and make it comparable to the one obtained for the tensile tests. Like most of the existing shear-included tensile test specimens, the axial loading is converted to shear loading at a particular region through the effect of geometry. A symmetric shape is generally preferred, since it can restrict the in-plane rotation of the shear section, keep shear increasing in a more monotonic path and double the force level thanks to the two shear zones. Due to the specific experimental conditions, such as dimensions of the furnace and the clamping system, the position of the extensometer or the restriction of sheet thickness (related to the further studies of size effect at mesoscale and hot temperature, several geometries were brought up and evaluated in an iterative procedure via finite element simulations. Both the numerical and experimental results reveal that the final geometry ensures some advantages. For instance, a relatively low triaxiality in the shear zone, limited in-plane rotation and no necking are observed. Moreover, it also prevents any out-of-plane displacement of the specimen which seems to be highly sensitive to the geometry, and presents a very limited influence of the material and the thickness.

  2. Axial magnetic field injection in magnetized liner inertial fusion

    Science.gov (United States)

    Gourdain, P.-A.; Adams, M. B.; Davies, J. R.; Seyler, C. E.

    2017-10-01

    MagLIF is a fusion concept using a Z-pinch implosion to reach thermonuclear fusion. In current experiments, the implosion is driven by the Z-machine using 19 MA of electrical current with a rise time of 100 ns. MagLIF requires an initial axial magnetic field of 30 T to reduce heat losses to the liner wall during compression and to confine alpha particles during fusion burn. This field is generated well before the current ramp starts and needs to penetrate the transmission lines of the pulsed-power generator, as well as the liner itself. Consequently, the axial field rise time must exceed hundreds of microseconds. Any coil capable of being submitted to such a field for that length of time is inevitably bulky. The space required to fit the coil near the liner, increases the inductance of the load. In turn, the total current delivered to the load decreases since the voltage is limited by driver design. Yet, the large amount of current provided by the Z-machine can be used to produce the required 30 T field by tilting the return current posts surrounding the liner, eliminating the need for a separate coil. However, the problem now is the field penetration time, across the liner wall. This paper discusses why skin effect arguments do not hold in the presence of resistivity gradients. Numerical simulations show that fields larger than 30 T can diffuse across the liner wall in less than 60 ns, demonstrating that external coils can be replaced by return current posts with optimal helicity.

  3. Axial ion-electron emission microscopy of IC radiation hardness

    Science.gov (United States)

    Doyle, B. L.; Vizkelethy, G.; Walsh, D. S.; Swenson, D.

    2002-05-01

    A new system for performing radiation effects microscopy (REM) has been developed at Sandia National Laboratory in Albuquerque. This system combines two entirely new concepts in accelerator physics and nuclear microscopy. A radio frequency quadrupole (RFQ) linac is used to boost the energy of ions accelerated by a conventional Tandem Van de Graaff-Pelletron to velocities of 1.9 MeV/amu. The electronic stopping power for heavy ions is near a maximum at this velocity, and their range is ˜20 μm in Si. These ions therefore represent the most ionizing form of radiation in nature, and are nearly ideal for performing single event effects testing of integrated circuits. Unfortunately, the energy definition of the RFQ-boosted ions is rather poor (˜ a few %), which makes problematic the focussing of such ions to the submicron spots required for REM. To circumvent this problem, we have invented ion electron emission microscopy (IEEM). One can perform REM with the IEEM system without focussing or scanning the ion beam. This is because the position on the sample where each ion strikes is determined by projecting ion-induced secondary electrons at high magnification onto a single electron position sensitive detector. This position signal is then correlated with each REM event. The IEEM system is now mounted along the beam line in an axial geometry so that the ions pass right through the electron detector (which is annular), and all of the electrostatic lenses used for projection. The beam then strikes the sample at normal incidence which results in maximum ion penetration and removes a parallax problem experienced in an earlier system. Details of both the RFQ-booster and the new axial IEEM system are given together with some of the initial results of performing REM on Sandia-manufactured radiation hardened integrated circuits.

  4. Rotation of dust plasma crystals in an axial magnetic field

    International Nuclear Information System (INIS)

    Cheung, F.; Prior, N.; Mitchell, L.

    2000-01-01

    Full text: Micron-sized melamine formaldehyde particles were introduced into argon plasma. As a result, the particles were negatively charged due to collision with the electrons within the plasma. With the right conditions, these particles formed a stable macroscopic crystal lattice, known as dust plasma crystal. In our experiment we conduct at Flinders University, we apply an external axial magnetic field to various configurations of dust plasma crystal. These configurations include small crystal lattices consisting of one to several particles, and large crystal lattices with many hundreds of particles. The magnetic field strength ranged from 0-32G and was uniform over the extent of the crystal. The crystals were observed to be rotating collectively in the left-handed direction under the influence of the axial magnetic field. In the case of the large crystals, the angular velocity was about 2 complete rotations per minute and was proportional to the applied magnetic field. The angular velocity changes only slightly depending on the plasma conditions. Neither radial variance in the angular velocity nor shear velocity in the vertical direction was observed in the crystal's rotational motion. In the case of the small crystals, we managed to rotate 2-6 particles (whether they are planar, 2 layers or tetrahedral). We discovered that the ease and the uniformity of the rotation of the different crystals increase as its rotational symmetry increases. Also an increase in the magnetic field strength will correspond to an increase in the angular velocity. Crystals in the shape of an annulus were also tested for theoretical reasons. The poster presentation will contain the experimental procedures, a detailed analysis and an explanation for such dust plasma crystal rotational motion

  5. Mind the gap - tip leakage vortex in axial turbines

    International Nuclear Information System (INIS)

    Dreyer, M; Farhat, M; Decaix, J; Münch-Alligné, C

    2014-01-01

    The tendency of designing large Kaplan turbines with a continuous increase of output power is bringing to the front the cavitation erosion issue. Due to the flow in the gap between the runner and the discharge ring, axial turbine blades may develop the so called tip leakage vortex (TLV) cavitation with negative consequences. Such vortices may interact strongly with the wake of guide vanes leading to their multiple collapses and rebounds. If the vortex trajectory remains close to the blade tip, these collapses may lead to severe erosion. One is still unable today to predict its occurrence and development in axial turbines with acceptable accuracy. Numerical flow simulations as well as the actual scale-up rules from small to large scales are unreliable. The present work addresses this problematic in a simplified case study representing TLV cavitation to better understand its sensitivity to the gap width. A Naca0009 hydrofoil is used as a generic blade in the test section of EPFL cavitation tunnel. A sliding mounting support allowing an adjustable gap between the blade tip and wall was manufactured. The vortex trajectory is visualized with a high speed camera and appropriate lighting. The three dimensional velocity field induced by the TLV is investigated using stereo particle image velocimetry. We have taken into account the vortex wandering in the image processing to obtain accurate measurements of the vortex properties. The measurements were performed in three planes located downstream of the hydrofoil for different values of the flow velocity, the incidence angle and the gap width. The results clearly reveal a strong influence of the gap width on both trajectory and intensity of the tip leakage vortex

  6. Mind the gap - tip leakage vortex in axial turbines

    Science.gov (United States)

    Dreyer, M.; Decaix, J.; Münch-Alligné, C.; Farhat, M.

    2014-03-01

    The tendency of designing large Kaplan turbines with a continuous increase of output power is bringing to the front the cavitation erosion issue. Due to the flow in the gap between the runner and the discharge ring, axial turbine blades may develop the so called tip leakage vortex (TLV) cavitation with negative consequences. Such vortices may interact strongly with the wake of guide vanes leading to their multiple collapses and rebounds. If the vortex trajectory remains close to the blade tip, these collapses may lead to severe erosion. One is still unable today to predict its occurrence and development in axial turbines with acceptable accuracy. Numerical flow simulations as well as the actual scale-up rules from small to large scales are unreliable. The present work addresses this problematic in a simplified case study representing TLV cavitation to better understand its sensitivity to the gap width. A Naca0009 hydrofoil is used as a generic blade in the test section of EPFL cavitation tunnel. A sliding mounting support allowing an adjustable gap between the blade tip and wall was manufactured. The vortex trajectory is visualized with a high speed camera and appropriate lighting. The three dimensional velocity field induced by the TLV is investigated using stereo particle image velocimetry. We have taken into account the vortex wandering in the image processing to obtain accurate measurements of the vortex properties. The measurements were performed in three planes located downstream of the hydrofoil for different values of the flow velocity, the incidence angle and the gap width. The results clearly reveal a strong influence of the gap width on both trajectory and intensity of the tip leakage vortex.

  7. Hysteretic Models Considering Axial-Shear-Flexure Interaction

    Science.gov (United States)

    Ceresa, Paola; Negrisoli, Giorgio

    2017-10-01

    Most of the existing numerical models implemented in finite element (FE) software, at the current state of the art, are not capable to describe, with enough reliability, the interaction between axial, shear and flexural actions under cyclic loading (e.g. seismic actions), neglecting crucial effects for predicting the nature of the collapse of reinforced concrete (RC) structural elements. Just a few existing 3D volume models or fibre beam models can lead to a quite accurate response, but they are still computationally inefficient for typical applications in earthquake engineering and also characterized by very complex formulation. Thus, discrete models with lumped plasticity hinges may be the preferred choice for modelling the hysteretic behaviour due to cyclic loading conditions, in particular with reference to its implementation in a commercial software package. These considerations lead to this research work focused on the development of a model for RC beam-column elements able to consider degradation effects and interaction between the actions under cyclic loading conditions. In order to develop a model for a general 3D discrete hinge element able to take into account the axial-shear-flexural interaction, it is necessary to provide an implementation which involves a corrector-predictor iterative scheme. Furthermore, a reliable constitutive model based on damage plasticity theory is formulated and implemented for its numerical validation. Aim of this research work is to provide the formulation of a numerical model, which will allow implementation within a FE software package for nonlinear cyclic analysis of RC structural members. The developed model accounts for stiffness degradation effect and stiffness recovery for loading reversal.

  8. Gender Differences in Axial Spondyloarthritis: Women Are Not So Lucky.

    Science.gov (United States)

    Rusman, T; van Vollenhoven, R F; van der Horst-Bruinsma, I E

    2018-05-12

    Ankylosing spondylitis (AS) was historically seen as a predominantly male disease. However, more recent data showed a more homogenous sex prevalence. Unfortunately, in many studies in axial spondyloarthritis (axSpA), the number of women included is low and the analyses are often not stratified for gender distribution. The purpose of this review is to aggregate the existing data on gender differences in axSpA in order to increase the awareness that female axSpA patients are still under-recognized. Several studies considering gender differences revealed that female axSpA patients had different disease manifestations due to different immunological, hormonal, and genetic responses. For instance, allelic frequencies of the AHNK-gene and tissue non-specific alkaline phosphatase (TNAP) haplotypes differed between men and women with ankylosing spondylitis (AS). In addition, different levels of tumor necrosis factor (TNF), interleukins IL-6, IL-17, and IL-18, were found between the two sexes. Furthermore, female patients show a higher diagnostic delay compared to males. Several studies indicate a higher frequency of extra-articular manifestations (EAM) in female axSpA patients, such as enthesitis, psoriasis, and inflammatory bowel disease (IBD), whereas acute anterior uveitis is more prevalent in male patients. Male AS patients more frequently show a higher Bath Ankylosing Spondylitis Radiology Index (BASRI) scores and modified Stoke Ankylosing Spondylitis Spine Scores (mSASSS) than females, which indicates that males have higher radiological damage and radiographic progression. However, disease activity (BASDAI) and quality of life (AsQol) scores are significantly higher in women, and more importantly, they have significantly lower response rates to treatment with TNF inhibitors (TNFi) and a significantly lower drug adherence. Despite the fact that men with axial SpA have a worse radiologic prognosis, women have a high disease burden, in part because they have a longer

  9. Axial Skeletal Scintigraphy in Cancer of the Breast

    Energy Technology Data Exchange (ETDEWEB)

    Galasko, C. S.B. [Royal Postgraduate Medical School and Hammersmith Hospital, London (United Kingdom)

    1969-05-15

    An initial study was made on eight patients shown to have osseous metastases on X-ray. Each patient was examined on two occasions after the injection of {sup 87m}Sr and {sup 18}F. Regions known to contain metastases were examined at regular intervals after each injection. The scintigrams were compared with X-ray skeletal surveys. In all patients the {sup 18}F scintigram gave better results than the {sup 87m}Sr scan. All metastases present on X-ray were detected with the gamma camera and in six patients the scintigram revealed additional lesions. The optimum times for scanning were 1 1/4-3 hours after injection of {sup 18}F and 3-4 1/2 hours after {sup 87m}Sr. Axial skeleton scintigrams using {sup 18}F and a gamma camera are now being done on: (i) patients with apparently 'early' cancer of the breast. (ii) patients who have had a mastectomy and in whom there is a suspicion but no overt evidence of metastases. (iii) patients with advanced cancer of the breast. By means of this method it is hoped: (a) to detect lesions not present on X-ray. (b) to assess progress following hormonal therapy. 'Healing' lesions tend to have a diminished uptake of the isotope, and the varying pattern may prove to be more easy to interpret than conventional X-rays. The technique of axial skeleton scanning with the gamma camera and {sup 18}F, and the results obtained in over 60 patients with cancer of the breast, are reported. (author)

  10. Linear Optical Response of Silicon Nanotubes Under Axial Magnetic Field

    Science.gov (United States)

    Chegel, Raad; Behzad, Somayeh

    2013-01-01

    We investigated the optical properties of silicon nanotubes (SiNTs) in the low energy region, E < 0.5 eV, and middle energy region, 1.8 eV < E < 2 eV. The dependence of optical matrix elements and linear susceptibility on radius and magnetic field, in terms of one-dimensional (1-d) wavevector and subband index, is calculated using the tight-binding approximation. It is found that, on increasing the nanotube diameter, the low-energy peaks show red-shift and their intensities are decreased. Also, we found that in the middle energy region all tubes have two distinct peaks, where the energy position of the second peak is approximately constant and independent of the nanotube diameter. Comparing the band structure of these tubes in different magnetic fields, several differences are clearly seen, such as splitting of degenerate bands, creation of additional band-edge states, and bandgap modification. It is found that applying the magnetic field leads to a phase transition in zigzag silicon hexagonal nanotubes (Si h-NTs), unlike in zigzag silicon gear-like nanotubes (Si g-NTs), which remain semiconducting in any magnetic field. We found that the axial magnetic field has two effects on the linear susceptibility spectrum, namely broadening and splitting. The axial magnetic field leads to the creation of a peak with energy less than 0.2 eV in metallic Si h-NTs, whereas in the absence of a magnetic field such a transition is not allowed.

  11. Evaluation of efficiency of axial profiling in WWER-440 fuel assemblies

    International Nuclear Information System (INIS)

    Ananjev, Yu. A.; Kurakin, K. Yu.; Artemov, V.G.; Ivanov, A.S.

    2005-01-01

    The present report deals with consideration of fuel enrichment axial profiling in WWER-440 assemblies. The study is performed on improving the effectiveness of fuel utilization using the example of implementing the axial profiling in the assemblies of the second generation. For simulation of fuel loadings the computer code package SAPFIR 9 5 and RC is used that allows for correct consideration of specific features of assemblies design changes. The methodical approach to assessment of effectiveness of implementing the axial profiling is considered with the use of capabilities of the mentioned code package. In conclusion the recommendations are given on using the fuel enrichment axial profiling in WWER-440 assemblies (Authors)

  12. Organo-axial volvulus of the small intestine: radiological case report and consideration for its mechanism.

    Science.gov (United States)

    Ishiguro, Toshitaka; Hiyama, Takashi; Nasu, Katsuhiro; Akashi, Yoshimasa; Minami, Manabu

    2017-07-01

    Gastrointestinal volvulus is mainly classified into two subtypes, mesentero-axial volvulus and organo-axial volvulus. The detailed imaging findings of organo-axial volvulus of the small intestine have never been reported as far as we know. In this article, we report a case of organo-axial volvulus of the small intestine, focusing on the computed tomography (CT) findings. An 80-year-old man was radiologically diagnosed as having organo-axial volvulus of the terminal ileum and it was confirmed by open surgery without adhesion or any other anatomical abnormalities. CT showed two specific findings, split-bowel sign and rotating-C sign, which we think reflect pathophysiologic features of organo-axial volvulus. We think the pathogenic mechanism of organo-axial volvulus can be explained by the convergence of the reversed-rotational twist following the formation of a twisted but non-obstructive circular loop, even if there is no adhesion. Radiologists should be aware that organo-axial volvulus can occur even in the small intestine, and in the case of small bowel obstruction with single transition point, the two pathophysiologic signs mentioned above must be looked for to diagnose the possibility of organo-axial volvulus.

  13. Fuel rod with axial regions of annular and standard fuel pellets

    International Nuclear Information System (INIS)

    Freeman, T.R.

    1991-01-01

    This patent describes a fuel rod for use in a nuclear reactor fuel assembly. It comprises: an elongated hollow cladding tube; a pair of end plugs connected to and sealing the cladding tube at opposite ends of thereof; and an axial stack of fuel pellets contained in and extending between the end plugs at the opposite ends of the tube, all of the fuel pellets contained in the tube being composed of fissile material being enriched above the level of natural enrichment; the fuel pellets in the stack thereof being provided in an arrangement of axial regions. The arrangement of axial regions including a pair of first axial regions defined respectively at the opposite ends of the pellet stack adjacent to the respective end plugs. The pellets in the first axial regions being identical in number and having annular configurations with an annulus of a first void size. The arrangement of axial regions also including another axial region defined between the first axial regions, some of the pellets in the another axial region having solid configurations

  14. Atropisomerism: the effect of the axial chirality in bioactive compounds; Atropoisomerismo: o efeito da quiralidade axial em substancias bioativas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Anderson Rouge dos; Pinheiro, Alessandra Campbell; Sodero, Ana Carolina Renno; Cunha, Andrea Sousa da; Padilha, Monica Costa; Sousa, Priscila Mesquita de; Fontes, Silvia Paredes [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica. Dept. de Quimica Organica; Veloso, Marcia Paranho [Universidade Federal de Alfenas, MG (Brazil); Fraga, Carlos Alberto Manssour [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Faculdade de Farmacia. Lab. de Avaliacao e Sintese de Substancias Bioativas (LASSBio)]. E-mail: cmfraga@pharma.ufrj.br

    2007-01-15

    Atropisomerism is a special kind of stereoisomeric relationship that arises from the freezing of a certain conformation of an organic molecule, associated with a high rotational barrier about a single covalent bond. Atropisomerism has been originally described in orto-functionalized biphenyl derivatives, but a lot of other organic functionalities can present this structural phenomenon, characterized by the presence of chiral properties in compounds that do not present classical stereogenic centers. Atropisomeric compounds, intermediates and catalysts have well-know importance in organic synthesis, but the influence of the axial chirality in substances able to modulate biological systems is still not very exploited in drug design and development. In this context, the present account describes the importance of this structural property in the medicinal chemistry of different classes of bioactive compounds or therapeutic agents, emphasizing how atropisomerism could affect the molecular recognition of a ligand or a prototype by the target bioreceptor. (author)

  15. Depresion en pacientes con alteraciones del tiroides

    OpenAIRE

    Radanovic-Grguric´, Ljiljana; Filakovic´, Pavo; Barkic´, Jelena; Mandic´, Nikola; Karner, Ivan; Smoje, Juraj

    2003-01-01

    Nuestro estudio fue realizado en un grupo de 53 mujeres con disfunción tiroidea y 28 mujeres con depresión mayor. Empleamos la Escala de la Depresión de Hamilton, la Escala de Autoevaluación de la Depresión de Zung y la Escala sobre la Impresión Clínica Global. Los resultados del estudio demuestran que la mayoría de los pacientes con disfunción tiroidea se mostraron clínicamente significativos en cuanto al trastorno depresivo. Los episodios depresivos son más frecuentes en pacientes con hipot...

  16. Aprende Ajedrez con Rey - Parte 2

    OpenAIRE

    ESTÉVEZ MONTERO, RAÚL; Lloret Mauri, Jaime

    2016-01-01

    Es una pieza audiovisual creada con el objeto de atraer la atención de los niños de muy corta edad con el ajedrez y familiarizarlos con todas sus piezas y movimientos. Es una animación dirigida a un público infantil presentada por dibujos animados en 2D, en la que se ha intentado respetar en todo momento el argot de la comunidad ajedredística. En este video se presenta la segunda parte. Estévez Montero, R.; Lloret Mauri, J. (2016). Aprende Ajedrez con Rey - Parte 2. http://hdl.handle.net/1...

  17. Aprende Ajedrez con Rey - Parte 1

    OpenAIRE

    ESTÉVEZ MONTERO, RAÚL; Lloret Mauri, Jaime

    2016-01-01

    Es una pieza audiovisual creada con el objeto de atraer la atención de los niños de muy corta edad con el ajedrez y familiarizarlos con todas sus piezas y movimientos. Es una animación dirigida a un público infantil presentada por dibujos animados en 2D, en la que se ha intentado respetar en todo momento el argot de la comunidad ajedredística. En este video se presenta la primera parte. Estévez Montero, R.; Lloret Mauri, J. (2016). Aprende Ajedrez con Rey - Parte 1. http://hdl.handle.net/1...

  18. FIBROSIS PULMONAR IDIOPÁTICA

    OpenAIRE

    Álvaro Undurraga P., DR.

    2015-01-01

    La FPI predomina en el sexo masculino, en edades avanzadas, con tos y/o disnea progresivas. Un 5% se presenta como una forma familiar. La tomografía axial computarizada de tórax, fundamental en el diagnóstico, en al menos un 50% hace innecesaria la biopsia. El diagnóstico es conjunto con clínicos, radiólogos y patólogos. La sobrevivencia media es de tres a cinco años desde el diagnóstico. La historia natural es un deterioro progresivo, pero hay formas rápidas y también pueden aparecer e...

  19. Visualization of bonding at an inclusion boundary using axial-shear strain elastography: a feasibility study

    International Nuclear Information System (INIS)

    Thitaikumar, Arun; Krouskop, Thomas A; Garra, Brian S; Ophir, Jonathan

    2007-01-01

    Ultrasound elastography produces strain images of compliant tissues under quasi-static compression. In axial-shear strain elastography, the local axial-shear strain resulting from application of quasi-static axial compression to an inhomogeneous material is imaged. The overall hypothesis of this work is that the pattern of axial-shear strain distribution around the inclusion/background interface is completely determined by the bonding at the interface after normalization for inclusion size and applied strain levels, and that it is feasible to extract certain features from the axial-shear strain elastograms to quantify this pattern. The mechanical model used in this study consisted of a single stiff circular inclusion embedded in a homogeneous softer background. First, we performed a parametric study using finite-element analysis (FEA) (no ultrasound involved) to identify possible features that quantify the pattern of axial-shear strain distribution around an inclusion/background interface. Next, the ability to extract these features from axial-shear strain elastograms, estimated from simulated pre- and post-compression noisy RF data, was investigated. Further, the feasibility of extracting these features from in vivo breast data of benign and malignant tumors was also investigated. It is shown using the FEA study that the pattern of axial-shear strain distribution is determined by the degree of bonding at the inclusion/background interface. The results suggest the feasibility of using normalized features that capture the region of positive and negative axial-shear strain area to quantify the pattern of the axial-shear strain distribution. The simulation results showed that it was feasible to extract the features, as identified in the FEA study, from axial-shear strain elastograms. However, an effort must be made to obtain axial-shear strain elastograms with the highest signal-to-noise ratio (SNR asse ) possible, without compromising the resolution. The in vivo

  20. Evaluación tomográfica y radiográfica de la obturación radicular tridimensional de conductos radiculares únicos tratados con tres técnicas de obturación radicular: Estudio in Vitro

    Directory of Open Access Journals (Sweden)

    Mónica Alexandra Pavón Granja

    2016-09-01

    Full Text Available El principal reto durante la terapia endodóntica es la obturación radicular, considerada como fase crítica ya que de esta va a depender el éxito o el fracaso. Por varios años se ha investigado tanto materiales como técnicas que permitan el sellado hermético tridimensional del sistema de conductos radiculares, biocompatibilidad que permita la adecuada reparación de los tejidos periapicales y que la obturación se mantenga con el tiempo proporcionando salud. Objetivo: Evaluar la adaptación tridimensional de tres técnicas de obturación radicular definitiva a nivel del tercio apical de conductos radiculares únicos. Materiales y métodos: Estudio de tipo experimental y aleatorizado, la muestra fue de 42 raíces de dientes uniradiculares divididos en 3 grupos de estudio (n=14, previamente se realizó un registro radiográfico periapical digital de toda la muestra posteriormente fueron instrumentados con técnica hibrida, desinfectados con NaOCl al 5,25% + activación ultrasónica y EDTA al 17%, GA fue sometido a técnica de obturación lateral en frío, GB aplicado técnica de obturación termomecánica McSpadden y GC se obturó con técnica termoplastificada (BeFill-VDW. Resultados: Los grupos C y B observados a través de tomografía computarizada presentaron mejores resultados de obturación radicular que el grupo A que no presentó un buen sellado apical, sin embargo, en el grupo C se observó mejores resultados que en A y B Conclusiones: Las técnicas de obturación radicular definitivas con la técnica termoplastificada mostraron ser ideales para proporcionar un sellado apical hermético durante el tratamiento endodóntico en la fase de obturación

  1. Rodolfo Kusch: La búsqueda del sí-mismo a través del encuentro con el otro

    OpenAIRE

    Graciela Maturo

    2010-01-01

    Este breve artículo se propone -dentro de sus limitados alcances- señalar algunos temas axiales en el pensamiento de Rodolfo Kusch (Argentina, 1920-1979) y dejar indicado ese rumbo como vía de un filosofar latinoamericano. Con referencias a la fenomenología, y en particular a Martin Heidegger, Max Scheler, Paul Ricoeur y Emmanuel Levinas, en cuya corriente cabe situar, con matices propios, al filósofo argentino, intentamos mostrar su originalidad en la búsqueda del sujeto cultural americano, ...

  2. Plantas cubanas con efecto antiinflamatorio

    Directory of Open Access Journals (Sweden)

    Ada Ivis Regalado Veloz

    Full Text Available La actividad antiinflamatoria suscita gran interés científico en el área farmacológica, debido a que muchas enfermedades en su evolución cursan por procesos inflamatorios (artritis reumatoide, ateroesclerosis, cáncer, diabetes, gota, asma, dermatitis, trastornos neurodegenerativos y diversas dolencias menores. Las enfermedades inflamatorias constituyen un problema de salud importante, debido a la falta de medicamentos eficaces y seguros para su uso por periodos prolongados. Hoy en día se trabaja en la búsqueda de alternativas de antiinflamatorios más seguros, en el que las plantas medicinales, una de las formas más antiguas de tratamiento, constituyen una elección a considerar. En este trabajo se realizó una revisión bibliográfica, sobre especies de plantas que crecen en Cuba que le reportan propiedades farmacológicas como antinflamatorios. En la revisión de la literatura se utilizó la base de datos Medline (vía PubMed, así como revistas nacionales desde el periodo de 2000 hasta el presente, con las palabras claves "inflamación" y "plantas cubanas antiinflamatorias" o "actividad antiinflamatoria" y "plantas medicinales".

  3. Hospitalidad, con y sin papeles

    Directory of Open Access Journals (Sweden)

    Ana Paula Penchaszadeh

    Full Text Available Resumen El objetivo de este artículo es vincular el trabajo sobre el archivo de Jacques Derrida con la experiencia de la hospitalidad. Se intentará mostrar que, por un lado, se trata siempre de los papeles, de la legitimidad que éstos otorgan o no tanto a nivel filosófico (deseo de poseer los papeles que autoricen tal o cual decisión interpretativa, como a nivel político ("tener papeles" como el principio básico de todo derecho a tener derechos, de todo derecho a la comunidad. Mas también, por otro lado, se intentará pensar aquello que arruina la idea misma de tener o no tener (papeles, la idea de propiedad, aquello que hace imposible fundar una decisión o identidad en última instancia y, por ende, una soberanía, una frontera. La hospitalidad, la llegada inminente del otro, representa un desafío político y ético para la filosofía: pues no se trata de un saber, sino de una experiencia transformando el sustrato del nos-otros, del ser común.

  4. Itinerari Musicali con la Wiild

    Directory of Open Access Journals (Sweden)

    Elisabetta Nanni

    2013-03-01

    Full Text Available La Wiild, acronimo di Wiimote Lavagna Digitale, è uno strumento didattico che utilizza il telecomando della Wii, il famoso gioco della Nintendo, insieme a un software libero, rendendolo così estremamente versatile. Non vincolato a software proprietario, il suo utilizzo è legato alla capacità dell’insegnante di ripartire dalla didattica, dalle risorse selezionate e dall’epistemologia di ogni singola disciplina, trovando così nel proprio contesto un ruolo per le tecnologie. Il contributo presenta ipotesi di lavoro per l’educazione musicale nella scuola secondaria di primo grado che si sviluppano sia attraverso lo studio del rapporto suono/segno con affinità pittoriche e successiva codificazione grafica, sia attraverso un’attività di laboratorio in cui co-costruire percorsi storico-musicali. La Wiild diventerà davvero utile ed efficace nel momento in cui, affiancando le risorse selezionate dal docente, verrà utilizzata senza essere notata, giocando un ruolo di strumento tecnologico «normale e trasparente».

  5. Axial distribution of absorbed doses in fast neutron field at the RB reactor

    International Nuclear Information System (INIS)

    Sokcic-Kostic, M.; Pesic, M.; Antic, D.; Ninkovic, M.

    1988-11-01

    The coupled fast thermal system CFTS at the RB reactor is created for obtaining fast neutron fields. The axial distribution of fast neutron flux density in its second configuration (CFTS-2) is measured. The axial distribution of absorbed doses is computed on the basis of mentioned experimental results. At the end these experimental and computed results are given. (Author)

  6. Behaviour of a neutral particle with spin in an axial magnetic field

    International Nuclear Information System (INIS)

    Sorokin, S.V.; Ehpp, V.Ya.

    1982-01-01

    Proceeding from the Tamm-Good equation taking into account the spin influence on motion trajectory, the neutral particle motion tracjectory and vector turn of spin polarizition in axial magnetic field have been found. The behaviour of a neutral particle possessing its own magnetic moment in an axially-symmetric stationary magnetic field is considered

  7. Passive axial magnetic bearing with Halbach magnetized array in magnetically suspended control moment gyro application

    International Nuclear Information System (INIS)

    Sun Jinji; Ren Yuan; Fang Jiancheng

    2011-01-01

    The paper presents a special configuration of passive axial magnetic bearing with segmented Halbach magnetized array in magnetically suspended control moment gyro (MSCMG). Peculiarity of presented passive axial magnetic bearing is its ability to provide angular stiffness so that it can produce gyro moment when it is used in MSCMG. The MSCMG with this passive axial magnetic bearing can efficiently reduce the power loss when it supplies gyro moment compared with the five degrees of freedom (5-DOF) MSCMG. The characteristics of the suspension force and stiffness of the passive axial magnetic bearing are studied using finite element method (FEM). The performance of the presented passive axial magnetic bearing with Halbach magnetized array is verified by a prototyped MSCMG. - Research highlights: → Passive axial magnetic bearing is used to provide angular stiffness. → Passive axial magnetic bearing is based on repulsion. → Layers Halbach magnetized array realizes higher stiffness per bearing volume. → Passive axial magnetic bearing can provide gyro moment in CMG. → Power loss of MSCMG with PMB does not increase when it provides gyro moment.

  8. Clinical characteristics of importance to outcome in patients with axial spondyloarthritis

    DEFF Research Database (Denmark)

    Andreasen, Rikke Asmussen; Kristensen, Lars Erik; Ellingsen, Torkell

    2017-01-01

    INTRODUCTION: Spondyloarthritis (SpA) is a heterogeneous spectrum of rheumatic diseases with either predominantly axial inflammatory symptoms of the spine and sacroiliac joints or predominantly peripheral arthritis. The two main entities of axial SpA (axSpA) are ankylosing spondylitis or non...

  9. Cdx and Hox genes differentially regulate posterior axial growth in mammalian embryos

    NARCIS (Netherlands)

    Young, Teddy; Rowland, Jennifer Elizabeth; van de Ven, Cesca; Bialecka, Monika; Novoa, Ana; Carapuco, Marta; van Nes, Johan; de Graaff, Wim; Duluc, Isabelle; Freund, Jean-Noël; Beck, Felix; Mallo, Moises; Deschamps, Jacqueline

    2009-01-01

    Hox and Cdx transcription factors regulate embryonic positional identities. Cdx mutant mice display posterior body truncations of the axial skeleton, neuraxis, and caudal urorectal structures. We show that trunk Hox genes stimulate axial extension, as they can largely rescue these Cdx mutant

  10. Guided wave propagation as a measure of axial loads in rails

    CSIR Research Space (South Africa)

    Loveday, PW

    2010-03-01

    Full Text Available Guided wave propagation has been proposed as a means to monitor the axial loads in continuously welded railway rails although no practical system has been developed. In this paper, the influence of axial load on the guided wave propagation...

  11. Constraining vectors and axial-vectors in walking technicolour by a holographic principle

    DEFF Research Database (Denmark)

    D. Dietrich, Dennis; Kouvaris, Christoforos

    2008-01-01

    We use a holographic principle to study the low-energy spectrum of walking technicolour models. In particular, we predict the masses of the axial vectors as well as the decay constants of vectors and axial vectors as functions of the mass of the techni-rho. Given that there are very few...

  12. Magmatic controls on axial relief and faulting at mid-ocean ridges

    Science.gov (United States)

    Liu, Zhonglan; Buck, W. Roger

    2018-06-01

    Previous models do not simultaneously reproduce the observed range of axial relief and fault patterns at plate spreading centers. We suggest that this failure is due to the approximation that magmatic dikes open continuously rather than in discrete events. During short - lived events, dikes open not only in the strong axial lithosphere but also some distance into the underlying weaker asthenosphere. Axial valley relief affects the partitioning of magma between the lithosphere and asthenosphere during diking events. The deeper the valley, the more magma goes into lithospheric dikes in each event and so the greater the average opening rate of those dikes. The long-term rate of lithospheric dike opening controls faulting rate and axial depth. The feedback between axial valley depth D and lithospheric dike opening rate allows us to analytically relate steady-state values of D to lithospheric thickness HL and crustal thickness HC. A two-dimensional model numerical model with a fixed axial lithospheric structure illustrates the analytic model implications for axial faulting. The predictions of this new model are broadly consistent with global and segment-scale trends of axial depth and fault patterns with HL and HC.

  13. A benchmark study of procedures for analysis of axial crushing of bulbous bows

    DEFF Research Database (Denmark)

    Yamada, Yasuhira; Pedersen, Preben Terndrup

    2008-01-01

    Simplified methods to estimate mean axial crushing forces of plated structures are reviewed and applied to a series of experimental results for axial crushing of large-scale bulbous bow models. Methods based on intersection unit elements such as L-, T- and X-type elements as well as methods based...

  14. Molecular design for nonpolar chiral-axial quadratic nonlinear optics

    Science.gov (United States)

    Wiggers, Gregory A.

    In this thesis the hyperpolarizability of various multi-dimensional molecules is studied theoretically/computationally, with particular focus on the second-rank Kleinman-disallowed (KD) component of the hyperpolarizability. This component, which transforms as a second-rank traceless symmetric tensor, could be utilized in certain chiral-axial molecular alignment schemes to produce a bulk response. Nonpolar chiral-axial systems have been proposed in contrast to polar media, which utilize the vector component of the molecular hyperpolarizability and require parallel alignment of the molecular dipoles. Such parallel alignment of dipoles must be "frozen in" in order to overcome the natural tendency for dipoles to align anti-parallel. This limits the density of chromophores that can be loaded into a polar material. Nonpolar materials do not have such limits in theory. The two geometric classes of molecules that can most easily be incorporated into nonpolar chiral-uniaxial materials are propeller-shaped (C3 or D3 symmetry) and Λ-shaped (C2v symmetry). This work describes efforts to design molecules within these classes that would be suitable for bulk NLO materials. The sum-over-states (SOS) expression is used to model the molecular hyperpolarizability, and quantum chemical calculations, along with linear absorption data (when available) provide the necessary parameters to evaluate truncated forms of the SOS expression. A host of chemical and geometric modifications will be considered in order to elucidate important structure/function relationships. Also, the SOS model will be tested in some cases when experimental measurements (via Kleinman-disallowed hyper-Rayleigh scattering) are available. While a majority of this work focuses on multi-dimensional molecules, a small section deals with the question of optimizing the hyperpolarizability of a one-dimensional system. It is suggested that the recently-proposed idea of "modulated conjugation" as a means for improving

  15. NASA Glenn's Single-Stage Axial Compressor Facility Upgraded

    Science.gov (United States)

    Brokopp, Richard A.

    2004-01-01

    NASA Glenn Research Center's Single-Stage Axial Compressor Facility was upgraded in fiscal year 2003 to expand and improve its research capabilities for testing high-speed fans and compressors. The old 3000-hp drive motor and gearbox were removed and replaced with a refurbished 7000-hp drive motor and gearbox, with a maximum output speed of 21,240 rpm. The higher horsepower rating permits testing of fans and compressors with higher pressure ratio or higher flow. A new inline torquemeter was installed to provide an alternate measurement of fan and compressor efficiency, along with the standard pressure and temperature measurements. A refurbished compressor bearing housing was also installed with bidirectional rotation capability, so that a variety of existing hardware could be tested. Four new lubrication modules with backup capability were installed for the motor, gearbox, torquemeter, and compressor bearing housing, so that in case the primary pump fails, the backup will prevent damage to the rotating hardware. The combustion air supply line for the facility inlet air system was activated to provide dry air for repeatable inlet conditions. New flow conditioning hardware was installed in the facility inlet plenum tank, which greatly reduced the inlet turbulence. The new inlet can also be easily modified to accommodate 20- or 22-in.-diameter fans and compressors, so a variety of existing hardware from other facilities (such as Glenn's 9- by 15-Foot Low-Speed Wind Tunnel) can be tested in the Single-Stage Axial Compressor Facility. An exhaust line was also installed to provide bleed capability to remove the inlet boundary layer. To improve the operation and control of the facility, a new programmable logic controller (PLC) was installed to upgrade from hardwired relay logic to software logic. The PLC also enabled the usage of human-machine interface software to allow for easier operation of the facility and easier reconfiguration of the facility controls when

  16. Investigation of a Co-Axial Dual-Mechanical Ports Flux-Switching Permanent Magnet Machine for Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Wei Hua

    2015-12-01

    Full Text Available In this paper, a co-axial dual-mechanical ports flux-switching permanent magnet (CADMP-FSPM machine for hybrid electric vehicles (HEVs is proposed and investigated, which is comprised of two conventional co-axial FSPM machines, namely one high-speed inner rotor machine and one low-speed outer rotor machine and a non-magnetic ring sandwiched in between. Firstly, the topology and operation principle of the CADMP-FSPM machine are introduced; secondly, the control system of the proposed electronically-controlled continuously-variable transmission (E-CVT system is given; thirdly, the key design specifications of the CADMP-FSPM machine are determined based on a conventional dual-mechanical ports (DMP machine with a wound inner rotor. Fourthly, the performances of the CADMP-FSPM machine and the normal DMP machine under the same overall volume are compared, and the results indicate that the CADMP-FSPM machine has advantages over the conventional DMP machine in the elimination of brushes and slip rings, improved thermal dissipation conditions for the inner rotor, direct-driven operation, more flexible modes, lower cogging torque and torque ripple, lower total harmonic distortion (THD values of phase PM flux linkage and phase electro-motive force (EMF, higher torque output capability and is suitable for the E-CVT systems. Finally, the pros and cons of the CADMP-FSPM machine are highlighted. This paper lays a theoretical foundation for further research on CADMP-FSPM machines used for HEVs.

  17. Caracterización etiológica del síndrome de Lennox-Gastaut sintomático

    Directory of Open Access Journals (Sweden)

    Ileana Valdivia Álvarez

    2012-03-01

    Full Text Available Introducción: el síndrome de Lennox-Gastaut es una encefalopatía epiléptica dependiente de la edad, de gran severidad, por su farmacorresistencia y las discapacidades asociadas. Objetivos: caracterizar el síndrome de Lennox-Gastaut sintomático según sexo, edad de inicio y diagnóstico, tipo de crisis predominantes, hallazgos en neuroimagen y etiología. Métodos: estudio descriptivo, retrospectivo con una muestra de 36 pacientes egresados del servicio de neuropediatría del Hospital Pediátrico "Juan M. Márquez", con diagnóstico de síndrome de Lennox-Gastaut sintomático y que tuvieran estudios de neuroimagen (tomografía axial computarizada y resonancia magnética nuclear. Las variables cualitativas se describieron estadísticamente mediante frecuencias absolutas y cifras porcentuales. Para los porcentajes de interés, se calculó su intervalo de confianza con el 95 % de confiabilidad (IC 95 %. Resultados y conclusiones: el síndrome de Lennox-Gastaut sintomático fue más frecuente en varones, que comenzaron con epilepsia antes del año de edad, el 33 % presentó síndrome de West. Más del 60 % se diagnosticó antes de los 4 años de edad. Las crisis más frecuentes fueron las tónicas y atónicas de cuello. La tomografía axial computarizada permite localizar zonas de atrofia y pocas lesiones estructurales, que se precisan por resonancia magnética nuclear como alteraciones de la migración neuronal. Después de las malformaciones del sistema nervioso central, la causa más frecuente fue la hipoxia perinatal.

  18. Topological invariants and the dynamics of an axial vector torsion field

    International Nuclear Information System (INIS)

    Drechsler, W.

    1983-01-01

    A generalized throry of gravitation is discussed which is based on a Riemann-Cartan space-time, U 4 , with an axial vector torsion field. Besides Einstein's equations determining the metric of the U 4 a system of nonlinear field equations is established coupling an axial vector source current to the axial vector torsion field. The properties of the solutions of these equations are discussed assuming a London-type condition relating the axial current and torsion field. To characterize the solutions use is made of the Euler and Pontrjagin forms and the associated quadratic curvature invariants for the U 4 space-time. It is found that there exists for a Riemann-Cartan space-time a relation between the zeros of the axial vector torsion field and the singularities of the Pontrjagin invariant, which is analogous to the well-known Hopf relation between the zeros of vector fields and the Euler characteristic. (author)

  19. Efficient Propulsion Structure with an Axial Flux Rotary Converter for HEV Drive Unit

    Directory of Open Access Journals (Sweden)

    Ales Havel

    2011-01-01

    Full Text Available This paper describes an efficient axial flux arrangement of the four quadrant rotary converter for hybrid electric vehicles. The design of the axial flux wound stator and both axial flux squirrel cage rotors is based on the arrangement of radial air gap induction motor and permanent magnet synchronous motor. The method of constant magnetic circuit volume is utilized for dimensions conversion, which results into basic dimensions of stator and rotor discs in axial flux conception. This allows the creation of real 3D models in the CAD application. Finally, the finite element simulations of electromagnetic induction in the axial flux stator pack are presented in the concluding part of this paper.

  20. What changed during the axial age: Cognitive styles or reward systems?

    Science.gov (United States)

    Baumard, Nicolas; Hyafil, Alexandre; Boyer, Pascal

    2015-01-01

    The ‘Axial Age’ (500–300 BCE) refers to the period during which most of the main religious and spiritual traditions emerged in Eurasian societies. Although the Axial Age has recently been the focus of increasing interest,1-5 its existence is still very much in dispute. The main reason for questioning the existence of the Axial Age is that its nature, as well as its spatial and temporal boundaries, remain very much unclear. The standard approach to the Axial Age defines it as a change of cognitive style, from a narrative and analogical style to a more analytical and reflective style, probably due to the increasing use of external memory tools. Our recent research suggests an alternative hypothesis, namely a change in reward orientation, from a short-term materialistic orientation to a long-term spiritual one.6 Here, we briefly discuss these 2 alternative definitions of the Axial Age. PMID:27066164