WorldWideScience

Sample records for fields comunicaciones inalambricas

  1. Wireless Communication Into MBB Heliostats Fields; Comunicaciones Inalambricas del Campo de Heliostatos MBB. Proyecto Sirec

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Navaja, G

    2002-07-01

    Autonomous heliostats field are a priority objective long time pursued by PSA. Removal of all the electric cables, trenches and related components will really mean an important cosi reduction in civil works and investment for future Solar Thermal Power Plants, Several previous developments have been required before making autonomous-heliostats fields an eventual reality. First, a new local control has been designed to adapt all heliostats components to work on 24V de supplied by a photovoltaic panel. Second, a specific radio modem has been designed for wireless. Communications. In April 199, the first autonomous heliostats was started up an main results were reported at the 10th Solar PACES International Symposium. The objective, fixed within the projects SIREC fimded with the FEDER European Regional Development Program, has been to scale these concepts to a mini-field to demonstrate the feasibility of the wireless communication and operation with 20 MBB heliostats located at the North side of CRS facilities of PSA. A specific radio modem has been designed for this application thanks to the scientific cooperation agreement between the University of Almeria and CIEMAT, 50% of the heliostats field has been implemented with a commercial radio-modem and the other 50% with specific radio-modem to compare the performance and capabilities. The capacities of both systems will be analysed and the main data obtained from the test campaign carried out, will be showed. (Author) 12 refs.

  2. Coexistencia e integracion de comunicaciones inalambricas en sistemas de transmision opticos

    Science.gov (United States)

    Perez Soler, Joaquin

    protection margins in order to ensure the coexistence between both technologies. The obtained protection margins are of great interest for the development of advanced interference mitigation techniques such as DAA (Detect-and-Avoid), in the framework of future cognitive radio technologies. In a second step, the wireless coexistence of MB-OFDM UWB and WiMAX technologies is analyzed from the point of view of access networks based on RoF systems. Two experimental field trials are here carried out. In the first one, the wireless convergence is evaluated in a multi-mode fibre RoF system, whereas in the second one, the RoF system is based on a standard single-mode fibre. These experimental results provide relevant fibre link transmission distances to enable the deployment of RoF networks. Moreover, a new optical transmission technique based on polarization division multiplexing is proposed and experimentally evaluated in order to ensure the wireless coexistence in RoF systems. Finally, the impact of the electro-optical Mach-Zehnder modulator is analyzed, since the dynamic range of this device limits the performance of the RoF system. Moreover, a new optical linearization technique for Mach-Zehnder modulators is proposed and evaluated in order to overcome this limitation.

  3. Bluetooth 4.0 Low Energy: la futura solucion inalambrica de bajo consumo

    OpenAIRE

    Morales Pedro, Ricard

    2011-01-01

    En los últimos años el sector de las telecomunicaciones se ha erigido como uno de los mas innovadores de nuestra sociedad, donde la irrupción de nuevos estandares de comunicación inalambrica esta permitiendo ir eliminando la necesidad de los cables de transmisión para conectar dispositivos. Con este proposito nació Bluetooth, una tecnologia que permite transmisiones inalambricas de corto alcance de forma robusta y sencilla, junto con un consumo reducido y un bajo coste. Tras la aparición de B...

  4. Comunicaciones móviles

    OpenAIRE

    Gorricho Moreno, Monica; Gorricho Moreno, Juan Luis

    2002-01-01

    Bibliografia El presente trabajo se encuadra dentro de la bibliografía básica de las comunicaciones móviles, con un tratamiento de la temática que se extiende hasta los futuros sistemas de tercera generación. El contenido del mismo comienza con una visión general de las comunicaciones móviles, que refiere desde los principios básicos de funcionamiento de los actuales y futuros sistemas celulares hasta la concreción de los mecanismos de implementación que posibilitan un correcto funcionamie...

  5. Portal web para comunicaciones seguras

    OpenAIRE

    Jurado Villalobos, Rodrigo

    2015-01-01

    Proyecto teórico-práctico de investigación, enfocado a obtener un mayor conocimiento del funcionamiento de los protocolos y funciones de seguridad criptógrafica así como explorar las limitaciones y buscar nuevas vías de implementar la seguridad de las comunicaciones a través del desarrollo de una aplicación que dé uso en un entorno “real” de estos protocolos de seguridad. Dicha aplicación consistirá en un portal web de mensajería entre usuarios que empleará sistemas criptográficos tanto en el...

  6. INFRAESTRUCTURA DE COMUNICACIONES EN MICRORREDES ELECTRICAS

    Directory of Open Access Journals (Sweden)

    Elvis Eduardo Gaona García

    2014-11-01

    Full Text Available Este artículo muestra un estudio de la actualidad técnica y tecnológica de la infraestructura de comunicaciones utilizadas en  microrredes eléctricas, en este sentido ha surgido la necesidad de investigar, analizar, mejorar y desarrollar métodos de comunicación tanto alámbricos como inalámbricos que permitan crear una infraestructura de comunicaciones que soporte las características de control, supervisión y trasmisión de información entre dispositivos de control en una microrred de forma eficiente, segura y confiable.Dadas estas características en el artículo se analizan  las diferentes arquitecturas y topologías propuestas entorno a comunicaciones en el ambiente Smart Grid que se puedan adaptar a la forma en que opera una microrred. Se muestran las propuestas  y desarrollos realizados en el  área de telecomunicaciones concerniente a protocolos de comunicaciones utilizados en microrredes eléctricas, con el fin de conocer las tecnologías, protocolos y algoritmos utilizados en la transmisión de datos.

  7. Treball Final de Master - Servidor de Comunicacions Unificades

    OpenAIRE

    Alavedra del Rio, Isaac

    2011-01-01

    L'objectiu d'aquest projecte és la creació d'una prova de concepte de comunicacions unificades utilitzant productes de programari lliure existents. Aquesta prova de concepte servirà per poder fer demostracions del funcionament general del programari implicat amb el mínim de preparacions, instal·lacions i configuracions prèvies possibles. El projecte es dividirà en dos appliances o LiveCD, creats a traves de Suse Studio, anomenats Comunicacions Unificades i Comunicacions Unificades 2. Els ...

  8. Tema 5. Comunicaciones y redes. Transparencias. Curso 2012-2013

    OpenAIRE

    Saiz Noeda, Maximiliano

    2012-01-01

    TEMA 5. COMUNICACIONES Y REDES. TRANSPARENCIAS. Este tema hace un recorrido por las tecnologías de comunicación entre sistemas electrónicos, los dispositivos y medios de comunicación más comunes, así como Internet como el recurso fundamental de comunicación en nuestra era.

  9. Tema 5. Comunicaciones y Redes. Transparencias. Curso 2010-2011

    OpenAIRE

    Saiz Noeda, Maximiliano

    2010-01-01

    TEMA 5. COMUNICACIONES Y REDES. TRANSPARENCIAS. Este tema hace un recorrido por las tecnologías de comunicación entre sistemas electrónicos, los dispositivos y medios de comunicación más comunes, así como Internet como el recurso fundamental de comunicación en nuestra era.

  10. Tema 5. Comunicaciones y Redes. Transparencias. Curso 2011-2012

    OpenAIRE

    Saiz Noeda, Maximiliano

    2011-01-01

    TEMA 5. COMUNICACIONES Y REDES. TRANSPARENCIAS. Este tema hace un recorrido por las tecnologías de comunicación entre sistemas electrónicos, los dispositivos y medios de comunicación más comunes, así como Internet como el recurso fundamental de comunicación en nuestra era.

  11. Posgrado en Comunicaciones, para profesionales de otras disciplinas

    Directory of Open Access Journals (Sweden)

    José Manuel De Pablos

    2015-01-01

    Full Text Available En América Latina enfrentamos un doble problema: los comunicadores saben poco o casi nada de las ocupaciones de otros profesionales –médicos, ingenieros, empresarios, economistas- y éstos carecen de las nociones y destrezas para incorporar las comunicaciones eficazmente a su práctica profesional. Probablemente sea utópico intentar formar periodistas que se acerquen al modelo polivalente del intelectual renacentista. En cambio puede ser más viable y productivo hacer un buen comunicador de un médico o un ingeniero. Este modelo de actualización y especialización puede mejorar sustancialmente la calidad del periodismo y ampliar los horizontes de la formación en comunicaciones

  12. La gestión comunicacional en la identidad corporativa de la Universidad del Zulia

    Directory of Open Access Journals (Sweden)

    Fanny Ramírez

    2004-01-01

    Full Text Available Partiendo de la identidad corporativa se compone de cuatro elementos a saber; los principios basico organizacionales (mision, vision, valores, politicas, objetivo y estrategias, el comportamiento organizacional, el simbolismo o identidad audiovisual y la comunicacion; se contrasta la teoria con la practica en varios estudios realizados como ejercicios de catedra y de la linea de investigacion "Gerencia comunicacional, identidad e imagen corporativa" en los programas de maestria ciencias de la comunicaciones y en estudios realizados como trabajos de ascenso y grado.

  13. Comunicaciones transnacionales: Cine y televisión

    Directory of Open Access Journals (Sweden)

    Raquel Salinas Bascur

    2015-05-01

    Full Text Available Las recientes discuciones sobre la política de comunicación internacional, el "flujo libre y balanceado de información", y el Nuevo Orden de Información, se han concentrado en la producción y distribución transnacional de información y material para los medios de comunicación social. Se ha notado que en la época actual, los flujos de información global se caraterizan por su desbalance y son inadecuados, y que en la mayoría de los países, estos flujos les convierten en recipientes pasivos de la información que es diseminada desde unos pocos países. Las corporaciones de comunicaciones transnacionales son una parte esencial del presente sistema transnacional. Su impacto en la conciencia de los pueblos es obvio, y puede ser aún más grande que el de otras industrias de un mayor significado económico. Sin embargo, se están estableciendo las bases del conocimiento que permitirán la formulación de una política real y adecuada al respecto del flujo transnacional de información e intercambio cultural.

  14. Sistema de comunicaciones para el control de una planta de biocombustible

    OpenAIRE

    SIGNES PALOP, JOSEP FELIP; Sempere Paya, Víctor Miguel; COLL LOZANO, CATERINA

    2012-01-01

    Tras el análisis exhaustivo de los protocolos más importantes, y con el objetivo de escalar la tecnología presente en la planta Perseo Bioethanol de Imecal, en la que se transforma la fracción orgánica de los residuos sólidos urbanos en un biocombustible líquido de segunda generación, para el diseño de un nuevo sistema de comunicaciones se escogió la tecnología Profinet. Signes Palop, JF.; Sempere Paya, VM.; Coll Lozano, C. (2012). Sistema de comunicaciones para el control d...

  15. Herramientas de software de simulación para redes de comunicaciones

    OpenAIRE

    Torres, Juan Antonio

    2015-01-01

    Actualmente los sistemas de computación y redes de comunicación son parte esencial del funcionamiento de las empresas, y una de las tareas más importantes, de los diseñadores de redes. El estudio del desempeño de las redes de comunicaciones a través de la simulación es una forma de abordar estas redes de comunicaciones. Las herramientas de simulación vista son: NetSim, Jimsim, KivaNS, Network Simulator, OMNET ++, Packet Tracer, OPNET Modeler, RouterSim Network Simulators, Toggit y ...

  16. Pensamento comunicacional canadense: as contribuições de Innis e McLuhan

    Directory of Open Access Journals (Sweden)

    Luiz C. Martino

    2009-09-01

    Full Text Available Resumo O presente trabalho visa apresentar o pensamento comunicacional canadense. Sustenta a idéia de Harold Innis como pioneiro, entendendo que sua obra, mais do que uma simples teoria, comporta um programa de pesquisa (no sentido de Imre Lakatos. Define o núcleo duro do programa innisiano, como: a a ação da técnica nos processos de comunicação e b a centralidade dos meios de comunicação para entender a organização social. Teses que estão na base de um projeto de incomparável valor epistemológico, visto que constituiriam uma possibilidade para o fundamento do próprio saber comunicacional. Palavras-chave: Pensamento comunicacional canadense; teoria da comunicação; Harold Innis; Marshall McLuhan; Escola de Toronto de Comunicação. Resumen El presente trabajo visa presentar el pensamiento comunicacional canadiense. Sustenta la idea de Harold Innis como pionero, entendiendo que su obra, más que una simple teoría, comporta un programa de investigación (en el sentido de Imre Lakatos. Define el núcleo duro del programa innisiano como: a la acción de la técnica en los procesos de comunicación y b la centralidad de los medios de comunicación para entender la organización social. Tesis que constituyen la base de un proyecto de incomparable valor epistemológico, visto que constituirían una posibilidad para el fundamento del propio saber comunicacional. Palabras-clave: Pensamiento comunicacional canadiense; teoría de la comunicación; Harold Innis; Marshall McLuhan; Toronto School of Communication (Escuela de Comunicación de Toronto. Abstract This article presents the main lines of thought within Canadian Communication. It sustains the thesis of Harold Innis as pioneer, understanding that his work, more than just a simple theory, it admits a research program (such as employed by Imre Lakatos. It defines as the hard core for the Innisian program: a the action of technique on communication processes and b the centrality of

  17. De la Auditoría Contable a la Auditoría de las Comunicaciones

    OpenAIRE

    Cerezo, Claudia Rita

    2013-01-01

    A partir del examen del concepto de Auditoría y de su campo de actuación, se realizará un análisis de la práctica de auditoría contable, de sus herramientas y de sus procedimientos. Luego, se expondrán conceptos básicos de Auditoría de las Comunicaciones. A continuación, y basándose en autores del área de la Comunicación, se analizarán puntos en común y diferencias entre la Auditoría Contable y la Auditoría en Comunicaciones. Se analizará el impacto de la comunicación en los negocios. Se conc...

  18. EL DESARROLLO DE LA IDENTIDAD CORPORATIVA: FUNCION INHERENTE DE LA GESTIÓN COMUNICACIONAL

    Directory of Open Access Journals (Sweden)

    Fanny Ramírez de Bermúdez

    2005-07-01

    Full Text Available En este trabajo se caracteriza la función de la gestión comunicacional en el desarrollo de la Identidad corporativa. Se establecieron los componentes de la Identidad corporativa; se conceptuó la doble naturaleza de la Identidad: (Emisión-Percepción y se identificó la relación entre el nivel de solidez de la identidad corporativa con el comportamiento de la gestión comunicacional. Mediante la técnica del análisis documental, primero, se explican teóricamente las variables establecidas para desarrollar una nueva propuesta; segundo se corrobora en el plano empírico la relación formulada como supuesto hipotético. Como resultado, se estableció, además de los tres componentes ampliamente explicados por diversos autores: (el simbolismo o identidad audiovisual, la comunicación y el comportamiento, un cuarto componente: Los principios básicos organizacionales. Se concluye que el mantenimiento de la identidad es responsabilidad inherente de una buena gestión comunicacional. La corroboración empírica evidencia también, que las organizaciones que se caracterizan por una débil Identidad en algunos de sus cuatro componentes, manifiestan una débil o nula gestión comunicacional y en consecuencia no cuentan con una sólida identificación. En definitiva la comunicación como cuarto componente ha de ser gestionado debido a su compleja naturaleza, puesto que él se engendra desde los principios básicos y sólo él hace posible la emisión de los mismos. Él se manifiesta mediante el comportamiento organizacional, el simbolismo y los mensajes.

  19. Diseño y actualización de una red de comunicaciones industrial

    OpenAIRE

    Ferrero Alcals, Lluís

    2013-01-01

    Actualització d'una xarxa de comunicacions industrial a partir de l'arquitectura actual; disseny i desenvolupament. [ANGLÈS] The complexity of the industrial network due to increased number of devices and control networks, and the obsolescence of some equipment and control applications requires rethinking the design of a new communications network to allow more flexibility, hardiness and low maintenance. In this project is presented the design of an industrial communications network from t...

  20. Servidor de comunicaciones unificadas con Raspberry Pi y Micro-Elastix

    OpenAIRE

    Peláez, David; Tipantuña, Christian; Universidad de Cuenca; Dirección de Investigación de la Universidad de Cuenca; DIUC

    2014-01-01

    El presente trabajo tiene como finalidad mostrar la configuración e implementación de un servidor de comunicaciones unificadas utilizando un Raspberry Pi como plataforma de hardware y la distribución de Elastix, micro-Elastix, desarrollada especialmente para trabajar en arquitecturas ARM. This paper shows the configuration and implementation of a unified communications server using a Raspberry Pi as the hardware platform and the Elastix distribution as software platform, specifically micro...

  1. Tecnologías inalambricas. Soluciones wireless

    OpenAIRE

    Paredes Rodriguez, Damián

    2003-01-01

    Actualmente existen dos estándares técnicos (aunque tecnologías de transmisión por ondas hay muchas) para la conexión sin cables en el entorno personal y en el de empresa: BlueTooth y Wi-Fi. BlueTooth es un sistema muy versátil que podemos encontrarlo disponible en un gran número de dispositivos. Sus principales desventajas son su velocidad (1 Mbps, aproximadamente) y cobertura (un máximo de 40 metros), que lo hacen poco aconsejable en entornos informáticos de cierta exigencia. Wi-Fi (W...

  2. Comunicaciones seguras sobre redes móviles ad hoc

    OpenAIRE

    Rocabado Moreno, Sergio Hernán; Arias Figueroa, Daniel; Sánchez, Ernesto

    2011-01-01

    En este proyecto se ha planteado investigar diferentes mecanismos para realizar comunicaciones seguras utilizando redes móviles ad-hoc, esto permitirá aprovechar las características inherentes de este tipo de redes, para llevar información crítica de forma segura a lugares donde no se disponga de acceso a redes de infraestructura. El resultado final será una propuesta que servirá de base para el desarrollo e implementación de sistemas móviles para emergencias médicas y también como material d...

  3. “Proyecto Couchsurfing como herramienta comunicacional para el intercambio cultural”

    OpenAIRE

    León Paredes, Gabriela Fernanda

    2013-01-01

    En esta era digital en la que vivimos, se evidencia cómo el ser humano se ve involucrado en procesos de transformación tanto a nivel comunicacional como de interacción con los demás. Estas transformaciones, están determinadas por las conexiones entre lo digital y lo humano, es decir, se da mucha importancia a los aspectos digitales que también promulgan las relaciones sociales. Por tanto, este trabajo muestra cómo las tecnologías de la ...

  4. Aproximación a la seguridad de las comunicaciones en Internet de las Cosas

    OpenAIRE

    Eterovic, Jorge; Cipriano, Marcelo

    2017-01-01

    Ya entrado el siglo XXI un sinnúmero de dispositivos y objetos almacenan, transmiten y reciben información con escasa o nula intervención de los seres humanos. Las Redes WSN y dispositivos de tipo RFID son ejemplo de ello. Pare el público en general estos sistemas resultan ser “invisibles”. Es decir que se ignora su existencia o se tiene una visión parcial o incompleta de los mismos. Esta invisibilidad también incluye a las tecnicas de protección y seguridad de dichas comunicaciones, tr...

  5. Aplicaciones del modelo On/Off al tráfico agregado en las redes de comunicaciones

    OpenAIRE

    Parra León, Andrés; Piedrahita, Elkin M; Salcedo, Octavio

    2011-01-01

    Los modelos que permiten recrear trazas de tráfico generadas en una red de comunicaciones, pueden utilizarse en predicciones y estimaciones de tráfico a fin de optimizar el uso de los recursos de la red; uno de estos es el modelo On/Off, el cual permite describir el comportamiento del tráfico agregado por una o más fuentes de información. La importancia de este artículo se centra en la incidencia que dicho modelo ha tenido al aplicarse en diversas tecnologías de comunicaciones, para esto se e...

  6. APLICACIÓN DE LAS COMUNICACIONES Y NUEVAS TECNOLOGÍAS AL CAMPO DEL APRENDIZAJE MOTOR

    Directory of Open Access Journals (Sweden)

    A. Oña

    2010-09-01

    Full Text Available

    RESUMEN

    En este artículo exponemos las posibilidades de las Nuevas Tecnologías en el campo del Aprendizaje Motor. Explicaremos con detalle las aplicaciones en Investigación, los programas informáticos especializados, las comunicaciones e Internet, el aprendizaje por modelos y práctica asistida, la Simulación y Realidad Virtual y la Tele-educación.
    PALABRAS CLAVE:Nuevas Tecnologías, Informática, Aprendizaje Motor, Comunicaciones e Internet

     

    ABSTRACT

    We expose in this paper the posibilities of News Technologies in Motor Learning. We will explain in detail the aplications in Research, Apply Software, Communications and Internet, Modeling Learning Practice Assisted, Simulation,Virtual Reality and Tele-Education.
    KEY WORDS: News Technologies, computer Science, Motor Learning, Communications and Internet.

     

  7. Social media y comercio electrónico. Pinterest como nueva herramienta comunicacional

    Directory of Open Access Journals (Sweden)

    Joan Francesc Fondevila Gascón

    2013-05-01

    Full Text Available Internet ha puesto al alcance de la sociedad las herramientas necesarias para convertir al individuo en un usuario activo. La tecnología ha transformado la forma lineal y rígida en la que se recibía la información, para dar paso a un flujo de contenidos hipertextual y bidireccional. Esta investigación cualitativa pretende vislumbrar si la red social Pinterest podría actuar como una herramienta comunicacional para fomentar el comercio electrónico. Hemos estudiado la percepción de los internautas sobre esta red social. De esta manera, a través de la observación online y de la entrevista en profundidad virtual, bajo el método de comparación constante de la teoría fundamentada, concluimos que los internautas perciben a Pinterest más como herramienta comunicacional que de e-commerce.

  8. Evaluación de la modulación digital DPSK y OQPSK utilizados en sistemas de comunicaciones ópticos sobre OPTISYSTEM.

    OpenAIRE

    Herrera Illescas, Milton Junior

    2015-01-01

    El proyecto de graduación denominado “EVALUACIÓN DE LA MODULACIÓN DIGITAL DPSK Y OQPSK UTILIZADOS EN SISTEMAS DE COMUNICACIONES ÓPTICOS SOBRE OPTISYSTEM” consistió en desarrollar dos modelos de simulación para la transmisión y recepción de información sobre sistemas de comunicaciones ópticas de alta velocidad. Estos modelos fueron diseñados en el software OptiSystem que permite modelar sistemas de comunicaciones a través de fibra óptica. En el Capítulo 1, se describe la parte preliminar del p...

  9. Satélites de comunicaciones: Una perspectiva para el Tercer Mundo

    Directory of Open Access Journals (Sweden)

    Neville D. Jayaweera

    2015-01-01

    Full Text Available "La ciencia y la tecnología pueden ser tomadas en préstamos, importadas y adaptadas del extranjero. Pero en última instancia la creatividad desde dentro es la única respuesta. Porque el desarrollo, en esencia, no es una cuestión de tecnología o de PNB, sino la expansión de una nueva conciencia, el movimiento de la mente humana, la inspiración del espíritu humano, el infundir confianza en la humanidad". Podemos aceptar la cita anterior como una pista de despegue útil a nuestra discusión, no porque todos podamos compartir la opinión de Kleijans sobre lo que es "en esencia" el desarrollo, sino porque su negación de que la ciencia, la tecnología y el PNB constituyan determinantes esenciales del desarrollo es en sí significativa. En primer lugar es significativa porque es una aceptación formal del fracaso de cierta ideología particular del desarrollo comunicacional, o sea del paradigma de la "modernización" que emana de los Estados Unidos en los decenios de los años 50 y 60 y que hasta ahora mantiene su imperio en muchos países en desarrollo. En segundo lugar, porque proviene del director de una institución que, desde que fuera fundada por un decreto del Congreso en 1960, ha sido el bastión de esa ideología, al menos en lo que se refiere a las comunicaciones.

  10. Desarrollo de un Sistema de Comunicaciones Ópticas Clásicas en Espacio Libre con Aplicación en Comunicaciones Cuánticas

    Directory of Open Access Journals (Sweden)

    Arturo Arvizu Mondragón

    2014-01-01

    Full Text Available Actualmente los enlaces ópticos en espacio libre tienen diversas aplicaciones (algunas comerciales y otras en desarrollo tales como: a enlaces horizontales de comunicaciones dentro de la misma capa de la atmósfera terrestre (denominados enlaces FSO por sus siglas en inglés “free space optics” permanentes o temporales (para situaciones de emergencia de corta distancia para comunicación entre edificios (Fsona, 2014 , y comunicación de alta velocidad en redes personales de área local óptica inalámbrica (Wang, K., et al, 2011, b enlaces verticales (denominados generalmente sistemas LASERCOM para comunicación entre aviones y satélites, entre satélites en diferentes órbitas (Chan, V., 2003, de satélites a estaciones terrenas y viceversa (operando en diversas capas de la atmósfera terrestre o en el espacio profundo (Hemmati, H., 2006, c conexión óptica inalámbrica de alta velocidad entre tarjetas de circuito impreso (por ejemplo para distribución de señales de reloj dentro de un satélite y/o para interconectar ductos y microprocesadores sin interferencia electromagnética (Savage, N., 2002. El desarrollo de enlaces ópticos para comunicación de tierra hacia y desde el espacio ha sido y es de gran interés para diversas agencias espaciales alrededor del mundo (JAXA, 2009, en particular, el sistema satelital europeo SILEX es un ejemplo de su aplicación (ESA, 2014; además, la NASA puso en funcionamiento en septiembre de 2013 la misión “Lunar Laser Communication Demonstration”, cuyo objetivo principal es demostrar la confiabilidad de la comunicación óptica entre una estación situada en órbita lunar y estaciones terrenas en nuestro planeta (NASA,2014. Generalmente los enlaces arriba mencionados son “clásicos” (operando con un relativamente alto número de fotones por período de observación, pero, recientemente ha crecido el interés en desarrollar sistemas de comunicaciones “cuánticos” (con bajo número de

  11. A dimensão comunicacional como recorte metodológico para o estudo das migrações

    Directory of Open Access Journals (Sweden)

    Pedro Russi

    2014-03-01

    Full Text Available El presente texto propone una reflexión sobre el lugar de lo comunicacional en los procesos metodológicos en la investigación cualitativa con migrantes. Para esto, se toma como base para análisis dos experiencias de investigación realizadas en Brasil. Se analiza la contribución del concepto de producción del espacio psicofísico como operador metodológico que permite discutir las imbricaciones de diversas dimensiones de la experiencia de vida en migración. Se concluye que, lo comunicacional demanda articulaciones y cuidados metodológicos que deben ser pensados en esa especificidad, para entenderlo mejor dentro de la dinámica de la experiencia migratoria.

  12. ARQUITECTURA DE SOLUCIÓN DE TELEFONÍA IP Y COMUNICACIONES UNIFICADAS PARA UNA CORPORACIÓN PETROLERA

    Directory of Open Access Journals (Sweden)

    Jesús Carabaño

    2010-09-01

    Full Text Available Normal 0 21 false false false ES-TRAD X-NONE X-NONE MicrosoftInternetExplorer4 Este trabajo presenta el modelo de Arquitectura de Solución desarrollado como respuesta a las necesidades de disponer de principios y lineamientos que permitieran guiar la evolución y el desarrollo de nuevas soluciones de telefonía y Comunicaciones Unificadas en la Corporación Petróleos de Venezuela. El aporte fundamental de este trabajo está constituido por los lineamientos de diseño para la construcción de un sistema de telefonía IP y comunicaciones unificadas de muy bajo costo utilizando software libre y estándares abiertos en un ambiente corporativo de alto tráfico, superando las expectativas de tiempo de instalación, servicio y funcionamiento comparado con los sistemas convencionales.

  13. Cuerpos-Espacios sonoros: Disonancias en la metrópolis comunicacional

    Directory of Open Access Journals (Sweden)

    Massimo Canevacci

    2008-01-01

    Full Text Available El artículo se concentra en el cambio de la ciudad industrial a la metrópolis comunicacional y en el consecuente cambio de sus habitantes que se adaptan y renuevan a las nuevas condiciones. Este proceso favorece el surgir de un nuevo sujeto (multividuo que cambia su visión del mundo y transforma los escenarios urbanos en lugares fragmentarios y musicales (soundscape. Este cambio es posible sólo gracias a la reapropiación performática de algunos espacios urbanos por parte de artistas y públicos dispuestos a profanar algunos escenarios destinados a fines institucionales o funcionales al desarrollo de la ciudad. En estos espacios el soundscape y el bodyscape interactúan desarrollando nuevos significados y nuevos sentidos en política. En Roma diferentes lugares han sido usadas en años recientes para poner en escena estas performances que se conectan con el cambio urbano y la consecuente modificación de la experiencia sensorial. Tales espacios son utilizados para poner en escena perfomances que resignifican contextos urbanos. En el ensayo se analizarán tres eventos romanos: Disonanze del 2006, La notte bianca del 2006 y la presentación del grupo finlandés Pan Sonic, escogida como una zona de grafitti.

  14. Zonas de vacancia comunicacional en los estudios sobre fútbol

    Directory of Open Access Journals (Sweden)

    Sodo, Juan Manuel

    2011-01-01

    Full Text Available [es] Pese a su tardía colocación como objeto legitimado al interior de las ciencias sociales, especialmente en América latina, los estudios sobre fútbol son abundantes. Contando con producciones de numerosos países, la masa textual generada al respecto crece y prolifera. No es nuestra intención en este artículo reponerla en la exhaustividad del detalle. Más bien se trata, primero, de cartografiar las procedencias disciplinares de esos textos. Y luego, de situar zonas de vacancia para investigaciones provenientes desde una mirada comunicacional. [en] In spite of its late placement as legitimized object to the interior of the social sciences, specially in Latin America, the studies on football are abundant. Relying on productions of numerous countries, the textual mass generated in the matter grows and proliferates. It is not our intention in this article to recover it with the thoroughness of the detail. Rather than that, the objective is to map the disciplinarian origins of these texts. And then, of placing zones of vacancy for researches that come from a communication perspective

  15. Tecnologías de la Información y Comunicaciones

    Directory of Open Access Journals (Sweden)

    José Luis Monteagudo Peña

    Full Text Available Las Tecnologías de la Información y las Comunicaciones constituyen una herramienta fundamental para soportar las actividades profesionales de investigación en biomedicina y salud. Su adopción y uso está ligado a la eficiencia y competitividad. Tras el análisis de las necesidades se han identificado las aplicaciones TICs cuyo dominio es recomendable. Las necesidades se refieren al desarrollo de las actividades propias de los proyectos de investigación pero también de formación continuada, docencia y desarrollo profesional. Sobre la base anterior, se propone una estructura de programa formativo basado en niveles y con una mezcla de bases generales comunes de tipo horizontal y áreas de especialización vertical. Finalmente, se pone de manifiesto que las nuevas tecnologías además de facilitar nuevos instrumentos significan nuevas culturas de trabajo y presentan nuevos dilemas de carácter ético y legal para los investigadores que necesitarán formarse en nuevos entornos de trabajo.

  16. Gestión comunicacional e imagen corporativa en la Universidad Nacional Abierta (UNA

    Directory of Open Access Journals (Sweden)

    Graciela Perozo de Jiménez

    2004-01-01

    Full Text Available El presente artículo tiene como objetivo determinar la imagen corporativa como herramienta de gestión comunicacional en la Universidad Nacional Abierta (UNA, de los Centros Locales: Táchira, Mérida, Trujillo, Lara, Falcón y Zulia. La investigación siguió la modalidad de trabajo de campo de tipo descriptiva, dentro del enfoque cuantitativo. La población estuvo constituida por 13.794 estudiantes y 138 miembros del personal académico de los centros locales del occidente del país, quedando la muestra conformada por 390 estudiantes y 103 miembros del personal académico. Como instrumento de recolección de datos se utilizaron 2 cuestionarios uno para cada muestra seleccionada con la finalidad de obtener información sobre la imagen corporativa en la UNA, a través de la dimensión:”necesidades en materia de comunicación y promoción”, los cuales se sometieron a validez de contenido por parte de diez (10 expertos y se calculó la confiabilidad obteniendo un coeficiente de 0,90 para ambos. Como técnica de análisis de datos se utilizó la estadística descriptiva, mediante distribución de frecuencias y medias aritméticas. Como resultado se determinó que la comunicación y la promoción tienen una tendencia media hacia una tendencia baja, por lo que las necesidades en materia de comunicación y promoción son muchas a fin de contar con una comunicación eficiente, clara y oportuna, que permita proyectar una imagen positiva de la Institución.

  17. Energy saving, social and government communication; Ahorrro de energia, sociedad y comunicacion gubernamental

    Energy Technology Data Exchange (ETDEWEB)

    Morales Camarena, Francisco [Comision Nacional para el Ahorro de Energia, Mexico, D.F. (Mexico)

    2001-07-01

    The actions for the energy efficiency and the utilization of renewable energies are multiple and dispersed, in each one of the energy consumption points of the country. For this reason, two important factors to foment these actions are to promote the social participation and the effective government communication towards the society: energy saving and social participation. One of the main faculties of the National Commission of Energy Saving (CONAE) is to foment the efficiency in the energy use, through actions coordinated with the different agencies and organizations of the Federal Public Administration, with the governments of the federal entities and the municipalities and, through coordinated operations, with the private and social sectors. The CONAE has established mechanisms of coordination and cooperation with the private and social sectors, having fomented programs, projects and actions whose purpose is the energy efficiency, outstanding: 1) Committees and work groups; 2) Cooperation Agreements; 3) the Advisory Council for the Foment of Renewable Energy. [Spanish] Las acciones para la eficiencia energetica y el aprovechamiento de las energias renovables son multiples y dispersas, en cada uno de los puntos de consumo de energia del pais. Por ello, dos factores importantes para fomentar estas acciones son promover la participacion social y la comunicacion gubernamental eficaz hacia la sociedad: Ahorro de energia y participacion social. Una de las principales facultades de la Comision Nacional de Ahorro de Energia es fomentar la eficiencia en el uso de energia, a traves de acciones coordinadas con las diversas dependencias y entidades de la Administracion Publica Federal, con los gobiernos de las entidades federativas y de los municipios y, a traves de acciones concertadas, con los sectores social y privado. La CONAE ha establecido mecanismos de coordinacion y de cooperacion con los sectores privado y social, fomentando programas, proyectos y acciones cuyo

  18. Tecnologías de la Información y Comunicaciones Information and Communication Technologies

    Directory of Open Access Journals (Sweden)

    José Luis Monteagudo Peña

    2004-03-01

    Full Text Available Las Tecnologías de la Información y las Comunicaciones constituyen una herramienta fundamental para soportar las actividades profesionales de investigación en biomedicina y salud. Su adopción y uso está ligado a la eficiencia y competitividad. Tras el análisis de las necesidades se han identificado las aplicaciones TICs cuyo dominio es recomendable. Las necesidades se refieren al desarrollo de las actividades propias de los proyectos de investigación pero también de formación continuada, docencia y desarrollo profesional. Sobre la base anterior, se propone una estructura de programa formativo basado en niveles y con una mezcla de bases generales comunes de tipo horizontal y áreas de especialización vertical. Finalmente, se pone de manifiesto que las nuevas tecnologías además de facilitar nuevos instrumentos significan nuevas culturas de trabajo y presentan nuevos dilemas de carácter ético y legal para los investigadores que necesitarán formarse en nuevos entornos de trabajo.Information and Communication Technologies are essential to support professional research activities in biomedicine and health. Their adoption and use is linked to efficiency and competitivity. After need analysis, TICs applications whose knowledge is recommended, are identified. Needs are referred to activities linked to the execution of research projects but also to teaching, continuous training and professional development. Based on that, it is proposed a formative programme structure with different competence levels and with a combination of horizontal common general skills and vertical specialization areas. Finally, it is outlighted that new technologies facilitate new instruments but also they represent new working cultures and present new ethic and legal dilemmas to the researchers that would need to be educated in new working environments.

  19. Estudio de técnicas de Cross-Layer para sistemas de comunicaciones inalámbricos

    OpenAIRE

    Robles Campillo, Lorena; Moya Román, Mireia

    2005-01-01

    El presente proyecto se sitúa en uno de los ámbitos de investigación más relevantes en la actualidad, las comunicaciones inalámbricas. En concreto se centra en las redes WLAN en modo ad-hoc basadas en el estándar IEEE 802.11. Los principales objetivos del proyecto son la propuesta, el estudio y el análisis de técnicas de Cross-Layer con el fin de mejorar la eficiencia y el rendimiento de los sistemas WLAN. Obteniendo estas mejoras potenciales se consigue optimizar el uso de los recursos...

  20. Influencia de la web 2.0 en el consumidor cuencano y propuesta comunicacional para las empresas

    OpenAIRE

    Calle Pesántez, Verónica Nataly

    2013-01-01

    En los últimos años el Internet ha evolucionado, permitiéndonos disfrutar de comunicaciones interpersonales a través de la web 2.0; de ahí que, ¿existe en nuestro medio un acercamiento entre consumidores y empresas? Las nuevas tecnologías y la apertura al Internet han provocado cambios en la sociedad y se desconoce al nuevo consumidor hiperconectado, lo que exige que las empresas cambien sus estrategias de comunicación. Como consecuencia de estos problemas, las empresas no podrán conocer, co...

  1. Páginas para una historia de las comunicaciones ópticas y la fotónica

    OpenAIRE

    Martín Pereda, José Antonio

    2001-01-01

    Este trabajo es el resultado de una parte del curso "Fundamentos Electrónicos de las Comunicaciones" (2001) que los Departamentos del Área de "Tecnología Electrónica" de la ETSIT UPM llevan Impartiendo, con carácter de asignatura Optativa, durante los últimos tres años. El material recogido a los largo de estos años se ha ido acumulando en una larga serie de transparencias que están esperando adquirir la forma de un breve texto escrito. Antes de que esto se convierta en realidad el a...

  2. Planeamiento estratégico, comunicación interna y ambiente laboral en la Dirección General de Concesiones en Comunicaciones. 2016

    OpenAIRE

    Ávila Cruz, Félix

    2016-01-01

    La presente investigación tuvo como objetivo general el estimar el modelo de regresión logística que describe la relación entre el Planeamiento estratégico frente a la Comunicación Interna y el Ambiente Laboral en la Dirección General de Concesiones en Comunicaciones año 2016; la población constituida por 110 trabajadores administrativos de la Dirección General de Concesiones en Comunicaciones, la muestra no probabilística consideró toda la población, en los cuales se ha emp...

  3. LA POLITICA UN PROCESO COMUNICACIONAL. LAS ELECCIONES EN LA CIUDAD DE PEREIRA, COLOMBIA, EN EL AÑO 2007

    Directory of Open Access Journals (Sweden)

    Olga Lucía Bedoya

    2009-01-01

    Full Text Available Los integrantes de los Grupos de Investigación en Comunicación Educativa y Sociedad -Imaginarios - Comunicación SIC de Colombia, han venido reflexionando, desde 1999, sobre la relación ciudad-ciudadano que se establece en los procesos de construcción de ciudad. En esta reflexión, la ciudad se ha abordado como un proceso dinámico, de lo que se deduce que es susceptible de transformaciones no sólo en el orden de lo físico, sino también de lo social, cultural, económico y político. La apuesta de este artículo, es poder visualizar la política como un proceso dinámico comunicacional en las Elecciones de Alcalde y Gobernador en el periodo electoral del año 2007 en la ciudad de Pereira (Risaralda, Colombia. En esta perspectiva, tomaremos la temporalidad como eje vinculante, de la siguiente manera: en el eje de las elecciones, distinguiremos las preselecciones, la elección y la pos-elección, donde se establecen enlaces comunicativos que permiten el funcionamiento del sistema político. Esto es lo que denominaremos modelo comunicacional, basado en la “operacionalización” de los conceptos de comunicación, acción y expectativas del sociólogo Niklas Luhmann.

  4. Application of unimodal optic fiber to communications among electric substations; Aplicacion de fibra optica unimodal a comunicaciones entre subestaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Pinon, Fernando; Hernandez Juarez, Taide [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-07-01

    The utilization of the unimodal fiber optics technology in the electric power systems, represents one of the best communication options because of its multiple advantages, that results in a better coordination of the technical and administrative activities, needed to carry the electric energy from its generation site to the most remote locations. In this document a study, in accordance with the available options for the design of communication systems via unimodal optic fiber, is presented. With this technology, ties of more than 100 kilometers without the need of repeating stations, can be made. [Espanol] La utilizacion de la tecnologia de fibra optica unimodal en los sistemas electricos de potencia representa una de las mejores alternativas de comunicacion por sus multiples ventajas que se traducen en una mejor coordinacion de las acitividades tecnicas y administrativas necesarias para llevar la energia electrica desde el lugar de generacion hasta los puntos mas distantes. En este documento se presenta un estudio de acuerdo a las opciones disponibles para el diseno de sistemas de comunicacion por fibra optica unimodal. Con esta tecnologia se pueden realizar enlaces mayores que 100 km sin necesidad de repetidores.

  5. Comunicaciones rurales en Cuba utilizando Redes Tolerantes al Retraso e Interrupciones

    Directory of Open Access Journals (Sweden)

    Andrés Subert Semanat

    2010-09-01

    Full Text Available Normal 0 21 false false false ES-TRAD X-NONE X-NONE MicrosoftInternetExplorer4 st1:*{behavior:url(#ieooui } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} La arquitectura Internet se ha extendido de forma imparable por todo el mundo, no obstante, las premisas que sustentan esta arquitectura no son aplicables a entornos donde es imposible mantener una comunicación extremo a extremo fiable, con baja latencia y bajas tasas de error; donde la comunicación entre los nodos sea casual o planificada. Las Redes tolerantes al retardo e interrupciones (DTN se han convertido en una solución para las comunicaciones en este tipo de entorno. En este trabajo se presenta un primer acercamiento al uso de esta arquitectura para solucionar los problemas de comunicación en poblados de la Sierra Maestra en Cuba. Para esto se estudian las tecnologías más utilizadas en entornos rurales y se evalúa la implementación de algunas de ellas en la Sierra Maestra. Por último se analiza al empleo de las DTN en el país.

  6. Propuesta de introducción de servicios de seguridad en redes y sistemas públicos de comunicaciones

    OpenAIRE

    Fernández del Val, Carlos

    2011-01-01

    El trabajo desarrollado se centra en la formalización de los mecanismos de seguridad para su incorporación a los protocolos de cómunicaciones con el fin de ofrecer servicios de seguridad para protección de la información en entornos dé comunicaciones públicas. Se aborda la problemática relacionada con la construcción de medidas de protección susceptibles de normalización y se diseñan los mecanismos de seguridad, basados en técnicas criptográficas, en razón de las amenazas se resuelven. Se sel...

  7. Propuesta de introducción de servicios de seguridad en redes y sistemas públicos de comunicaciones

    OpenAIRE

    Fernández del Val, Carlos

    1990-01-01

    El trabajo desarrollado se centra en la formalización de los mecanismos de seguridad para su incorporación a los protocolos de cómunicaciones con el fin de ofrecer servicios de seguridad para protección de la información en entornos dé comunicaciones públicas. Se aborda la problemática relacionada con la construcción de medidas de protección susceptibles de normalización y se diseñan los mecanismos de seguridad, basados en técnicas criptográficas, en razón de las amenazas se resuelven. Se sel...

  8. Evolución de las redes de datos: Hacia una plataforma de comunicaciones completamente óptica

    Directory of Open Access Journals (Sweden)

    Gustavo Puerto Leguizamón

    2008-01-01

    Full Text Available Este artículo presenta una introducción a las redes de comunicaciones ópticas, para lo cual se describe la evolución que están experimentando dichas redes a fin de soportar las futuras demandas en el transporte de tráfico IP. Esta evolución se debe en gran parte al desarrollo de dispositivos que permiten el procesamiento de señales en el domino óptico. De la misma forma se presenta un modelo de router de conmutación de paquetes ópticos basado en el paradigma de intercambio de etiqueta con capacidad de conmutación de paquetes IP a 10 Gb/s. Por otra parte, se ha incorporado en el router la capacidad de procesar paquetes de tamaño variable y se comprueba experimentalmente sus prestaciones.

  9. LAS COMUNICACIONES INTEGRADAS DE MARKETING (CIM COMO PILAR DE LA ESTRATEGIA DE MARKETING VERDE Y SUS IMPLICACIONES EN LA GESTIÓN AMBIENTAL

    Directory of Open Access Journals (Sweden)

    NELCY ROCÍO ESCOBAR MORENO

    2012-01-01

    Full Text Available Este documento examina el constructo de Comunicaciones Integradas de Marketing (CIM, desde su definición hasta su aplicación a partir de la perspectiva del mercadeo verde en la estrategia organizacional. El texto presenta tres grandes discusiones, primero, una reflexión particular sobre los aportes e implicaciones más importantes de las Comunicaciones Integradas de Marketing y de cada uno de sus instrumentos a la estrategia de gestión ambiental de las organizaciones. Luego, una caracterización general del consumidor verde y de otros stakeholders de la organización, en particular, de su papel en el proceso estratégico de la comunicación verde. Finalmente, como conclusión de este trabajo, se plantean algunas consideraciones sobre la necesaria aplicación de este concepto en la propuesta de gestión ambiental organizacional en la actualidad.

  10. Grandes organizaciones empresariales en México y Chile: un análisis de perfiles con respecto a sus comunicaciones sobre responsabilidad social

    Directory of Open Access Journals (Sweden)

    Teodoro R. Wendlandt Amezaga

    2015-06-01

    Full Text Available El presente estudio identificó subgrupos de empresas con base en sus comunicaciones sobre responsabilidad social (CRS y estableció diferencias entre estos en lo relativo a su país de origen, procedencia del capital, extensión en sus comunicaciones y actividad industrial. De manera no probabilística se seleccionaron un total de 300 grandes empresas de México y Chile. Mediante una prueba de conglomerados no jerárquicos K-medias, se identificaron dos subgrupos de empresas de acuerdo con sus frecuencias de CRS (principios motivacionales [F = 217.1, p < .000], procesos de gestión [F = 990.4, p < .000] y grupos de interés [F = 1317.3, p < .000]. El primer conglomerado integrado por 100 empresas (33% se denominó perfil bajo de comunicaciones sobre responsabilidad social (PB-CRS y el segundo, que incluyó a 200 empresas (67%, se denominó perfil alto de comunicaciones sobre responsabilidad social (PA-CRS. En el subgrupo PA-CRS existe una mayor proporción de empresas de origen mexicano (X2=38.50, p<.000, de capital de procedencia extranjera (X2=53.40, p<.000, con niveles de extensión media (X2=4.76, p=.029 o extensiva (X2=143.15, p<.000, con actividades industriales, de bienes de consumo (X2=10.12, p=.001, químicos (X2=16.13, p <.000, recursos naturales (X2=13.50, p<.000 y materiales-construcción (X2=6.54, p=.011

  11. La estrategia comunicacional en el sector mega-minero. Un estudio del caso La Alumbrera en Argentina

    Directory of Open Access Journals (Sweden)

    Julieta Godfrid

    2016-06-01

    Full Text Available En los últimos años se produjo en la Argentina una rápida expansión de la mega-minería a cielo abierto, lo que vino acompañado de un creciente aumento de la conflictividad socio-ambiental que cuestiona en profundidad las consecuencias de la actividad extractiva. En este contexto, las múltiples críticas a la mega-minería deslegitimaron profundamente la imagen del sector y de las empresas que llevan adelante este tipo de actividad. A partir de allí, las corporaciones mega-mineras se vieron frente a la necesidad de construir una nueva estrategia comunicacional integral que les permitiera mejorar su imagen y construir consenso en torno a la actividad. El presente trabajo indaga en torno a las nuevas estrategias comunicacionales del sector mega-minero que se llevan a cabo bajo el paradigma de la Responsabilidad Social Empresaria y el “marketing experiencial”. Para ello se trabaja a partir del estudio de caso del emprendimiento mega-minero más antiguo del país, la empresa La Alumbrera (Provincia de Catamarca.

  12. La gestión comunicacional basada en la cultura organizacional e identidad corporativa de la Universidad Nacional Abierta (UNA

    Directory of Open Access Journals (Sweden)

    Graciela Perozo de Jiménez

    2006-01-01

    Full Text Available El presente estudio tuvo como propósito determinar la cultura organizacional e identidad corporativa como instrumentos de gestión comunicacional en la Universidad Nacional Abierta, de los Centros Locales del occidente del país. La investigación siguió la modalidad de trabajo de campo de tipo descriptiva, dentro del enfoque cuantitativo. La población estuvo constituida por 138 sujetos miembros del personal académico de los centros locales del occidente del país, quedando la muestra conformada por 103 miembros del personal académico. Como instrumento de recolección de datos se utilizó un (1 cuestionario con la finalidad de obtener información sobre la comunicación corporativa en la UNA, a través de dos dimensiones para su estudio: Cultura organizacional e Identidad corporativa. El cual se sometió a validez de contenido por parte de 10 expertos y se calculo la confiabilidad obteniendo un coeficiente de 0,90. Como técnica de análisis de datos se utilizó la estadística descriptiva, mediante distribución de frecuencias y medias aritméticas. Como resultados se obtuvo las principales características del comportamiento organizacional e identidad corporativa del personal académico de los Centros Locales del occidente del país de la UNA.

  13. Nuevas tendencias del turismo y las tecnologías de información y las comunicaciones

    Directory of Open Access Journals (Sweden)

    Jorge Bonilla

    2013-11-01

    Full Text Available El turismo ha evolucionado desde sus inicios hasta la actualidad. Hay principalmente tres factores que han generado cambios en el sistema turístico. Primero, un cambio en la visión social del mundo y del comportamiento del ser humano en su entorno, factor que está más que todo relacionado con lo sociológico y lo natural. Segundo, la evolución de los medios de transporte y gracias también a las nuevas tecnologías. Tercero, el surgimiento de nuevos medios de comunicación y de la tecnología como motor de cambio. Este trabajo se ocupará del primero y del tercero donde se explicarán los cambios que ha sufrido el mercado y que actualmente marcan las nuevas tendencias del turismo aprovechando además las tecnologías de información y de las comunicaciones.

  14. Tecnologías de la información y las comunicaciones para personas con necesidades educativas especiales

    Directory of Open Access Journals (Sweden)

    Yois Smith Pascuas-Rengifo

    2015-01-01

    Full Text Available Se presenta una revisión sistemática de literatura que identifica la aplicabilidad de las tecnologías de la información y las comunicaciones (TIC en la educación para personas con necesidades educativas especiales (NEE y cómo ha sido su uso en el fortalecimiento del aprendi - zaje de esta población. Se identifica la importancia en el uso de software para mejorar la habilidad mental y el desarrollo de tareas, además del uso de hardware para facilitar el intercambio de datos. A partir de esta investigación se refleja la importancia que tiene cada una de las soluciones propuestas y la necesidad de continuar desarrollando herramientas que potencien el proceso de enseñanza y aprendizaje que a su vez se podría relacionar con el mejoramiento de la calidad de vida de esta población.

  15. El lado oscuro de las tecnologías de la información y las comunicaciones

    Directory of Open Access Journals (Sweden)

    Andrius Plepys

    2007-12-01

    Full Text Available Las tecnologías de la información y las comunicaciones (TIC, tienen un profundo impacto en la economía y en el ambiente. La mejora en el desempeño de las tic lleva a un amento creciente del consumo de productos y servicios relacionados con TIC, lo cual tiene numerosas implicaciones ambientales en diferentes niveles. En este artículo, los autores resaltan la analogía entre los efectos rebote en el sector de energía y los efectos del crecimiento en TIC. De la literatura de economía energética se toman diferentes taxonomías de los efectos rebote con el fin de estructurar la discusión sobre las implicaciones ambientales del crecimiento en el uso de productos y aplicaciones de las TIC. El autor distingue dos niveles de impactos ambientales de las TIC. El primero, tiene que ver con ciclo de vida del hardware de las TIC y el segundo con la forma como se usan las aplicaciones de las TIC. Por medio de ejemplos, el artículo ilustra la complejidad de los impactos ambientales y resalta el rol decisivo del comportamiento humano en determinar su significancia. Los temas presentados son de gran relevancia para cualquier tomador de decisiones que ha puesto grandes expectativas en las TIC, y que necesita ser advertido sobre sus potenciales implicaciones ambientales en los complejos sistemas socioeconómicos de hoy. Se suelen hacer inversiones cuantiosas en este sector con la expectativa de crecimiento económico y mejoramiento ambiental, pero se ignora que el efecto rebote causa el riesgo de mala asignación de recursos. Disponer de mayor información sobre los efectos y causas de estos, permitirá a los tomadores de decisiones optimizar el desarrollo con un balance entre el crecimiento y la calidad ambiental.

  16. Evaluación de algoritmos Cross-Layer para la optimización de sistemas de comunicaciones inalámbricas

    OpenAIRE

    Ramos Conejo, Ismael

    2006-01-01

    El proyecto tiene como objetivo principal el estudio de técnicas Cross-layer para optimizar el rendimiento de las redes inalámbricas en modo ad-hoc, a partir del estándar IEEE 802.11. El principio de funcionamiento de las técnicas Cross-layer se basa en el intercambio de información entre las capas del modelo OSI que forman el sistema de comunicaciones, para mejorar su rendimiento. De cara a realizar este estudio se ha implementado un software en el lenguaje de programación C++, q...

  17. La comunicación organizacional satisfactoria en el ministerio de tecnologías de la información y las comunicaciones (Min TIC) de Colombia

    OpenAIRE

    Jiménez Estrada, Néstor Alonso

    2017-01-01

    Propósito – Evidenciar, con el rigor de la investigación científica en administración, la dificultad en la comunicación organizacional (LCO) del Ministerio de Tecnologías de la Información y las Comunicaciones (Min TIC), describiendo cómo es esta desde el punto de vista del Cuestionario sobre la Satisfacción en la Comunicación (CSQ), con el fin de plantear una propuesta encaminada a mejorarla objetivamente. Diseño/metodología/enfoque – Es un estudio descriptivo basado en el uso de un mono-...

  18. Comunicaciones para la formación de las islas eléctricas del Sistema Argentino de Interconexión

    OpenAIRE

    Issouribehere, Pedro; Rodríguez, José; Gutiérrez, Alfredo

    2003-01-01

    El Sistema de Comunicaciones descripto tiene por misión dar soporte al “Proyecto Islas Eléctricas del Sistema Argentino de Interconexión”. Etapa I. Se presenta la definición de un Sistema de Referencia que permite caracterizar en forma general los requerimientos del Sistema de Telecomunicaciones y Teleprotección con el objetivo de estimar un costo mínimo justificable para la aplicación y un plazo acorde en su ejecución.

  19. A aplicação dos recursos da seguridade social, a partir da perspectiva da teoria dos sistemas, da teoria comunicacional e do caos

    OpenAIRE

    Júnior, Dávio Antonio Prado Zarzana

    2011-01-01

    Este trabalho, focalizando o custeio da Seguridade Social, pretende realizar três verificações: a primeira, a existência ou não de desvios na aplicação dos recursos arrecadados para este financiamento, inclusive a partir da formulação de um conceito de desvio. A segunda, examinar os desequilíbrios que esses possíveis desvios produziriam, sob a ótica da Teoria dos Sistemas, utilizando-se, em adição, terminologia própria da Teoria Comunicacional. E a terceira, perscrutar a pos...

  20. Implementació d'un esquema criptogràfic per a la gestió segura d'historials mèdics a través d'una xarxa de comunicacions

    OpenAIRE

    Salas Montalà, Armand

    2008-01-01

    Aquest projecte es proposa dissenyar i implementar un sistema de gestió d'historials mèdics per a ser usat remotament a través d'una xarxa de comunicacions, amb un èmfasi principal en l'assoliment d'un nivell de seguretat considerat alt. Este proyecto se propone diseñar e implementar un sistema de gestión de historiales médicos para ser usado remotamente a través de una red de comunicaciones, con un énfasis principal en la consecución de un nivel de seguridad considerado alto. This p...

  1. Diseño y fabricación de capa de comunicaciones basada en LoRa para plataforma modular de redes de sensores inalámbricas

    OpenAIRE

    Gómez Ortiz, Gonzalo Javier

    2017-01-01

    Este Trabajo Fin de Grado tiene por objetivo explorar la tecnología LoRaWAN y diseñar y fabricar un prototipo para la plataforma Cookies. LoRaWAN es una especificación de comunicaciones inalámbricas entre dispositivos desarrollada por la LoRa Alliance —una asociación de empresas, universidades y diversos organismos que en enero de 2017 ya contaba con 423 miembros—. Está especialmente pensada para usarse en los ámbitos del Internet de las Cosas (IoT), las comunicaciones de máquina a máquina...

  2. Plan comunicacional para incrementar las ventas y participación de mercado de la empresa ALVESA, ubicada en la ciudad de Santo Domingo, provincia Santo Domingo de los Tsáchilas.

    OpenAIRE

    Alvarado Muñoz, Héctor Patricio

    2017-01-01

    Se elaboró un Plan Comunicacional para incrementar las ventas y la participación en el mercado de los productos que distribuye la empresa ALVESA, ubicada de la ciudad de Santo Domingo, provincia Santo Domingo de los Tsáchilas. Se realizó un profundo análisis sobre la situación actual de la empresa para identificar los problemas que afectan los factores antes mencionados, determinándose así que no existe un proceso comunicacional adecuado que posibilite el fortalecimiento de la...

  3. Risk perception, scientific culture and communication media; Percepcion del riesgo, cultura cientifica y medios de comunicacion

    Energy Technology Data Exchange (ETDEWEB)

    Pinto Lobo, M. R.

    2002-07-01

    The people who asked me to give a talk for the Spanish Nuclear Society's 28th Annual Meeting, at the invitation of WIN (Women in Nuclear), have challenged me, or at least that is what my colleagues believe, to tackle the difficult task of venturing into fields unfamiliar to anyone who is not involved in University teaching in communication and journalism. However, the challenge was very appealing to me, first of all because it was an invitation from WIN (Women in Nuclear), which I would like to congratulate, together with the Steering Committee, for having selected Salamanca as the meeting venue in this very important year for this city (it has been selected as European cultural city for 2002, along with the Belgian city of Bruges), If there is any place that has been immersed in scientific culture throughout the centuries it is Salamanca, where every one of its stones could tell us a history of the convergence and divergence between knowledge and society. This Universidad Pontificia of Salamanca also encloses centuries of wisdom within its walls. I have mentioned the first reason for accepting the challenge: the invitation from WIN Espana. The second reason why I accepted is that, some years ago, the world of nuclear energy, them unknown to me, started coming up in conversations with friends, one of whom works in this field. That history of discovery began in a levelly little Swiss town, in Grundenwald, not far from Eintein's Bern, whom I will mention later on.

  4. Perspectivas de las Tecnologías de la Información y las Comunicaciones en la formación permanente del profesorado universitario

    Directory of Open Access Journals (Sweden)

    Dr. C. Oscar Antonio Martínez Molina

    2018-02-01

    Full Text Available El acelerado avance científico y tecnológico pasa por el ámbito educativo haciendo que asuma nuevos retos de elevación del nivel educativo. Las Tecnologías de la Información y las Comunicaciones en la educación proporcionan potencia, fortalecimiento y transformación en el quehacer educativo, al momento que incrementa, en la práctica docente, la calidad del servicio. En el presente artículo se exponen las herramientas tecnológicas en el uso de las TIC en la formación permanente del profesorado universitario, haciéndose una adecuada utilización de las Tecnologías de la Información y las Comunicaciones lo que marcará gran impacto en la organización, desarrollo y productos en el proceso de enseñanza-aprendizaje si se tiene en cuenta que las nuevas tecnologías de la información y de la comunicación han evolucionado espectacularmente en los últimos años, debido especialmente a su capacidad de interconexión a través de la Red. Esta nueva fase de desarrollo va a tener gran impacto en la organización de la enseñanza y el proceso de aprendizaje

  5. Riesgo de aparición del efecto boomerang en las comunicaciones contra la violencia The Risk of Emergence of Boomerang Effect in Communication against Violence

    Directory of Open Access Journals (Sweden)

    José Antonio Ruiz San Román

    2011-10-01

    Full Text Available Los comportamientos violentos causan inquietud entre los responsables públicos (políticos, educadores, asistentes sociales, asociaciones de madres y padres, etc. que, desde diversos ámbitos, toman medidas que tratan de dar solución al problema de la violencia. La difusión de campañas institucionales de comunicación en contra de la violencia y el fomento de la publicación de noticias relacionadas con sucesos violentos suelen ser algunas de las acciones utilizadas. No obstante, parte de los datos y de la literatura disponible han demostrado que su eficacia no siempre es la esperada e, incluso, dichas acciones pueden llegar a tener efectos contrarios al deseado y reforzar las actitudes de los que piensan que la violencia es necesaria. Se sostiene la hipótesis de que la mayoría de la población asumiría como propios los mensajes contrarios a la violencia. Sin embargo –y esto es la cuestión clave y más problemática– son justo aquellos individuos con mayor propensión a la violencia (precisamente aquellos a quienes deberían dirigirse tales comunicaciones quienes podrían reaccionar ante el mensaje antiviolencia de un modo no deseado. Se da una dramática paradoja: el mensaje antiviolencia podría aumentar la predisposición a desarrollar comportamientos violentos. Estaríamos ante un caso de lo que cierta literatura denomina efecto boomerang. Por último, se señala la necesidad de un estudio detallado sobre determinados efectos de los medios de comunicación (insensibilización, imitación, accesibilidad y reactancia, que podrían ayudar a explicar la aparición de dicho efecto boomerang.Violent behaviors cause concern among people, policy makers, politicians, educators, social workers, parents associations, etc. From different fields and perspectives, measures are taken to try to solve the problem of violence. Institutional communication campaigns against violence and the publication of news related to violent events are often

  6. Public communication and nuclear energy; La comunicacion publica y la energia nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Cornado, A.

    2006-07-01

    The article tries to explain why on occasion the public's perception of nuclear is more negative than of any other form of electricity generation or issue related to this field, when in reality public opinion has been gradually losing interest in nuclear in recent years. In fact, we could say that as nuclear loses its interest, its presence in the media grows in relation to the environmental aspects of electricity generation, of which nuclear form a part. Of the accusations directed at the nuclear industry, probably the most frequent one concerns the lack of transparency and lack of information on its activities. This article shows how the nuclear sector is probably one that generates more and better information on its own business. However, the lack of social acceptance of this activity, and of the energy business in general, is recognized. To solve this, mention is made of the example of France and Finland, where a well planned communication policy, implemented on a sustained basis over time, and the invitation to society to take part in these issues have favored a substantial improvement of public acceptance of electric generation sources, and specifically the nuclear option. The article ends with some recommendations that could be applied to Spain. (Author)

  7. Public Communication on Urban Air Pollution; La Comunicacion al Publico sobre Contaminacion Atmosferica Urbana

    Energy Technology Data Exchange (ETDEWEB)

    Otra, C.; Sala, R.

    2014-02-01

    The aim of this study was to analyze the state of public information in the field of air pollution in Spain. We conducted semi-structured interviews with members of public agencies, technical experts, scientists, and members of non governmental associations together with a documentary analysis of air pollution documents (plans, reports, etc.). We tried to characterize the information actions on air quality carried out in Spanish cities during the last years. In the results section we first analyze the ideas, concerns and considerations that underlie the actions of public information on air pollution, as well as the main challenges of public communication on this subject, according to the documents and the different experts consulted. We analyze the various contents of information transmitted nowadays (on levels of pollution, health impacts and mitigation or protection actions), as well as the mechanisms by which it is communicated, both continuously and in the case of threshold overcoming episodes. We also review the different media used to communicate air pollution information (Internet, mobile applications and other forms) and other issues such as information audiences, or the perceived impacts of information provided. Finally, the implications for more diverse and effective public involvement strategies in air pollution are discussed. (Author)

  8. fields

    Directory of Open Access Journals (Sweden)

    Brad J. Arnold

    2014-07-01

    Full Text Available Surface irrigation, such as flood or furrow, is the predominant form of irrigation in California for agronomic crops. Compared to other irrigation methods, however, it is inefficient in terms of water use; large quantities of water, instead of being used for crop production, are lost to excess deep percolation and tail runoff. In surface-irrigated fields, irrigators commonly cut off the inflow of water when the water advance reaches a familiar or convenient location downfield, but this experience-based strategy has not been very successful in reducing the tail runoff water. Our study compared conventional cutoff practices to a retroactively applied model-based cutoff method in four commercially producing alfalfa fields in Northern California, and evaluated the model using a simple sensor system for practical application in typical alfalfa fields. These field tests illustrated that the model can be used to reduce tail runoff in typical surface-irrigated fields, and using it with a wireless sensor system saves time and labor as well as water.

  9. Comunicacions unificades amb Elastix

    OpenAIRE

    Martín Jiménez, Alejandro

    2016-01-01

    The effectiveness of their communications largely determines the success of the company. Today, any technology Officer must make important decisions about the evolution of their systems. Thus, the presence on the market increasingly popular new unified communications products require to consider the various options offered. About this, is proposed to design a solution based on the free software Elastix due to the competitive corporate world offers a cost/performance very important. This proje...

  10. La regulación. Análisis a partir de las funciones jurisdiccionales de la Comisión de Regulación de Comunicaciones

    Directory of Open Access Journals (Sweden)

    Julián Andrés Pimiento Echeverri

    2013-07-01

    Full Text Available La posición tradicional de la doctrina colombiana ha sido la de asimilar la regulación a una modalidad nueva de actuación del Estado, pero sin que medie una definición del término. Mediante un examen de la evolución de la intervención del Estado en la economía se busca definir esta noción para luego tratar de identificar los diferentes instrumentos regulatorios del ordenamiento jurídico colombiano, en concreto, de aquellas atribuciones que fueron conferidas por la Ley 1341 de 2009 a la Comisión de Regulación de Comunicaciones.

  11. Implementación de un sistema de seguridad para las comunicaciones en medidores inteligentes de baja tensión en Smart Grids

    OpenAIRE

    Sáenz Leguizamón, Javier Alejandro

    2015-01-01

    La Integración de la red eléctrica y las tecnologías de la información y las comunicaciones (TIC) son el futuro de la energía, el mundo moderno no puede ser concebido sin electricidad y la infraestructura actual está mal adaptada a las necesidades modernas, cada día la demanda de energía es mayor y el medio ambiente sufre debido a la generación de CO2, necesitamos una red inteligente con mejor administración de la energía; implementando estas tecnologías se espera reducir signi...

  12. Las tecnologías de la información y las comunicaciones desarrollan los servicios de la biblioteca laboral del IPEL espirituano.

    Directory of Open Access Journals (Sweden)

    Yaney Hernández Paz

    2007-06-01

    Full Text Available A pesar de la Brecha Digital a que estamos sometidos por el bloqueo imperialista nuestra sociedad cubana hace grandes esfuerzos por insertarse en la era de la información, donde las Tecnologías de la Información y las Comunicaciones están presentes en casi todos los procesos de un país para su desarrollo. En tal sentido el Instituto Provincial de Estudios Laborales realizó proyectos de colaboración para introducir estas tecnologías y de esa manera lograr avances y mejoras en la prestación de los servicios. La Biblioteca Laboral del Instituto espirituano comenzó una nueva etapa en su trayectoria e historia a partir de la llegada de las computadoras debido a que estas han permitido brindar un mejor servicio a los usuarios que exigen una respuesta rápida, directa, relevante y actualizada a sus necesidades de información y conocimiento. En este trabajo se presenta una valoración del efecto que ha tenido la implementación de las Tecnologías de la Información y las Comunicaciones en la Biblioteca Laboral. Para lograr este objetivo se aplicaron encuestas y entrevistas a los usuarios, se revisaron y analizaron los registros de lectura en sala y copia de documentos en soporte digital, comprobándose que las tecnologías diversifican las formas de entrega de información a los usuarios, contribuyen a aumentar el volumen de bibliografía y la calidad de la misma por los diferentes formatos en los que se puede presentar la información, como es la multimedia.

  13. Comportamiento de las comunicaciones bucosinusales por extracciones dentarias en la atencion primaria de salud Behavior of bucco-sinus communications due to dental extractions in Primary Health Care

    Directory of Open Access Journals (Sweden)

    María Consuelo Paredes Suárez

    2012-06-01

    Full Text Available Se realizó una investigación aplicada del tipo de estudio descriptivo, retrospectivo, longitudinal, con el propósito de determinar el comportamiento de las comunicaciones buco-sinusales en la atención primaria de salud, en el municipio Maracaibo, Estado Zulia en el período comprendido de diciembre 2006 a diciembre de 2008. El universo estuvo constituido por todos los pacientes que asistieron a la consulta, solicitando una extracción dentaria en el maxilar superior; la muestra estuvo constituida por los 38 pacientes que tuvieron una comunicación buco-sinusal como complicación de la extracción dentaria, incluidas solo las iatrogénicas traumáticas y accidentales y las asociadas a otras patologías. Los datos se recogieron de las historias clínicas individuales y de un formulario confeccionado al efecto, se utilizaron como indicadores los números absolutos y por cientos, se confeccionaron tablas y gráficos estadísticos para una mejor interpretación de los resultados. Dentro de los principales resultados, el sexo femenino fue el mayormente afectado y el grupo de edad de 35-59 años en ambos sexos, la exodoncia del primer y segundo molar superior izquierdo resultó la que más incidió, las comunicaciones iatrogénicas traumáticas dominaron por su frecuencia. Las comunicaciones buco sinusales inmediatas resultaron mayoritarias y el tratamiento médico-quirúrgico fue el más utilizado, siendo el tratamiento inmediato el de mayor éxito terapéutico. La diversidad de criterios en cuanto al diagnóstico y tratamiento de esta complicación de la extracción dentaria, el manejo inadecuado en la atención primaria, la estrategia inmediata de formar Estomatólogos Generales integrales de perfil amplio, se considera importante buscar puntos comunes, aunar criterios y definir conductas terapéuticas.An applied type, descriptive, retrospective and longitudinal study was conducted to determine the behavior of bucco-sinus communications in

  14. La Revolución Comunicacional y el Uso Didáctico del Periódico en la Enseñanza Geográfica

    Directory of Open Access Journals (Sweden)

    José Armando Santiago Rivera

    2016-12-01

    Full Text Available El artículo analiza en el contexto de la revolución comunicacional, el uso didáctico del periódico en la enseñanza geográfica. Se asume que la prensa populariza diariamente noticias, informaciones y conocimientos al facilitar datos a la ciudadanía sobre sucesos ambientales, geográficos y sociales, mientras en la práctica escolar cotidiana se preserva el apego al libro, con la aplicación pedagógica y didáctica de acento tradicional. Eso determinó metodológicamente, realizar una revisión bibliográfica que explica el periódico como medio de comunicación social y la problemática geográfica, el uso didáctico del periódico e innovar la enseñanza de la geografía, el periódico y sus efectos pedagógicos en la enseñanza de la geografía en la habitual actividad escolar. Concluye al destacar la importancia del periódico pues contribuye a formar esencialmente una matriz de opinión crítica y reflexiva sobre la geografía cotidiana comunitaria en el inicio del nuevo milenio. Palabras clave Revolución comunicacional, periódico, enseñanza geográfica. Communicational Revolution and the Didactic Use of Newspapers in Teaching Geography Abstract The article analyzes the context of the Communications Revolution; the educational use of newspapers in teaching Geography. It is assumed that the Press popularizes daily news, information and knowledge to provide information to the public on environmental, geographical and social events, while in everyday practice school attached to the book is preserved, with the pedagogical and didactic application of traditional accent. It determined methodologically, conduct and literature review that explains the newspaper as a means of social communication and the problem of geographical, educational use of newspapers. In order to innovate in the teaching of geography, newspapers and its pedagogical effect on the teaching of geography in the usual school activity. It concludes by highlighting the

  15. A COPA E A MÍDIA: reflexões sobre a mais-valia ideológica, a soberania comunicacional e o jornalismo

    Directory of Open Access Journals (Sweden)

    Elaine Tavares

    2010-10-01

    Full Text Available http://dx.doi.org/10.5007/2175-8042.2009n32-33p156O texto traz uma reflexão sobre a forma como a mídia comercial tem atuado no que diz respeito ao anúncio das benesses da realização da Copa do Mundo no Brasil em 2014. A análise se faz a partir dos conceitos de mais-valia ideológica, proposto por Ludovico Silva, soberania comunicacional, uma construção coletiva dos comunicadores populares venezuelanos e brasileiros, e o jornalismo como forma de conhecimento, proposto por Adelmo Genro Filho. Parte-se da pedagogia de sedução capitalista, incensada pela mídia, e chega-se a propostas de controle popular soberano e jornalismo libertador.

  16. A arte nas ruas da cidade: estratégia de ressignificação e de interação comunicacional

    Directory of Open Access Journals (Sweden)

    Ione Maria Ghislene Bentz

    2015-12-01

    Full Text Available O texto investiga os efeitos das retóricas visuais na composição de metáforas/alegorias urbanas, através da produção de significados simbólicos e das relações de comunicação mediadas pelas tecnologias urbanas. Esses artefatos estão de tal modo presentes no cotidiano, que se tornaram próteses no corpo da cidade. Foram escolhidas temáticas e práticas contemporâneas, representantes de formas de natureza no espaço urbano, que produzem um diálogo com a cultura sob a forma de narrativas. A matriz narrativa trabalha: (a o elemento lúdico, presente nas diversas formas de manifestação; e (b o elemento de crítica social, presente nos argumentos narrativos dos textos em análise. O desenvolvimento do tema obedece aos parâmetros das teorias da linguagem, da compreensão da semiose e da interação comunicacional. Objetiva-se identificar e compreender os efeitos dos sentidos e as formas de interação, ambos mediados, em semioses complexas, por dispositivos urbanos.

  17. Internal and external communication. A tool for value creation; Comunicacion interna y externa. Una herramienta para la creacion de valor

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, J.

    2009-07-01

    Communication both internal and external in the Cofrentes Nuclear Power plant has become an essential element. In fact, it always has been. Over the past 25 years, we have strived to consolidate communication plans that, today, provided us with a large body of knowledge in this field. (Author)

  18. Gestión comunicacional de la agenda de internacionalización de los doctorados de la Universidad del Zulia

    Directory of Open Access Journals (Sweden)

    Mary Ollarves

    2012-05-01

    Full Text Available En la presente investigación el objetivo general fue determinar la gestión comunicacional de la agenda de internacionalización de los doctorados de la Universidad del Zulia, en las divisiones de estudios para graduados de las Facultades Ciencias Jurídicas y Políticas, Ciencias Económicas y Sociales y Humanidades y Educación. Se destacan los aportes de los autores Ramírez (2005, Serna (2000, Monzón (2001, Wimmer y Dominick (2001, Rivera (2008, Otegui (2008, Núñez (2008, Trejo (2001; Gacel-ávila (2000, García (2001, Jaramillo y De Lisio (2004, entre otros. El estudio es de tipo cuantitativoy se utilizó como técnica la entrevista semi estructurada dirigida a los directores de: Relaciones Interinstitucionales, General de Comunicación, Divisiones de Estudios para Graduados y Coordinadores de los programas de doctorados, todos de la Universidad del Zulia. La investigación propone integrar la gestión comunicacionala la agenda académica,para promocionar la política de internacionalización de los doctorados de la Universidad del Zulia en el marco de los convenios interinstitucionales. Los resultados demostraron que ciertamente, existe una debilidad en los principios básicos organizacionales y poco interés por proyectar una imagen corporativa, aunque se han hecho adelantos significativos desde la dirección de Relaciones Interinstitucionales y la División de Estudios para Graduados de la Facultad de Humanidades y Educación para posicionarse mundialmente en el área.

  19. Segredos e verdades no processo comunicacional da família com a criança com câncer

    Directory of Open Access Journals (Sweden)

    Amanda Aparecida Borges

    Full Text Available RESUMO Objetivo: Compreender a experiência da família ao estabelecer a comunicação com a criança em relação ao seu câncer. Métodos: Trata-se de um estudo de abordagem qualitativa, no qual foram entrevistadas famílias de criança com câncer de uma instituição de saúde do interior do estado de Minas Gerais. Optou-se pelo Interacionismo Simbólico como referencial teórico e a Análise de Conteúdo Temática como método. Resultados: A análise dos dados identificou que o estigma do câncer influencia na maneira como a família estabelece a comunicação com a criança. A família faz uma seleção de palavras para buscar sentido à normalidade, afastando da criança informações que trazem ideia do comprometimento do seu futuro e, consequentemente, a morte. Conclusão: O estudo destaca o apoio emocional como fio condutor do processo comunicacional entre família e criança. A família leva à criança mensagens que deixam explícita a esperança de vencer a situação vivenciada. Assim, deve-se pesquisar estratégias usadas pelos profissionais de saúde para auxiliar a família na comunicação sobre a doença da criança.

  20. Condiciones de acceso, uso y apropiación de las Tecnologías de la Información y las Comunicaciones en jóvenes

    OpenAIRE

    Chaves Vargas, Joana Carolina

    2014-01-01

    Las Tecnologías de la Información y las Comunicaciones (TIC) han tenido alcances en varios contextos entre los que se encuentran el educativo. Este trabajo busca mostrar las condiciones de acceso, uso y apropiación de las TIC en los jóvenes del “Proyecto SED”. Se inicia con un análisis bibliográfico de las diferentes categorías de acceso, uso y apropiación de TIC, continuando con la relación entre TIC y educación. Posteriormente se explican la metodología utilizada en el desarrollo del trabaj...

  1. Estudio comparativo de los Códecs de voz para comunicaciones de Voip utilizando teléfonos inteligentes - caso de estudio Universidad Católica de Cuenca sede Azogues

    OpenAIRE

    Ortega Ortega, Martín Educardo

    2015-01-01

    Este trabajo de investigación presenta un estudio comparativo de los códecs de voz para comunicaciones de VoIP en la Universidad Católica de Cuenca Sede Azogues, mediante la aplicación de diferentes escenarios reales de pruebas utilizando teléfonos móviles celulares inteligentes con cuentas SIP registradas en aplicaciones softphones y configuradas con la dirección IP interna del servidor de VoIP cuando la conexión sea a través de la red WLAN interna del campus universitario,...

  2. Intervención comunicacional en la promoción del perfil ambiental del profesorado del Colegio Nacional Integrado Jorge Basadre en Santa María del Valle, Huánuco. Perú-2011

    Directory of Open Access Journals (Sweden)

    Angélica SOTOMAYOR BACA

    2015-05-01

    Full Text Available En la búsqueda de medidas de mitigación y remediación de la crisis ambiental, la preparación de profesores para la Educación Ambiental es, en la actualidad, reconocida como una prioridad. Ello determina la necesidad de una transformación continua del rol docente, constituyéndose en agentes activos en la formación integral de nuevas generaciones, abordando los problemas ambientales con enfoques emergentes.El objetivo de esta investigación es comprobar si a lo largo de la intervención comunicacional se logra mejorar el perfil ambiental del profesorado del Colegio Nacional Integrado Jorge Basadre en Santa María del Valle, del distrito y provincia de Huánuco-Perú. Y, por tanto, optimizar sus capacidades hacia la enseñanzaaprendizaje del cuidado del ambiente, incorporando en el alumno el compromiso con el cuidado del ambiente. El estudio es experimental, prospectivo, longitudinal y analítico, con diseño de un solo grupo antes y después; de treinta y seis participantes voluntarios de la intervención comunicacional, desarrollada en sesiones mensuales, en un periodo de cinco meses. Se aplicaron satisfactoriamente una encuesta y dos escalas validadas y fiabilizadas. Se comprueban las hipótesis mediante el análisis de varianza de un factor de contrastes multivariados y la prueba t para medias de una muestra relacionada; apoyados en el SPWS V19. La influencia de la intervención comunicacional es demostrada mediante las diferencias significativas obtenidas en los momentos posteriores a la intervención respecto al momento basal. Según los hallazgos, se confirman las hipótesis que establecen diferencias en el comportamiento habitual, en la práctica pedagógica y en las percepciones hacia la educación ambiental de los participantes. Sin embargo, la intervención no mejora la práctica de valores y principios ambientales del profesorado, lo que supone la incidencia de futuros estudios que favorezcan tales cambios. De manera general, la

  3. Disseny i desenvolupament d'un esquema criptogràfic per gestionar de forma segura els historials mèdics dels pacients a través d'una xarxa de comunicacions.

    OpenAIRE

    Rodríguez Guerra, Juan José

    2008-01-01

    Desenvolupament d'un esquema criptogràfic per gestionar de forma segura els historials mèdics dels pacients a través d'una xarxa de comunicacions. L'aplicació proporciona les propietats bàsiques de seguretat que hem esmentat, a més de la propietat de no-repudi que permet assegurar que una informació referent a una visita ha estat introduïda per un metge autoritzat i concret. Desarrollo de un esquema criptográfico para gestionar de forma segura los historiales médicos de los pacien...

  4. Diseño de un modelo de comunicaciones unificadas para mejorar la gestión de la información en la municipalidad provincial de Churcampa Huancavelica 2010

    OpenAIRE

    Almidon Ortiz, Carlos Alcides

    2012-01-01

    El presente trabajo Diseño de un Modelo de Comunicaciones Unificadas para Mejorar la Gestión de la Información en La Municipalidad Provincial de Churcampa, trata sobre el diseño de una infraestructura de red administrada que nos permita transmitir voz, data y video, en la interacción de cada una de las oficinas de la Municipalidad, además de distribuir adecuadamente las salidas a internet a las diferentes oficinas priorizando a las oficinas que manejan software integrados con el gobierno cent...

  5. Automatic guided wave communication system using steel pipes as communication channel for flood detection in steel offshoreoilrigs; Sistema automatico de comunicacion de ondas guiadas para la deteccion de tubos de refuerzo inundados en plataformas petroleras costa fuera

    Energy Technology Data Exchange (ETDEWEB)

    Mijarez Cstro, Rito; Martinez Ramirez, Fernando [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2010-10-09

    An automatic guided wave Pulse Position Modulation (PPM) system, using steel tubes as communication channel, for detecting flooding in the hollow sub-sea structures of offshore oilrigs is presented. The system employs two smart piezoelectric based sensors and modulators and a demodulator based on a piezoelectric transducer, a Digital Signal Processor (DSP) and a microcontroller. Experiments performed in the laboratory, in a tubular steel heliport structure and the base of a deck of an oilrig under construction, have successfully distinguished automatically guided wave encoded information. [Spanish] Este articulo presenta un trabajo de investigacion en el cual se desarrolla un sistema automatico de comunicacion de ondas guiadas por modulacion por posicion de pulsos (PPM), orientado a la deteccion de miembros inundados en los tubos de refuerzo de las plataformas petroleras costa fuera. El sistema utiliza de manera novedosa tubos de acero como medio de comunicacion y emplea dos sensores/moduladores inteligentes compuestos de cristales piezoelectricos, electronica basada en un microcontrolador y baterias. La instrumentacion del demodulador consta de un transductor piezoelectrico de ultrasonido, un procesador digital de senales (DSP) y un microcontrolador, el cual lleva a cabo de manera automatica la deteccion de ondas guiadas. Los experimentos se realizaron en aire, en laboratorio, en una estructura tubular de acero del helipuerto y en la base de una plataforma bajo construccion.

  6. La Convención de las Naciones Unidas sobre la Utilización de las Comunicaciones Electrónicas en los Contratos Internacionales: relevancia práctica y lecciones aprendidas

    Directory of Open Access Journals (Sweden)

    Luca G. Castellani

    2015-12-01

    Full Text Available La Convención de las Naciones Unidas sobre la Utilización de las Comunicaciones Electrónicas en los Contratos Internacionales es el primer tratado suscrito con el objetivo de facilitar el uso transfronterizo de las comunicaciones electrónicas en las relaciones comerciales. Este artículo describe los objetivos de la política detrás de la preparación de dicho instrumento, su ámbito de aplicación y sus principales disposiciones sustantivas. Se hace referencia específica a la interacción de esa Convención con otros tratados ya adoptados por Colombia y otros Estados, como la Convención sobre el Reconocimiento y Ejecución de las Sentencias Arbitrales Extranjeras (la “Convención de Nueva York” y la Convención de las Naciones Unidas sobre Contratos de Compraventa Internacional de Mercaderías (cisg. Por último, el artículo analiza los patrones en la adopción de la Convención en la última década y concluye que Colombia debería considerar la posibilidad de ratificar la Convención, que ha firmado en 2007, para fortalecer su economía digital mediante la modernización de la legislación vigente sobre el comercio electrónico.

  7. Algunas consideraciones teóricas acerca del uso de las tecnologías de la información y las comunicaciones en la enseñanza superior.

    Directory of Open Access Journals (Sweden)

    Yamilet Trelles Mutis

    2007-03-01

    Full Text Available El trabajo, que a continuación se expone se titula Algunas consideraciones teóricas acerca del uso de las tecnologías de la información y las comunicaciones en la enseñanza superior, en el mismo se presentan algunas consideraciones teóricas acerca del uso de las tecnologías de la información y las comunicaciones. Se ofrecen consideraciones sobre la necesidad de implementar un Sitio Web en la biblioteca universitaria, donde los usuarios de esta institución tendrán la posibilidad de acceder y evaluar los recursos digitales en la gestión de la información desde cualquier punto de la red necesarios para la docencia y la investigación. En la búsqueda del conocimiento se utilizan métodos y técnicas con sus diferentes instrumentos de la investigación educacional. Se expone la metodología para el diseño del sistema.

  8. LAS TECNOLOGÍAS DE LA INFORMACIÓN Y LAS COMUNICACIONES COMO HERRAMIENTAS PARA LA GESTIÓN DEL PATRIMONIO CULTURAL CON UNA VISIÓN EMPRENDEDORA

    Directory of Open Access Journals (Sweden)

    Cecilia Valdespino Tamayo

    2016-01-01

    Full Text Available El patrimonio cultural no se limita a monumentos y colecciones de objetos, comprende también tradiciones o expresiones vivas heredadas de nuestros antepasados y transmitidas a nuestros descendientes. La importancia de este recurso inmaterial no radica solo en la manifestación cultural en sí, sino en el cúmulo de conocimientos y técnicas que se transmiten de generación en generación. Se basa en el reconocimiento por las comunidades, grupos o individuos que lo crean, mantienen y transmiten. La difusión es uno de los tres pilares de la gestión del patrimonio. Su definición merece una revisión a la luz de nuevas disciplinas y estrategias de comunicación incorporadas en los últimos diez años. El espíritu empresarial y la visión emprendedora junto al desarrollo tecnológico están generando un profundo impacto en todos los ámbitos de la vida diaria, desencadenando aspectos positivos en la gestión y conservación del patrimonio cultural. En este trabajo se da a conocer el papel que han desempeñado las Tecnologías de la Información y las Comunicaciones, como herramienta insustituible, en la difusión del patrimonio. Se describe el aporte de  tres de las principales líneas de desarrollo de software a este pilar fundamental (Realidad Virtual, Sistemas de Información Geográfica y Portales WEB, las herramientas y tecnologías más utilizadas en estas ramas, así como los sistemas informáticos desarrollados a partir de investigaciones científicas realizadas  en la Carrera de Ingeniería en Ciencias Informáticas de la Universidad de Granma, como resultado de un trabajo intencionado realizado con la dirección de Patrimonio y  Cultura en la provincia.

  9. Estrategias del periodismo feminista: prácticas y política en la reconfiguración del espacio comunicacional

    Directory of Open Access Journals (Sweden)

    Valeria F. Hasan

    2014-12-01

    Full Text Available La militancia dentro del movimiento de mujeres y los feminismos latinoamericanos se ha visto impactada fuertemente en los últimos años por la gran expansión de las TICs. Como sucede en otros ámbitos de la lucha política, el espacio virtual, también se erige como un lugar de debate por los sentidos, la construcción de hegemonía, el debate contrahegemónico. En esta relación de fuerzas, el periodismo feminista y/o de género viene jugando un rol fundamental en tanto, por un lado, realiza una tarea imprescindible de ruptura del orden establecido y por el otro, está provocando un cambio fundamental al interior del colectivo periodístico mismo. Presentamos aquí el análisis de un caso centrado en una experiencia comunicacional radial con perspectiva de género, basado en noticias de mujeres, diversidad, derechos humanos, cultura y comunicación, con la generación de debates, entrevistas y desde perspectivas críticas, que logró construir un público local, sus “escuchas de aire” y un público regional/nacional/internacional, sus “escuchas virtuales”, quienes conformaron una verdadera comunidad virtual contrahegemónica feminista. De esta manera, la experiencia concretó una inserción en dos sentidos complementarios. Por un lado, en la comunidad local, con prácticas concretas y alfabetización de audiencias de radio tradicionales, y por el otro, en el intercambio con feministas y periodistas de género de otras latitudes que cobraron al mismo tiempo el doble rol de prosumidoras y receptoras del programa al participar como oyentes y como voces autorizadas representantes de demandas y problemáticas de sus países y/o colectivas feministas.

  10. Communication government agencies: the case of FCC/ Organismos de regulación y control de las comunicaciones: el caso de la FCC

    Directory of Open Access Journals (Sweden)

    Dra. Ana I. Segovia Alonso; asegovia@ccinf.ucm.es

    2009-01-01

    Full Text Available The Federal Communications Commission (FCC is one of the pioneering regulatory agencies in relation to the communication system within the capitalist model. From a general perspective, beginning with its constitution, plan of action, and regulatory decisions, we carry out a research of the historical, political and economic conditions under which this commission operates and was created. The main objective is to outline the reasons for the failures and mistakes of the FCC, that has been accused –since its origins- of acting in defence of the industry interests it seemingly regulates, and not in the public interest; and of being a creature of Congress, with no real independence from the politic, economic, and judiciary power. The final purpose of this essay is to suggest the necessary democratization of the communicative space, which needs an agency transformation that could change the current defence of the existing status quo. La Comisión Federal de Comunicaciones (FCC es uno de los organismos pioneros en el control y regulación del sistema comunicativo en el modelo capitalista. Desde una mirada general a partir de su composición, formas de actuación, y decisiones normativas, se realiza un estudio de los condicionamientos históricos, políticos y económicos bajo los cuales se crea y desarrolla su labor esta Comisión. El objetivo fundamental es delinear las razones de los errores y negligencias de la FCC, acusada desde sus inicios de actuar en defensa de los intereses de la industria a la que pretende regular, y no en interés del público; y de ser una criatura del Congreso sin independencia del poder político, ni económico, ni judicial. El propósito final del presente artículo es plantear la necesaria democratización del espacio comunicativo, que pasa por una transformación de estos organismos y su defensa del status quo existente.

  11. INTEGRACIÓN DE LAS TECNOLOGÍAS DE LA INFORMACIÓN Y LAS COMUNICACIONES A CONTENIDOS DE ASIGNATURAS COMO RETO DIDÁCTICO

    Directory of Open Access Journals (Sweden)

    Saadia Noemí Reyes Benítez

    2014-08-01

    Full Text Available El dominio de habilidades informáticas aumenta el nivel de las posibilidades de los estudiantes y la calidad de la asimilación de los conocimientos. Aunque se aprecia que la aplicación de las tecnologías de la información y la comunicación (TIC en los procesos formativos es un fin deseado, en la Facultad de Ciencias Económicas se corrobora la existencia de resultados no coherentes con lo estipulado. Así, el objetivo de este trabajo consiste en diseñar un procedimiento para la aplicación de las tecnologías de la información y la comunicación en los procesos. El procedimiento contribuye integrar las tecnologías de la información y la comunicación a través de la utilización de la plataforma interactiva MOODLE, partiendo de la premisa de que es el profesor quien genera y sistematiza la interacción estudiante-TIC en los procesos formativos.PALABRAS CLAVE: Tecnologías de la información y las comunicaciones; TIC; estrategia curricular de computación; habilidades informáticas; plataforma interactiva MOODLEINTEGRATION OF INFORMATION AND COMMUNICATIONS TECHNOLOGIES TO THE CONTENTS OF SUBJECTS AS A DIDACTIC CHALLENGE  ABSTRACTThe domain of computer abilities increases the level of the possibilities of the students and the quality of the assimilation of the knowledge. Although it is appreciated that the application of information and communication technologies (ICT to formative processes are a wanted end, in the Faculty of Economic Sciences it is corroborated the existence of having not been coherent with that specified. This way, the objective of this work consists on designing a procedure for the application of the technologies of the information and the communication in the processes. The procedure contributes to integrate the technologies of the information and the communication through the use of the interactive platform MOODLE, leaving of the premise that it is the professor who generates and systematizes the interaction

  12. [Direccion General de Comunicacion. Programa Nacional de Comunicacion en Poblacion].

    Science.gov (United States)

    1988-06-01

    Peru's National Population Council is currently developing a national program of population communication. The program will be coordinated with public and private sector activities and will seek help from international organizations. The objective of the program is to promote changes in population knowledge, attitudes, and behaviors in priority social sectors and general public opinion to achieve a better harmony between population growth and distribution and socioeconomic development. The program strategy is to begin with identification of priority audiences. Other components of the strategy include quality control, coordination, decentralization, participation, use of low-cost technologies with high impact, and a multidisciplinary focus. An inventory of institutional activities in population communication will be a major activity.

  13. Servicios en comunicaciones de emergencia

    Directory of Open Access Journals (Sweden)

    Henry Zárate Ceballos

    2014-07-01

    Full Text Available Las telecomunicaciones han sufrido transformaciones a lo largo de los últimos años y han modificado a las sociedades y los modelos culturales del mundo. En la actualidad es necesario afrontar realidades adicionales como lo son el cambio climático y las situaciones de origen antrópico y no antrópico, apoyados en la tecnología. Es por ello que se deben modelar y simular sistemas de telecomunicaciones en emergencia garantizando la prestación de servicios de telecomunicaciones en situaciones de emergencia en sus diferentes etapas de prevención, atención y recuperación. El diseño de redes con modelos robustos es útil para el manejo de diferentes tipos de paquetes y el manejo de prioridades de tráfico de información.

  14. Protección de los consumidores en el sector de las tecnologías de la información y las comunicaciones. Situación actual y posibles tendencias.

    Directory of Open Access Journals (Sweden)

    Wolfgang Kilian

    2013-12-01

    Full Text Available El derecho de protección a los consumidores en el campo de las tecnologías de la información y las comunicaciones (TIC se refiere a la legislación específica a favor de los consumidores que actúan en un entorno electrónico con fines particulares. La Directiva marco 2002/21/CE define como “consumidor” a “cualquier persona física que utilice o solicite un servicio de comunicaciones electrónicas disponible para el público para fines no profesionales”.Esos consumidores pueden tener acceso a Internet, firmar contratos electrónicos sobre bienes y servicios de empresa a consumidor (B2C y servirse de la telefonía móvil o de otros equipos digitales. La diversidad y disponibilidad de los servicios de comunicación electrónica en la actual “sociedad de la información” aumentan continuamente.La legislación introducida por la Unión Europea y sus Estados miembros se refiere sobretodo a la ley de contratos. Además, varias directivas de la UE en el área de las telecomunicaciones,que regulan la infraestructura de las telecomunicaciones, se ocupan de los intereses de los consumidoresen lo que atañe a la relación entre prestadores y usuarios de redes. En cambio, rara vez se considera la pertinencia de las directivas relativas a la protección de datos de los consumidores de TIC.

  15. El apoyo social en estudiantes universitarios y su relación con las comunicaciones cara a cara y las comunicaciones mediadas por las Tecnologías de la Información y la Comunicación (TIC

    Directory of Open Access Journals (Sweden)

    Camilo Madariaga

    2016-01-01

    Full Text Available Partiendo de que el apoyo social es provisto tanto en comunicaciones cara a cara como en aquellas mediadas por las TIC; el presente artículo analiza la forma en que desde ambos modelos de comunicación este se da en un grupo de estudiantes universitarios. La información se recolectó con la escala Assis. Los apoyos material y emocional se recibieron mayoritariamente por la comunicación cara a cara, lo que sugiere que es la modalidad predominante tanto en hombres como mujeres (60,1 % para su provisión social. Sin embargo, que el apoyo informativo sea más recibido por la comunicación mediada por las TIC, pone de relieve su alto nivel de penetración social y su impacto en las formas de interactuar. Se estableció que la existencia de una relación entre el apoyo emocional y el sexo es mayor en mujeres. Lo mismo ocurre entre su provisión y la edad, especialmente en personas más jóvenes, y aunque se esperaba hallar una relación entre la edad y las modalidades de comunicación, al final no se estableció. Para los universitarios ambos modelos de comunicación son complementarios y facilitan la provisión de apoyo de manera integral, en un continuo. Abstract Given that social support is provided in face-to-face communications and ICT mediated communication, this article discusses the types of social support from both communication models in a group of college students. The information was collected with Assis scale. The material and emotional support is mainly given by the face-to-face communication, suggesting that is the predominant form, both men and women (60.1% for the provision of social support. However, the informational support is more received by mediated communication ICT, demonstrating its high level of social penetration and its impact on ways of interacting. The existence of a relationship between emotional support and sex was established, being higher in women. Similarly between its provision and age, being higher in younger

  16. Uso y apropiación de las tecnologías de la información y las comunicaciones en las pymes y su relación con la competitividad

    Directory of Open Access Journals (Sweden)

    Albeiro Patiño Builes

    2012-01-01

    Full Text Available En el presente artículo se hace un repaso de algunos usos de las Tecnologías de la Información y las Comunicaciones (TIC en las pymes, tanto del mundo en general como de América Latina y Colombia, en particular, con el fin de mostrar los aportes que estas herramientas han hecho al aumento de la productividad y la competitividad de algunos países. De acuerdo con estudios realizados por diferentes instituciones a nivel mundial, el Producto Interno Bruto (PIB y la productividad aumentan en la medida en que crece el uso y apropiación de las TIC en las pymes. La investigación fue realizada con base en información secundaria, y los resultados muestran cómo los países desarrollados han potenciado de forma considerable el uso de las TIC en sus empresas, mientras que en América Latina se nota un menor grado de avance. Colombia es superado en este sentido por países como México, Brasil y Costa Rica.

  17. OLVIDOS Y RECUERDOS DE UN MONTAJE COMUNICACIONAL. Una aproximación a las memorias subterráneas de ex militantes del Movimiento de Izquierda Revolucionaria en Chile

    Directory of Open Access Journals (Sweden)

    María Olga RUIZ

    Full Text Available RESUMEN Este trabajo se aproxima a un acontecimiento escasamente investigado y que, sin embargo, circula como una memoria subterránea entre los sobrevivientes y ex militantes del Movimiento de Izquierda Revolucionario; me refiero a la llamada Conferencia de Prensa de Villa Grimaldi, montaje comunicacional organizado por la DINA (Dirección de Inteligencia Nacional que tuvo como protagonista a un grupo de militantes de esta organización que se encontraban secuestrados en el Cuartel Terranova (Villa Grimaldi. El operativo consistió en que los prisioneros llamaran públicamente a deponer la resistencia armada en contra de la dictadura, declarando la derrota política y militar del MIR. Una vez realizado el montaje, los cuatro militantes fueron acusados de traición y condenados a muerte por ésta organización, medida que finalmente no se implementó. En este artículo me aproximo a las diversas memorias (muchas de ellas en conflicto que existen en torno a este acontecimiento, incluyendo el testimonio de sus dos sobrevivientes.

  18. ¿Efectos Limitados o Poderosos? Una Revisión a la Investigación sobre los Efectos de las Comunicaciones de Campaña en México

    Directory of Open Access Journals (Sweden)

    Oniel Francisco Diaz Jimenez

    2014-04-01

    Full Text Available La investigación sobre los efectos de la comunicación política en México ha experimentado un importante avance durante las últimas décadas. Diversos trabajos desde la ciencia política y los estudios en comunicación de masas han realizado aportaciones significativas a la literatura acerca de los efectos de los medios y las campañas electorales en nuevas democracias, con México como estudio de caso. Este artículo ofrece una revisión de los hallazgos de diversos estudios sobre los efectos de las comunicaciones de campaña en elecciones presidenciales sobre el aprendizaje político, la cultura política y el comportamiento político de los mexicanos, señalando también aquellas áreas en las cuales la investigación es aún escasa.

  19. Communication system and spectral analysis for Ge-Li and GeHp detectors; Sistema de comunicaciones y analisis de espectros para detectores Ge-Li y GeHp

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J; Castano, P; Bonino, A D; Righetti, M A

    1991-12-31

    An integral communication and spectral analysis system (SICADE) was developed and implemented to satisfy the need to optimize and automate the measurement system used in Atucha I nuclear power plant for the activity in the primary loop`s water extracted by the TV system. The importance of these measurements is based on the fact that from the spectrometric analysis of the samples extracted, the Iodines-GN and Iodines-Iodines relations, which allow to detect the presence of deficient fuel elements, are calculated. The system developed is based on two modules integrated in a unique set commanded by the operators through the screen dialogue. (Author). [Espanol] Dada la necesidad de optimizar y automatizar el sistema de medicion utilizado en la Central Nuclear Atucha I para la actividad en el agua del circuito primario extraida a traves del sistema TV se desarrollo e implemento un sistema integral de Comunicacion y Analisis de espectros (SICADE). La importancia de estas mediciones radica en el hecho que del analisis espectrometrico de las muestras extraidas se calculan las relaciones entre Iodos-GN e Iodos-Iodos que permiten detectar la presencia de elementos combustibles fallados. El sistema desarrollado esta basado en dos modulos integrados en un unico conjunto comandado por el operador a traves del dialogo por pantalla. (Autor).

  20. Particularidades en la mejora del proceso de gestión de las Tecnologías de la Información y las Comunicaciones/Particularities of the process improvement in management Information Technology and Communications

    Directory of Open Access Journals (Sweden)

    Jennifer Ruiz-Alvarez

    2013-01-01

    Full Text Available En el siglo XXI resulta una cuestión indispensable estar a la par con los avances tecnológicos enpos de lograr los objetivos y metas organizacionales. Por esta razón, las Tecnologías de laInformación y las Comunicaciones (TICs juegan un papel relevante en el desarrollo de cadaempresa, para lo cual requieren mantenerse en una mejora continua con relación a los estándaresinternacionales. El Complejo de Investigaciones Tecnológicas Integradas (CITI surge en la actualrevolución tecnológica, por lo que su diseño organizacional incluye el proceso estratégico Gestiónde las TICs. Éste ha transitado por varias etapas en su diseño, donde se ha demostrado lacomplejidad que tiene la actualización sistemática del mismo, lo que hace conveniente desarrollary aplicar un instrumento metodológico que permita continuamente redefinir los elementos clavesde su funcionamiento, en correspondencia con los modelos más actuales a nivel internacional, quecontribuya a una adecuada gestión de la organización.

  1. Los medios de enseñanza y las tecnologías de la información y las Comunicaciones en la formación de Tecnólogos de la Salud

    Directory of Open Access Journals (Sweden)

    Ivaida García Acosta

    2014-10-01

    Full Text Available Introducción: los medios de enseñanza constituyen uno de los componentes del proceso docente educativo que favorece la concepción científica del mundo y la asimilación de los conocimientos. Objetivo: caracterizar los medios de enseñanza y el uso de las tecnologías de la información y las comunicaciones en el proceso de formación de tecnólogos de la salud en la carrera de Bioanálisis Clínico. Material y métodos: estudio de corte pedagógico en la carrera de Bioanálisis Clínico de la Filial Tecnológica "Simón Bolivar" de Pinar del Río donde se emplearon métodos del nivel teórico y del nivel empírico como la encuesta a alumnos y la entrevista a profesores. Se hizo coincidir de forma intencionada el universo y la muestra (67 estudiantes y 17 profesores. Resultados: los medios más utilizados fueron los tradicionales, se considera insuficiente los productos informáticos en la institución, se valora como positivo y necesario el uso de las nuevas tecnologías para la confección de medios de enseñanza. Conclusiones: los medios más utilizados en el aprendizaje de los contenidos de las asignaturas en la carrera son los medios tradicionales. Se carece de bibliografía básica en las asignatura para la dirección adecuada del proceso enseñanza-aprendizaje y de medios de enseñanza apoyados por la tecnología para satisfacer la asequibilidad en su asimilación y la motivación por el aprendizaje.

  2. Identificación de los factores y eventos de riesgo operativo dentro del proceso de gestión de tecnologías de información y comunicaciones basado en COBIT 5.0 en instituciones financieras públicas, caso Banco del Estado

    OpenAIRE

    Córdova Quilodrán, Saúl Alejandro

    2014-01-01

    137 hojas : ilustraciones, 29 x 21 cm + CD-ROM 5708 Resumen.- La presente investigación tiene como objetivo general la Identificación de los factores y eventos de riesgo operativo dentro del proceso de Gestión De Tecnologías de Información y Comunicaciones basado en COBIT 5.0 en el Banco del Estado, entendiéndose como factor de riesgo a la causa primaria o el origen de un evento de riesgo operativo. Los factores son los procesos, personas, tecnología de información y eventos externos, mien...

  3. Nota biobibliográfica + poética + creaciones («angel fieramente humano», «antología del bienestar», «el sueño de una nación», «La flecha del amor», «el comienzo de la soledad» y «comunicacion» + cuestionario (Victoria Pineda

    Directory of Open Access Journals (Sweden)

    Pablo del Barco

    2014-03-01

    Full Text Available Nota biobibliográfica + poética + creaciones («angel fieramente humano», «antología del bienestar», «el sueño de una nación», «La flecha del amor», «el comienzo de la soledad» y «comunicacion» + cuestionario (Victoria Pineda

  4. DISEÑO E IMPLEMENTACIÓN DEL SISTEMA DE COMUNICACIONES BASADO EN CAN PARA LA AVIÓNICA EN UN VEHÍCULO AÉREO AUTÓNOMO NO TRIPULADO DESIGN AND IMPLEMENTATION OF A COMMUNICATION SYSTEM BASED ON CAN FOR AVIONICS IN A ROBOT MINI-HELICOPTER

    Directory of Open Access Journals (Sweden)

    Jairo Miguel Vergara Díaz

    2007-07-01

    Full Text Available La necesidad de diseñar el sistema de comunicaciones para la aviónica de un mini helicóptero robot basada en la arquitectura distribuida CAN es la propuesta presentada. El sistema de comunicaciones involucra los aspectos de hardware y software necesarios para permitir el intercambio de datos sobre una red o bus de aviónica desde los sensores y/o hacia los actuadores con el computador central o computador de vuelo. La principal característica de la arquitectura es que permite escalabilidad en la agregación de nuevos dispositivos, garantizando los requerimientos temporales necesarios para la adquisición de datos. Se presentan resultados de intercambio de datos sobre la red de aviónica mostrando las frecuencias de operación alcanzadas.This paper presents the design of the internal communication system for avionics of a robot mini-helicopter based on the CAN distributed architecture. The communication system involves several hardware and software aspects related to data exchange on avionics bus from sensors and actuators with the flight computer. The main characteristic of the architecture is scalability in the addition of new devices, maintaining time requirements for data acquisition. Results of data exchange on the avionics network showing the reached operating update rates for each node are shown.

  5. Estetização da política vs. formação da opinião pública: uma aporia da razão comunicacional? = Aesthetization of politics vs. public opinion formation: an wasteland of communicational reason?

    Directory of Open Access Journals (Sweden)

    Trevisan, Amarildo Luiz

    2007-01-01

    Full Text Available Quando Benjamin debate a tese de estetização da política, feita pelo fascismo, introduz um problema importante para o agir comunicacional. Ao escrever a obra de arte na época de sua reprodutividade técnica,ele termina apontando para o comunismo como uma entidade capaz de ainda se contrapor ao movimento fascista, acenando com a resposta de politização da arte. No entanto, no momento em que fenecerem as esperanças escatológicas depositadas no comunismo, como superar o eclipse da política pela sua transformação em mero espetáculo? É nesse contexto que pretendo debater o encobrimento da política tornando fim em si mesmo, que se reflete fora de si apenas enquanto preocupação com a imagem, e a alternativa de formação da opinião pública proposta pela razão comunicacional

  6. New tools for communication in the nuclear field: the Massive Open Online Courses. Application to Nuclear Transmutation; Nuevas herramientas para la comunicacion en el campo nuclear: Los MOOCS (Curso online masivos en abierto). Aplicacion a la transmutacion nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Alonso-Ramos, M.; Fernandez-Luna, A. J.; Gonzalez-Romero, E. M.; Sanchez-Elvira, A.; Castro Gil, M.; Ogando, F.; Sanz, J.; Martin, S.

    2014-07-01

    One of the fundamental activities for the segmentation of the inmates of the Reactor is the preparation of the areas to carry out the Court itself same. The plant designed for operation differs greatly needs required for segmentation. Undertake both procedures of maintenance such as the adaptation of tooling and tools used during the active life of the plant. (Author)

  7. Periodismo, nuevos medios y poder comunicacional

    Directory of Open Access Journals (Sweden)

    Corbiére, Federico

    2011-01-01

    Full Text Available [es] El fenómeno de las redes sociales y su acelerado uso por audiencias y políticos, abre no pocas incógnitas en la ya compleja actividad periodística. La cada vez más acentuada interdependencia en red -de agendas globales- encuentra en el microblogging una fuente informativa de novedades locales que emergen de las redes sociales. Su atractivo: el suspenso de un “continuará…” que pone a sus protagonistas en un momento triunfal del relato, asociado a la espectacularidad de la polémica y a la continua sorpresa, que privilegia el melodrama en 140 caracteres al chequeo de fuentes. Los protagonistas de las noticias (sujetos del enunciado encarnados en los llamados políticos 2.0 pasan a ser actores principales en la producción y circulación de la información (sujeto de la enunciación. Esta novedad subvierte el orden interpelante–interpelado entre medios y audiencias, escapa al simple análisis de contenidos y obliga a revisar cómo se establecen los “contratos de lectura” (Veron, 1985 que, a diferencia de aquellos estudios centrados sobre el soporte papel, hoy deben anexar los cláusulas preexistentes surgidas de las redes sociales, que no negocian e ingresan de manera indirecta y naturalizada en el newsmaking la agenda noticiosa. [en] The social networking phenomenon and its widespread use audiences and political, opens a few unknowns in the complex journalistic activity. The ever increasing interdependence network -global issues- located in the microblogging a source of local news information emerging from social networks. Its appeal: the suspense of a “continued ...” that puts its players in a triumphant moment in the story, coupled with the spectacular of the controversy and the continuing surprise, which favors the melodrama in 140 characters to check sources.The protagonists of news (subject of the statement embodied in the so-called political 2.0 become major players in the production and circulation of information (the subject of enunciation. This development subverts the interpellation order between media and audiences, beyond the simple content analysis and requires review how to establish “contracts of reading” (Veron, 1985 which, unlike those studies focused on the paper, today must append the existing clauses arising from social networks that do not negotiate and enter indirectly and naturalized in the news making the news agenda

  8. EL PERIODISMO CIVICO COMO COMUNICACION POLITICA

    Directory of Open Access Journals (Sweden)

    Ana María Miralles C.

    1998-01-01

    Full Text Available La autora retoma el ejercicio del periodismo cívico como el espacio en el cual la formación de la opinión pública adquiere características de un proyecto político dinámico en el que el ciudadano es el ente fundamental.

  9. Combination Classes and "Hora de comunicacion."

    Science.gov (United States)

    Eldredge, Dee L.

    1989-01-01

    Ways to combine small classes of higher education students studying Spanish at various levels are described, including judicious use of language laboratories, staggering of the different level groups, and rotation of activities geared toward students' individual proficiency levels. (CB)

  10. Las Tecnologías de la Información y las Comunicaciones en los usos del conocimiento sociohumanístico (Information and Communications Technologies in the uses of social-humanistic knowledge

    Directory of Open Access Journals (Sweden)

    Roberto López Dosagües

    2014-05-01

    Full Text Available Resumen El presente artículo es parte de una investigación doctoral, que analiza un aspecto del uso de las tecnologías de la información y las comunicaciones en la primera década del siglo XXI, en un objeto específico del conocimiento: el sociohumanístico. El objetivo propuesto es demostrar desde esta área del saber, que lejos de eliminar el trabajo repetitivo, aburrido y tedioso, además de mejorar el acceso a la información, el entrenamiento y la calidad de la justicia social y la democracia, la realidad en el uso de estas tecnologías ha estado casi siempre del lado opuesto, dando lugar a nuevas divisiones o profundizando las ya existentes. Los métodos de Observación, Análisis y Síntesis, así como el Análisis Documental, especialmente durante la aplicación de la técnica del análisis de contenidos de bibliografía y datos estadísticos, fue la metodología empleada en la obtención de los resultados. Se develan maneras disímiles de usos del conocimiento sociohumanístico en su digitalización, desde las redes informáticas a nivel internacional. Propone a su vez, modos de usarlos para construir un futuro mejor y permita desarrollar lo que es vital para la vida humana, a partir de la formulación de objetivos e instrumentos que favorezcan su difusión y empleo. ¿Tecnologías para qué y para quién? Ni los objetivos ni los instrumentos pueden ser neutrales respecto a estas preguntas. Abstract This article is part of a doctoral research, which examines one aspect of the use of information technology and communications in the first decade of the 21st century, in a given area of knowledge: humanities and social sciences. The objective of the investigations is to demonstrate from this area of knowledge that the reality on the use of these technologies has almost always been on the opposite side, creating new divisions or deepening existing ones. Far from eliminating repetitive, boring, tedious work, this area of knowledge

  11. COMMUNICATIONAL THINKING IN THE STATE ORCHESTRA OF MATO GROSSO AND THE FIELD OF CONCERT MUSIC IN CUIABÁ

    Directory of Open Access Journals (Sweden)

    Yuji Gushiken

    2016-12-01

    Full Text Available Na perspectiva da “comunicação como cultura”, este artigo tem como questão central a relação entre pensamento comunicacional e a formação da música de concerto como campo artístico-cultural, num estudo de caso da Orquestra do Estado de Mato Grosso (OEMT. Criada em 2005, a OEMT instituiu um novo momento para a música de concerto em Cuiabá, capital de Mato Grosso, estado do Centro-Oeste com parte de seu território na Amazônia Legal. O funcionamento da OEMT na primeira década de atividade (2005-2015 atualiza-se com o desenvolvimento paralelo de estratégias de comunicação organizacional que redimensionam as relações da orquestra junto a seus diversos públicos. A interface entre distintos campos profissionais evidencia a dimensão comunicacional das práticas artísticas e culturais na contemporaneidade.   PALAVRAS-CHAVE: Comunicação; Música de concerto; Orquestra do Estado de Mato Grosso; Cuiabá.     ABSTRACT In the perspective of “communication as culture”, this article has as its central question the relationship between communicational thinking and the formation of concert music as an artistic-cultural field, in a case study of the State Orchestra of Mato Grosso (OEMT. Created in 2005, OEMT instituted a new moment for concert music in Cuiabá, capital of Mato Grosso, state of the Midwest with part of its territory in the Legal Amazon. The operation of OEMT in the first decade of activity (2005-2015 is updated with the parallel development of organizational communication strategies that reshape the relations of the orchestra with its different audiences. The interface between different professional fields evidences the communicational dimension of the artistic and cultural practices in the contemporaneity.   KEYWORDS: Communication; Concert music; State Orchestra of  Mato Grosso; Cuiabá.     RESUMEN Desde la perspectiva de la “comunicación como cultura”, este artículo tiene como cuestión central la

  12. Field transformations to multivalued fields

    Energy Technology Data Exchange (ETDEWEB)

    Kleinert, H [Institut fuer Theoretische Physik, Arnimallee 14, D-14195 Berlin (Germany)

    2007-05-15

    Changes of field variables may lead to multivalued fields which do not satisfy the Schwarz integrability conditions. Their quantum field theory needs special care as is shown in an application to the superfluid and superconducting phase transitions.

  13. Visual field

    Science.gov (United States)

    ... your visual field. How the Test is Performed Confrontation visual field exam. This is a quick and ... to achieve this important distinction for online health information and services. Learn more about A.D.A. ...

  14. Presentation of the project MobiKids Communication technologies, environmental exposures and risk of brain tumors in young people; Presentacion del proyecto MobiKids: Tecnologias de la comunicacion, exposiciones ambientales y riesgo de tumores cerebrales en gente joven

    Energy Technology Data Exchange (ETDEWEB)

    Cardis, E.; Alguacil, J.; Aragones, N.; Morales, M.; Carretero, G.; Ferreras, E.; Kinci, L.; Kogevinas, M.; Pollan, M.; Solis, R.; Vriheid, M.; Zumel, A.

    2011-07-01

    MOBI-Kids, an international study coordinated by CREAL, Barcelona, aims to assess the possible relationship between exposure in children and adolescents to electromagnetic fields (EMF) from communication technologies (RF - and extremely low frequency - ELF) and the risk of developing a brain tumor. It also investigated the effects of other risk factors, including environmental exposures in childhood and in utero.

  15. Aplicación de las tecnologías de la informática y las comunicaciones en la vinculación de los 18 puntos cardinales de la acupuntura con el sistema osteomioarticular Application of the information technologies and knowledge to link up the 18 cardinal points of acupuncture with the osteomyoarticular system

    Directory of Open Access Journals (Sweden)

    Iraida Hidalgo Gato Castillo

    2010-06-01

    Full Text Available El objetivo de esta investigación fue elaborar un sistema de medios de enseñanza aplicando las Tecnologías de la Informática y las Comunicaciones (TICs para la vinculación de los 18 puntos cardinales de la acupuntura con los contenidos del sistema osteomioarticular (SOMA que se imparte en la asignatura Morfofisiología Humana II en el primer semestre de Medicina. Dichos medios consistió en un material electrónico de apoyo a la docencia, el que incluyó: 1: Folleto digital donde se propone la distribución de los 18 puntos cardinales de la acupuntura en el sistema osteomioarticular; destacando además el momento oportuno donde se debe realizar la vinculación por parte del profesor, la utilización de los puntos de acupuntura, como terapéutica alternativa y/o enfatizar los conocimientos de la anatomía de superficie. 2: Guía de estudio modelo para la consolidación sobre: esqueleto de los miembros superiores utilizando el modelo WebQuest .3. Secuencia de diapositivas con hipervínculo donde se relacionan los puntos de acupuntura con la anatomía de superficie del esqueleto axil y sus músculos correspondientes, y la de los miembros superiores e inferiores. 4. Ejercicios de autoevaluación vinculando el contenido del sistema osteomioarticular con los puntos cardinales del cuerpo humano en la práctica médica comunitaria. Se concluye que el sistema de medios de enseñanza aplicando las Tecnologías de la Informática y las Comunicaciones (TICs permitirá a los estudiantes establecer las relaciones entre el SOMA y la anatomía de superficie con la acupuntura.The aim of this research was to create a system of teaching aids based on the Information Technologies and Knowledge to link up the 18 cardinal points of acupuncture with the contents of osteomyoarticular system that is taught in the first term of the medical studies through the subject: Human Morphology-2. These teaching aids were compromised of an electronic supporting material to

  16. Magnetic Field

    DEFF Research Database (Denmark)

    Olsen, Nils

    2015-01-01

    he Earth has a large and complicated magnetic field, the major part of which is produced by a self-sustaining dynamo operating in the fluid outer core. Magnetic field observations provide one of the few tools for remote sensing the Earth’s deep interior, especially regarding the dynamics...... of the fluid flow at the top of the core. However, what is measured at or near the surface of the Earth is the superposition of the core field and fields caused by magnetized rocks in the Earth’s crust, by electric currents flowing in the ionosphere, magnetosphere, and oceans, and by currents induced...... in the Earth by time-varying external fields. These sources have their specific characteristics in terms of spatial and temporal variations, and their proper separation, based on magnetic measurements, is a major challenge. Such a separation is a prerequisite for remote sensing by means of magnetic field...

  17. Communication of 2 June 2009 received from the Permanent Mission of the United Kingdom regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material; Comunicacion de fecha 2 de junio de 2009 recibida de la Mision Permanente del Reino Unido en relacion con la exportacion de materiales nucleares y de determinadas categorias de equipo y otros materiales

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-31

    The Director General has received a note ver bale from the Permanent Mission of the United Kingdom, dated 2 June 2009, in which it requests that the Agency circulate to all Member States a letter of 28 May 2009 from the Chairman of the Zangger Committee, Mr. Pavel Klucky, to the Director General, on behalf of the Governments of Argentina, Australia, Austria, Belgium, Bulgaria, Canada, China, Croatia, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Kazakhstan, the Republic of Korea, Luxemburg, the Netherlands, Norway, Poland, Portugal, Romania, the Russian Federation, Slovakia, Slovenia, South Africa, Spain, Sweden, Switzerland, Turkey, Ukraine, the United Kingdom and the United States of America, concerning a number of corrections to the communication regarding the export of nuclear material and of certain categories of equipment and other material published in INFCIRC/209/Rev.2 [Spanish] El Director General ha recibido una nota verbal de la Mision Permanente del Reino Unido, de fecha 2 de junio de 2009, en la que se pide que el Organismo distribuya a todos los Estados Miembros una carta de fecha 28 de mayo de 2009 del Presidente del Comite Zangger, Sr. Pavel Klucky, en nombre de los Gobiernos de Alemania, Argentina, Australia, Austria, Belgica, Bulgaria, Canada, China, Corea (Republica de), Croacia, Dinamarca, Eslovaquia, Eslovenia, Espana, Estados Unidos de America, Federacion de Rusia, Finlandia, Francia, Grecia, Hungria, Irlanda, Italia, Japon, Kazajstan, Luxemburgo, Noruega, Paises Bajos, Polonia, Portugal, Reino Unido de Gran Bretana e Irlanda del Norte, Rumania, Sudafrica, Suecia, Suiza, Turquia y Ucrania, en relacion con varias correcciones hechas a la comunicacion referente a la exportacion de materiales nucleares y de determinadas categorias de equipo y otros materiales publicadas en el documento INFCIRC/209/Rev.2.

  18. Phase field

    International Nuclear Information System (INIS)

    Radhakrishnan, B.; Gorti, S.B.; Clarno, K.; Tonks, M.R.

    2015-01-01

    In this work, the phase-field method and its application to microstructure evolution in reactor fuel and clad are discussed. The examples highlight the capability of the phase-field method to capture evolution processes that are influenced by both thermal and elastic stress fields that are caused by microstructural changes in the solid-state. The challenges that need to be overcome before the technique can become predictive and material-specific are discussed. (authors)

  19. Monitoring of social networks and their links with the external communication plan of Cofrentes NPP; Monitorizacion de redes sociales y su vinculacion con el plan de comunicacion externa de CN Cofrentes

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Garcia, C.; Tejedor Garcia, E.

    2015-07-01

    Currently, new communication models are being established in the society. Companies, as part of society and as socially responsible entities should be part of these changes and, therefore, adapt themselves to these new models of communication. In one approach and study of this new model, some experiences obtained by Cofrentes Nuclear Power Plant are studied, a SWOT analysis of the situation is made and are raised the three main objectives Cofrentes NPP should pursue if it enters in the social networks field. (Author)

  20. Field Report

    DEFF Research Database (Denmark)

    Gorm Hansen, Louise Lyngfeldt

    2012-01-01

    This field report expresses perfectly the kind of confusion almost all of us experience when entering the field. How do we know whether what we’re doing is “right” or not? What in particular should we record when we don’t have time to write down everything among all the myriad impressions thrusting...

  1. Field Notes

    Data.gov (United States)

    US Agency for International Development — This is a mobile application for capturing images , data, and geolocation for USAID projects in the field. The data is then stored on a server in AllNet. The...

  2. Selfdecomposable Fields

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Sauri, Orimar; Szozda, Benedykt

    In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master Lévy measure and the associated Lévy-Itô representation. We give the dilation criterion for selfdecomposa......In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master Lévy measure and the associated Lévy-Itô representation. We give the dilation criterion...... for selfdecomposability analogous to the classical one. Next, we give necessary and sufficient conditions (in terms of the kernel functions) for a Volterra field driven by a Lévy basis to be selfdecomposable. In this context we also study the so-called Urbanik classes of random fields. We follow this with the study...... of existence and selfdecomposability of integrated Volterra fields. Finally, we introduce infinitely divisible field-valued Lévy processes, give the Lévy-Itô representation associated with them and study stochastic integration with respect to such processes. We provide examples in the form of Lévy...

  3. Selfdecomposable Fields

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Sauri, Orimar; Szozda, Benedykt

    In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master L\\'evy measure and the associated L\\'evy-It\\^o representation. We give the dilation criterion for selfdec......In the present paper we study selfdecomposability of random fields, as defined directly rather than in terms of finite-dimensional distributions. The main tools in our analysis are the master L\\'evy measure and the associated L\\'evy-It\\^o representation. We give the dilation criterion...... for selfdecomposability analogous to the classical one. Next, we give necessary and sufficient conditions (in terms of the kernel functions) for a Volterra field driven by a L\\'evy basis to be selfdecomposable. In this context we also study the so-called Urbanik classes of random fields. We follow this with the study...... of existence and selfdecomposability of integrated Volterra fields. Finally, we introduce infinitely divisible field-valued L\\'evy processes, give the L\\'evy-It\\^o representation associated with them and study stochastic integration with respect to such processes. We provide examples in the form of L...

  4. Random Fields

    Science.gov (United States)

    Vanmarcke, Erik

    1983-03-01

    Random variation over space and time is one of the few attributes that might safely be predicted as characterizing almost any given complex system. Random fields or "distributed disorder systems" confront astronomers, physicists, geologists, meteorologists, biologists, and other natural scientists. They appear in the artifacts developed by electrical, mechanical, civil, and other engineers. They even underlie the processes of social and economic change. The purpose of this book is to bring together existing and new methodologies of random field theory and indicate how they can be applied to these diverse areas where a "deterministic treatment is inefficient and conventional statistics insufficient." Many new results and methods are included. After outlining the extent and characteristics of the random field approach, the book reviews the classical theory of multidimensional random processes and introduces basic probability concepts and methods in the random field context. It next gives a concise amount of the second-order analysis of homogeneous random fields, in both the space-time domain and the wave number-frequency domain. This is followed by a chapter on spectral moments and related measures of disorder and on level excursions and extremes of Gaussian and related random fields. After developing a new framework of analysis based on local averages of one-, two-, and n-dimensional processes, the book concludes with a chapter discussing ramifications in the important areas of estimation, prediction, and control. The mathematical prerequisite has been held to basic college-level calculus.

  5. Field theories with subcanonical fields

    International Nuclear Information System (INIS)

    Bigi, I.I.Y.

    1976-01-01

    The properties of quantum field theories with spinor fields of dimension less than the canonical value of 3/2 are studied. As a starting point for the application of common perturbation theory we look for the linear version of these theories. A gange-interaction is introduced and with the aid of power counting the renormalizability of the theory is shown. It follows that in the case of a spinor-field with negative dimension renormalization can only be attained if the interaction has a further symmetry. By this symmetry the theory is determined in an unequivocal way. The gange-interaction introduced in the theory leads to a spontaneous breakdown of scale invariance whereby masses are produced. At the same time the spinor-field operators can now be separated in two orthogonal sections with opposite norm. It is proposed to use the section with negative (positive) norm to describe hadrons (leptons) respectively. (orig./WL) [de

  6. Gauge fields

    International Nuclear Information System (INIS)

    Itzykson, C.

    1978-01-01

    In these notes the author provides some background on the theory of gauge fields, a subject of increasing popularity among particle physicists (and others). Detailed motivations and applications which are covered in the other lectures of this school are not presented. In particular the application to weak interactions is omitted by referring to the introduction given by J. Ilipoulos a year ago (CERN Report 76-11). The aim is rather to stress those aspects which suggest that gauge fields may play some role in a future theory of strong interactions. (Auth.)

  7. The purpose of the communication process of group activities in the Family Health Strategy Finalidad del proceso de comunicación de las actividades en grupo en la Estrategia Salud de la Familia Finalidade do processo comunicacional das atividades em grupo na Estratégia Saúde da Família

    Directory of Open Access Journals (Sweden)

    Leticia Silveira Cardoso

    2011-04-01

    Full Text Available This study identified the purposes of the communication process in the group activities of the Family Health strategy from the perspective of nurses. Semi-structured interviews were conducted and recorded with 60 nurses and non-participant observation with 19 group activities, analyzed according to qualitative content analysis. Five categories emerged: Health education, Clinical follow-up, Co-responsibilization of patients, Team-Community Interaction, and Work Organization. These categories revealed that the establishment of reciprocal interactions among professionals, patients and families favor health promotion because it encourages the exchange of knowledge among the participants concerning their health experiences.Se objetivó identificar los sentidos de finalidad del proceso de comunicación en las actividades en grupo de la Estrategia Salud de la Familia, en la perspectiva de los enfermeros. Se usó las técnicas de entrevista semiestructurada grabada con 60 enfermeros y de observación no participante en 19 actividades en grupo, analizadas según el abordaje cualitativo de contenido. Se evidenció cinco categorías: Educación en Salud, Acompañamiento Clínico, Corresponsabilidad de los Clientes, Interacción Equipo Comunidad y Organización del Trabajo. Ellos permitieron inferir que el establecimiento de interacciones de reciprocidad entre profesionales, clientes y familia favorece la intervención promotora de la salud por estimular el intercambio de conocimientos entre los participantes al respecto de sus experiencias de salud.Objetivou-se, por este estudo, identificar os sentidos de finalidade do processo comunicacional nas atividades em grupo da Estratégia Saúde da Família, na perspectiva dos enfermeiros. Usaram-se as técnicas de entrevista semiestruturada gravada, com 60 enfermeiros, e de observação não participante, em 19 atividades em grupo, analisadas segundo abordagem qualitativa de conteúdo. Evidenciaram-se cinco

  8. Field theory

    CERN Multimedia

    1999-11-08

    In these lectures I will build up the concept of field theory using the language of Feynman diagrams. As a starting point, field theory in zero spacetime dimensions is used as a vehicle to develop all the necessary techniques: path integral, Feynman diagrams, Schwinger-Dyson equations, asymptotic series, effective action, renormalization etc. The theory is then extended to more dimensions, with emphasis on the combinatorial aspects of the diagrams rather than their particular mathematical structure. The concept of unitarity is used to, finally, arrive at the various Feynman rules in an actual, four-dimensional theory. The concept of gauge-invariance is developed, and the structure of a non-abelian gauge theory is discussed, again on the level of Feynman diagrams and Feynman rules.

  9. Gauge fields

    International Nuclear Information System (INIS)

    Mills, R.

    1989-01-01

    This article is a survey of the history and ideas of gauge theory. Described here are the gradual emergence of symmetry as a driving force in the shaping of physical theory; the elevation of Noether's theorem, relating symmetries to conservation laws, to a fundamental principle of nature; and the force of the idea (''the gauge principle'') that the symmetries of nature, like the interactions themselves, should be local in character. The fundamental role of gauge fields in mediating the interactions of physics springs from Noether's theorem and the gauge principle in a remarkably clean and elegant way, leaving, however, some tantalizing loose ends that might prove to be the clue to a future deeper level of understanding. The example of the electromagnetic field as the prototype gauge theory is discussed in some detail and serves as the basis for examining the similarities and differences that emerge in generalizing to non-Abelian gauge theories. The article concludes with a brief examination of the dream of total unification: all the forces of nature in a single unified gauge theory, with the differences among the forces due to the specific way in which the fundamental symmetries are broken in the local environment

  10. El celebrante, estudio sobre comunicaciones interpersonales, algunos aspectos

    Directory of Open Access Journals (Sweden)

    Lic.Susana Sanguineti

    2001-01-01

    Full Text Available En las relaciones cotidianas, cuando un individuo llega a la presencia de otros, éstos tratan de adquirir información acerca de él. Todo lo relacionado a ese individuo les interesará: su forma de vida, su posicionamiento económico y social, su particular forma de ser, su forma de relacionarse.

  11. Narrativas transmídia: diversidade social, discursiva e comunicacional

    Directory of Open Access Journals (Sweden)

    Denis Porto-Renó

    2011-01-01

    Full Text Available En la actualidad, los procesos de comunicación experimentan una revolución en el campo estructural y en el de las lenguas. Estos cambios son el producto de comportamientos y contribuciones comunicacionales ofrecidos a la sociedad contemporánea, por ejemplo, redes sociales y movilidad. Sin embargo, la comunicación no asimiló tales cambios por completo, a pesar de los estudios que tienen en cuenta la narrativa transmedia. Basado en un estudio reflexivo e investigativo, este artículo ofrece análisis acerca de la narrativa transmedia como lenguaje social en la ficción y elperiodismo. Esperamos contribuir con nuevas investigaciones sobre el tema.

  12. Communication and external relations; Comunicacion y relaciones externas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    A company's identity is what it really is, whereas its image is what others perceive or think it is. Therefore, it should suffice to simply combine these two concepts-identity and image-to simplify communication activities. However, identity and image are complex, varying concepts that are conditioned by environment, opinions, expectations, attitudes, market evolution and many other factors. In Cofrentes, we have always been aware of the difficulties involved in successful communication at all levels and, therefore, from the very beginning, even before the Plant was started up, channels were established for public service and relations with all the entities of Cofrentes NPP physical, human and institutional environment in its three possible spheres of influence at the local, provincial and national levels. (Author)

  13. COMUNICACIONES CORTAS TERPENOS ISLADOS DE LOS FRUTOS DE CLUSIA ssp.

    Directory of Open Access Journals (Sweden)

    Jaime González

    2010-10-01

    Full Text Available Se aislaron triterpenos de los frutos de tres especies de Clusia (familia Guttiferae. En C.multlflora y C. grandiflora se encontraron eufenol, epímero en C-20 del tirucallol, y 3 ceto eufano antes no reportados para este género. También se encontró isocariofileno en C. grandiflora.

  14. Las comunicaciones móviles en los edificios inteligentes

    OpenAIRE

    Reyes Muñoz, María Angélica

    2011-01-01

    Este trabajo presenta una plataforma de red móvil aplicada a los entornos de edificios inteligentes. En primer lugar, los edificios inteligentes han sido definidos como “aquellos que utilizan la tecnología computacional para gestionar de manera autónoma todos los servicios que ofrece un entorno de un edificio tales como optimizar el confort del usuario, el consumo de energía y la seguridad” [Callaghan 00].Desde el punto de vista de las telecomunicaciones específicamente desde e...

  15. Ritualismo jurídico o derecho a las comunicaciones

    Directory of Open Access Journals (Sweden)

    Arturo Bregaglio

    2015-01-01

    Full Text Available La producción del derecho en América Latina, ha estado hegemonizada por concepciones antidemocráticas y, en materia de legislación de telecomunicaciones, anclada en normas tradicionalistas, conservadora del orden autoritario y aferrada a tono solemne de la formalidad jurídica, del cumplimiento del rito. Los nuevos ordenamientos jurídicos latinoamericanos y en particular las legislaciones de telecomunicaciones, exigen códigos interpretativos impregnados de legalidad y realismo,teniendo como límites máximos ciertos y expresos a los Derechos Humanos y al orden democrático.

  16. Comunicaciones multimediales en entornos médicos

    OpenAIRE

    Zambón, M.; Ferro, Edgardo; Santos, Rodrigo; Orozco, Javier D.

    1998-01-01

    DICOM es una especificación desarrollada con la intención de normalizar la forma en que se adquieren, codifican, transmiten e interpretan las imágenes médicas y la información adjunta. La norma está definida al nivel de aplicación, y permite cualquier red de interconexión compatible con el modelo de referencia ISO/OSI ó TCP/IP. DICOM fue originalmente diseñada para la transmisión y almacenamiento de imágenes médicas. La norma provee los mecanismos necesarios para implementar en forma ...

  17. Cerebro, lenguaje y comunicacion (Brain, Language, and Communication).

    Science.gov (United States)

    Strejilevich, Leonardo

    1978-01-01

    Discusses the relationship between the brain, language, and communication in the following sections: (1) combining words, (2) language as a system, (3) language as a function of the brain, (4) the science of communication, and (5) language as a social institution. (NCR)

  18. COMUNICACION Y CIUDADANIA: DEL BARRIO A LA CIUDAD

    Directory of Open Access Journals (Sweden)

    Gabriel Kaplún

    1998-01-01

    Full Text Available El proceso de descentralización municipal de Montevideo ha sido para un grupo de universitarios uruguayos un fértil campo de aprendizaje sobre los límites y potencialidades de sus roles profesionales, los problemas de la comunicación en el espacio urbano, las relaciones entre poder y palabra.

  19. An experience in the management of personal dosimetry and Information and Communication Technologies; Una experiencia en la gestión de la dosimetría personal y las Tecnologías de la Información y las Comunicaciones

    Energy Technology Data Exchange (ETDEWEB)

    Galán Montenegro, P.; Sánchez Hidalgo, M.; Bodineau, C.; Oliveros Fernández, B.

    2015-07-01

    étrico, se requiere realizar una gestión más personalizada y directa de la dosimetría individual de cada uno de los trabajadores expuestos y transmitir una información rápida y personal. Debido al número total de trabajadores expuestos y de la diversidad y dispersión de los centros bajo control dosimétrico se hace imposible este tipo de gestión sin emplear grandes recursos. Para conseguir los objetivos de una gestión más personalizada en un escenario como el descrito, y reducir la tasa de no recambio mensual de los dosímetros personales y de las dosis administrativas asignadas, en el año 2009 se pusieron en marcha en este centro algunas medidas utilizando las plataformas de las Tecnologías de la Información y las Comunicaciones (TIC) y otras de gestión de trabajadores, cuyo resultado ha sido el de la reducción de la tasa de no recambio mensual de los dosímetros personales en un 75 %.

  20. Field training

    International Nuclear Information System (INIS)

    Mumford, G.E.; Hadaway, E.H.

    1991-01-01

    Individualized, personal training can be used to increase an employee's awareness of the HSE program. Such training can stimulate personal commitment and provide personal skills that can be utilized for the benefit of the overall HSE effort. But, providing such training within our industry can be a difficult task due to the scheduling, travel arrangements, and cost associated with bringing employees from isolated, remote locations to centrally located training facilities. One method of overcoming these obstacles involves the use of field instructors to provide the training at the many, and varied number of individuals can be reached with minimal disruption to their work scheduling or to their time off. In fact, this type of on-site training is already used by some oil companies and drilling contractors with encouraging results. This paper describes one drilling contractor's experiences with such a training program. The results after eight years how that this program not only can provide and efficient, economical means of employee training, but also can have a direct application to employee motivation regarding a company's HSE effort

  1. An electric field in a gravitational field

    International Nuclear Information System (INIS)

    Harpaz, Amos

    2005-01-01

    The behaviour of an electric field in a gravitational field is analysed. It is found that due to the mass (energy) of the electric field, it is subjected to gravity and it falls in the gravitational field. This fall curves the electric field, a stress force (a reaction force) is created, and the interaction of this reaction force with the static charge gives rise to the creation of radiation

  2. Infographics as a communication resource in the process of acquiring information and understanding of typography A infografia como recurso comunicacional no processo de aquisição de informação e compreensão de tipografia

    Directory of Open Access Journals (Sweden)

    Uriá Fassina Firmino

    2012-05-01

    extrai a ideia de que o processo de construção e não somente a consulta de infográficos também pode ser utilizado na curva de aprendizagem, funcionando como seu agente. Considerando pontos de dificuldade no estudo de tipografia, sugere-se um recurso orientado aaprimorar o processo comunicacional e de compreensão de conteúdo de tipografia: a criação de infográficos estritamente direcionados ao tema que atuarão tanto como objetos passivos de consulta, como fios condutores da comunicação e da investigação e também como exercício prático que estimulahabilidades básicas do designer. A visualização da informação e os infográficos são recursos amplamente utilizados na mídia impressa e nas ciências que tratam da complexidade, visando diminuir as barreiras de entendimento do conteúdo. Tal recurso mostra-se útil para tratar de tipografia, uma das áreas de conhecimento base da comunicação e do design visual que está relacionada tanto com o projeto quanto ao uso consciente de símbolos alfabéticos na construção da mensagem. Esta pesquisa indica, ainda, que os desdobramentos do objeto em estudo podem ter aplicação didático-pedagógica e serem úteis para a transmissão de informação também em outras áreas, não se limitando ao universo da tipografia, ao passo que se revela como linguagem em ascensão que tem olhos no hibridismo dos processos comunicacionais imagético-visuais.

  3. Quantized fields in external field. Pt. 2

    International Nuclear Information System (INIS)

    Bellissard, J.

    1976-01-01

    The case of a charged scalar field is considered first. The existence of the corresponding Green's functions is proved. For weak fields, as well as pure electric or scalar external fields, the Bogoliubov S-operator is shown to be unitary, covariant, causal up-to-a-phase. These results are generalised to a class of higher spin quantized fields, 'nicely' coupled to external fields, which includes the Dirac theory, and in the case of minimal and magnetic dipole coupling, the spin one Petiau-Duffin-Kemmer theory. (orig.) [de

  4. Gravitation and vacuum field

    International Nuclear Information System (INIS)

    Tevikyan, R.V.

    1986-01-01

    This paper presents equations that describe particles with spins s = 0, 1/2, 1 completely and which also describe 2s + 2 limiting fields as E → ∞. It is shown that the ordinary Hilbert-Einstein action for the gravitation field must be augmented by the action for the Bose vacuum field. This means that one must introduce in the gravitational equations a cosmological term proportional to the square of the strength of the Bose vacuum field. It is shown that the theory of gravitation describes three realities: matter, field, and vacuum field. A new form of matter--the vacuum field--is introduced into field theory

  5. Fractal vector optical fields.

    Science.gov (United States)

    Pan, Yue; Gao, Xu-Zhen; Cai, Meng-Qiang; Zhang, Guan-Lin; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian

    2016-07-15

    We introduce the concept of a fractal, which provides an alternative approach for flexibly engineering the optical fields and their focal fields. We propose, design, and create a new family of optical fields-fractal vector optical fields, which build a bridge between the fractal and vector optical fields. The fractal vector optical fields have polarization states exhibiting fractal geometry, and may also involve the phase and/or amplitude simultaneously. The results reveal that the focal fields exhibit self-similarity, and the hierarchy of the fractal has the "weeding" role. The fractal can be used to engineer the focal field.

  6. Electric Field Imaging

    Data.gov (United States)

    National Aeronautics and Space Administration — NDE historically has focused technology development in propagating wave phenomena with little attention to the field of electrostatics and emanating electric fields....

  7. How fields vary.

    Science.gov (United States)

    Krause, Monika

    2018-03-01

    Field theorists have long insisted that research needs to pay attention to the particular properties of each field studied. But while much field-theoretical research is comparative, either explicitly or implicitly, scholars have only begun to develop the language for describing the dimensions along which fields can be similar to and different from each other. In this context, this paper articulates an agenda for the analysis of variable properties of fields. It discusses variation in the degree but also in the kind of field autonomy. It discusses different dimensions of variation in field structure: fields can be more or less contested, and more or less hierarchical. The structure of symbolic oppositions in a field may take different forms. Lastly, it analyses the dimensions of variation highlighted by research on fields on the sub- and transnational scale. Post-national analysis allows us to ask how fields relate to fields of the same kind on different scales, and how fields relate to fields on the same scale in other national contexts. It allows us to ask about the role resources from other scales play in structuring symbolic oppositions within fields. A more fine-tuned vocabulary for field variation can help us better describe particular fields and it is a precondition for generating hypotheses about the conditions under which we can expect to observe fields with specified characteristics. © London School of Economics and Political Science 2017.

  8. Magnetic Field Calculator

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Magnetic Field Calculator will calculate the total magnetic field, including components (declination, inclination, horizontal intensity, northerly intensity,...

  9. Magnetic field reconnexion in a sheared field

    International Nuclear Information System (INIS)

    Ugai, M.

    1981-01-01

    A nonlinear development of the Petschek mode in a sheared magnetic field where there is a field component Bsub(z) along an X line is numerically studied. It is found that finite-amplitude intermediate waves, adjacent to the slow shock, may eventually stand in the quasi-steady configuration; on the other hand, the fundamental characteristics of the Petschek-mode development are scarcely influenced, either qualitatively or quantitatively, by the Bsub(z) field. (author)

  10. Wake fields and wake field acceleration

    International Nuclear Information System (INIS)

    Bane, K.L.F.; Wilson, P.B.; Weiland, T.

    1984-12-01

    In this lecture we introduce the concepts of wake fields and wake potentials, examine some basic properties of these functions, show how they can be calculated, and look briefly at a few important applications. One such application is wake field acceleration. The wake field accelerator is capable of producing the high gradients required for future very high energy e + e - linear colliders. The principles of wake field acceleration, and a brief description of experiments in progress in this area, are presented in the concluding section. 40 references, 27 figures

  11. On Jacobi-fields

    International Nuclear Information System (INIS)

    Bruening, E.

    1981-01-01

    The concept of a Jacobi-field is introduced as such a field for which the field-operators have the form of a generalized Jacobi-matrix with respect to the n-field-sector decomposition of the state-space. It is argued that the class of Jacobi-fields is of interest for relativistic quantum field theory for two reasons: (a) Jacobi-fields allow a direct association of particles (charges etc.) with fields. The concept of (generalized) creation- and annihilation-operators is thus available. (b) Jacobi-fields belong to that class of fields which can be characterized in terms of finitely many vacuum expectation values. A characterization of Jacobi-fields in terms of continuity and hermiticity properties of their system of vacuum expectation values is derived. Furthermore it is argued that all examples of relativistic quantum fields in a four-dimensional space-time are Jacobi-fields. This is evident for generalized free fields and Wick-powers of free fields, but is also true for a class of generalized Wick-powers of generalized free fields. (Auth.)

  12. Field Trips. Beginnings Workshop.

    Science.gov (United States)

    Cartwright, Sally; Aronson, Susan S.; Stacey, Susan; Winbush, Olga

    2001-01-01

    Five articles highlight benefits and organization of field trips: (1) "Field Trips Promote Child Learning at Its Best"; (2) "Planning for Maximum Benefit, Minimum Risk"; (3) "Coaching Community Hosts"; (4) "The Story of a Field Trip: Trash and Its Place within Children's Learning and Community"; and (5) "Field Trip Stories and Perspectives" (from…

  13. Field Campaign Guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Voyles, J. W. [DOE ARM Climate Research Facility, Washington, DC (United States); Chapman, L. A. [DOE ARM Climate Research Facility, Washington, DC (United States)

    2015-12-01

    This document establishes a common set of guidelines for the Atmospheric Radiation Measurement (ARM) Climate Research Facility for planning, executing, and closing out field campaigns. The steps that guide individual field campaigns are described in the Field Campaign Tracking System and are specifically tailored to meet the scope of each field campaign.

  14. The Galactic magnetic fields

    International Nuclear Information System (INIS)

    Han Jinlin

    2006-01-01

    A good progress has been made on studies of Galactic magnetic fields in last 10 years. I describe what we want to know about the Galactic magnetic fields, and then review we current knowledge about magnetic fields in the Galactic disk, the Galactic halo and the field strengths. I also listed many unsolved problems on this area

  15. Gauge fields in a torsion field

    International Nuclear Information System (INIS)

    Rosu, Ion

    2004-01-01

    In this paper we analyse the motion and the field equations in a non-null curvature and torsion space. In this 4-n dimensional space, the connection coefficients are γ bc a = 1/2S bc a + 1/2T bc a, where S bc a is the symmetrical part and T bc a are the components of the torsion tensor. We will consider that all the fields depend on x = x α , α = 1,2,3,4 and do not depend on y = y k , k=1,2,...,n. The factor S bc a depends on the components of the metric tensor g αβ (x) and on the gauge fields A ν s 0 (x) and the components of the torsion depend only on the gauge fields A ν s 0 (x). We take into consideration the particular case for which the geodesic equations coincide with the motion equations in the presence of the gravitational and the gauge fields. In this case the field equations are Einstein equations in a 4-n dimensional space. We show that both the geodesic equations and the field equations can be obtained from a variational principle. (author)

  16. Engineering field theory

    CERN Document Server

    Baden Fuller, A J

    2014-01-01

    Engineering Field Theory focuses on the applications of field theory in gravitation, electrostatics, magnetism, electric current flow, conductive heat transfer, fluid flow, and seepage.The manuscript first ponders on electric flux, electrical materials, and flux function. Discussions focus on field intensity at the surface of a conductor, force on a charged surface, atomic properties, doublet and uniform field, flux tube and flux line, line charge and line sink, field of a surface charge, field intensity, flux density, permittivity, and Coulomb's law. The text then takes a look at gravitation

  17. Ambient Field Analysis at Groningen Gas Field

    Science.gov (United States)

    Spica, Z.; Nakata, N.; Beroza, G. C.

    2016-12-01

    We analyze continuous ambient-field data at Groningen gas field (Netherlands) through cross-correlation processing. The Groningen array is composed of 75 shallow boreholes with 6 km spacing, which contain a 3C surface accelerometer and four 5-Hz 3C borehole geophones spaced at 50 m depth intervals. We successfully retrieve coherent waves from ambient seismic field on the 9 components between stations. Results show high SNR signal in the frequency range of 0.125-1 Hz, and the ZZ, ZR, RZ, RR and TT components show much stronger wave energy than other components as expected. This poster discuss the different type of waves retrieved, the utility of the combination of borehole and surface observations, future development as well as the importance to compute the 9 components of the Green's tensor to better understand the wave field propriety with ambient noise.

  18. Covariant Noncommutative Field Theory

    Energy Technology Data Exchange (ETDEWEB)

    Estrada-Jimenez, S [Licenciaturas en Fisica y en Matematicas, Facultad de Ingenieria, Universidad Autonoma de Chiapas Calle 4a Ote. Nte. 1428, Tuxtla Gutierrez, Chiapas (Mexico); Garcia-Compean, H [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN P.O. Box 14-740, 07000 Mexico D.F., Mexico and Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Monterrey Via del Conocimiento 201, Parque de Investigacion e Innovacion Tecnologica (PIIT) Autopista nueva al Aeropuerto km 9.5, Lote 1, Manzana 29, cp. 66600 Apodaca Nuevo Leon (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato P.O. Box E-143, 37150 Leon Gto. (Mexico); Ramirez, C [Facultad de Ciencias Fisico Matematicas, Universidad Autonoma de Puebla, P.O. Box 1364, 72000 Puebla (Mexico)

    2008-07-02

    The covariant approach to noncommutative field and gauge theories is revisited. In the process the formalism is applied to field theories invariant under diffeomorphisms. Local differentiable forms are defined in this context. The lagrangian and hamiltonian formalism is consistently introduced.

  19. Covariant Noncommutative Field Theory

    International Nuclear Information System (INIS)

    Estrada-Jimenez, S.; Garcia-Compean, H.; Obregon, O.; Ramirez, C.

    2008-01-01

    The covariant approach to noncommutative field and gauge theories is revisited. In the process the formalism is applied to field theories invariant under diffeomorphisms. Local differentiable forms are defined in this context. The lagrangian and hamiltonian formalism is consistently introduced

  20. Understanding Vector Fields.

    Science.gov (United States)

    Curjel, C. R.

    1990-01-01

    Presented are activities that help students understand the idea of a vector field. Included are definitions, flow lines, tangential and normal components along curves, flux and work, field conservation, and differential equations. (KR)

  1. Magnetic Field Grid Calculator

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Magnetic Field Properties Calculator will computes the estimated values of Earth's magnetic field(declination, inclination, vertical component, northerly...

  2. Gauge field copies

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.; Tiomno, J.

    1979-01-01

    The construction of field strength copies without any gauge constraint is discussed. Several examples are given, one of which is not only a field strength copy but also (at the same time) a 'current copy'. (author) [pt

  3. Cosmological magnetic fields - V

    Indian Academy of Sciences (India)

    Magnetic fields seem to be everywhere that we can look in the universe, from our own ... The field tensor is observer-independent, while the electric and magnetic .... based on string theory [11], in which vacuum fluctuations of the field are ...

  4. Unified field theory

    International Nuclear Information System (INIS)

    Prasad, R.

    1975-01-01

    Results of researches into Unified Field Theory over the past seven years are presented. The subject is dealt with in chapters entitled: the choice of affine connection, algebraic properties of the vector fields, field laws obtained from the affine connection based on the path integral method, application to quantum theory and cosmology, interpretation of physical theory in terms of geometry. (U.K.)

  5. Politics of aviation fields

    Science.gov (United States)

    Vivent, Jacques

    1922-01-01

    In short, the "politics of aviation" lies in a few propositions: the need of having as large a number of fields as possible and of sufficient area; the utilization of the larger part of the existing military fields; the selection of uncultivated or unproductive fields, whenever technical conditions permit; ability to disregard (save in exceptional cases) objections of an agricultural nature.

  6. Finite discrete field theory

    International Nuclear Information System (INIS)

    Souza, Manoelito M. de

    1997-01-01

    We discuss the physical meaning and the geometric interpretation of implementation in classical field theories. The origin of infinities and other inconsistencies in field theories is traced to fields defined with support on the light cone; a finite and consistent field theory requires a light-cone generator as the field support. Then, we introduce a classical field theory with support on the light cone generators. It results on a description of discrete (point-like) interactions in terms of localized particle-like fields. We find the propagators of these particle-like fields and discuss their physical meaning, properties and consequences. They are conformally invariant, singularity-free, and describing a manifestly covariant (1 + 1)-dimensional dynamics in a (3 = 1) spacetime. Remarkably this conformal symmetry remains even for the propagation of a massive field in four spacetime dimensions. We apply this formalism to Classical electrodynamics and to the General Relativity Theory. The standard formalism with its distributed fields is retrieved in terms of spacetime average of the discrete field. Singularities are the by-products of the averaging process. This new formalism enlighten the meaning and the problem of field theory, and may allow a softer transition to a quantum theory. (author)

  7. ZEPHYR - poloidal field system

    International Nuclear Information System (INIS)

    Seidel, U.

    1982-04-01

    The basics of the poloidal field system of the ZEPHYR experiment are considered. From the physical data the requirements for the poloidal field are derived. Hence an appropriate coil configuration consisting of coil locations and corresponding currents is obtained. A suitable electrical circuit feeding the coils is described. A preliminary assessment of the dynamic control of the poloidal field system is given. (orig.)

  8. Magnetic field line Hamiltonian

    International Nuclear Information System (INIS)

    Boozer, A.H.

    1985-02-01

    The basic properties of the Hamiltonian representation of magnetic fields in canonical form are reviewed. The theory of canonical magnetic perturbation theory is then developed and applied to the time evolution of a magnetic field embedded in a toroidal plasma. Finally, the extension of the energy principle to tearing modes, utilizing the magnetic field line Hamiltonian, is outlined

  9. Omnigenous magnetic fields

    International Nuclear Information System (INIS)

    Stupakov, G.V.

    1982-01-01

    In omnigenous magnetic fields particles' drift surfaces coincide with plasma magnetic surfaces. In this paper we formulate equations of omnigenous magnetic fields in natural curvilinear coordinates. An analysis of fields which are omnigenous only in the paraxial approximation is presented. (author)

  10. Far field acceleration

    International Nuclear Information System (INIS)

    Fernow, R.C.

    1995-07-01

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail

  11. Cosmic Magnetic Fields

    Science.gov (United States)

    Sánchez Almeida, J.; Martínez González, M. J.

    2018-05-01

    Magnetic fields play an important role in many astrophysical processes. They are difficult to detect and characterize since often their properties have to be inferred through interpreting the polarization of the light. Magnetic fields are also challenging to model and understand. Magnetized plasmas behave following highly non-linear differential equations having no general solution, so that every astrophysical problem represents a special case to be studied independently. Hence, magnetic fields are often an inconvenient subject which is overlooked or simply neglected (the elephant in the room, as they are dubbed in poster of the school). Such difficulty burdens the research on magnetic fields, which has evolved to become a very technical subject, with many small disconnected communities studying specific aspects and details. The school tried to amend the situation by providing a unifying view of the subject. The students had a chance to understand the behavior of magnetic fields in all astrophysical contexts, from cosmology to the Sun, and from starbursts to AGNs. The school was planed to present a balanced yet complete review of our knowledge, with excursions into the unknown to point out present and future lines of research. The subject of Cosmic Magnetic Fields was split into seven different topics: cosmic magnetic field essentials, solar magnetic fields, stellar magnetic fields, the role of magnetic fields on AGN feedback, magnetic fields in galaxies, magnetic fields in galaxy clusters and at larger scales, and primordial magnetic fields and magnetic fields in the early Universe. The corresponding lectures were delivered by seven well known and experienced scientists that have played key roles in the major advances of the field during the last years: F. Cattaneo, P. Judge, O. Kochukhov, R. Keppens, R. Beck, K. Dolag, and F. Finelli. Their lectures were recorded and are freely available at the IAC website: http://iactalks.iac.es/talks/serie/19.

  12. Quantum field theory

    International Nuclear Information System (INIS)

    Ryder, L.H.

    1985-01-01

    This introduction to the ideas and techniques of quantum field theory presents the material as simply as possible and is designed for graduate research students. After a brief survey of particle physics, the quantum theory of scalar and spinor fields and then of gauge fields, is developed. The emphasis throughout is on functional methods, which have played a large part in modern field theory. The book concludes with a bridge survey of ''topological'' objects in field theory and assumes a knowledge of quantum mechanics and special relativity

  13. Unitary field theories

    International Nuclear Information System (INIS)

    Bergmann, P.G.

    1980-01-01

    A problem of construction of the unitary field theory is discussed. The preconditions of the theory are briefly described. The main attention is paid to the geometrical interpretation of physical fields. The meaning of the conceptions of diversity and exfoliation is elucidated. Two unitary field theories are described: the Weyl conformic geometry and Calitzy five-dimensioned theory. It is proposed to consider supersymmetrical theories as a new approach to the problem of a unitary field theory. It is noted that the supergravitational theories are really unitary theories, since the fields figuring there do not assume invariant expansion

  14. Field emission electronics

    CERN Document Server

    Egorov, Nikolay

    2017-01-01

    This book is dedicated to field emission electronics, a promising field at the interface between “classic” vacuum electronics and nanotechnology. In addition to theoretical models, it includes detailed descriptions of experimental and research techniques and production technologies for different types of field emitters based on various construction principles. It particularly focuses on research into and production of field cathodes and electron guns using recently developed nanomaterials and carbon nanotubes. Further, it discusses the applications of field emission cathodes in new technologies such as light sources, flat screens, microwave and X-ray devices.

  15. Strong Magnetic Field Characterisation

    Science.gov (United States)

    2012-04-01

    an advertised surface field of approximately 0.5 T were used to supply the static magnetic field source. The disc magnet had a diameter of 50 mm and... colour bar indicates the magnetic field strength set to an arbitrary 0.25 T. The white area has a field >0.25 T. The size of the arrow is proportional...9 shows the magnetic field strength along a slice in the XZ plane. The colours represent the total UNCLASSIFIED 10 UNCLASSIFIED DSTO-TR-2699

  16. Classical field theory

    CERN Document Server

    Franklin, Joel

    2017-01-01

    Classical field theory, which concerns the generation and interaction of fields, is a logical precursor to quantum field theory, and can be used to describe phenomena such as gravity and electromagnetism. Written for advanced undergraduates, and appropriate for graduate level classes, this book provides a comprehensive introduction to field theories, with a focus on their relativistic structural elements. Such structural notions enable a deeper understanding of Maxwell's equations, which lie at the heart of electromagnetism, and can also be applied to modern variants such as Chern–Simons and Born–Infeld. The structure of field theories and their physical predictions are illustrated with compelling examples, making this book perfect as a text in a dedicated field theory course, for self-study, or as a reference for those interested in classical field theory, advanced electromagnetism, or general relativity. Demonstrating a modern approach to model building, this text is also ideal for students of theoretic...

  17. Earth's electric field

    International Nuclear Information System (INIS)

    Kelley, M.C.

    1978-01-01

    The earth becomes charged during thunderstorm activity and discharges through the weak conducting atmosphere. Balloon and rocket studies infer that a high altitude electric field penetrates virtually unattenuated through the atmosphere, at least as far as balloon heights. The field has two primary sources. At low and mid latitudes, interaction between the earth's magnetic field and the neutral wind creates electric fields. At latitudes above 60 0 , the high altitude electrical structure is dominated by the interaction between the solar wind and the earth's magnetic field. The auroral light is emitted by atmospheric atoms and molecules excited by electrons with potentials of many thousands volts. The potentials are induced by the solar wind. Recent satellite data shows that the electrons get this energy by passing through a localized electric field about 6000 km above the auroral zone. Several rocket and satellite experiments used to study the earth's electric field are discussed

  18. Forces in electromagnetic field and gravitational field

    OpenAIRE

    Weng, Zihua

    2008-01-01

    The force can be defined from the linear momentum in the gravitational field and electromagnetic field. But this definition can not cover the gradient of energy. In the paper, the force will be defined from the energy and torque in a new way, which involves the gravitational force, electromagnetic force, inertial force, gradient of energy, and some other new force terms etc. One of these new force terms can be used to explain why the solar wind varies velocity along the magnetic force line in...

  19. Continuum gauge fields from lattice gauge fields

    International Nuclear Information System (INIS)

    Goeckeler, M.; Kronfeld, A.S.; Schierholz, G.; Wiese, U.J.

    1993-01-01

    On the lattice some of the salient features of pure gauge theories and of gauge theories with fermions in complex representations of the gauge group seem to be lost. These features can be recovered by considering part of the theory in the continuum. The prerequisite for that is the construction of continuum gauge fields from lattice gauge fields. Such a construction, which is gauge covariant and complies with geometrical constructions of the topological charge on the lattice, is given in this paper. The procedure is explicitly carried out in the U(1) theory in two dimensions, where it leads to simple results. (orig.)

  20. Polarimetry of random fields

    Science.gov (United States)

    Ellis, Jeremy

    On temporal, spatial and spectral scales which are small enough, all fields are fully polarized. In the optical regime, however, instantaneous fields can rarely be examined, and, instead, only average quantities are accessible. The study of polarimetry is concerned with both the description of electromagnetic fields and the characterization of media a field has interacted with. The polarimetric information is conventionally presented in terms of second order field correlations which are averaged over the ensemble of field realizations. Motivated by the deficiencies of classical polarimetry in dealing with specific practical situations, this dissertation expands the traditional polarimetric approaches to include higher order field correlations and the description of fields fluctuating in three dimensions. In relation to characterization of depolarizing media, a number of fourth-order correlations are introduced in this dissertation. Measurements of full polarization distributions, and the subsequent evaluation of Stokes vector element correlations and Complex Degree of Mutual Polarization demonstrate the use of these quantities for material discrimination and characterization. Recent advancements in detection capabilities allow access to fields near their sources and close to material boundaries, where a unique direction of propagation is not evident. Similarly, there exist classical situations such as overlapping beams, focusing, or diffusive scattering in which there is no unique transverse direction. In this dissertation, the correlation matrix formalism is expanded to describe three dimensional electromagnetic fields, providing a definition for the degree of polarization of such a field. It is also shown that, because of the dimensionality of the problem, a second parameter is necessary to fully describe the polarimetric properties of three dimensional fields. Measurements of second-order correlations of a three dimensional field are demonstrated, allowing the

  1. Covariant electromagnetic field lines

    Science.gov (United States)

    Hadad, Y.; Cohen, E.; Kaminer, I.; Elitzur, A. C.

    2017-08-01

    Faraday introduced electric field lines as a powerful tool for understanding the electric force, and these field lines are still used today in classrooms and textbooks teaching the basics of electromagnetism within the electrostatic limit. However, despite attempts at generalizing this concept beyond the electrostatic limit, such a fully relativistic field line theory still appears to be missing. In this work, we propose such a theory and define covariant electromagnetic field lines that naturally extend electric field lines to relativistic systems and general electromagnetic fields. We derive a closed-form formula for the field lines curvature in the vicinity of a charge, and show that it is related to the world line of the charge. This demonstrates how the kinematics of a charge can be derived from the geometry of the electromagnetic field lines. Such a theory may also provide new tools in modeling and analyzing electromagnetic phenomena, and may entail new insights regarding long-standing problems such as radiation-reaction and self-force. In particular, the electromagnetic field lines curvature has the attractive property of being non-singular everywhere, thus eliminating all self-field singularities without using renormalization techniques.

  2. Partial Komori fields and imperative Komori fields

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2009-01-01

    This paper is concerned with the status of 1/0 and ways to deal with it. These matters are treated in the setting of Komori fields, also known as non-trivial cancellation meadows. Different viewpoints on the status of 1/0 exist in mathematics and theoretical computer science. We give a simple

  3. Nonlocal continuum field theories

    CERN Document Server

    2002-01-01

    Nonlocal continuum field theories are concerned with material bodies whose behavior at any interior point depends on the state of all other points in the body -- rather than only on an effective field resulting from these points -- in addition to its own state and the state of some calculable external field. Nonlocal field theory extends classical field theory by describing the responses of points within the medium by functionals rather than functions (the "constitutive relations" of classical field theory). Such considerations are already well known in solid-state physics, where the nonlocal interactions between the atoms are prevalent in determining the properties of the material. The tools developed for crystalline materials, however, do not lend themselves to analyzing amorphous materials, or materials in which imperfections are a major part of the structure. Nonlocal continuum theories, by contrast, can describe these materials faithfully at scales down to the lattice parameter. This book presents a unif...

  4. Simulated workplace neutron fields

    International Nuclear Information System (INIS)

    Lacoste, V.; Taylor, G.; Rottger, S.

    2011-01-01

    The use of simulated workplace neutron fields, which aim at replicating radiation fields at practical workplaces, is an alternative solution for the calibration of neutron dosemeters. They offer more appropriate calibration coefficients when the mean fluence-to-dose equivalent conversion coefficients of the simulated and practical fields are comparable. Intensive Monte Carlo modelling work has become quite indispensable for the design and/or the characterization of the produced mixed neutron/photon fields, and the use of Bonner sphere systems and proton recoil spectrometers is also mandatory for a reliable experimental determination of the neutron fluence energy distribution over the whole energy range. The establishment of a calibration capability with a simulated workplace neutron field is not an easy task; to date only few facilities are available as standard calibration fields. (authors)

  5. Nonequilibrium quantum field theories

    International Nuclear Information System (INIS)

    Niemi, A.J.

    1988-01-01

    Combining the Feynman-Vernon influence functional formalism with the real-time formulation of finite-temperature quantum field theories we present a general approach to relativistic quantum field theories out of thermal equilibrium. We clarify the physical meaning of the additional fields encountered in the real-time formulation of quantum statistics and outline diagrammatic rules for perturbative nonequilibrium computations. We derive a generalization of Boltzmann's equation which gives a complete characterization of relativistic nonequilibrium phenomena. (orig.)

  6. Organic magnetic field sensor

    Energy Technology Data Exchange (ETDEWEB)

    McCamey, Dane; Boehme, Christoph

    2017-01-24

    An organic, spin-dependent magnetic field sensor (10) includes an active stack (12) having an organic material with a spin-dependence. The sensor (10) also includes a back electrical contact (14) electrically coupled to a back of the active stack (12) and a front electrical contact (16) electrically coupled to a front of the active stack (12). A magnetic field generator (18) is oriented so as to provide an oscillating magnetic field which penetrates the active stack (12).

  7. Elementary quantum field theory

    International Nuclear Information System (INIS)

    Thirring, W.; Henley, E.M.

    1975-01-01

    The first section of the book deals with the mathematical and physical description of a quantum field with the Bose-Einstein statistics and discusses observables, invariants of the field, and inner symmetries. The second section develops further methods for solvable interactions of a quantum field with static source. Section 3 explains with the aid of the Chew-Low model especially pion-nucleon scattering, static properties of nucleons, electromagnetic phenomena, and nuclear forces. (BJ/LN) [de

  8. Wake field accelerators

    International Nuclear Information System (INIS)

    Wilson, P.B.

    1986-02-01

    In a wake field accelerator a high current driving bunch injected into a structure or plasma produces intense induced fields, which are in turn used to accelerate a trailing charge or bunch. The basic concepts of wake field acceleration are described. Wake potentials for closed cavities and periodic structures are derived, as are wake potentials on a collinear path with a charge distribution. Cylindrically symmetric structures excited by a beam in the form of a ring are considered

  9. Geomagnetic field, global pattern

    OpenAIRE

    Macmillan, Susan

    2011-01-01

    The geomagnetic field is generated in the fluid outer core region of the Earth by electrical currents flowing in the slowly moving molten iron. In addition to sources in the Earth’s core, the geomagnetic field observable on the Earth’s surface has sources in the crust and in the ionosphere and magnetosphere. The signal from the core dominates, accounting for over 95% of the field at the Earth’s surface. The geomagnetic field varies on a range of scales, both temporal and spatial; the...

  10. Effective quantum field theories

    International Nuclear Information System (INIS)

    Georgi, H.M.

    1993-01-01

    The most appropriate description of particle interactions in the language of quantum field theory depends on the energy at which the interactions are studied; the description is in terms of an ''effective field theory'' that contains explicit reference only to those particles that are actually important at the energy being studied. The various themes of the article are: local quantum field theory, quantum electrodynamics, new physics, dimensional parameters and renormalizability, socio-dynamics of particle theory, spontaneously broken gauge theories, scale dependence, grand unified and effective field theories. 2 figs

  11. Closed string field theory

    International Nuclear Information System (INIS)

    Strominger, A.

    1987-01-01

    A gauge invariant cubic action describing bosonic closed string field theory is constructed. The gauge symmetries include local spacetime diffeomorphisms. The conventional closed string spectrum and trilinear couplings are reproduced after spontaneous symmetry breaking. The action S is constructed from the usual ''open string'' field of ghost number minus one half. It is given by the associator of the string field product which is non-vanishing because of associativity anomalies. S does not describe open string propagation because open string states associate and can thereby be shifted away. A field theory of closed and open strings can be obtained by adding to S the cubic open string action. (orig.)

  12. Dielectrics in electric fields

    CERN Document Server

    Raju, Gorur G

    2003-01-01

    Discover nontraditional applications of dielectric studies in this exceptionally crafted field reference or text for seniors and graduate students in power engineering tracks. This text contains more than 800 display equations and discusses polarization phenomena in dielectrics, the complex dielectric constant in an alternating electric field, dielectric relaxation and interfacial polarization, the measurement of absorption and desorption currents in time domains, and high field conduction phenomena. Dielectrics in Electric Fields is an interdisciplinary reference and text for professionals and students in electrical and electronics, chemical, biochemical, and environmental engineering; physical, surface, and colloid chemistry; materials science; and chemical physics.

  13. Geomagnetic field of earth

    International Nuclear Information System (INIS)

    Delipetrev, Marjan; Delipetrev, Blagoj; Panovska, Sanja

    2008-01-01

    In this paper is introduced the theory of geomagnetic field of the Earth. A homogenous and isotropic sphere is taken for a model of Earth with a bar magnet at its center as a magnetic potential. The understanding of the real origin of geomagnetic field produced from differential rotation of inner core with respect to the outer core of Earth is here presented. Special attention is given to the latest observed data of the established net of geomagnetic repeat stations in the Republic of Macedonia. Finally, the maps of elements of geomagnetic field and the equation for calculation of normal magnetic field of Earth are provided. (Author)

  14. Fields, symmetries, and quarks

    International Nuclear Information System (INIS)

    Mosel, U.

    1989-01-01

    'Fields, symmetries, and quarks' covers elements of quantum field theory, symmetries, gauge field theories and phenomenological descriptions of hadrons, with special emphasis on topics relevant to nuclear physics. It is aimed at nuclear physicists in general and at scientists who need a working knowledge of field theory, symmetry principles of elementary particles and their interactions and the quark structure of hadrons. The book starts out with an elementary introduction into classical field theory and its quantization. As gauge field theories require a working knowledge of global symmetries in field theories this topic is then discussed in detail. The following part is concerned with the general structure of gauge field theories and contains a thorough discussion of the still less widely known features of Non-Abelian gauge field theories. Quantum Chromodynamics (QCD), which is important for the understanding of hadronic matter, is discussed in the next section together with the quark compositions of hadrons. The last two chapters give a detailed discussion of phenomenological bag-models. The MIT bag is discussed, so that all theoretical calculations can be followed step by step. Since in all other bag-models the calculational methods and steps are essentially identical, this chapter should enable the reader to actually perform such calculations unaided. A last chapter finally discusses the topological bag-models which have become quite popular over the last few years. (orig.)

  15. Numerical Electromagnetic Models of Cube-Shaped Boxes - An Initial Investigation for Near-Field Prediction of HF Shipboard Environments

    Science.gov (United States)

    1987-12-01

    de Armamento y Electronica 2 Comandancia de la Armada Av. Vollmer San Benardino Caracas, 1011 Venezuela 10. Director de Comunicaciones 2 Comandancia...Prof. Harry Atwater, Code 62An 1 Naval Postgraduate School Monterey, CA 93943-5000 6. Capitdn de Corbeta 5 Carlos R Molina T Comandancia de la Armada Av...Vollmer San Benardino Caracas, 1011 Venezuela 7. Escuela Naval de Venezuela 2 Director Comandancia de la Armada Av. Vollmer San Benardino Caracas

  16. Effective field theories

    International Nuclear Information System (INIS)

    Mack, G.; Kalkreuter, T.; Palma, G.; Speh, M.

    1992-05-01

    Effective field theories encode the predictions of a quantum field theory at low energy. The effective theory has a fairly low utraviolet cutoff. As a result, loop corrections are small, at least if the effective action contains a term which is quadratic in the fields, and physical predictions can be read straight from the effective Lagrangean. Methods will be discussed how to compute an effective low energy action from a given fundamental action, either analytically or numerically, or by a combination of both methods. Basically, the idea is to integrate out the high frequency components of fields. This requires the choice of a 'blockspin', i.e. the specification af a low frequency field as a function of the fundamental fields. These blockspins will be fields of the effective field theory. The blockspin need not be a field of the same type as one of the fundamental fields, and it may be composite. Special features of blockspin in nonabelian gauge theories will be discussed in some detail. In analytical work and in multigrid updating schemes one needs interpolation kernels A from coarse to fine grid in addition to the averaging kernels C which determines the blockspin. A neural net strategy for finding optimal kernels is presented. Numerical methods are applicable to obtain actions of effective theories on lattices of finite volume. The special case of a 'lattice' with a single site (the constraint effective potential) is of particular interest. In a higgs model, the effective action reduces in this case to the free energy, considered as a function of a gauge covariant magnetization. Its shape determines the phase structure of the theory. Its loop expansion with and without gauge fields can be used to determine finite size corrections to numerical data. (orig.)

  17. twistors and gauge fields

    Directory of Open Access Journals (Sweden)

    A. G. Sergeev

    1986-01-01

    Full Text Available We describe briefly the basic ideas and results of the twistor theory. The main points: twistor representation of Minkowsky space, Penrose correspondence and its geometrical properties, twistor interpretation of linear massless fields, Yang-Mills fields (including instantons and monopoles and Einstein-Hilbert equations.

  18. Hyperfunction quantum field theory

    International Nuclear Information System (INIS)

    Nagamachi, S.; Mugibayashi, N.

    1976-01-01

    The quantum field theory in terms of Fourier hyperfunctions is constructed. The test function space for hyperfunctions does not contain C infinitely functios with compact support. In spite of this defect the support concept of H-valued Fourier hyperfunctions allows to formulate the locality axiom for hyperfunction quantum field theory. (orig.) [de

  19. Mean field games

    KAUST Repository

    Gomes, Diogo A.

    2014-01-06

    In this talk we will report on new results concerning the existence of smooth solutions for time dependent mean-field games. This new result is established through a combination of various tools including several a-priori estimates for time-dependent mean-field games combined with new techniques for the regularity of Hamilton-Jacobi equations.

  20. Quantum field theory

    CERN Document Server

    Sadovskii, Michael V

    2013-01-01

    This book discusses the main concepts of the Standard Model of elementary particles in a compact and straightforward way. The work illustrates the unity of modern theoretical physics by combining approaches and concepts of the quantum field theory and modern condensed matter theory. The inductive approach allows a deep understanding of ideas and methods used for solving problems in this field.

  1. Killing fields; The politics

    Energy Technology Data Exchange (ETDEWEB)

    Philips, Alasdair

    1990-02-01

    An overview considers the NRPB guidelines on possible health effects of low-level alternating electrical and magnetic fields and examines work by individuals on the hazards of microwave radiation, overhead power lines and childhood cancer, and the problems caused by electromagnetic fields at 50 Hz frequency. (U.K.).

  2. Moving Field Guides

    Science.gov (United States)

    Cassie Meador; Mark Twery; Meagan. Leatherbury

    2011-01-01

    The Moving Field Guides (MFG) project is a creative take on site interpretation. Moving Field Guides provide an example of how scientific and artistic endeavors work in parallel. Both begin with keen observations that produce information that must be analyzed, understood, and interpreted. That interpretation then needs to be communicated to others to complete the...

  3. Respirator field performance factors

    International Nuclear Information System (INIS)

    Skaggs, B.J.; DeField, J.D.; Strandberg, S.W.; Sutcliffe, C.R.

    1985-01-01

    The Industrial Hygiene Group assisted OSHA and the NRC in measurements of respirator performance under field conditions. They reviewed problems associated with sampling aerosols within the respirator in order to determine fit factors (FFs) or field performance factor (FPF). In addition, they designed an environmental chamber study to determine the effects of temperature and humidity on a respirator wearer

  4. Magnetic field on board

    International Nuclear Information System (INIS)

    Estevez Radio, H.; Fernandez Arenal, C.A.

    1995-01-01

    Here, the calculation of the magnetic field on board ships is performed, using matrix calculus, in a similar way as when the magnetic field in matter is studied. Thus the final formulas are written in a more compact form and they are obtained through a simpler way, more suitable for the university education. (Author)

  5. Pregnancy and electromagnetic fields

    International Nuclear Information System (INIS)

    Bisseriex, Ch.; Laurent, P.; Cabaret, Ph.; Bonnet, C.; Marteau, E.; Le Berre, G.; Tirlemont, S.; Castro, H.; Becker, A.; Demaret, Ph.; Donati, M.; Ganem, Y.; Moureaux, P.

    2011-07-01

    This document briefly indicates the status of knowledge regarding the effect of magnetic fields on biological tissues and pregnancy, outlines the lack of data on some frequencies and the weakness of studies on long term effects on child development. It evokes the issue of exposure assessment and that of identification of workstations exposed to electromagnetic fields

  6. Magnetic field line Hamiltonian

    International Nuclear Information System (INIS)

    Boozer, A.H.

    1984-03-01

    The magnetic field line Hamiltonian and the associated canonical form for the magnetic field are important concepts both for understanding toroidal plasma physics and for practical calculations. A number of important properties of the canonical or Hamiltonian representation are derived and their importance is explained

  7. Fields From Markov Chains

    DEFF Research Database (Denmark)

    Justesen, Jørn

    2005-01-01

    A simple construction of two-dimensional (2-D) fields is presented. Rows and columns are outcomes of the same Markov chain. The entropy can be calculated explicitly.......A simple construction of two-dimensional (2-D) fields is presented. Rows and columns are outcomes of the same Markov chain. The entropy can be calculated explicitly....

  8. Pulsed electric fields

    Science.gov (United States)

    The concept of pulsed electric fields (PEF) was first proposed in 1967 to change the behavior or microorganisms. The electric field phenomenon was identified as membrane rupture theory in the 1980s. Increasing the membrane permeability led to the application of PEF assisted extraction of cellular co...

  9. MAGNETIC FIELDS OF STARS

    OpenAIRE

    Bychkov, V. D.; Bychkova, L. V.; Madej, J.

    2008-01-01

    Now it is known about 1212 stars of the main sequence and giants (from them 610 stars - it is chemically peculiarity (CP) stars) for which direct measurements of magnetic fields were spent (Bychkov et al.,2008). Let's consider, what representations were generated about magnetic fields (MT) of stars on the basis of available observations data.

  10. Quantization and nonlocal fields

    International Nuclear Information System (INIS)

    Kolerov, G.I.

    1977-01-01

    A relation between the postulate of causality and quatization conditions is considered for the scalar field. A formalism of outer forms given on the functional space is used. A current commutator is obtained for nonlogical fields in the space-like region

  11. Mean field games

    KAUST Repository

    Gomes, Diogo A.

    2014-01-01

    In this talk we will report on new results concerning the existence of smooth solutions for time dependent mean-field games. This new result is established through a combination of various tools including several a-priori estimates for time-dependent mean-field games combined with new techniques for the regularity of Hamilton-Jacobi equations.

  12. Unified field theory

    International Nuclear Information System (INIS)

    Vollendorf, F.

    1976-01-01

    A theory is developed in which the gravitational as well as the electromagnetic field is described in a purely geometrical manner. In the case of a static central symmetric field Newton's law of gravitation and Schwarzschild's line element are derived by means of an action principle. The same principle leads to Fermat's law which defines the world lines of photons. (orig.) [de

  13. Pregnant Field Students' Guilt

    Science.gov (United States)

    Baum, Nehami

    2006-01-01

    This study examined guilt feelings among social work students who were pregnant for the first time during field work training. Semi-structured interviews were conducted either in the 9th month (n=5) or 2-12 months after delivery (n=5). Content analysis revealed 6 main triggers, illustrated by excerpts, which stimulated field students' guilt…

  14. Electromagnetic fields in biological systems

    National Research Council Canada - National Science Library

    Lin, James C

    2012-01-01

    "Focusing on exposure, induced fields, and absorbed energy, this volume covers the interaction of electromagnetic fields and waves with biological systems, spanning static fields to terahertz waves...

  15. The Coriolis field

    Science.gov (United States)

    Costa, L. Filipe; Natário, José

    2016-05-01

    We present a pedagogical discussion of the Coriolis field, emphasizing its not-so-well-understood aspects. We show that this field satisfies the field equations of the so-called Newton-Cartan theory, a generalization of Newtonian gravity that is covariant under changes of arbitrarily rotating and accelerated frames. Examples of solutions of this theory are given, including the Newtonian analogue of the Gödel universe. We discuss how to detect the Coriolis field by its effect on gyroscopes, of which the gyrocompass is an example. Finally, using a similar framework, we discuss the Coriolis field generated by mass currents in general relativity, and its measurement by the gravity probe B and LAGEOS/LARES experiments.

  16. Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...... or meromorphic (allowing poles as singularities) functions. There already exists a well-developed theory for iterative holomorphic dynamical systems, and successful relations found between iteration theory and flows of vector fields have been one of the main motivations for the recent interest in holomorphic...... vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...

  17. Finite fields and applications

    CERN Document Server

    Mullen, Gary L

    2007-01-01

    This book provides a brief and accessible introduction to the theory of finite fields and to some of their many fascinating and practical applications. The first chapter is devoted to the theory of finite fields. After covering their construction and elementary properties, the authors discuss the trace and norm functions, bases for finite fields, and properties of polynomials over finite fields. Each of the remaining chapters details applications. Chapter 2 deals with combinatorial topics such as the construction of sets of orthogonal latin squares, affine and projective planes, block designs, and Hadamard matrices. Chapters 3 and 4 provide a number of constructions and basic properties of error-correcting codes and cryptographic systems using finite fields. Each chapter includes a set of exercises of varying levels of difficulty which help to further explain and motivate the material. Appendix A provides a brief review of the basic number theory and abstract algebra used in the text, as well as exercises rel...

  18. Dual double field theory

    Energy Technology Data Exchange (ETDEWEB)

    Bergshoeff, Eric A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Hohm, Olaf [Simons Center for Geometry and Physics, Stony Brook University,Stony Brook, NY 11794-3636 (United States); Penas, Victor A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Riccioni, Fabio [INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy)

    2016-06-06

    We present the dual formulation of double field theory at the linearized level. This is a classically equivalent theory describing the duals of the dilaton, the Kalb-Ramond field and the graviton in a T-duality or O(D,D) covariant way. In agreement with previous proposals, the resulting theory encodes fields in mixed Young-tableau representations, combining them into an antisymmetric 4-tensor under O(D,D). In contrast to previous proposals, the theory also requires an antisymmetric 2-tensor and a singlet, which are not all pure gauge. The need for these additional fields is analogous to a similar phenomenon for “exotic' dualizations, and we clarify this by comparing with the dualizations of the component fields. We close with some speculative remarks on the significance of these observations for the full non-linear theory yet to be constructed.

  19. Field theory and strings

    International Nuclear Information System (INIS)

    Bonara, L.; Cotta-Ramusino, P.; Rinaldi, M.

    1987-01-01

    It is well-known that type I and heterotic superstring theories have a zero mass spectrum which correspond to the field content of N=1 supergravity theory coupled to supersymmetric Yang-Mills theory in 10-D. The authors study the field theory ''per se'', in the hope that simple consistency requirements will determine the theory completely once one knows the field content inherited from string theory. The simplest consistency requirements are: N=1 supersymmetry; and absence of chiral anomalies. This is what the authors discuss in this paper here leaving undetermined the question of the range of validity of the resulting field theory. As is known, a model of N=1 supergravity (SUGRA) coupled to supersymmetric Yang-Mills (SYM) theory was known in the form given by Chapline and Manton. The coupling of SUGRA to SYM was determined by the definition of the ''field strength'' 3-form H in this paper

  20. Narrowing the field

    DEFF Research Database (Denmark)

    Knudsen, Bo Nissen

    characteristics and the sequence of information in the series. Adding to the challenge is the macrostructural variation: The areas covered in printed form are covered with shifting principles of selecting the names to be published. Finding the right balance between letting the algorithms structure this complex....... As of now, no less than 45 different database fields have been found necessary to structure the information found in a single place-name entry – some fields mandatory, some nonmandatory. And using a relational database structure, some fields have multiple occurrences within one entry (i.e. multiple source...... forms for one entry a.s.f.). Having made the conscious decision to split up the information into so many categories (i.e. fields) – instead of employing a broad 'other information' field – sophisticated algorithms have been developed in order to identify information category from typographical...

  1. Magnetic fields in cosmology

    International Nuclear Information System (INIS)

    Madsen, M.S.

    1989-01-01

    The possible role of a large-scale relic magnetic field in the history of the Universe is considered. The perturbation of the cosmic microwave back-ground radiation on large angular scales due to a homogeneous magnetic field is estimated in a simple relativistic model. This allows corresponding limits to be placed on the magnitude of any such large-scale relic magnetic field at the present time. These limits are essentially the strongest which can be set on the largest scales. A corresponding bound is obtained by use of the requirement that the field should not spoil the predictions of primordial nucleosynthesis. It is noted that the existence of large-scale cosmic magnetic fields would circumvent the limits previously set - also on the basis of nucleosynthesis considerations - on the large-scale anisotropy now present in the Universe. (author)

  2. Complex Polynomial Vector Fields

    DEFF Research Database (Denmark)

    Dias, Kealey

    vector fields. Since the class of complex polynomial vector fields in the plane is natural to consider, it is remarkable that its study has only begun very recently. There are numerous fundamental questions that are still open, both in the general classification of these vector fields, the decomposition...... of parameter spaces into structurally stable domains, and a description of the bifurcations. For this reason, the talk will focus on these questions for complex polynomial vector fields.......The two branches of dynamical systems, continuous and discrete, correspond to the study of differential equations (vector fields) and iteration of mappings respectively. In holomorphic dynamics, the systems studied are restricted to those described by holomorphic (complex analytic) functions...

  3. Gauge fields and inflation

    Science.gov (United States)

    Maleknejad, A.; Sheikh-Jabbari, M. M.; Soda, J.

    2013-07-01

    The isotropy and homogeneity of the cosmic microwave background (CMB) favors “scalar driven” early Universe inflationary models. However, gauge fields and other non-scalar fields are far more common at all energy scales, in particular at high energies seemingly relevant to inflation models. Hence, in this review we consider the role and consequences, theoretical and observational, that gauge fields can have during the inflationary era. Gauge fields may be turned on in the background during inflation, or may become relevant at the level of cosmic perturbations. There have been two main classes of models with gauge fields in the background, models which show violation of the cosmic no-hair theorem and those which lead to isotropic FLRW cosmology, respecting the cosmic no-hair theorem. Models in which gauge fields are only turned on at the cosmic perturbation level, may source primordial magnetic fields. We also review specific observational features of these models on the CMB and/or the primordial cosmic magnetic fields. Our discussions will be mainly focused on the inflation period, with only a brief discussion on the post inflationary (p)reheating era. Large field models: The initial value of the inflaton field is large, generically super-Planckian, and it rolls slowly down toward the potential minimum at smaller φ values. For instance, chaotic inflation is one of the representative models of this class. The typical potential of large-field models has a monomial form as V(φ)=V0φn. A simple analysis using the dynamical equations reveals that for number of e-folds Ne larger than 60, we require super-Planckian initial field values,5φ0>3M. For these models typically ɛ˜η˜Ne-1. Small field models: Inflaton field is initially small and slowly evolves toward the potential minimum at larger φ values. The small field models are characterized by the following potential V(φ)=V0(1-(), which corresponds to a Taylor expansion about the origin, but more realistic

  4. The earth's magnetic field

    International Nuclear Information System (INIS)

    Merrill, R.T.

    1983-01-01

    After a historical introduction in Chapter 1, the more traditional aspects of geomagnetism relating to the present field and historical observations are presented in Chapter 2. The various methods and techniques and theoretical background of palaeomagnetism are given in Chapter 3. Chapters 4, 5 and 6 present the results of palaeomagnetic and archaeomagnetic studies in three topics. Chapter 4 relates to studies of the geomagnetic field roughly back to about 50,000 years ago. Chapter 5 is about reversals of the geomagnetic field and Chapter 6 presents studies of the field for times older than 50,000 years and on the geological time scale of millions or hundreds of millions of years. Chapters 7, 8 and 9 provide insight into dynamo theory. Chapter 7 is essentially a non-mathematical attempt to explain the physical basis of dynamo theories to palaeomagnetists. This is followed in Chapter 8 by a more advanced theoretical treatment. Chapter 9 explains theoretical aspects of secular variation and the origin of reversals of the geomagnetic field. Chapter 10 is our attempt to relate theory to experiment and vice versa. The final two chapters consider the magnetic fields of the moon, sun, planets and meteorites, in an attempt to determine the necessary and sufficient conditions for magnetic field generation in large solar system bodies. (author)

  5. The Juno Magnetic Field Investigation

    DEFF Research Database (Denmark)

    Connerney, J. E. P.; Benn, Mathias; Bjarnø, Jonas Bækby

    2017-01-01

    The Juno Magnetic Field investigation (MAG) characterizes Jupiter’s planetary magnetic field and magnetosphere, providing the first globally distributed and proximate measurements of the magnetic field of Jupiter. The magnetic field instrumentation consists of two independent magnetometer sensor ...

  6. Robotics Potential Fields

    Directory of Open Access Journals (Sweden)

    Jordi Lucero

    2009-01-01

    Full Text Available This problem was to calculate the path a robot would take to navigate an obstacle field and get to its goal. Three obstacles were given as negative potential fields which the robot avoided, and a goal was given a positive potential field that attracted the robot. The robot decided each step based on its distance, angle, and influence from every object. After each step, the robot recalculated and determined its next step until it reached its goal. The robot's calculations and steps were simulated with Microsoft Excel.

  7. International Geomagnetic Reference Field

    DEFF Research Database (Denmark)

    Finlay, Chris; Maus, S.; Beggan, C. D.

    2010-01-01

    The eleventh generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2009 by the International Association of Geomagnetism and Aeronomy Working Group V‐MOD. It updates the previous IGRF generation with a definitive main field model for epoch 2005.0, a main field...... model for epoch 2010.0, and a linear predictive secular variation model for 2010.0–2015.0. In this note the equations defining the IGRF model are provided along with the spherical harmonic coefficients for the eleventh generation. Maps of the magnetic declination, inclination and total intensity...

  8. Room Acoustical Fields

    CERN Document Server

    Mechel, Fridolin

    2013-01-01

    This book presents the theory of room acoustical fields and revises the Mirror Source Methods for practical computational use, emphasizing the wave character of acoustical fields.  The presented higher methods include the concepts of “Mirror Point Sources” and “Corner sources which allow for an excellent approximation of complex room geometries and even equipped rooms. In contrast to classical description, this book extends the theory of sound fields describing them by their complex sound pressure and the particle velocity. This approach enables accurate descriptions of interference and absorption phenomena.

  9. On the Schrodinger field

    International Nuclear Information System (INIS)

    Takahashi, Y.

    1986-01-01

    A brief but systematic discussion of the Schrodinger field is presented from the view point of quantized field theory. It is pointed out that the local momentum conservation equation is not of the usual continuity equation type when two-body potential interaction is presented and nevertheless the total momentum is globally conserved. The Schrodinger equation can be cast into a multicomponent equation containing only first order derivatives, depending on its spin contents. In case of spin 1/2, the g-factor is shown to be 2 even in purely non-relativistic Schrodinger field, in contrast with the general belief that g=2 is a relativistic effect

  10. Ridge and Furrow Fields

    DEFF Research Database (Denmark)

    Møller, Per Grau

    2016-01-01

    Ridge and furrow is a specific way of ploughing which makes fields of systematic ridges and furrows like a rubbing washboard. They are part of an overall openfield system, but the focus in this paper is on the functionality of the fields. There are many indications that agro-technological reasons...... systems and the establishment of basic structures like villages (with churches) and townships and states (in northern Europe). The fields can be considered as a resilient structure lasting for 800 years, along with the same basic physical structures in society....

  11. Geophysical Field Theory

    International Nuclear Information System (INIS)

    Eloranta, E.

    2003-11-01

    The geophysical field theory includes the basic principles of electromagnetism, continuum mechanics, and potential theory upon which the computational modelling of geophysical phenomena is based on. Vector analysis is the main mathematical tool in the field analyses. Electrostatics, stationary electric current, magnetostatics, and electrodynamics form a central part of electromagnetism in geophysical field theory. Potential theory concerns especially gravity, but also electrostatics and magnetostatics. Solid state mechanics and fluid mechanics are central parts in continuum mechanics. Also the theories of elastic waves and rock mechanics belong to geophysical solid state mechanics. The theories of geohydrology and mass transport form one central field theory in geophysical fluid mechanics. Also heat transfer is included in continuum mechanics. (orig.)

  12. Field Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Field Research Facility (FRF) located in Duck, N.C. was established in 1977 to support the U.S. Army Corps of Engineers' coastal engineering mission. The FRF is...

  13. Reversed field pinch diagnostics

    International Nuclear Information System (INIS)

    Weber, P.G.

    1986-01-01

    The Reversed Field Pinch (RFP) is a toroidal, axisymmetric magnetic confinement configuration characterized by a magnetic field configuration in which the toroidal magnetic field is of similar strength to the poloidal field, and is reversed at the edge compared to the center. The RFP routinely operates at high beta, and is a strong candidate for a compact fusion device. Relevant attributes of the configuration will be presented, together with an overview of present and planned experiments and their diagnostics. RFP diagnostics are in many ways similar to those of other magnetic confinement devices (such as tokamaks); these lectures will point out pertinent differences, and will present some diagnostics which provide special insights into unique attributes of the RFP

  14. Algebraic conformal field theory

    International Nuclear Information System (INIS)

    Fuchs, J.; Nationaal Inst. voor Kernfysica en Hoge-Energiefysica

    1991-11-01

    Many conformal field theory features are special versions of structures which are present in arbitrary 2-dimensional quantum field theories. So it makes sense to describe 2-dimensional conformal field theories in context of algebraic theory of superselection sectors. While most of the results of the algebraic theory are rather abstract, conformal field theories offer the possibility to work out many formulae explicitly. In particular, one can construct the full algebra A-bar of global observables and the endomorphisms of A-bar which represent the superselection sectors. Some explicit results are presented for the level 1 so(N) WZW theories; the algebra A-bar is found to be the enveloping algebra of a Lie algebra L-bar which is an extension of the chiral symmetry algebra of the WZW theory. (author). 21 refs., 6 figs

  15. Earth's Magnetic Field

    DEFF Research Database (Denmark)

    This volume provides a comprehensive view on the different sources of the geomagnetic field both in the Earth’s interior and from the field’s interaction with the terrestrial atmosphere and the solar wind. It combines expertise from various relevant areas of geomagnetic and near Earth space...... research with the aim to better characterise the state and dynamics of Earth’s magnetic field. Advances in the exploitation of geomagnetic observations hold a huge potential not only for an improved quantitative description of the field source but also for a better understanding of the underlying processes...... and space observations, and on state-of-the-art empirical models and physics-based simulations. Thus, it provides an in-depth overview over recent achievements, current limitations and challenges, and future opportunities in the field of geomagnetism and space sciences....

  16. The master field revisited

    International Nuclear Information System (INIS)

    Gopakumar, R.

    1996-01-01

    We review recent work on the master field in large N theories. In particular the mathematical framework appropriate for its construction is sketched. The calculational utility of this framework is demonstrated in the case of QCD 2 . (orig.)

  17. Field Geology/Processes

    Science.gov (United States)

    Allen, Carlton; Jakes, Petr; Jaumann, Ralf; Marshall, John; Moses, Stewart; Ryder, Graham; Saunders, Stephen; Singer, Robert

    1996-01-01

    The field geology/process group examined the basic operations of a terrestrial field geologist and the manner in which these operations could be transferred to a planetary lander. Four basic requirements for robotic field geology were determined: geologic content; surface vision; mobility; and manipulation. Geologic content requires a combination of orbital and descent imaging. Surface vision requirements include range, resolution, stereo, and multispectral imaging. The minimum mobility for useful field geology depends on the scale of orbital imagery. Manipulation requirements include exposing unweathered surfaces, screening samples, and bringing samples in contact with analytical instruments. To support these requirements, several advanced capabilities for future development are recommended. Capabilities include near-infrared reflectance spectroscopy, hyper-spectral imaging, multispectral microscopy, artificial intelligence in support of imaging, x ray diffraction, x ray fluorescence, and rock chipping.

  18. Maine Field Station

    Data.gov (United States)

    Federal Laboratory Consortium — In 2000 NOAA's National Marine Fisheries Service established the Maine Field Station in Orono, ME to have more direct involvement in the conservation of the living...

  19. Three dimensional field computation

    International Nuclear Information System (INIS)

    Trowbridge, C.W.

    1981-06-01

    Recent research work carried out at Rutherford and Appleton Laboratories into the Computation of Electromagnetic Fields is summarised. The topics covered include algorithms for integral and differential methods for the solution of 3D magnetostatic fields, comparison of results with experiment and an investigation into the strengths and weaknesses of both methods for an analytic problem. The paper concludes with a brief summary of the work in progress on the solution of 3D eddy currents using differential finite elements. (author)

  20. Magnetic field of Mercury

    International Nuclear Information System (INIS)

    Jackson, D.J.; Beard, D.B.

    1977-01-01

    The geomagnetic field, suitably scaled down and parameterized, is shown to give a very good fit to the magnetic field measurements taken on the first and third passes of the Mariner 10 space probe past Mercury. The excellence of the fit to a reliable planetary magnetospheric model is good evidence that the Mercury magnetosphere is formed by a simple, permanent, intrinsic planetary magnetic field distorted by the effects of the solar wind. The parameters used for a best fit to all the data are (depending slightly on the choice of data) 2.44--2.55 for the ratio of Mercury's magnetic field strength at the subsolar point to that of the earth's subsolar point field (this results in a dipole moment of 170 γR/sub M/ 3 (R/sub M/ is Mercury Radius), i.e., 2.41 x 10 22 G cm 3 in the same direction as the earth's dipole), approx.-113 γR/sub M/ 4 for the planetary quadrupole moment parallel to the dipole moment, 10degree--17degree for the tilt of the planet dipole toward the sun, 4.5degree for the tilt of the dipole toward dawn, and 2.5degree--7.6degree aberration angle for the shift in the tail axis from the planet-sun direction because of the planet's orbital velocity. The rms deviation overall for the entire data set compared with the theoretical fitted model for the magnetic field strength was 17 γ (approx.4% of the maximum field measured). If the data from the first pass that show presumed strong time variations are excluded, the overall rms deviation for the field magnitude is only 10 γ

  1. Magnetic field dosimeter development

    International Nuclear Information System (INIS)

    Lemon, D.K.; Skorpik, J.R.; Eick, J.L.

    1980-09-01

    In recent years there has been increased concern over potential health hazards related to exposure of personnel to magnetic fields. If exposure standards are to be established, then a means for measuring magnetic field dose must be available. To meet this need, the Department of Energy has funded development of prototype dosimeters at the Battelle Pacific Northwest Laboratory. This manual reviews the principle of operation of the dosimeter and also contains step-by-step instructions for its operation

  2. DSM-5 field survey

    DEFF Research Database (Denmark)

    Lochner, Christine; Grant, Jon E; Odlaug, Brian Lawrence

    2012-01-01

    The aim of this multisite field survey was to examine the DSM-IV-TR criteria, proposed DSM-5 diagnostic criteria, as well as a number of possible additional diagnostic criteria, in patients with hair-pulling disorder (HPD, or trichotillomania).......The aim of this multisite field survey was to examine the DSM-IV-TR criteria, proposed DSM-5 diagnostic criteria, as well as a number of possible additional diagnostic criteria, in patients with hair-pulling disorder (HPD, or trichotillomania)....

  3. Collective field accelerator

    International Nuclear Information System (INIS)

    Luce, J.S.

    1978-01-01

    A collective field accelerator which operates with a vacuum diode and utilizes a grooved cathode and a dielectric anode that operates with a relativistic electron beam with a ν/γ of approx. 1, and a plurality of dielectric lenses having an axial magnetic field thereabout to focus the collectively accelerated electrons and ions which are ejected from the anode. The anode and lenses operate as unoptimized r-f cavities which modulate and focus the beam

  4. Controlling magnetic field profiles

    International Nuclear Information System (INIS)

    Freeman, J.R.

    1979-04-01

    A method for designing solenoid magnets with controlled field profiles is discussed. The method, originated by D.B. Montgomery, minimizes both the field errors and the power consumption. An NOS time-sharing computer program for the CDC-6600, entitled MAGCOR, was constructed to provide an interactive magnet design capability. Results obtained during the design of magnets for a radial line electron accelerator are presented. 9 figures

  5. Gauge field theories

    International Nuclear Information System (INIS)

    Leite Lopes, J.

    1981-01-01

    The book is intended to explain, in an elementary way, the basic notions and principles of gauge theories. Attention is centred on the Salem-Weinberg model of electro-weak interactions, as well as neutrino-lepton scattering and the parton model. Classical field theory, electromagnetic, Yang-Mills and gravitational gauge fields, weak interactions, Higgs mechanism and the SU(5) model of grand unification are also discussed. (U.K.)

  6. Radial Field Piezoelectric Diaphragms

    Science.gov (United States)

    Bryant, R. G.; Effinger, R. T., IV; Copeland, B. M., Jr.

    2002-01-01

    A series of active piezoelectric diaphragms were fabricated and patterned with several geometrically defined Inter-Circulating Electrodes "ICE" and Interdigitated Ring Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is a radially distributed electric field that mechanically strains the piezoceramic along the Z-axis (perpendicular to the applied electric field). Unlike other piezoelectric bender actuators, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements (several times that of the equivalent Unimorph) while maintaining a constant circumference. One of the more intriguing aspects is that the radial strain field reverses itself along the radius of the RFD while the tangential strain remains relatively constant. The result is a Z-deflection that has a conical profile. This paper covers the fabrication and characterization of the 5 cm. (2 in.) diaphragms as a function of poling field strength, ceramic thickness, electrode type and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage at low frequencies. The unique features of these RFDs include the ability to be clamped about their perimeter with little or no change in displacement, the environmentally insulated packaging, and a highly repeatable fabrication process that uses commodity materials.

  7. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1978-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centers the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFC's with a major radius R = 2-6 cm, minor radius a approximately 2 cm, and a total length l approximately 35 cm. The observed temperatures are T/sub e/ approximately 100 eV and T/sub i/ = 150-350 eV with a peak density n approximately 2 x 10 15 cm -3 . After the plasma reaches equilibrium, the RFC remains stable for up to 30 μs followed by the rapid growth of the rotational m = 2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behavior of the m = 2 mode qualitatively agrees with the theoretically predicted instability for rotational velocities exceeding some critical value

  8. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    Linford, R.K.; Armstrong, W.T.; Platts, D.A.; Sherwood, E.G.

    1979-01-01

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centres the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFCs with a major radius R=2-6cm, a minor radius a approximately 2cm, and a total length l approximately 35cm. The observed temperatures are Tsub(e) approximately 100eV and Tsub(i)=150-350eV with a peak density n approximately 2x10 15 cm -3 . After the plasma has reached equilibrium, the RFC remains stable for up to 30μs, followed by the rapid growth of the rotational m=2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behaviour of the m=2 mode agrees qualitatively with the theoretically predicted instability for rotational velocities exceeding some critical value. (author)

  9. Magnetic field screens

    International Nuclear Information System (INIS)

    Mansfield, P.; Turner, R.; Chapman, B.L.W.; Bowley, R.M.

    1990-01-01

    A screen for a magnetic coil, for producing, for example, a homogeneous, gradient or RF field in nuclear magnetic resonance imaging, is described. It is provided by surround the coil with a set of electrical conductors. The currents within the conductors are controlled in such a manner that the field is neutralised in a specific region of space. The current distribution within the conductors is determined by calculating the current within a hypothetical superconductive shield which would have the effect of neutralising the field, the current through the conductors thereby being a substitute for the superconductive shield. The conductors may be evenly spaced and connected in parallel, their resistances being determined by thickness or composition to provide the desired current, or they may carry equal currents but be differently spaced. A further set or sets of controlled conductors outside the first set may ensure that the first set does not upset the field from the NMR coil. The shield may selectively reflect certain fields while transmitting others and may prevent acoustic vibration e.g. when switching gradient fields. An RF coil arrangement may consist of two orthogonal coils, one coil within the other for use as a transmit/receive set or as a double resonance transmitter; a shield between the coils is in series with, and formed from the same winding as, the inner coil. (author)

  10. Contribuciones tecnicas para la medida de la contaminacion electromagnetica de microondas. Estudio en diversas poblaciones

    Science.gov (United States)

    Segura Garcia, Jaume

    La contaminacion ambiental por campos electromagneticos ha resultado ser en estos ultimos anos uno de los problemas mas acuciantes del panorama tecnologico y de salud publica. En el primero de los casos porque las inversiones realizadas son enormes y en el segundo porque cada vez es mayor el numero de articulos, "technical reports" e informes medicos que afirman la existencia de una cierta causalidad, aunque sea debil, entre los campos electromagneticos y ciertos cuadros sintomatologicos. En nuestro caso, hemos dedicado bastantes esfuerzos a investigar el llamado "sindrome de radiofrecuencia / microondas", denominado asi en la literatura cientifica por presentarse en operarios de estaciones de radar y en trabajadores de potentes emisoras de radio y television. En esta memoria presentamos un resumen del trabajo realizado durante los ultimos anos en la medida de la contaminacion electromagnetica ambiental asociado a las comunicaciones inalambricas. En ella se recogen los fundamentos fisicos y propiedades de las ondas electromagneticas, la tecnologia empleada en los sistemas de telefonia celular y los antecedentes relativos a la investigacion de la interaccion de las ondas electromagneticas con organismos vivos. Se desarrolla un procedimiento de medida que ha conducido a la elaboracion de los primeros "mapas de radiofrecuencia" similares, en el aspecto descriptivo, a los mapas de ruido desarrollados en el area de la contaminacion acustica. Por ultimo, se analiza la respuesta subjetiva de los residentes, personas que viven en el entorno de cobertura de las estaciones base de telefonia movil y que se ven sometidos a determinados niveles de radiacion electromagnetica, con el fin de situar este fenomeno al nivel que le corresponde en el ambito de la respuesta subjetiva ciudadana.

  11. Magnetic fields at Neptune

    International Nuclear Information System (INIS)

    Ness, N.F.; Acuna, M.H.; Burlaga, L.F.; Connerney, J.E.P.; Lepping, R.P.; Neubauer, F.M.

    1989-01-01

    The National Aeronautics and Space Administration Goddard Space Flight Center-University of Delaware Bartol Research Institute magnetic field experiment on the Voyager 2 spacecraft discovered a strong and complex intrinsic magnetic field of Neptune and an associated magnetosphere and magnetic tail. A maximum magnetic field of nearly 10,000 nanoteslas (1 nanotesla = 10 -5 gauss) was observed near closest approach, at a distance of 1.18 R N . The planetary magnetic field between 4 and 15 R N can be well represented by an offset tilted magnetic dipole (OTD), displaced from the center of Neptune by the surprisingly large amount of 0.55 R N and inclined by 47 degrees with respect to the rotation axis. Within 4 R N , the magnetic field representation must include localized sources or higher order magnetic multipoles, or both, which are not yet well determined. As the spacecraft exited the magnetosphere, the magnetic tail appeared to be monopolar, and no crossings of an imbedded magnetic field reversal or plasma neutral sheet were observed. The auroral zones are most likely located far from the rotation poles and may have a complicated geometry. The rings and all the known moons of Neptune are imbedded deep inside the magnetosphere, except for Nereid, which is outside when sunward of the planet. The radiation belts will have a complex structure owing to the absorption of energetic particles by the moons and rings of Neptune and losses associated with the significant changes in the diurnally varying magnetosphere configuration. In an astrophysical context, the magnetic field of Neptune, like that of Uranus, may be described as that of an oblique rotator

  12. Magnetic Fields Versus Gravity

    Science.gov (United States)

    Hensley, Kerry

    2018-04-01

    Deep within giant molecular clouds, hidden by dense gas and dust, stars form. Unprecedented data from the Atacama Large Millimeter/submillimeter Array (ALMA) reveal the intricate magnetic structureswoven throughout one of the most massive star-forming regions in the Milky Way.How Stars Are BornThe Horsehead Nebulasdense column of gas and dust is opaque to visible light, but this infrared image reveals the young stars hidden in the dust. [NASA/ESA/Hubble Heritage Team]Simple theory dictates that when a dense clump of molecular gas becomes massive enough that its self-gravity overwhelms the thermal pressure of the cloud, the gas collapses and forms a star. In reality, however, star formation is more complicated than a simple give and take between gravity and pressure. Thedusty molecular gas in stellar nurseries is permeated with magnetic fields, which are thought to impede the inward pull of gravity and slow the rate of star formation.How can we learn about the magnetic fields of distant objects? One way is by measuring dust polarization. An elongated dust grain will tend to align itself with its short axis parallel to the direction of the magnetic field. This systematic alignment of the dust grains along the magnetic field lines polarizes the dust grains emission perpendicular to the local magnetic field. This allows us to infer the direction of the magnetic field from the direction of polarization.Magnetic field orientations for protostars e2 and e8 derived from Submillimeter Array observations (panels a through c) and ALMA observations (panels d and e). Click to enlarge. [Adapted from Koch et al. 2018]Tracing Magnetic FieldsPatrick Koch (Academia Sinica, Taiwan) and collaborators used high-sensitivity ALMA observations of dust polarization to learn more about the magnetic field morphology of Milky Way star-forming region W51. W51 is one of the largest star-forming regions in our galaxy, home to high-mass protostars e2, e8, and North.The ALMA observations reveal

  13. Theoretical physics. Field theory

    International Nuclear Information System (INIS)

    Landau, L.; Lifchitz, E.

    2004-01-01

    This book is the fifth French edition of the famous course written by Landau/Lifchitz and devoted to both the theory of electromagnetic fields and the gravity theory. The talk of the theory of electromagnetic fields is based on special relativity and relates to only the electrodynamics in vacuum and that of pointwise electric charges. On the basis of the fundamental notions of the principle of relativity and of relativistic mechanics, and by using variational principles, the authors develop the fundamental equations of the electromagnetic field, the wave equation and the processes of emission and propagation of light. The theory of gravitational fields, i.e. the general theory of relativity, is exposed in the last five chapters. The fundamentals of the tensor calculus and all that is related to it are progressively introduced just when needed (electromagnetic field tensor, energy-impulse tensor, or curve tensor...). The worldwide reputation of this book is generally allotted to clearness, to the simplicity and the rigorous logic of the demonstrations. (A.C.)

  14. Field error lottery

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, C.J.; McVey, B. (Los Alamos National Lab., NM (USA)); Quimby, D.C. (Spectra Technology, Inc., Bellevue, WA (USA))

    1990-01-01

    The level of field errors in an FEL is an important determinant of its performance. We have computed 3D performance of a large laser subsystem subjected to field errors of various types. These calculations have been guided by simple models such as SWOOP. The technique of choice is utilization of the FELEX free electron laser code that now possesses extensive engineering capabilities. Modeling includes the ability to establish tolerances of various types: fast and slow scale field bowing, field error level, beam position monitor error level, gap errors, defocusing errors, energy slew, displacement and pointing errors. Many effects of these errors on relative gain and relative power extraction are displayed and are the essential elements of determining an error budget. The random errors also depend on the particular random number seed used in the calculation. The simultaneous display of the performance versus error level of cases with multiple seeds illustrates the variations attributable to stochasticity of this model. All these errors are evaluated numerically for comprehensive engineering of the system. In particular, gap errors are found to place requirements beyond mechanical tolerances of {plus minus}25{mu}m, and amelioration of these may occur by a procedure utilizing direct measurement of the magnetic fields at assembly time. 4 refs., 12 figs.

  15. Multi-valued fields

    CERN Document Server

    Ershov, Yuri L

    2001-01-01

    For more than 30 years, the author has studied the model-theoretic aspects of the theory of valued fields and multi-valued fields. Many of the key results included in this book were obtained by the author whilst preparing the manuscript. Thus the unique overview of the theory, as developed in the book, has been previously unavailable. The book deals with the theory of valued fields and mutli-valued fields. The theory of Prüfer rings is discussed from the `geometric' point of view. The author shows that by introducing the Zariski topology on families of valuation rings, it is possible to distinguish two important subfamilies of Prüfer rings that correspond to Boolean and near Boolean families of valuation rings. Also, algebraic and model-theoretic properties of multi-valued fields with near Boolean families of valuation rings satisfying the local-global principle are studied. It is important that this principle is elementary, i.e., it can be expressed in the language of predicate calculus. The most important...

  16. Electromagnetic fields and cancer

    International Nuclear Information System (INIS)

    Singh, Neeta; Mathur, R.; Behari, J.

    1997-01-01

    Several studies in recent years have raised the possibility that exposure to electromagnetic fields (EMFs) may be hazardous to human health, in particular by promotion or initiation of cancer. Recent reports have indicated increased cancer risk from industrial and domestic exposure to environmental ELF fields and to RF fields that are amplitude modulated at ELF. EMF fields have been reported to affect biological systems in various ways, affecting changes in the morphology and or functional behavior of cells, which have been observed in a variety of tissues. Although the mechanism of interaction of EMFs with living cells are not known, it has been proposed that they have multiple effects and can affect cell signalling, including modification of plasma membrane permeability and ion transport. Our findings suggest that EMFs can affect post translational modification of proteins such as poly ADP-ribosylation by epigenetic mechanism and that the effect of EMFs are highly specific regarding both the cell type and the frequency and amplification of the applied field. (author)

  17. String field theory

    International Nuclear Information System (INIS)

    Kaku, M.

    1987-01-01

    In this article, the authors summarize the rapid progress in constructing string field theory actions, such as the development of the covariant BRST theory. They also present the newer geometric formulation of string field theory, from which the BRST theory and the older light cone theory can be derived from first principles. This geometric formulation allows us to derive the complete field theory of strings from two geometric principles, in the same way that general relativity and Yang-Mills theory can be derived from two principles based on global and local symmetry. The geometric formalism therefore reduces string field theory to a problem of finding an invariant under a new local gauge group they call the universal string group (USG). Thus, string field theory is the gauge theory of the universal string group in much the same way that Yang-Mills theory is the gauge theory of SU(N). The geometric formulation places superstring theory on the same rigorous group theoretical level as general relativity and gauge theory

  18. Cosmic magnetic fields

    CERN Document Server

    Kronberg, Philipp P

    2016-01-01

    Magnetic fields are important in the Universe and their effects contain the key to many astrophysical phenomena that are otherwise impossible to understand. This book presents an up-to-date overview of this fast-growing topic and its interconnections to plasma processes, astroparticle physics, high energy astrophysics, and cosmic evolution. The phenomenology and impact of magnetic fields are described in diverse astrophysical contexts within the Universe, from galaxies to the filaments and voids of the intergalactic medium, and out to the largest redshifts. The presentation of mathematical formulae is accessible and is designed to add insight into the broad range of topics discussed. Written for graduate students and researchers in astrophysics and related disciplines, this volume will inspire readers to devise new ways of thinking about magnetic fields in space on galaxy scales and beyond.

  19. Nonlocal quantum field theory

    International Nuclear Information System (INIS)

    Efimov, G.V.

    1976-01-01

    The basic ideas for creating the theory of nonlocal interactions of a scalar one-component field are presented. Lagrangian describing a non-interacting field is the ordinary one so that non-interacting particles are described by standard methods of the Fock space. Form factors introduced have been chosen from a class of analytic functionals and quantized. Conditions of microcausality have been considered in detail. The convergence of all integrals corresponding to the arbitrary Feynman diagrams in spinor electrodynamics is guaranteed in the frame of the rules formulated. It is noted in conclusion that the spinor electrodynamics with nonlocal interaction contains no ultraviolet divergencies and satisfies all the requirements of the quantum field theory; in this sense it is mathematically more consistent than its local version

  20. Collinear wake field acceleration

    International Nuclear Information System (INIS)

    Bane, K.L.F.; Chen, P.; Wilson, P.B.

    1985-04-01

    In the Voss-Weiland scheme of wake field acceleration a high current, ring-shaped driving bunch is used to accelerate a low current beam following along on axis. In such a structure, the transformer ratio, i.e., the ratio of maximum voltage that can be gained by the on-axis beam and the voltage lost by the driving beam, can be large. In contrast, it has been observed that for an arrangement in which driving and driven bunches follow the same path, and where the current distribution of both bunches is gaussian, the transformer ratio is not normally greater than two. This paper explores some of the possibilities and limitations of a collinear acceleration scheme. In addition to its application to wake field acceleration in structures, this study is also of interest for the understanding of the plasma wake field accelerator. 11 refs., 4 figs

  1. Gyrokinetic field theory

    International Nuclear Information System (INIS)

    Sugama, H.

    1999-08-01

    The Lagrangian formulation of the gyrokinetic theory is generalized in order to describe the particles' dynamics as well as the self-consistent behavior of the electromagnetic fields. The gyrokinetic equation for the particle distribution function and the gyrokinetic Maxwell's equations for the electromagnetic fields are both derived from the variational principle for the Lagrangian consisting of the parts of particles, fields, and their interaction. In this generalized Lagrangian formulation, the energy conservation property for the total nonlinear gyrokinetic system of equations is directly shown from the Noether's theorem. This formulation can be utilized in order to derive the nonlinear gyrokinetic system of equations and the rigorously conserved total energy for fluctuations with arbitrary frequency. (author)

  2. Electromagnetic fields and life

    CERN Document Server

    Presman, A S

    1970-01-01

    A broad region of the electromagnetic spectrum long assumed to have no influence on living systems under natural conditions has been critically re-examined over the past decade. This spectral region extends from the superhigh radio frequencies, through de­ creasing frequencies, to and including essentially static electric and magnetic fields. The author of this monograph, A. S. Presman, has reviewed not only the extensive Russian literatur!;"l, but also al­l most equally comprehensively the non-Russian literature, dealing with biological influences of these fields. Treated also is literature shedding some light on possible theoretical foundations for these phenomena. A substantial, rapidly increasing number of studies in many laboratories and countries has now clearly established bio­ logical influences which are independent of the theoretically predictable, simple thermal effects. Indeed many of the effects are produced by field strengths very close to those within the natural environment. The author has,...

  3. Electromagnetic fields and waves

    CERN Document Server

    Iskander, Magdy F

    2013-01-01

    The latest edition of Electromagnetic Fields and Waves retains an authoritative, balanced approach, in-depth coverage, extensive analysis, and use of computational techniques to provide a complete understanding of electromagnetic—important to all electrical engineering students. An essential feature of this innovative text is the early introduction of Maxwell's equations, together with the quantifying experimental observations made by the pioneers who discovered electromagnetics. This approach directly links the mathematical relations in Maxwell's equations to real experiments and facilitates a fundamental understanding of wave propagation and use in modern practical applications, especially in today's wireless world. New and expanded topics include the conceptual relationship between Coulomb's law and Gauss's law for calculating electric fields, the relationship between Biot-Savart's and Ampere's laws and their use in calculating magnetic fields from current sources, the development of Faraday's law from e...

  4. Supersymmetric gauge field theories

    International Nuclear Information System (INIS)

    Slavnov, A.A.

    1976-01-01

    The paper is dealing with the role of supersymmetric gauge theories in the quantum field theory. Methods of manipulating the theories as well as possibilities of their application in elementary particle physics are presented. In particular, the necessity is explained of a theory in which there is symmetry between Fermi and Bose fields, in other words, of the supersymmetric gauge theory for construction of a scheme for the Higgs particle connecting parameters of scalar mesons with those of the rest fields. The mechanism of supersymmetry breaking is discussed which makes it possible to remain the symmetric procedure of renormalization intact. The above mechanism of spontaneous symmetry breaking is applied to demonstrate possibilities of constructing models of weak and electromagnetic interactions which would be acceptable from the point of view of experiments. It is noted that the supersymmetric gauge theories represent a natural technique for description of vector-like models

  5. Reversed field pinch experiments

    International Nuclear Information System (INIS)

    Roberston, S.

    1991-05-01

    The Reversatron RFP is usually operated with toroidal field windings which are a continuous helix of 144 turns. These windings produce a poloidal current which is uniform around the torus. The distribution of current is fixed by the geometry so that the applied field has only an m = 0, n = 0 component. The windings cannot act to stabilize an m = 0 mode with |n| > 0 or any m = 1 mode because these modes will excite no current in the windings. It has recently been suggested that parallel connected field coils might act as a shell by forcing the flux within each winding to be the same. Coils connected in parallel must have the same voltage at their terminals and thus must enclose the same volt-seconds or flux. Data from ZT-40 show that the discharges are more quiescent when parallel or series-parallel connected windings are used

  6. Energy of the field for the field

    International Nuclear Information System (INIS)

    2001-01-01

    Considering the problems that are presented in the field related with the lack of available energy is presented, the Biogas like energy alternative. This is a resulting product of the fermentation anaerobic (without air) of the organic residuals under appropriate conditions of humidity. It is a mixture of gases in which they prevail: Methane (CH 4 ) in a 55 to 70 percent, Dioxide of Carbon (CO 2 ) in a 28 to 43 percent and others as the hydro sulphide by 2 percent. The composition of the biogas depends of: the quality of the used material, of the biodigestor type, of the ambient temperature, of the adopted time of retention. Some of the advantages of the use of this alternative are: better sanitary conditions in the rural means. Decrease in the consumption of inorganic fertilizers. Increase of the agricultural productivity with the employment of the Bio fertilizing (20/25 bigger percent) in comparison with the fresh manure; conservation of natural resources as fuels, fossils and firewood; energy production in the own local consumption. Perfect ecological solution for the obtaining of renewable energy and bio fertilizing

  7. Microcanonical quantum field theory

    International Nuclear Information System (INIS)

    Strominger, A.

    1983-01-01

    Euclidean quantum field theory is equivalent to the equilibrium statistical mechanics of classical fields in 4+1 dimensions at temperature h. It is well known in statistical mechanics that the theory of systems at fixed temperature is embedded within the more general and fundamental theory of systems at fixed energy. We therefore develop, in precise analogy, a fixed action (macrocanonical) formulation of quantum field theory. For the case of ordinary renormalizable field theories, we show (with one exception) that the microcanonical is entirely equivalent to the canonical formulation. That is, for some particular fixed value of the total action, the Green's functions of the microcanonical theory are equal, in the bulk limit, to those of the canonical theory. The microcanonical perturbation expansion is developed in some detail for lambdaphi 4 . The particular value of the action for which the two formulations are equivalent can be calculated to all orders in perturbation theory. We prove, using Lehmann's Theorem, that this value is one-half Planck unit per degree of freedom, if fermionic degrees of freedom are counted negatively. This is the 4+1 dimensional analog of the equipartition theorem. The one exception to this is supersymmetric theories. A microcanonical formulation exists if and only if supersymmetry is broken. In statistical mechanics and in field theory there are systems for which the canonical description is pathological, but the microcanonical is not. An example of such a field theory is found in one dimension. A semiclassical expansion of the microcanonical theory is well defined, while an expansion of the canonical theory is hoplessly divergent

  8. Tripolar electric field Structure in guide field magnetic reconnection

    Science.gov (United States)

    Fu, Song; Huang, Shiyong; Zhou, Meng; Ni, Binbin; Deng, Xiaohua

    2018-03-01

    It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection). In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg). Once the amplitude of a guide field exceeds 0.3 times the asymptotic magnetic field B0, the traditional bipolar Hall electric field is clearly replaced by a tripolar electric field, which consists of a newly emerged electric field and the bipolar Hall electric field. The newly emerged electric field is a convective electric field about one ion inertial length away from the neutral sheet. It arises from the disappearance of the Hall electric field due to the substantial modification of the magnetic field and electric current by the imposed guide field. The peak magnitude of this new electric field increases linearly with the increment of guide field strength. Possible applications of these results to space observations are also discussed.

  9. Tripolar electric field Structure in guide field magnetic reconnection

    Directory of Open Access Journals (Sweden)

    S. Fu

    2018-03-01

    Full Text Available It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection. In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg. Once the amplitude of a guide field exceeds 0.3 times the asymptotic magnetic field B0, the traditional bipolar Hall electric field is clearly replaced by a tripolar electric field, which consists of a newly emerged electric field and the bipolar Hall electric field. The newly emerged electric field is a convective electric field about one ion inertial length away from the neutral sheet. It arises from the disappearance of the Hall electric field due to the substantial modification of the magnetic field and electric current by the imposed guide field. The peak magnitude of this new electric field increases linearly with the increment of guide field strength. Possible applications of these results to space observations are also discussed.

  10. Quaternionic quantum field theory

    International Nuclear Information System (INIS)

    Adler, S.L.

    1986-01-01

    In this paper the author describes a new kind of quantum mechanics or quantum field theory based on quaternions. Quaternionic quantum mechanics has a Schrodinger equation, a Dirac transformation theory, and a functional integral. Quaternionic quantum mechanics does not seem to have (except in the complex quantum mechanics specialization): A correspondence principle, and beyond this a commuting tensor product, asymptotic states, an S-matrix, a canonical formalism, coherent states or a Euclidean continuation. A new kind of quantum mechanics exists. There are many interesting formal questions to study, which should enable one to decide whether quaternionic quantum field theory is relevant for particle physics

  11. Quantum field theory

    CERN Document Server

    Mandl, Franz

    2010-01-01

    Following on from the successful first (1984) and revised (1993) editions, this extended and revised text is designed as a short and simple introduction to quantum field theory for final year physics students and for postgraduate students beginning research in theoretical and experimental particle physics. The three main objectives of the book are to: Explain the basic physics and formalism of quantum field theory To make the reader proficient in theory calculations using Feynman diagrams To introduce the reader to gauge theories, which play a central role in elementary particle physic

  12. Field studies courses open

    Science.gov (United States)

    Fourteen month-long courses combining applied academics with training in field research methodology are being offered this summer by the School for Field Studies. The courses, held in eight countries during May, June, July, and August, provide unique opportunities for participants to work as a team under primitive conditions.‘Our courses bind together the academic challenge of the research problem, the physical challenge of the site itself, and the interpersonal challenge of the expedition team in a dynamic way so that both cognitive and affective learning are accelerated,’ according to Jim Elder, the school's director.

  13. WORKSHOP: Thermal field theory

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1989-04-15

    The early history of the Universe is a crucial testing ground for theories of elementary particles. Speculative ideas about the constituents of matter and their interactions are reinforced if they are consistent with what we suppose happened near the beginning of time and discarded if they are not. The cosmological consequences of these theories are usually deduced using a general statistical approach called thermal field theory. Thus, 75 physicists from thirteen countries met in Cleveland, Ohio, last October for the first 'Workshop on Thermal Field Theories and their Applications'.

  14. Gauge field theories

    International Nuclear Information System (INIS)

    Pokorski, S.

    1987-01-01

    Quantum field theory forms the present theoretical framework for the understanding of the fundamental interactions of particle physics. This book examines gauge theories and their symmetries with an emphasis on their physical and technical aspects. The author discusses field-theoretical techniques and encourages the reader to perform many of the calculations presented. This book includes a brief introduction to perturbation theory, the renormalization programme, and the use of the renormalization group equation. Several topics of current research interest are covered, including chiral symmetry and its breaking, anomalies, and low energy effective lagrangians and some basics of supersymmetry

  15. Finite temperature field theory

    CERN Document Server

    Das, Ashok

    1997-01-01

    This book discusses all three formalisms used in the study of finite temperature field theory, namely the imaginary time formalism, the closed time formalism and thermofield dynamics. Applications of the formalisms are worked out in detail. Gauge field theories and symmetry restoration at finite temperature are among the practical examples discussed in depth. The question of gauge dependence of the effective potential and the Nielsen identities are explained. The nonrestoration of some symmetries at high temperature (such as supersymmetry) and theories on nonsimply connected space-times are al

  16. Interpolating string field theories

    International Nuclear Information System (INIS)

    Zwiebach, B.

    1992-01-01

    This paper reports that a minimal area problem imposing different length conditions on open and closed curves is shown to define a one-parameter family of covariant open-closed quantum string field theories. These interpolate from a recently proposed factorizable open-closed theory up to an extended version of Witten's open string field theory capable of incorporating on shell closed strings. The string diagrams of the latter define a new decomposition of the moduli spaces of Riemann surfaces with punctures and boundaries based on quadratic differentials with both first order and second order poles

  17. Gela offshore field

    Energy Technology Data Exchange (ETDEWEB)

    Pagliughi, G

    1965-06-01

    The field of Gela, off the southern shore of Sicily, is the only producing offshore field in the Mediterranean. It produces from Triassic dolimite limestones of 434-m thickness, water level at -3517 m. It is a water-drive reservoir producing 10/sup 0/F API oil and has 79 wells, some of them on shore. Most offshore wells are directional wells from shore; there are also 2 fixed platforms and a special mobile platform. The wells are on pump (stroke, 72 in.; capacity 200 tons per day). The crude goes directly to a combination refinery-petrochemical complex at Gela.

  18. DSM-5 field survey

    DEFF Research Database (Denmark)

    Lochner, Christine; Grant, Jon E; Odlaug, Brian Lawrence

    2012-01-01

    Pathologic skin picking (skin picking disorder [SPD]) is a prevalent and disabling condition, which has received increasing study. It is timely to consider including SPD in DSM-5. The aim of this field survey was to investigate possible diagnostic criteria for SPD.......Pathologic skin picking (skin picking disorder [SPD]) is a prevalent and disabling condition, which has received increasing study. It is timely to consider including SPD in DSM-5. The aim of this field survey was to investigate possible diagnostic criteria for SPD....

  19. Finite quantum field theories

    International Nuclear Information System (INIS)

    Lucha, W.; Neufeld, H.

    1986-01-01

    We investigate the relation between finiteness of a four-dimensional quantum field theory and global supersymmetry. To this end we consider the most general quantum field theory and analyse the finiteness conditions resulting from the requirement of the absence of divergent contributions to the renormalizations of the parameters of the theory. In addition to the gauge bosons, both fermions and scalar bosons turn out to be a necessary ingredient in a non-trivial finite gauge theory. In all cases discussed, the supersymmetric theory restricted by two well-known constraints on the dimensionless couplings proves to be the unique solution of the finiteness conditions. (Author)

  20. On vector fields having properties of Reeb fields

    OpenAIRE

    Hajduk, Boguslaw; Walczak, Rafal

    2011-01-01

    We study constructions of vector fields with properties which are characteristic to Reeb vector fields of contact forms. In particular, we prove that all closed oriented odd-dimensional manifold have geodesible vector fields.

  1. Electromagnetic fields and their impacts

    Science.gov (United States)

    Prša, M. A.; Kasaš-Lažetić, K. K.

    2018-01-01

    The main goal of this paper is to briefly recall some different electromagnetic field definitions, some macroscopic sources of electromagnetic fields, electromagnetic fields classification regarding time dependences, and the ways of field determination in concrete cases. After that, all the mechanisms of interaction between electromagnetic field and substance, on atomic level, are described in details. Interaction between substance and electric field is investigated separately from the substance and magnetic field interaction. It is demonstrated that, in all cases of the unique electromagnetic field, total interaction can be treated as a superposition of two separated interactions. Finally, the main electromagnetic fields surrounding us is cited and discussed.

  2. Tripolar electric field Structure in guide field magnetic reconnection

    OpenAIRE

    S. Fu; S. Huang; M. Zhou; B. Ni; X. Deng

    2018-01-01

    It has been shown that the guide field substantially modifies the structure of the reconnection layer. For instance, the Hall magnetic and electric fields are distorted in guide field reconnection compared to reconnection without guide fields (i.e., anti-parallel reconnection). In this paper, we performed 2.5-D electromagnetic full particle simulation to study the electric field structures in magnetic reconnection under different initial guide fields (Bg). Once the amplit...

  3. Memories in process: a communication study about the videos of companhia do latão and ói nóis aqui traveiz Memórias em processo: um estudo comunicacional sobre os vídeos da companhia do latão e do ó nóis aqui traveiz

    Directory of Open Access Journals (Sweden)

    Danilo do Amaral Santos Lagoeiro

    2012-05-01

    Full Text Available The work aims to reflect on the relevance of the proposed method of Bertolt Brecht theatrical production through his reworking from the Brazilian culture, analyzing the videos, through their connections with the theatrical performances, two brazilian groups namely: Companhia do Latão (Sao Paulo and Ói Nóis Aqui Traveiz (Porto Alegre. The analytical methodology merges aesthetic and philosophical notions coined by Brecht and Walter Benjamin on the observations collected during a field survey along the two theater groups, aiming at a broader understanding of the connection between the theather and their audiovisual recordings on DVD. Examines the use of the effect-V in their video productions. Yet some formal experiments that intersection video theater in the service of memory and stage productions own experimental research in this field.O trabalho visa refletir sobre a atualidade das propostas do método de Bertolt Brecht de encenação teatral através de sua reelaboração a partir da cultura brasileira, analisando os vídeos, através de suas conexões com os espetáculos teatrais, de dois grupos brasileiros a saber: a Companhia do Latão (São Paulo e o Ói Nóis Aqui Traveiz (Porto Alegre. A metodologia analítica funde noções estético-filosóficas cunhadas por Brecht e Walter Benjamin às observações recolhidas durante uma pesquisa de campo junto aos dois grupos teatrais, objetivando uma compreensão mais ampla da conexão entre os espetáculos teatrais e os respectivos registros audiovisuais em DVD. Analisa o uso do efeito-V em suas produções em vídeo. E ainda algumas experiências formais dessa interseção vídeo-teatro a serviço da memória das produções cênicas e da própria pesquisa experimental nesse campo.

  4. Electromagnetic Fields and Cancer

    Science.gov (United States)

    ... and magnetic fields (1 Hz to 100 kHz) . Health Physics 2010; 99(6):818-36. doi: 10.1097/ ... and health: review of current status of research. Health Physics 2013; 105(6):561-75. [PubMed Abstract] AGNIR. ...

  5. Ultrasonogram in obstetric field

    International Nuclear Information System (INIS)

    Joo, K. B.; Song, C. H.; Lee, H. B.

    1980-01-01

    The clinical evaluation of 535 cases of sonogram from Mar. 1, 1979 to Oct. 30, 1979 in obstetric field at Department of Radiology and Ob. and Gy. Eul-Ji General Hospital. We present these cases: normal pregnancy, missed abortion, twin pregnancy, hydatidiform mole and ectopic pregnancy, with brief review of literature.

  6. Linking lab and field

    International Nuclear Information System (INIS)

    Cronje, P.B.

    1988-01-01

    The multitude of different supplements recommended for animals grazing natural pastures, which testifies to the need for a metabolic basis for supplementary feeding practices. The first approach to this problem was to simulate different feeding conditions in the laboratory, where the metabolic responses of body tissues to changes in the supply of purified nutrients could be studied using radioisotope techniques. The second step was to link these fundamental studies to field conditions. The results of these studies suggest that the efficiency of feed conversion and growth rates of ruminants grazing winter pastures in the highveld region of South Africa could be substantially improved by strategic supplementation with glucose precursors. Acetate clearance rate represents a valuable link in the process of applying information obtained from controlled laboratory experiments to field conditions. As this technique is inexpensive, quick and simple to carry out, it is ideally suited to application under field conditions where the use of isotopes is impractical. By providing a link with field conditions, it greatly extended the scope and practical application of isotope tracer techniques

  7. Warp Field Mechanics 101

    Science.gov (United States)

    White, Harold

    2011-01-01

    This paper will begin with a short review of the Alcubierre warp drive metric and describes how the phenomenon might work based on the original paper. The canonical form of the metric was developed and published in [6] which provided key insight into the field potential and boost for the field which remedied a critical paradox in the original Alcubierre concept of operations. A modified concept of operations based on the canonical form of the metric that remedies the paradox is presented and discussed. The idea of a warp drive in higher dimensional space-time (manifold) will then be briefly considered by comparing the null-like geodesics of the Alcubierre metric to the Chung-Freese metric to illustrate the mathematical role of hyperspace coordinates. The net effect of using a warp drive technology coupled with conventional propulsion systems on an exploration mission will be discussed using the nomenclature of early mission planning. Finally, an overview of the warp field interferometer test bed being implemented in the Advanced Propulsion Physics Laboratory: Eagleworks (APPL:E) at the Johnson Space Center will be detailed. While warp field mechanics has not had a Chicago Pile moment, the tools necessary to detect a modest instance of the phenomenon are near at hand.

  8. Parafermionic conformal field theory

    International Nuclear Information System (INIS)

    Kurak, V.

    1989-09-01

    Conformal parafermionic field theories are reviewed with emphasis on the computation of their OPE estructure constants. It is presented a simple computational of these for the Z(N) parafermions, unveilling their Lie algebra content. (A.C.A.S.) [pt

  9. What Are Electromagnetic Fields?

    Science.gov (United States)

    ... field causes a compass needle to orient in a North-South direction and is used by birds and fish for navigation. Human-made sources of ... and form the basis of telecommunications as well as radio and television ... In microwaves ovens, we use them to quickly heat food. At ...

  10. Superspace conformal field theory

    Energy Technology Data Exchange (ETDEWEB)

    Quella, Thomas [Koeln Univ. (Germany). Inst. fuer Theoretische Physik; Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-07-15

    Conformal sigma models and WZW models on coset superspaces provide important examples of logarithmic conformal field theories. They possess many applications to problems in string and condensed matter theory. We review recent results and developments, including the general construction of WZW models on type I supergroups, the classification of conformal sigma models and their embedding into string theory.

  11. Superspace conformal field theory

    International Nuclear Information System (INIS)

    Quella, Thomas

    2013-07-01

    Conformal sigma models and WZW models on coset superspaces provide important examples of logarithmic conformal field theories. They possess many applications to problems in string and condensed matter theory. We review recent results and developments, including the general construction of WZW models on type I supergroups, the classification of conformal sigma models and their embedding into string theory.

  12. Field Guide to Radiometry

    CERN Document Server

    Grant, Barbara

    2011-01-01

    Written from a systems engineering perspective, this SPIE Field Guide covers topics in optical radiation propagation, material properties, sources, detectors, system components, measurement, calibration, and photometry. The book's organization and extensive collection of diagrams, tables, and graphs will enable the reader to efficiently identify and apply relevant information to radiometric problems arising amid the demands of today's fast-paced technical environment.

  13. Field ion microscopy

    International Nuclear Information System (INIS)

    Ramanathan, D.

    1975-01-01

    The basic features of the Field-Ion Microscope (FIM) and the theory of image formation are explained. Design parameters of the FIM, factors limiting its resolution, interpretation of the image, etc are briefly outlined. Relative merits of the various imaging gases and the applications of the FIM are also covered. (K.B.)

  14. Planetary plasmas and fields

    International Nuclear Information System (INIS)

    Roederer, J.G.

    1976-01-01

    The magnetospheres of earth, Jupiter, and Mercury are discussed. The main features and physical processes characteristic of the quiet time earth magnetosphere are examined. Jupiter's larger and more distant magnetosphere is compared with the earth's and recent findings are reviewed. The plasma and field environment of Mercury is also discussed and similarities with the earth's magnetosphere are noted

  15. Reflections on the Field.

    Science.gov (United States)

    Kauffman, James M.

    2003-01-01

    Reflections on the field of special education offer six ideas: (1) the value of science; (2) the continuing value of separate and special education for some students; (3) the continuing importance of prevention; (4) the importance of academic instruction; (5) the importance of social justice for the poor; and (6) a renewed emphasis on human…

  16. Axiomatic conformal field theory

    International Nuclear Information System (INIS)

    Gaberdiel, M.R.; Goddard, P.

    2000-01-01

    A new rigourous approach to conformal field theory is presented. The basic objects are families of complex-valued amplitudes, which define a meromorphic conformal field theory (or chiral algebra) and which lead naturally to the definition of topological vector spaces, between which vertex operators act as continuous operators. In fact, in order to develop the theory, Moebius invariance rather than full conformal invariance is required but it is shown that every Moebius theory can be extended to a conformal theory by the construction of a Virasoro field. In this approach, a representation of a conformal field theory is naturally defined in terms of a family of amplitudes with appropriate analytic properties. It is shown that these amplitudes can also be derived from a suitable collection of states in the meromorphic theory. Zhu's algebra then appears naturally as the algebra of conditions which states defining highest weight representations must satisfy. The relationship of the representations of Zhu's algebra to the classification of highest weight representations is explained. (orig.)

  17. NPOESS Field Terminal Updates

    Science.gov (United States)

    Heckmann, G.; Route, G.

    2009-12-01

    The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground data processing segment for NPOESS is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence and Information Systems. The IDPS processes NPOESS satellite data to provide environmental data products (aka, Environmental Data Records or EDRs) to NOAA and DoD processing centers operated by the United States government. The IDPS will process EDRs beginning with the NPOESS Preparatory Project (NPP) and continuing through the lifetime of the NPOESS system. IDPS also provides the software and requirements for the Field Terminal Segment (FTS). NPOESS provides support to deployed field terminals by providing mission data in the Low Rate and High Rate downlinks (LRD/HRD), mission support data needed to generate EDRs and decryption keys needed to decrypt mission data during Selective data Encryption (SDE). Mission support data consists of globally relevant data, geographically constrained data, and two line element sets. NPOESS provides these mission support data via the Internet accessible Mission Support Data Server and HRD/LRD downlinks. This presentation will illustrate and describe the NPOESS capabilities in support of Field Terminal users. This discussion will include the mission support data available to Field Terminal users, content of the direct broadcast HRD and LRD

  18. Gravitational Field Shielding by Scalar Field and Type II Superconductors

    Directory of Open Access Journals (Sweden)

    Zhang B. J.

    2013-01-01

    Full Text Available The gravitational field shielding by scalar field and type II superconductors are theoret- ically investigated. In accord with the well-developed five-dimensional fully covariant Kaluza-Klein theory with a scalar field, which unifies the Einsteinian general relativity and Maxwellian electromagnetic theory, the scalar field cannot only polarize the space as shown previously, but also flatten the space as indicated recently. The polariza- tion of space decreases the electromagnetic field by increasing the equivalent vacuum permittivity constant, while the flattening of space decreases the gravitational field by decreasing the equivalent gravitational constant. In other words, the scalar field can be also employed to shield the gravitational field. A strong scalar field significantly shield the gravitational field by largely decreasing the equivalent gravitational constant. According to the theory of gravitational field shielding by scalar field, the weight loss experimentally detected for a sample near a rotating ceramic disk at very low tempera- ture can be explained as the shielding of the Earth gravitational field by the Ginzburg- Landau scalar field, which is produced by the type II superconductors. The significant shielding of gravitational field by scalar field produced by superconductors may lead to a new spaceflight technology in future.

  19. Evaluate existing radiation fields

    International Nuclear Information System (INIS)

    Aldrich, J.M.; Haggard, D.L.; Endres, G.W.R.; Fix, J.J.

    1981-01-01

    Knowledge of the spectrum of energies for beta, gamma, and neutron radiation experienced in the field is crucial to the proper interpretation of personnel dose. Calibration sources and techniques are determined on the basis of their relationship to field exposure. Selected techniques were used to obtain neutron, photon, and beta energy spectra data at several Hanford locations. Four neutron energy spectra and dose measurement methods were used: (1) multisphere spectrometer system; (2) tissue equivalent proportional counter (TEPC); (3) RASCAL (9'' to 3'' sphere ratios); and (4) helium-3 neutron spectrometer. Gamma spectroscopy was done using standard techniques. A specially designed TLD dosimeter was used to obtain beta spectrum measurements. The design and use of each of these instruments is described in the body of this report. Data collected and analyzed for each of the Hanford locations are included

  20. Algebraic quantum field theory

    International Nuclear Information System (INIS)

    Foroutan, A.

    1996-12-01

    The basic assumption that the complete information relevant for a relativistic, local quantum theory is contained in the net structure of the local observables of this theory results first of all in a concise formulation of the algebraic structure of the superselection theory and an intrinsic formulation of charge composition, charge conjugation and the statistics of an algebraic quantum field theory. In a next step, the locality of massive particles together with their spectral properties are wed for the formulation of a selection criterion which opens the access to the massive, non-abelian quantum gauge theories. The role of the electric charge as a superselection rule results in the introduction of charge classes which in term lead to a set of quantum states with optimum localization properties. Finally, the asymptotic observables of quantum electrodynamics are investigated within the framework of algebraic quantum field theory. (author)

  1. Fisheyes in the field

    DEFF Research Database (Denmark)

    Jakobsen, Mikkel Rønne; Hornbæk, Kasper Anders Søren

    2009-01-01

    multiple methods (experience sampling, logging, thinking aloud, and interviews) to describe how the visualization is adopted and used. At the concrete level, our results suggest that the visualization was used as frequently as other tools in the programming environment. We also propose extensions......Information visualizations have been shown useful in numerous laboratory studies, but their adoption and use in real-life tasks are curiously under-researched. We present a field study of ten programmers who work with an editor extended with a fisheye view of source code. The study triangulates...... to the interface and discuss features that were not used in practice. At the methodological level, the study identifies contributions distinct to individual methods and to their combination, and discusses the relative benefits of laboratory studies and field studies for the evaluation of information visualizations....

  2. Field services experiences

    International Nuclear Information System (INIS)

    Colflesh, J.A.; Kruse, P.W.; Merluzzi, R.A.

    1985-01-01

    Combustion Engineering (C-E) is a large diversified manufacturer of products and services for the energy field. At this time, C-E has supplied the nuclear steam supply systems for eleven operating nuclear power plants with two additional units currently undergoing start-up testing. The focus of C-E's commitment in the nuclear power plant services area is the Nuclear Services organization within the Nuclear Power Systems Division. The Nuclear Services organization provides services on a timely cost efficient basis; and dedicates resources to developing new products and services which are truly responsive to the needs of operating power plants world wide. In the paper, C-E's capabilities and experience in the field of nuclear services are described. Highlighted are our capabilities in the areas of transition management services, operating services and engineering services

  3. Quantum field theory

    International Nuclear Information System (INIS)

    Mancini, F.

    1986-01-01

    Theoretical physicists, coming from different countries, working on different areas, gathered at Positano: the Proceedings contain all the lectures delivered as well as contributed papers. Many areas of physics are represented, elementary particles in high energy physics, quantum relativity, quantum geometry, condensed matter physics, statistical mechanics; but all works are concerned with the use of the methods of quantum field theory. The first motivation of the meeting was to pay homage to a great physicist and a great friend; it was also an occasion in which theoretical physicists got together to discuss and to compare results in different fields. The meeting was very intimate; the relaxed atmosphere allowed constructive discussions and contributed to a positive exchange of ideas. (orig.)

  4. Geologic Field Database

    Directory of Open Access Journals (Sweden)

    Katarina Hribernik

    2002-12-01

    Full Text Available The purpose of the paper is to present the field data relational database, which was compiled from data, gathered during thirty years of fieldwork on the Basic Geologic Map of Slovenia in scale1:100.000. The database was created using MS Access software. The MS Access environment ensures its stability and effective operation despite changing, searching, and updating the data. It also enables faster and easier user-friendly access to the field data. Last but not least, in the long-term, with the data transferred into the GISenvironment, it will provide the basis for the sound geologic information system that will satisfy a broad spectrum of geologists’ needs.

  5. Transmission line fields

    International Nuclear Information System (INIS)

    Jeffers, D.E.

    1991-01-01

    There were reports from Russia in the late 1960's and early 1970's that staff in new 500-kV and 750-kV substations were suffering from headaches and other symptoms broadly associated with fatigue. Whilst the Russian results were not confirmed by independent studies, they did serve to stimulate public concern. In 1979 published results of a study of childhood cancer in Denver, Colorado concentrated attention onto the magnetic rather than the electric field. Research programmes in the United Kingdom and elsewhere are briefly described. Although some studies suggest an association between exposure to 50/60 Hz fields and cancer, other studies do not. Having reviewed the evidence, the International Radiation Protection Association, the World Health Organisation, the U.S. Congress Office of Technology Assessment and the U.K. National Radiological Protection Board all consider that the relation is not established. (author)

  6. Quantum Field Theory

    CERN Document Server

    Zeidler, Eberhard

    This is the first volume of a modern introduction to quantum field theory which addresses both mathematicians and physicists ranging from advanced undergraduate students to professional scientists. The book tries to bridge the existing gap between the different languages used by mathematicians and physicists. For students of mathematics it is shown that detailed knowledge of the physical background helps to motivate the mathematical subjects and to discover interesting interrelationships between quite different mathematical topics. For students of physics, fairly advanced mathematics is presented, which is beyond the usual curriculum in physics. It is the author's goal to present the state of the art of realizing Einstein's dream of a unified theory for the four fundamental forces in the universe (gravitational, electromagnetic, strong, and weak interaction). From the reviews: "… Quantum field theory is one of the great intellectual edifices in the history of human thought. … This volume differs from othe...

  7. Particles and quantum fields

    CERN Document Server

    Kleinert, Hagen

    2016-01-01

    This is an introductory book on elementary particles and their interactions. It starts out with many-body Schrödinger theory and second quantization and leads, via its generalization, to relativistic fields of various spins and to gravity. The text begins with the best known quantum field theory so far, the quantum electrodynamics of photon and electrons (QED). It continues by developing the theory of strong interactions between the elementary constituents of matter (quarks). This is possible due to the property called asymptotic freedom. On the way one has to tackle the problem of removing various infinities by renormalization. The divergent sums of infinitely many diagrams are performed with the renormalization group or by variational perturbation theory (VPT). The latter is an outcome of the Feynman-Kleinert variational approach to path integrals discussed in two earlier books of the author, one representing a comprehensive treatise on path integrals, the other dealing with critial phenomena. Unlike ordin...

  8. Wake field acceleration experiments

    International Nuclear Information System (INIS)

    Simpson, J.D.

    1988-01-01

    Where and how will wake field acceleration devices find use for other than, possibly, accelerators for high energy physics? I don't know that this can be responsibly answered at this time. What I can do is describe some recent results from an ongoing experimental program at Argonne which support the idea that wake field techniques and devices are potentially important for future accelerators. Perhaps this will spawn expanded interest and even new ideas for the use of this new technology. The Argonne program, and in particular the Advanced Accelerator Test Facility (AATF), has been reported in several fairly recent papers and reports. But because this is a substantially new audience for the subject, I will include a brief review of the program and the facility before describing experiments. 10 refs., 7 figs

  9. ISR Radial Field Magnet

    CERN Multimedia

    1983-01-01

    There were 37 (normal) + 3 (special) Radial Field magnets in the ISR to adjust vertically the closed orbit. Gap heights and strengths were 200 mm and .12 Tm in the normal magnets, 220 mm and .18 Tm in the special ones. The core length was 430 mm in both types. Due to their small length as compared to the gap heights the end fringe field errors were very important and had to be compensated by suitably shaping the poles. In order to save on cables, as these magnets were located very far from their power supplies, the coils of the normal type magnets were formed by many turns of solid cpper conductor with some interleaved layers of hollow conductor directly cooled by circulating water

  10. Education as "Dilemmatic Field"

    DEFF Research Database (Denmark)

    Tateo, Luca

    2018-01-01

    Psychology of education must discuss a number of relevant ethical, political and societal issues that cannot be simply overlooked as non pertinent to the discipline. For too long educational and developmental psychology have take divergent routes and have not enough dialogued with other fields...... such as pedagogy. I argue that it is first of all necessary to conceptualize the work of schooling, that is educational processes of teaching and learning in specific social contexts, as complex and dilemmatic fields. I discuss contributions from the past and current debate to support my claim that education...... is inherently ambivalent and dilemmatic, while educational psychology is too often normative and prescriptive. As many authors have discussed educational processes as battlefields between political and economic tendencies, we cannot avoid to discuss the relationship of such tendencies and the developmental...

  11. On Scale and Fields

    DEFF Research Database (Denmark)

    Kadish, David

    2017-01-01

    This paper explores thematic parallels between artistic and agricultural practices in the postwar period to establish a link to media art and cultural practices that are currently emerging in urban agriculture. Industrial agriculture has roots in the post-WWII abundance of mechanical and chemical...... equipment and research. These systems are highly mechanically efficient. With minimal physical labour, they extract ever staggering crop yields from ever poorer soils in shifting climatic conditions. However, the fact of mechanical efficiency is used to mask a set of problems with industrial......-scale agricultural systems that range from spreading pests and diseases to poor global distribution of concentrated regional food wealth. That the conversion of vegetatively diverse farmland into monochromatic fields was popularized at the same time as the arrival of colour field paintings like Barnett Newman...

  12. Microcontinuum field theories

    CERN Document Server

    Eringen, A Cemal

    1999-01-01

    Microcontinuum field theories constitute an extension of classical field theories -- of elastic bodies, deformations, electromagnetism, and the like -- to microscopic spaces and short time scales. Material bodies are here viewed as collections of large numbers of deformable particles, much as each volume element of a fluid in statistical mechanics is viewed as consisting of a large number of small particles for which statistical laws are valid. Classical continuum theories are valid when the characteristic length associated with external forces or stimuli is much larger than any internal scale of the body under consideration. When the characteristic lengths are comparable, however, the response of the individual constituents becomes important, for example, in considering the fluid or elastic properties of blood, porous media, polymers, liquid crystals, slurries, and composite materials. This volume is concerned with the kinematics of microcontinua. It begins with a discussion of strain, stress tensors, balanc...

  13. Effective quantum field theories

    International Nuclear Information System (INIS)

    Georgi, H.M.

    1989-01-01

    Certain dimensional parameters play a crucial role in the understanding of weak and strong interactions based on SU(2) x U(1) and SU(3) symmetry group theories and of grand unified theories (GUT's) based on SU(5). These parameters are the confinement scale of quantum chromodynamics and the breaking scales of SU(2) x U(1) and SU(5). The concepts of effective quantum field theories and renormalisability are discussed with reference to the economics and ethics of research. (U.K.)

  14. Noncommutative field theory

    International Nuclear Information System (INIS)

    Douglas, Michael R.; Nekrasov, Nikita A.

    2001-01-01

    This article reviews the generalization of field theory to space-time with noncommuting coordinates, starting with the basics and covering most of the active directions of research. Such theories are now known to emerge from limits of M theory and string theory and to describe quantum Hall states. In the last few years they have been studied intensively, and many qualitatively new phenomena have been discovered, on both the classical and the quantum level

  15. Energy from field crops

    Energy Technology Data Exchange (ETDEWEB)

    Zubr, J.

    1990-04-15

    At the Research Station of Royal Veterinary and Agricultural University, Copenhagen, Denmark, investigation concerning cultivation and exploitation of field crops for production of fuels was carried out during the period 1986-1989. High yielding crops, such as sugar beet - BETA VULGARIS, jerusalem artichoke - HELIANTHUS TUBEROSUS, rhubarb - RHEUM RHAPONTICUM, and comfrey - SYMPHYTUM ASPERUM, were grown experimentally in the field. Different cultivation methods for the crops were used and evaluated. Simultaneously with the field experiment, laboratory investigation was carried out to determine the energy potential of different products and by-products from the crops processes, such as alcoholic and methanogenic fermantation. Production expenses for the crops were determined, and cost of the fuels was estimated. The experimental results show that beet is a superior crop for the climatic conditions of Northern Europe. In the season 1986, yields exceeded 20 t TS/ha in the form of roots and tops, where achieved. A combined exploitation of beet roots and tops via alcoholic and methanogenic fermantation gave a gross energy corresponding to 80 hl OE/ha/yr. Using methanogenic fermentation exclusively, from ensiled beet roots and tops, gross energy yield corresponding to 85 hl IE/ha/yr, was achieved. The cost of energy in the form of alcohol from beet roots was estimated to be 5.17 DKK/1 OE (0.64 ECU/l OE). The cost of energy in the form of methane from ensiled beet tops, was estimated to be 2.68 DKK/l OE (0.33 ECU/l OE). At the present time, methane produced on the basis of ensiled beet roots and tops appears to be competitive with fossil fuels. Irrespective of the cost, however, the possibility of producing clean energy from field crops remains of interest for the future. (author) 27 refs.

  16. Quantized gauge field

    International Nuclear Information System (INIS)

    Arodz, H.

    1987-01-01

    The two formulations of quantum theory of the free electromagnetic field are presented. In the Coulomb gauge approach the independent dynamical variables have been identified and then, in order to quantize the theory, it has been sufficient to apply the straightforward canonical quantization. In the Gupta-Bleuler approach the auxilliary theory is first considered. The straightforward canonical quantization of it leads to the quantum theory defined in the space G with indefinite norm. 15 refs. (author)

  17. Affine field theories

    International Nuclear Information System (INIS)

    Cadavid, A.C.

    1989-01-01

    The author constructs a non-Abelian field theory by gauging a Kac-Moody algebra, obtaining an infinite tower of interacting vector fields and associated ghosts, that obey slightly modified Feynman rules. She discusses the spontaneous symmetry breaking of such theory via the Higgs mechanism. If the Higgs particle lies in the Cartan subalgebra of the Kac-Moody algebra, the previously massless vectors acquire a mass spectrum that is linear in the Kac-Moody index and has additional fine structure depending on the associated Lie algebra. She proceeds to show that there is no obstacle in implementing the affine extension of supersymmetric Yang-Mills theories. The result is valid in four, six and ten space-time dimensions. Then the affine extension of supergravity is investigated. She discusses only the loop algebra since the affine extension of the super-Poincare algebra appears inconsistent. The construction of the affine supergravity theory is carried out by the group manifold method and leads to an action describing infinite towers of spin 2 and spin 3/2 fields that interact subject to the symmetries of the loop algebra. The equations of motion satisfy the usual consistency check. Finally, she postulates a theory in which both the vector and scalar fields lie in the loop algebra of SO(3). This theory has an expanded soliton sector, and corresponding to the original 't Hooft-Polyakov solitonic solutions she now finds an infinite family of exact, special solutions of the new equations. She also proposes a perturbation method for obtaining an arbitrary solution of those equations for each level of the affine index

  18. Mobile Field Goniospectrometry

    Science.gov (United States)

    Peltoniemi, J. I.; Kaasalainen, S.; Näränen, J.

    2004-05-01

    Multiangle remote sensing needs multiangle models and multiangle ground reference data. The ground data can be measured using goniometers. Many targets are in difficult terrains and hard to bring into laboratory, which makes the ground data collection more complicated We have developed several field goniometers to measure the directional and spectral reflection signatures of various targets. The heaviest of the instruments is fully manual and very robust for field work. It can be transported using a light trailer and mounted in an hour. The new very light goniometer measures the BRDF automatically in few minutes. It can be carried by two persons even large distances to difficult places. Both of these instruments use the ASD Field Spec PRO FR spectrometer with a 4m light fibre allowing optics to be mounted up and the heavy parts down. The dimensions --- arm length about 2m --- and optics (1--8 degree view angles) limit the useful spot diameter to about 3, 10 or 30cm, making the system useful for small vegetation and soil. These two wide angle goniometers are complemented by a narrow angle backscattering goniometer utilising beamsplitters to measure up to exact backscattering direction and about 15 degree around. We present BRDF and spectra for undergrowth (lichen, moss, peat, twigs) from a field campaign in August 2003, and various grasses dry and wet. We recognise significant differences in the directional pattern between different species (factors of 2-10) and varying structural properties, making the use of directional signal for remote sensing very attractive. We are working with scattering models of snow and soil, and will continue with vegetation soon.

  19. Particles, fields, Universe

    International Nuclear Information System (INIS)

    Zeldovich, Ya. B.

    1984-01-01

    A general review is given on the historical development and on the present status of main physical ideas and theories. The concepts of particles, fields and interactions are discussed in detail including most recent developments. The present basic theories of physics: general relativity, gauge theory of electroweak interaction and quantum chromodynamics, their new results and their possible unification are analyzed. The author emphasizes the importance of knowledge as an inherent need of mankind. (D.Gy)

  20. Topics in field theory

    International Nuclear Information System (INIS)

    Velasco, E.S.

    1986-01-01

    This dissertation deals with several topics of field theory. Chapter I is a brief outline of the work presented in the next chapters. In chapter II, the Gauss-Bonnet-Chern theorem for manifolds with boundary is computed using the path integral representation of the Witten index for supersymmetric quantum mechanical systems. In chapter III the action of N = 2 (Poincare) supergravity is obtained in terms of N = 1 superfields. In chapter IV, N = 2 supergravity coupled to the (abelian) vector multiplet is projected into N - 1 superspace. There, the resulting set of constraints is solved in terms of unconstrained prepotential and the action in terms of N = 1 superfields is constructed. In chapter V the set of constraints for N = 2 conformal supergravity is projected into N = 1 superspace and solved in terms of N = 1 conformal supergravity fields a d matter prepotentials. In chapter VI the role of magnetic monopoles in the phase structure of the change one fixed length abelian Higgs model ins the latticer is investigated using analytic and numerical methods. The technique of monopole suppression is used to determine the phase transition lines that are monopole driven. Finally in chapter VII, the role of the charge of the Higgs field in the abelian Higgs model in the lattice is investigated

  1. Mapping the Field

    DEFF Research Database (Denmark)

    Goerres, Achim; Vanhuysse, Pieter

    2012-01-01

    Whereas the call for a political science based study of older people and ageing is not new (Cutler 1977; Heclo 1988), relatively little unified progress has been made so far. This chapter maps the field of generational politics and introduces our edited volume "Ageing Populations in Post-Industri......Whereas the call for a political science based study of older people and ageing is not new (Cutler 1977; Heclo 1988), relatively little unified progress has been made so far. This chapter maps the field of generational politics and introduces our edited volume "Ageing Populations in Post...... boxes by asking a number of central questions. How does population aging change political support for redistribution towards different age groups in society, including not just elderly people but also families with children? How, and when, do established parties in aging democracies implement policies......? The answers provided in this volume promise to be of major interest to scholars in fields such as political economy, political sociology, social policy, comparative politics, demography, and gerontology....

  2. Venus gravity fields

    Science.gov (United States)

    Sjogren, W. L.; Ananda, M.; Williams, B. G.; Birkeland, P. W.; Esposito, P. S.; Wimberly, R. N.; Ritke, S. J.

    1981-01-01

    Results of Pioneer Venus Orbiter observations concerning the gravity field of Venus are presented. The gravitational data was obtained from reductions of Doppler radio tracking data for the Orbiter, which is in a highly eccentric orbit with periapsis altitude varying from 145 to 180 km and nearly fixed periapsis latitude of 15 deg N. The global gravity field was obtained through the simultaneous estimation of the orbit state parameters and gravity coefficients from long-period variations in orbital element rates. The global field has been described with sixth degree and order spherical harmonic coefficients, which are capable of resolving the three major topographical features on Venus. Local anomalies have been mapped using line-of-sight accelerations derived from the Doppler residuals between 40 deg N and 10 deg S latitude at approximately 300 km spatial resolution. Gravitational data is observed to correspond to topographical data obtained by radar altimeter, with most of the gravitational anomalies about 20-30 milligals. Simulations evaluating the isostatic states of two topographic features indicate that at least partial isostasy prevails, with the possibility of complete compensation.

  3. Heavy fields and gravity

    Energy Technology Data Exchange (ETDEWEB)

    Goon, Garrett [Institute of Physics, Universiteit van Amsterdam,Science Park 904, Amsterdam, 1090 GL (Netherlands)

    2017-01-11

    We study the effects of heavy fields on 4D spacetimes with flat, de Sitter and anti-de Sitter asymptotics. At low energies, matter generates specific, calculable higher derivative corrections to the GR action which perturbatively alter the Schwarzschild-(A)dS family of solutions. The effects of massive scalars, Dirac spinors and gauge fields are each considered. The six-derivative operators they produce, such as ∼R{sup 3} terms, generate the leading corrections. The induced changes to horizon radii, Hawking temperatures and entropies are found. Modifications to the energy of large AdS black holes are derived by imposing the first law. An explicit demonstration of the replica trick is provided, as it is used to derive black hole and cosmological horizon entropies. Considering entropy bounds, it’s found that scalars and fermions increase the entropy one can store inside a region bounded by a sphere of fixed size, but vectors lead to a decrease, oddly. We also demonstrate, however, that many of the corrections fall below the resolving power of the effective field theory and are therefore untrustworthy. Defining properties of black holes, such as the horizon area and Hawking temperature, prove to be remarkably robust against higher derivative gravitational corrections.

  4. In-field analysis

    International Nuclear Information System (INIS)

    Stewart, Richard

    2010-01-01

    Full text: A new technology for in-field measurement of hydrocarbons in soil promises rapid results. Standard industry practice in Australia for measuring hydrocarbons in soil is to send a soil sample to an off-site accredited laboratory for analysis. This typically costs $25-50 per sample and takes 5-7 days to turnaround the results. While there are in-field hydrocarbon measurement technologies available in the US, most involve extracting the hydrocarbons from the soil and analysing the resulting liquid. These methods are time- consuming and often involve toxic solvents and clumsy equipment. A new technology developed by Ziltek and CSIRO allows for real-time me as-urement in the field. The user simply pulls the trigger on a hand-held infrared spectrometer and within a few seconds gets a digital read-out of the hydrocarbon concentration. The technology requires no toxic solvents or consumables, and sampling positions can also be logged automatically using GPS coordinates. A new technology developed by Ziltek and CSIRO allows for real-time measurement in the field. The user simply pulls the trigger on a hand-held infrared spectrometer and within a few seconds gets a digital read-out of the hydrocarbon concentration. The technology requires no toxic solvents or consumables, and sampling positions can also be logged automatically using GPS coordinates. The technology is essentially a software application that can be used with any third-party supplied hand-held infrared device. A working prototype has been tested at several contaminated sites across Australia, with very promising results. The site trials involved taking in-situ measurements using an infrared instrument before sending the soil to an external laboratory for conventional analysis - and comparing the results. Ziltek technical director Dr Ben Dearman noted at some sites the variation between the infrared results and lab results was less than 10 per cent.The technology gives a single concentration value in

  5. Introduction to gauge field theory

    International Nuclear Information System (INIS)

    Bailin, David; Love, Alexander

    1986-01-01

    The book is intended as an introduction to gauge field theory for the postgraduate student of theoretical particle physics. The topics discussed in the book include: path integrals, classical and quantum field theory, scattering amplitudes, feynman rules, renormalisation, gauge field theories, spontaneous symmetry breaking, grand unified theory, and field theories at finite temperature. (UK)

  6. Quantum fields in curved space

    International Nuclear Information System (INIS)

    Birrell, N.D.; Davies, P.C.W.

    1982-01-01

    The book presents a comprehensive review of the subject of gravitational effects in quantum field theory. Quantum field theory in Minkowski space, quantum field theory in curved spacetime, flat spacetime examples, curved spacetime examples, stress-tensor renormalization, applications of renormalization techniques, quantum black holes and interacting fields are all discussed in detail. (U.K.)

  7. Quality for quantum free fields

    International Nuclear Information System (INIS)

    Leyland, Pen; Roberts, John; Testard, Daniel; Centre National de la Recherche Scientifique, 13 - Marseille

    1978-07-01

    A proof is given concerning duality for the free neutral scalar boson field (abstract duality). Then real subspaces of a complex Hilbert space and the Von Neumann algebra associated with real subspaces are considered. Lastly duality for free fields (free electromagnetic field and free scalar field of any mass) is studied

  8. Stochastic quantization of Proca field

    International Nuclear Information System (INIS)

    Lim, S.C.

    1981-03-01

    We discuss the complications that arise in the application of Nelson's stochastic quantization scheme to classical Proca field. One consistent way to obtain spin-one massive stochastic field is given. It is found that the result of Guerra et al on the connection between ground state stochastic field and the corresponding Euclidean-Markov field extends to the spin-one case. (author)

  9. Covariant field equations in supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Vanhecke, Bram [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium); Ghent University, Faculty of Physics, Gent (Belgium); Proeyen, Antoine van [KU Leuven, Institute for Theoretical Physics, Leuven (Belgium)

    2017-12-15

    Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Covariant field equations in supergravity

    International Nuclear Information System (INIS)

    Vanhecke, Bram; Proeyen, Antoine van

    2017-01-01

    Covariance is a useful property for handling supergravity theories. In this paper, we prove a covariance property of supergravity field equations: under reasonable conditions, field equations of supergravity are covariant modulo other field equations. We prove that for any supergravity there exist such covariant equations of motion, other than the regular equations of motion, that are equivalent to the latter. The relations that we find between field equations and their covariant form can be used to obtain multiplets of field equations. In practice, the covariant field equations are easily found by simply covariantizing the ordinary field equations. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Vector Fields on Product Manifolds

    OpenAIRE

    Kurz, Stefan

    2011-01-01

    This short report establishes some basic properties of smooth vector fields on product manifolds. The main results are: (i) On a product manifold there always exists a direct sum decomposition into horizontal and vertical vector fields. (ii) Horizontal and vertical vector fields are naturally isomorphic to smooth families of vector fields defined on the factors. Vector fields are regarded as derivations of the algebra of smooth functions.

  12. Unbalanced field RF electron gun

    Science.gov (United States)

    Hofler, Alicia

    2013-11-12

    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  13. Workplace photon radiation fields

    International Nuclear Information System (INIS)

    Burgess, P.H.; Bartlett, D.T.; Ambrosi, P.

    1999-01-01

    The knowledge of workplace radiation fields is essential for measures in radiation protection. Information about the energy and directional distribution of the incident photon radiation was obtained by several devices developed by the National Radiation Protection Board, United Kingdom, by the Statens Stralskyddsinstitut, Sweden, together with EURADOS and by the Physikalisch-Technische Bundesanstalt, Germany. The devices are described and some results obtained at workplaces in nuclear industry, medicine and science in the photon energy range from 20 keV to 7 MeV are given. (author)

  14. Near field communications handbook

    CERN Document Server

    Ahson, Syed A; Furht, Borko

    2011-01-01

    Near Field Communication, or NFC, is a short-range high frequency wireless communication technology that enables the exchange of data between devices over about a decimeter. The technology is a simple extension of the ISO 14443 proximity-card standard (contact less card, RFID) that combines the interface of a smart card and a reader into a single device with practical implications. A complete reference for NFC, this handbook provides technical information about all aspects of NFC, as well as applications. It covers basic concepts as well as research grade material and includes a discussion of

  15. Topics in field theory

    CERN Document Server

    Karpilovsky, G

    1989-01-01

    This monograph gives a systematic account of certain important topics pertaining to field theory, including the central ideas, basic results and fundamental methods.Avoiding excessive technical detail, the book is intended for the student who has completed the equivalent of a standard first-year graduate algebra course. Thus it is assumed that the reader is familiar with basic ring-theoretic and group-theoretic concepts. A chapter on algebraic preliminaries is included, as well as a fairly large bibliography of works which are either directly relevant to the text or offer supplementary material of interest.

  16. Geometrical description of fields

    International Nuclear Information System (INIS)

    Sokolik, H.

    1979-01-01

    The author suggests a purely algebraic interpretation of interaction. The main idea is to consider interaction as a deformation of an inhomogeneous algebra composed of momentum operators and an arbitrary group admitting the equation of the theory. The only difference between this approach and the conventional one is that the generalized momentum operators do not commute with aech other, due not merely to the introduction of some external interaction field, but to the change of the structure of the algebra from which the theory stems

  17. Holographic effective field theories

    Energy Technology Data Exchange (ETDEWEB)

    Martucci, Luca [Dipartimento di Fisica ed Astronomia “Galileo Galilei' , Università di Padova,and INFN - Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Zaffaroni, Alberto [Dipartimento di Fisica, Università di Milano-Bicocca,and INFN - Sezione di Milano-Bicocca, I-20126 Milano (Italy)

    2016-06-28

    We derive the four-dimensional low-energy effective field theory governing the moduli space of strongly coupled superconformal quiver gauge theories associated with D3-branes at Calabi-Yau conical singularities in the holographic regime of validity. We use the dual supergravity description provided by warped resolved conical geometries with mobile D3-branes. Information on the baryonic directions of the moduli space is also obtained by using wrapped Euclidean D3-branes. We illustrate our general results by discussing in detail their application to the Klebanov-Witten model.

  18. High Field Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-12-15

    A Workshop was held in Frascati at the end of September under the title 'Generation of High Fields for Particle Acceleration to Very High Energies'. It was organized by the CERN Accelerator School, the European Committee for Future Accelerators (ECFA) and the Italian INFN and was a further stage in the exploratory moves towards new techniques of acceleration. Such techniques might become necessary to respond to the needs of high energy physics some decades from now when the application of conventional techniques will probably have reached their limits.

  19. Beyond the field

    DEFF Research Database (Denmark)

    Larsen, Anna Folke; Lilleør, Helene Bie

    2014-01-01

    We estimate the impact of a Farmer Field School intervention among small-scale farmers in northern Tanzania on two main development objectives: food security and poverty. We employ a series of evaluation methodologies, including a Quasi-Difference-in-Difference setup, to account for potential...... selection into the project, despite lack of baseline data. We find strong positive effects on food security, but no effect on poverty. Investigating possible mechanisms for this result shows that reallocation of labor resources toward own agricultural production and improved production smoothing may have...

  20. Quantum fields and dissipation

    International Nuclear Information System (INIS)

    Henning, P.

    1996-06-01

    The description of thermal or non-equilibrium systems necessitates a quantum field theory which differs from the usual approach in two aspects: 1. The Hilbert space is doubled; 2. Stable quasi-particles do not exist in interacting systems. A mini-review of these two aspects is given from a practical viewpoint including two applications. For thermal states it is shown how infrared divergences occuring in perturbative quasi-particle theories are avoided, whereas for non-equilibrium states a memory effect is shown to arise in the thermalization. (orig.)

  1. Higgs Effective Field Theories

    CERN Document Server

    2016-01-01

    The main focus of this meeting is to present new theoretical advancements related to effective field theories, evaluate the impact of initial results from the LHC Run2, and discuss proposals for data interpretation/presentation during Run2. A crucial role of the meeting is to bring together theorists from different backgrounds and with different viewpoints and to extend bridges towards the experimental community. To this end, we would like to achieve a good balance between senior and junior speakers, enhancing the visibility of younger scientists while keeping some overview talks.

  2. The First Chandra Field

    Energy Technology Data Exchange (ETDEWEB)

    Weisskopf, Martin C.; /NASA, Marshall; Aldcroft, Thomas L.; /Harvard-Smithsonian Ctr. Astrophys.; Cameron, Robert A.; /Harvard-Smithsonian Ctr. Astrophys. /SLAC; Gandhi,; Foellmi, Cedric; /European Southern Obs., Chile; Elsner, Ronald F.; /NASA, Marshall; Patel, Sandeep K.; /USRA, Huntsville; Wu, Kinwah; /Mullard Space Sci. Lab.; O' Dell, Stephen; /NASA, Marshall

    2005-09-09

    Before the official first-light images, the Chandra X-ray Observatory obtained an X-ray image of the field to which its focal plane was first exposed. We describe this historic observation and report our study of the first Chandra field. Chandra's Advanced CCD Imaging Spectrometer (ACIS) detected 15 X-ray sources, the brightest being dubbed ''Leon X-1'' to honor the Chandra Telescope Scientist, Leon Van Speybroeck. Based upon our analysis of the X-ray data and spectroscopy at the European Southern Observatory (ESO; La Silla, Chile), we find that Leon X-1 is a Type-1 (unobscured) active galactic nucleus (AGN) at a redshift z = 0.3207. Leon X-1 exhibits strong Fe II emission and a broad-line Balmer decrement that is unusually flat for an AGN. Within the context of the Eigenvector-1 correlation space, these properties suggest that Leon X-1 may be a massive ({ge} 10{sup 9} M{sub {circle_dot}}) black hole, accreting at a rate approaching its Eddington limit.

  3. Measurement of radiofrequency fields

    International Nuclear Information System (INIS)

    Leonowich, J.A.

    1992-05-01

    We are literally surrounded by radiofrequency (RFR) and microwave radiation, from both natural and man-made sources. The identification and control of man-made sources of RFR has become a high priority of radiation safety professionals in recent years. For the purposes of this paper, we will consider RFR to cover the frequencies from 3 kHz to 300 MHz, and microwaves from 300 MHz to 300 GHz, and will use the term RFR interchangeably to describe both. Electromagnetic radiation and field below 3 kHz is considered Extremely Low Frequency (ELF) and will not be discussed in this paper. Unlike x- and gamma radiation, RFR is non-ionizing. The energy of any RFR photon is insufficient to produce ionizations in matter. The measurement and control of RFR hazards is therefore fundamentally different from ionizing radiation. The purpose of this paper is to acquaint the reader with the fundamental issues involved in measuring and safely using RFR fields. 23 refs

  4. Gauge field theory

    International Nuclear Information System (INIS)

    Aref'eva, I.Ya.; Slavnov, A.A.

    1981-01-01

    This lecture is devoted to the discussion of gauge field theory permitting from the single point of view to describe all the interactions of elementary particles. The authors used electrodynamics and the Einstein theory of gravity to search for a renormgroup fixing a form of Lagrangian. It is shown that the gauge invariance added with the requirement of the minimum number of arbitraries in Lagrangian fixes unambigously the form of the electromagnetic interaction. The generalization of this construction for more complicate charge spaces results in the Yang-Mills theory. The interaction form in this theory is fixed with the relativity principle in the charge space. A quantum scheme of the Yang-Mills fields through the explicit separation of true dynamic variables is suggested. A comfortable relativistically invariant diagram technique for the calculation of a producing potential for the Green functions is described. The Ward generalized identities have been obtained and a procedure of the elimination of ultraviolet and infrared divergencies has been accomplished. Within the framework of QCD (quantum-chromodynamic) the phenomenon of the asymptotic freedom being the most successful prediction of the gauge theory of strong interactions was described. Working methods with QCD outside the framework of the perturbation theory have been described from a coupling constant. QCD is represented as a single theory possessing both the asymptotical freedom and the freedom retaining quarks [ru

  5. Conformal invariant quantum field theory and composite field operators

    International Nuclear Information System (INIS)

    Kurak, V.

    1976-01-01

    The present status of conformal invariance in quantum field theory is reviewed from a non group theoretical point of view. Composite field operators dimensions are computed in some simple models and related to conformal symmetry

  6. UVIS Flat Field Uniformity

    Science.gov (United States)

    Quijano, Jessica Kim

    2009-07-01

    The stability and uniformity of the low-frequency flat fields {L-flat} of the UVIS detector will be assessed by using multiple-pointing observations of the globular clusters 47 Tucanae {NGC104} and Omega Centauri {NGC5139}, thus imaging moderately dense stellar fields. By placing the same star over different portions of the detector and measuring relative changes in its brightness, it will be possible to determine local variations in the response of the UVIS detector. Based on previous experience with STIS and ACS, it is deemed that a total of 9 different pointings will suffice to provide adequate characterization of the flat field stability in any given band. For each filter to be tested, the baseline consists of 9 pointings in a 3X3 box pattern with dither steps of about 25% of the FOV, or 40.5", in either the x or y direction {useful also for CTE measurements, if needed in the future}. During SMOV, the complement of filters to be tested is limited to the following 6 filters: F225W, F275W, F336W, for Omega Cen, and F438W, F606W, and F814W for 47 Tuc. Three long exposures for each target are arranged such that the initial dither position is observed with the appropriate filters for that target within one orbit at a single pointing, so that filter-to-filter differences in the observed star positions can be checked. In addition to the 9 baseline exposures, two sets of short exposures will be taken:a} one short exposure will be taken of OmegaCen with each of the visible filters {F438W, F606W and F814W} in order to check the geometric distortion solution to be obtained with the data from proposal 11444;b} for each target, a single short exposure will be taken with each filter to facilitate the study of the PSF as a function of position on the detector by providing unsaturated images of sparsely-spaced bright stars.This proposal corresponds to Activity Description ID WF39. It should execute only after the following proposal has executed:WF21 - 11434

  7. Electron-Cloud Wake Fields

    CERN Document Server

    Rumolo, Giovanni

    2002-01-01

    The electron cloud gives rise to coherent and incoherent single-bunch wake fields, both in the longitudinal and in the transverse direction, and to coherent coupled-bunch wakes. These wake fields can be computed using the simulation programs ECLOUD and HEADTAIL developed at CERN. We present the wake fields simulated for the LHC beam in the CERN SPS and at injection into the LHC in different magnetic field configurations (field-free region, dipole, and solenoid), where the magnetic field affects both the elec-tron motion during a bunch passage and the overall electron distribution in the beam pipe.

  8. The Emerging Strategic Entrepreneurship Field

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Lyngsie, Jacob

    The field of strategic entrepreneurship is a fairly recent one. Its central idea is that opportunity-seeking and advantage-seeking — the former the central subject of the entrepreneurship field, the latter the central subject of the strategic management field — are processes that need...... to be considered jointly. The purpose of this brief chapter is to explain the emergence of SE theory field in terms of a response to research gaps in the neighboring fields of entrepreneurship and strategic management; describe the main tenets of SE theory; discuss its relations to neighboring fields; and finally...

  9. Magnetic fields in diffuse media

    CERN Document Server

    Pino, Elisabete; Melioli, Claudio

    2015-01-01

    This volume presents the current knowledge of magnetic fields in diffuse astrophysical media. Starting with an overview of 21st century instrumentation to observe astrophysical magnetic fields, the chapters cover observational techniques, origin of magnetic fields, magnetic turbulence, basic processes in magnetized fluids, the role of magnetic fields for cosmic rays, in the interstellar medium and for star formation. Written by a group of leading experts the book represents an excellent overview of the field. Nonspecialists will find sufficient background to enter the field and be able to appreciate the state of the art.

  10. Two field formulation of closed string field theory

    International Nuclear Information System (INIS)

    Bogojevic, A.R.

    1990-09-01

    A formulation of closed string field theory is presented that is based on a two field action. It represents a generalization of Witten's Chern-Simons formulation of 3d gravity. The action contains only 3 string interactions and no string field truncations, unlike the previous non-polynomial action of Zwiebach. The two field action is found to follow from a purely cubic, background independent action similar to the one for open strings. (orig.)

  11. Fractional Stochastic Field Theory

    Science.gov (United States)

    Honkonen, Juha

    2018-02-01

    Models describing evolution of physical, chemical, biological, social and financial processes are often formulated as differential equations with the understanding that they are large-scale equations for averages of quantities describing intrinsically random processes. Explicit account of randomness may lead to significant changes in the asymptotic behaviour (anomalous scaling) in such models especially in low spatial dimensions, which in many cases may be captured with the use of the renormalization group. Anomalous scaling and memory effects may also be introduced with the use of fractional derivatives and fractional noise. Construction of renormalized stochastic field theory with fractional derivatives and fractional noise in the underlying stochastic differential equations and master equations and the interplay between fluctuation-induced and built-in anomalous scaling behaviour is reviewed and discussed.

  12. Introduction to field theory

    CERN Multimedia

    CERN. Geneva; CERN. Geneva

    2001-01-01

    Starting from the notion of path integrals as developed by Feynman, we discuss field theory in zero spacetime dimensions. The concepts of perturbation expansions, connected amplitudes, Feynman diagrams, classical solutions, renormalization and the effective action are developed. The model is extended to four spacetime dimensions, and the full Feynman rules for relativisitc scalar theory derived. The S matrix and the concept of unitarity are discussed, leading to the amputation rules for S matrix elements from considerations of unitarity. The rules are extended to include particles with spin-1/2 and spin-1. The high-energy behaviour of the theory is discussed as a method to derive the gauge symmetry of the various models.

  13. High field electron linacs

    International Nuclear Information System (INIS)

    Le Duff, J.

    1985-12-01

    High field electron linacs are considered as potential candidates to provide very high energies beyond LEP. Since almost twenty years not much improvement has been made on linac technologies as they have been mostly kept at low and medium energies to be used as injectors for storage rings. Today, both their efficiency and their performances are being reconsidered, and for instance the pulse compression sheme developed at SLAC and introduced to upgrade the energy of that linac is a first step towards a new generation of linear accelerators. However this is not enough in terms of power consumption and more development is needed to improve both the efficiency of accelerating structures and the performances of RF power sources

  14. High field superconducting magnets

    Science.gov (United States)

    Hait, Thomas P. (Inventor); Shirron, Peter J. (Inventor)

    2011-01-01

    A superconducting magnet includes an insulating layer disposed about the surface of a mandrel; a superconducting wire wound in adjacent turns about the mandrel to form the superconducting magnet, wherein the superconducting wire is in thermal communication with the mandrel, and the superconducting magnet has a field-to-current ratio equal to or greater than 1.1 Tesla per Ampere; a thermally conductive potting material configured to fill interstices between the adjacent turns, wherein the thermally conductive potting material and the superconducting wire provide a path for dissipation of heat; and a voltage limiting device disposed across each end of the superconducting wire, wherein the voltage limiting device is configured to prevent a voltage excursion across the superconducting wire during quench of the superconducting magnet.

  15. Fast harmonic field mapper

    International Nuclear Information System (INIS)

    Au, R.; Fowler, M.; Hanawa, H.; Riedel, J.; Qua, Z.G.

    1984-01-01

    In early 1983 it was decided to mount coils on arms separated by 120 degrees and buck them out so that the third harmonic dphi/dt component would be cancelled and thus the first and second field harmonics could be very accurately measured. The original intention was to do as others had done, namely, use fast ADC's to read the voltages, and computer process the result to get the Fourier components. However, because of the 100 to 1 dynamic range of the fast ADC's and the likelihood that noise would be a problem, the authors decided to do things differently. Using a fast Fourier transform analyzer was considered, but this instrument is very expensive, so they decided to use a completely electronic analog approach: The authors decided to use active bandpass filters to render the harmonic components

  16. Conflict field energy

    International Nuclear Information System (INIS)

    Krebsbach-Gnath, C.

    1981-01-01

    Violent social controversies characterize the treatment of the energy problem. Solutions of this conflict decisively depend on the knowledge and evaluation of the causes and the possible development. How is it possible to explain the opinions, views, and the attitude of the population to different kinds of energy. Which factors are decisive for the explosive effect and the stability of the conflict in the field of nulcear energy. What will happen when there arises a possible lack of energy. Which socio-political effects will such a lack have. Are there new proposals for solving problems in the nulcear-energy debate. The contributions of this book are results of scientific and empiric works. They provide perceptive approaches and analyses to the problems and by discussing them are useful in giving an orientation for political action. (orig.) [de

  17. Field theory of strings

    International Nuclear Information System (INIS)

    Ramond, P.

    1987-01-01

    We review the construction of the free equations of motion for open and closed strings in 26 dimensions, using the methods of the Florida Group. Differing from previous treatments, we argue that the constraint L 0 -anti L 0 =0 should not be imposed on all the fields of the closed string in the gauge invariant formalism; we show that it can be incorporated in the gauge invariant formalism at the price of being unable to extract the equations of motion from a Langrangian. We then describe our purely algebraic method to introduce interactions, which works equally well for open and closed strings. Quartic interactions are absent except in the Physical Gauge. Finally, we speculate on the role of the measure of the open string path functional. (orig.)

  18. Gauge field models

    International Nuclear Information System (INIS)

    Becchi, C.; Rouet, A.; Stora, R.

    1975-10-01

    Stora's analysis is continued in discussing the nonabelian (Yang-Mills) gauge field models (G.F.M.). The gauge independence of the physical scattering operator is discussed in some details and the connection between its unitary and the Slavnov symmetry outlined. Only the models involving semisimple gauge groups are considered. This greatly simplifies the analysis of the possible quantum corrections to the Quantum Action Principle which is reduced to the study of the cohomology group of the Lie algebra characterizing the gauge theory. The discussion is at the classical level for the algebraic properties of the SU(2) Higgs-Kibble-Englert-Brout-Faddeev-Popov lagrangian and its invariance under Slavnov identity transformations is exhibited. The renormalization of the Slavnov identity in the G.M.F. involving semisimple gauge groups is studied. The unitary and gauge independence of the physical S operator in the SU(2) H.K. model is dealt with [fr

  19. Strong field laser physics

    CERN Document Server

    2008-01-01

    Since the invention of the laser in the 1960s, people have strived to reach higher intensities and shorter pulse durations. High intensities and ultrashort pulse durations are intimately related. Recent developments have shown that high intensity lasers also open the way to realize pulses with the shortest durations to date, giving birth to the field of attosecond science (1 asec = 10-18s). This book is about high-intensity lasers and their applications. The goal is to give an up to date introduction to the technology behind these laser systems and to the broad range of intense laser applications. These applications include AMO (atomic molecular and optical) physics, x-ray science, attosecond science, plasma physics and particle acceleration, condensed matter science and laser micromachining, and finally even high-energy physics.

  20. Asymmetrical field emitter

    Science.gov (United States)

    Fleming, J.G.; Smith, B.K.

    1995-10-10

    A method is disclosed for providing a field emitter with an asymmetrical emitter structure having a very sharp tip in close proximity to its gate. One preferred embodiment of the present invention includes an asymmetrical emitter and a gate. The emitter having a tip and a side is coupled to a substrate. The gate is connected to a step in the substrate. The step has a top surface and a side wall that is substantially parallel to the side of the emitter. The tip of the emitter is in close proximity to the gate. The emitter is at an emitter potential, and the gate is at a gate potential such that with the two potentials at appropriate values, electrons are emitted from the emitter. In one embodiment, the gate is separated from the emitter by an oxide layer, and the emitter is etched anisotropically to form its tip and its asymmetrical structure. 17 figs.

  1. A general field-covariant formulation of quantum field theory

    International Nuclear Information System (INIS)

    Anselmi, Damiano

    2013-01-01

    In all nontrivial cases renormalization, as it is usually formulated, is not a change of integration variables in the functional integral, plus parameter redefinitions, but a set of replacements, of actions and/or field variables and parameters. Because of this, we cannot write simple identities relating bare and renormalized generating functionals, or generating functionals before and after nonlinear changes of field variables. In this paper we investigate this issue and work out a general field-covariant approach to quantum field theory, which allows us to treat all perturbative changes of field variables, including the relation between bare and renormalized fields, as true changes of variables in the functional integral, under which the functionals Z and W=lnZ behave as scalars. We investigate the relation between composite fields and changes of field variables, and we show that, if J are the sources coupled to the elementary fields, all changes of field variables can be expressed as J-dependent redefinitions of the sources L coupled to the composite fields. We also work out the relation between the renormalization of variable-changes and the renormalization of composite fields. Using our transformation rules it is possible to derive the renormalization of a theory in a new variable frame from the renormalization in the old variable frame, without having to calculate it anew. We define several approaches, useful for different purposes, in particular a linear approach where all variable changes are described as linear source redefinitions. We include a number of explicit examples. (orig.)

  2. Chameleon field theories

    International Nuclear Information System (INIS)

    Khoury, Justin

    2013-01-01

    Chameleons are light scalar fields with remarkable properties. Through the interplay of self-interactions and coupling to matter, chameleon particles have a mass that depends on the ambient matter density. The manifestation of the fifth force mediated by chameleons therefore depends sensitively on their environment, which makes for a rich phenomenology. In this paper, we review two recent results on chameleon phenomenology. The first result a pair of no-go theorems limiting the cosmological impact of chameleons and their generalizations: (i) the range of the chameleon force at cosmological density today can be at most ∼Mpc; (ii) the conformal factor relating Einstein- and Jordan-frame scale factors is essentially constant over the last Hubble time. These theorems imply that chameleons have negligible effect on the linear growth of structure, and cannot account for the observed cosmic acceleration except as some form of dark energy. The second result pertains to the quantum stability of chameleon theories. We show how requiring that quantum corrections be small, so as to allow reliable predictions of fifth forces, leads to an upper bound of m −3 ) 1/3 eV for gravitational strength coupling, whereas fifth force experiments place a lower bound of m > 0.0042 eV. An improvement of less than a factor of 2 in the range of fifth force experiments could test all classical chameleon field theories whose quantum corrections are well-controlled and couple to matter with nearly gravitational strength regardless of the specific form of the chameleon potential. (paper)

  3. Field Audit Checklist Tool (FACT)

    Science.gov (United States)

    Download EPA's The Field Audit Checklist Tool (FACT). FACT is intended to help auditors perform field audits, to easily view monitoring plan, quality assurance and emissions data and provides access to data collected under MATS.

  4. Vacuum in intensive gauge fields

    International Nuclear Information System (INIS)

    Matinian, S.G.

    1977-12-01

    The behaviour of vacuum in a covariantly constant Yang-Mills field is considered. The expressions for the effective Lagrangian in an intensive field representing the asymptotic freedom of the theory are found

  5. Functional representations for quantized fields

    International Nuclear Information System (INIS)

    Jackiw, R.

    1988-01-01

    This paper provides information on Representing transformations in quantum theory bosonic quantum field theories: Schrodinger Picture; Represnting Transformations in Bosonic Quantum Field Theory; Two-Dimensional Conformal Transformations, Schrodinger picture representation, Fock space representation, Inequivalent Schrodinger picture representations; Discussion, Self-Dual and Other Models; Field Theory in de Sitter Space. Fermionic Quantum Field Theories: Schroedinger Picture; Schrodinger Picture Representation for Two-Dimensional; Conformal Transformations; Fock Space Dynamics in the Schrodinger Picture; Fock Space Evaluation of Anomalous Current and Conformal Commutators

  6. Geomagnetic Field During a Reversal

    Science.gov (United States)

    Heirtzler, J. R.

    2003-01-01

    It has frequently been suggested that only the geomagnetic dipole, rather than higher order poles, reverse during a geomagnetic field reversal. Under this assumption the geomagnetic field strength has been calculated for the surface of the Earth for various steps of the reversal process. Even without an eminent a reversal of the field, extrapolation of the present secular change (although problematic) shows that the field strength may become zero in some geographic areas within a few hundred years.

  7. TFTR magnetic field design analyses

    International Nuclear Information System (INIS)

    Davies, K.; Iwinski, E.; McWhirter, J.M.

    1975-11-01

    The three main magnetic field windings for the TFTR are the toroidal field (TF) windings, the ohmic heating (OH) winding, and the equilibrium field (EF) winding. The following information is provided for these windings: (1) descriptions, (2) functions, (3) magnetic designs, e.g., number and location of turns, (4) design methods, and (5) descriptions of resulting magnetic fields. This report does not deal with the thermal, mechanical support, or construction details of the windings

  8. Model of unified gauge fields

    International Nuclear Information System (INIS)

    Leite Lopes, J.

    1998-04-01

    In this work, we discuss the physical ideas which represents the basis for the unified gauge field model. Despite of the difficulties that we presently have for embodying in a natural manner muons and hadrons in that model, we have the feeling that we are on the way which seems to lead to the construction of a theory in which the Maxwell electromagnetic field and the Fermi weak interaction field are manifestations of a unique subjacent physical entity - the unified gauge fields. (author)

  9. Magnetic Field Topology in Jets

    Science.gov (United States)

    Gardiner, T. A.; Frank, A.

    2000-01-01

    We present results on the magnetic field topology in a pulsed radiative. jet. For initially helical magnetic fields and periodic velocity variations, we find that the magnetic field alternates along the, length of the jet from toroidally dominated in the knots to possibly poloidally dominated in the intervening regions.

  10. Quantization of fields with constraints

    Energy Technology Data Exchange (ETDEWEB)

    Gitman, D.M.; Tyutin, I.V.

    1990-01-01

    The quantization of singular field theories, in particular, gauge theories, is one of the key problems in quantum field theory. This book - which addresses the reader acquainted with the foundations of quantum field theory - provides a comprehensive analysis of this problem and techniques for its solution. The main topics are canonical and Lagrangian quantization and the path integral method. (orig.).

  11. High magnetic field MRI system

    International Nuclear Information System (INIS)

    Maeda, Hideaki; Urata, Masami; Satoh, Kozo

    1990-01-01

    A high field superconducting magnet, 4-5 T in central magnetic field, is required for magnetic resonance spectroscopic imaging (MRSI) on 31 P, essential nuclei for energy metabolism of human body. This paper reviews superconducting magnets for high field MRSI systems. Examples of the cross-sectional image and the spectrum of living animals are shown in the paper. (author)

  12. Field emission in RF cavities

    International Nuclear Information System (INIS)

    Bonin, B.

    1996-01-01

    Electron field emission limits the accelerating gradient in superconducting cavities. It is shown how and why it is an important problem. The phenomenology of field emission is then described, both in DC and RF regimes. Merits of a few plausible 'remedies' to field emission are discussed. (author)

  13. Estimation of Motion Vector Fields

    DEFF Research Database (Denmark)

    Larsen, Rasmus

    1993-01-01

    This paper presents an approach to the estimation of 2-D motion vector fields from time varying image sequences. We use a piecewise smooth model based on coupled vector/binary Markov random fields. We find the maximum a posteriori solution by simulated annealing. The algorithm generate sample...... fields by means of stochastic relaxation implemented via the Gibbs sampler....

  14. Electric fields in the magnetosphere

    International Nuclear Information System (INIS)

    Falthammar, C.G.

    1989-01-01

    Electric field measurements on the satellites GEOS-1, GEOS-2, ISEE-1, and Viking have extended the empirical knowledge of electric fields in space so as to include the outer regions of the magnetosphere. While the measurements confirm some of the theoretically expected properties of the electric fields, they also reveal unexpected features and a high degree of complexity and variability. The existence of a magnetospheric dawn-to-dusk electric field, as expected on the basis of extrapolation from low altitude measurements, is confirmed in an average sense. However, the actual field exhibits large spatial and temporal variations, including strong fields of inductive origin. At the magnetopause, the average (dawn-to-dusk directed) tangential electric field component is typically obscured by irregular fluctuations of larger amplitude. The magnetic-field aligned component of the electric field, which is of particular importance for ionosphere-magnetosphere coupling and for auroral acceleration, is even now very difficult to measure directly. However, the data from electric field measurements provide further support for the conclusion, based on a variety of evidence, that a non-vanishing magnetic-field aligned electric field exists in the auroral acceleration region

  15. Characteristic of Rings. Prime Fields

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph

    2015-12-01

    Full Text Available The notion of the characteristic of rings and its basic properties are formalized [14], [39], [20]. Classification of prime fields in terms of isomorphisms with appropriate fields (ℚ or ℤ/p are presented. To facilitate reasonings within the field of rational numbers, values of numerators and denominators of basic operations over rationals are computed.

  16. Low field magnetic resonance imaging

    Science.gov (United States)

    Pines, Alexander; Sakellariou, Dimitrios; Meriles, Carlos A.; Trabesinger, Andreas H.

    2010-07-13

    A method and system of magnetic resonance imaging does not need a large homogenous field to truncate a gradient field. Spatial information is encoded into the spin magnetization by allowing the magnetization to evolve in a non-truncated gradient field and inducing a set of 180 degree rotations prior to signal acquisition.

  17. Quantization of the Radiation Field

    Indian Academy of Sciences (India)

    field,quantization,Lamb shift. Avinash Khare ... actions as well as for theories beyond like grand unified theories. Further, the same ... cules as well as condensed matter physics, not to men- tion their ... of an electromagnetic field by a moving electron, and of the reaction of this field on the electron have not yet been touched.".

  18. Introduction to string field theory

    International Nuclear Information System (INIS)

    Horowitz, G.T.

    1989-01-01

    A light cone gauge superstring field theory is constructed. The BRST approach is described discussing generalizations to yield gauge invariant free superstring field theory and interacting theory for superstrings. The interaction term is explicitly expressed in terms of first quantized oscillators. A purily cubic action for superstring field theory is also derived. (author)

  19. Fields on a random lattice

    International Nuclear Information System (INIS)

    Itzykson, C.

    1983-10-01

    We review the formulation of field theory and statistical mechanics on a Poissonian random lattice. Topics discussed include random geometry, the construction of field equations for arbitrary spin, the free field spectrum and the question of localization illustrated in the one dimensional case

  20. Matching tomographic IMRT fields with static photon fields

    International Nuclear Information System (INIS)

    Sethi, A.; Leybovich, L.; Dogan, N.; Emami, B.

    2001-01-01

    The matching of abutting radiation fields presents a challenging problem in radiation therapy. Due to sharp penumbra of linear accelerator beams, small (1-2 mm) errors in field positioning can lead to large (>30%) hot or cold spots in the abutment region. With head and neck immobilization devices (thermoplastic mask/aquaplast) an average setup error of 3 mm has been reported. Therefore hot or cold spots approaching 50% of the prescription dose may occur along the matchline. Although abutting radiation fields have been investigated for static fields, there is no reported study regarding matching of tomographic IMRT and static fields. Compared to static fields, the matching of tomographic IMRT fields with static fields is more complicated. Since IMRT and static fields are planned on separate treatment planning computers, the dose in the abutment region is not specified. In addition, commonly used techniques for matching fields, such as feathering of junctions, are not practical. We have developed a method that substantially reduces dose inhomogeneity in the abutment region. In this method, a 'buffer zone' around the matchline was created and was included as part of the target for both IMRT and static field plans. In both fields, a small dose gradient (≤3%/mm) in the buffer zone was created. In the IMRT plan, the buffer zone was divided into three sections with dose varying from 83% to 25% of prescription dose. The static field dose profile was modified using either a specially designed physical (hard) or a dynamic (soft) wedge. When these modified fields were matched, the combined dose in the abutment region varied by ≤10% in the presence of setup errors spanning 4 mm (±2 mm) when the hard wedge was used and 10 mm (±5 mm) with the soft wedge

  1. Titan's Gravitational Field

    Science.gov (United States)

    Schubert, G.; Anderson, J. D.

    2013-12-01

    Titan's gravitational field is inferred from an analysis of archived radio Doppler data for six Cassini flybys. The analysis considers each flyby separately in contrast to the approach of lumping all the data together in a massive inversion. In this way it is possible to gain an improved understanding of the character of each flyby and its usefulness in constraining the gravitational coefficient C22 . Though our analysis is not yet complete and our final determination of C22 could differ from the result we report here by 1 or 2 sigma, we find a best-fit value of C22 equal to (13.21 × 0.17) × 10-6, significantly larger than the value of 10.0 × 10-6 obtained from an inversion of the lumped Cassini data. We also find no determination of the tidal Love number k2. The larger value of C22 implies a moment of inertia factor equal to 0.3819 × 0.0020 and a less differentiated Titan than is suggested by the smaller value. The larger value of C22 is consistent with an undifferentiated model of the satellite. While it is not possible to rule out either value of C22 , we prefer the larger value because its derivation results from a more hands on analysis of the data that extracts the weak hydrostatic signal while revealing the effects of gravity anomalies and unmodeled spacecraft accelerations on each of the six flybys.

  2. The North Field Development

    International Nuclear Information System (INIS)

    1993-01-01

    The Qatar Europe LNG Company's activities include gas production, gathering, treatment, liquefaction, shipping and marketing of Liquefied Natural Gas (LNG) and by-products. The (LNG) project to be developed by the Company shall be initially capable of processing 1200 mmscfd of raw gas and associated quantities of condensate from the North Field. Hydrocarbons produced will be delivered to shore in the industrial area (Ras Laffan) via a sub sea pipeline system. Raw gas is used as a feedstock into the liquefaction plant which is initially capable of producing 6.1 Million Tonnes Per Annum (MTPA) of (LNG). The initial quantity of (LNG) will be exported from (Ras Laffan) loading terminal to a receiving terminal located on the North East coast of Italy via a dedicated fleet of (LNG) carriers. The whole project (Upstream, Downstream and Shipping) shall be executed on an integrated scheme basis under the the direct control of the Qatar Europe LNG Company and in accordance with the overall Master Schedule in order to ensure a delivery of first shipment of (LNG) in the 2 nd half of 1997. 3 figs

  3. Superstring field theory

    International Nuclear Information System (INIS)

    Green, M.B.

    1984-01-01

    Superstring field theories are formulated in terms of light-cone-gauge superfields that are functionals of string coordinates chi(sigma) and theta(sigma). The formalism used preserves only the manifest SU(4) symmetry that corresponds to rotations among six of the eight transverse directions. In type I theories, which have one ten-dimensional supersymmetry and describe both open and closed strings, there are five interaction terms of two basic kinds. One kind is a breaking or joining interaction, which is a string generalization of a cubic Yang-Mills coupling. It is relevant to both the three open-string vertex and the open-string to closed-string transition vertex. The other kind is an exchange or crossing-over interaction, which is a string generalization of a cubic gravitational coupling. All the interactions can be uniquely determined by requiring continuity of the coordinates chi(sigma) and theta(sigma) (which implies local conservation of the conjugate momenta) and by imposing the global supersymmetry algebra. Specific local operators are identified for each of the two kinds of interactions. In type II theories, which have two ten-dimensional supersymmetries and contain closed strings only, the entire interaction hamiltonian consists of a single cubic vertex. The higher-order contact terms of the N=8 supergravity theory that arises in the low-energy limit give an effective description of the exchange of massive string modes. (orig.)

  4. Digestible quantum field theory

    CERN Document Server

    Smilga, Andrei

    2017-01-01

    This book gives an intermediate level treatment of quantum field theory, appropriate to a reader with a first degree in physics and a working knowledge of special relativity and quantum mechanics. It aims to give the reader some understanding of what QFT is all about, without delving deep into actual calculations of Feynman diagrams or similar. The author serves up a seven‐course menu, which begins with a brief introductory Aperitif. This is followed by the Hors d'oeuvres, which set the scene with a broad survey of the Universe, its theoretical description, and how the ideas of QFT developed during the last century. In the next course, the Art of Cooking, the author recaps on some basic facts of analytical mechanics, relativity, quantum mechanics and also presents some nutritious “extras” in mathematics (group theory at the elementary level) and in physics (theory of scattering). After these preparations, the reader should have a good appetite for the Entrées ‐ the central par t of the book where the...

  5. Logarithmic conformal field theory

    Science.gov (United States)

    Gainutdinov, Azat; Ridout, David; Runkel, Ingo

    2013-12-01

    Conformal field theory (CFT) has proven to be one of the richest and deepest subjects of modern theoretical and mathematical physics research, especially as regards statistical mechanics and string theory. It has also stimulated an enormous amount of activity in mathematics, shaping and building bridges between seemingly disparate fields through the study of vertex operator algebras, a (partial) axiomatisation of a chiral CFT. One can add to this that the successes of CFT, particularly when applied to statistical lattice models, have also served as an inspiration for mathematicians to develop entirely new fields: the Schramm-Loewner evolution and Smirnov's discrete complex analysis being notable examples. When the energy operator fails to be diagonalisable on the quantum state space, the CFT is said to be logarithmic. Consequently, a logarithmic CFT is one whose quantum space of states is constructed from a collection of representations which includes reducible but indecomposable ones. This qualifier arises because of the consequence that certain correlation functions will possess logarithmic singularities, something that contrasts with the familiar case of power law singularities. While such logarithmic singularities and reducible representations were noted by Rozansky and Saleur in their study of the U (1|1) Wess-Zumino-Witten model in 1992, the link between the non-diagonalisability of the energy operator and logarithmic singularities in correlators is usually ascribed to Gurarie's 1993 article (his paper also contains the first usage of the term 'logarithmic conformal field theory'). The class of CFTs that were under control at this time was quite small. In particular, an enormous amount of work from the statistical mechanics and string theory communities had produced a fairly detailed understanding of the (so-called) rational CFTs. However, physicists from both camps were well aware that applications from many diverse fields required significantly more

  6. Rydberg atoms in strong fields

    International Nuclear Information System (INIS)

    Kleppner, D.; Tsimmerman, M.

    1985-01-01

    Experimental and theoretical achievements in studying Rydberg atoms in external fields are considered. Only static (or quasistatic) fields and ''one-electron'' atoms, i.e. atoms that are well described by one-electron states, are discussed. Mainly behaviour of alkali metal atoms in electric field is considered. The state of theoretical investigations for hydrogen atom in magnetic field is described, but experimental data for atoms of alkali metals are presented as an illustration. Results of the latest experimental and theoretical investigations into the structure of Rydberg atoms in strong fields are presented

  7. Quantum electrodynamics of strong fields

    International Nuclear Information System (INIS)

    Greiner, W.

    1983-01-01

    Quantum Electrodynamics of Strong Fields provides a broad survey of the theoretical and experimental work accomplished, presenting papers by a group of international researchers who have made significant contributions to this developing area. Exploring the quantum theory of strong fields, the volume focuses on the phase transition to a charged vacuum in strong electric fields. The contributors also discuss such related topics as QED at short distances, precision tests of QED, nonperturbative QCD and confinement, pion condensation, and strong gravitational fields In addition, the volume features a historical paper on the roots of quantum field theory in the history of quantum physics by noted researcher Friedrich Hund

  8. Urban Fields in the making

    DEFF Research Database (Denmark)

    Hovgesen, Henrik Harder; Nielsen, Thomas Alexander Sick

    cities and accentuates the concept of the ?urban field? suggested by John Friedmann (1978). The concept of ?urban field? suggest that mobility has been democratizised and increased to a level where several cities can be part of the same functionally integrated urban field. As a consequence...... the significance of the single urban centre and the city as an entity will change markedly. This paper aims to analyse the development towards urban travel- and commuter fields in Denmark. The question asked is to what degree urban fields are emerging? ? And what is the speed of this development....

  9. Studies in quantum field theory

    International Nuclear Information System (INIS)

    Bender, C.M.; Mandula, J.E.; Shrauner, J.E.

    1982-01-01

    Washington University is currently conducting research in many areas of high energy theoretical and mathematical physics. These areas include: strong-coupling approximation; classical solutions of non-Abelian gauge theories; mean-field approximation in quantum field theory; path integral and coherent state representations in quantum field theory; lattice gauge calculations; the nature of perturbation theory in large orders; quark condensation in QCD; chiral symmetry breaking; the l/N expansion in quantum field theory; effective potential and action in quantum field theories, including QCD

  10. Topics in quantum field theory

    International Nuclear Information System (INIS)

    Svaiter, N.F.

    2006-11-01

    This paper presents some important aspects on quantum field theory, covering the following aspects: the triumph and limitations of the quantum field theory; the field theory in curved spaces - Hawking and Unruh-Davies effects; the problem of divergent theory of the zero-point; the problem of the spinning detector and the Trocheries-Takeno vacuum; the field theory at finite temperature - symmetry breaking and phase transition; the problem of the summability of the perturbative series and the perturbative expansion for the strong coupling; quantized fields in presence of classical macroscopic structures; the Parisi-Wu stochastic quantization method

  11. Field reversal in mirror machines

    International Nuclear Information System (INIS)

    Pearlstein, L.D.; Anderson, D.V.; Boozer, A.H.

    1978-01-01

    This report discusses some of the physics issues anticipated in field-reversed mirrors. The effect of current cancellation due to electrons is described. An estimate is made of the required impurity level to maintain a field-reversed configuration. The SUPERLAYER code is used to simulate the high-β 2XIIB results, and favorable comparisons require inclusion of quasilinear RF turbulence. Impact of a quadrupole field on field-line closure and resonant transport is discussed. A simple self-consistent model of ion currents is presented. Conditions for stability of field-reversed configurations to E x B driven rotations are determined

  12. EL DESARROLLO DE LA IDENTIDAD CORPORATIVA: FUNCIÓN INHERENTE DE LA GESTIÓN COMUNICACIONAL

    Directory of Open Access Journals (Sweden)

    Fanny Ramírez de Bermúdez

    2005-07-01

    Full Text Available In this work, the function of the communication management is characterized in the development of the corporate Identity. In order to accomplish that, the components of the corporate Identity were established, regarded the double nature of the Identity: (Emission - perception and the relation was identified among the level of solidity of the corporate identity with the behavior of the communication management. In the first analysis, the variables are explained theoretically established to develop a new offer; second is corroborated in the empirical plane the relation formulated as hypothetical supposition. As result, it was established, besides all three components widely explained by diverse authors: (the symbolism or audio-visual identity, the communication and the behavior, a fourth component: The basic organizational principles. One concludes that the maintenance of the identity is an inherent responsibility of a good communication management. The empirical corroboration demonstrates also, that the organizations that are characterized by a weak identity in some of its four components, they demonstrate weak or void communication management and in consequence they do not possess a solid identification. Definitively the communication, since fourth component has to be managed due to its complex nature, since it is generated from the basic principles and only it makes the emission of the same ones possible. It shows itself by means of the behavior organizational, the symbolism and the messages.

  13. Communication techniques and nuclear energy; Tecnicas de comunicacion y energia nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Carpintero Santamaria, N.

    2005-07-01

    The paper presents some thoughts on several factors related to nuclear energy and the way they are presented by the mass media, usually provoking controversy to the Spanish society and thus, undermining public acceptance. Some possibilities for boosting nuclear energy among public opinion are suggested, emphasizing the fact that nuclear power is essential because it is both ecologically and economically sound. (Author)

  14. External communication in environmental projects; La comunicacion externa en los proyectos ambientales

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Feltrer, C.

    2004-07-01

    The public's awareness of industrial projects is constantly growing. In addition, if such project imply any sort of environmental impact, their awareness increases and may result in a series of deterrents to the start-up of the said projects. The present article focuses on one of the most powerful of management tools through, at the same time, the one most often forgotten by companies: external communication. In the first part of the article, we shall analyse the reasons why many industrial projects never actually see the light of day. Starting from three working hypotheses, we came to the conclusion that we must be proactive in our communication if we wish our development to be durable and to last. In the second part, we put forward a method for planning communication aimed at first of all, foreseeing, and, ultimately, solving situations arising from the deterrents already mentioned. We have used a classical planning model from which to develop a specific application called Environmental Communication. (Author)

  15. Diseño hardware de una tarjeta de control y comunicaciones

    OpenAIRE

    Sánchez Salvador, David

    2017-01-01

    En la actualidad convivimos con infinidad de sistemas electrónicos, desde pequeños weareables como las pulseras inteligentes a grandes equipos como radares, pasando por equipos sin ningún tipo de lógica programada como una radio. Estos dispositivos electrónicos se desarrollan en base a un software generalmente, obviando la diferencia de complejidad según la aplicación, pero todos ellos se crean sobre un hardware. Dicho hardware puede ser una PCB sencilla con algunos componentes o un conjunto ...

  16. Do copyright à co-pirataria comunicacional da violência

    OpenAIRE

    Joron, Philippe

    2008-01-01

    A violência sempre se constituiu, para as ciências humanas e sociais, um tema privilegiado de investigação, mesmo que de modo indireto, considerando-se sua obstinação para potencialmente desviar o laço social de seus ideais de perfeição. Esta problemá tica sempre sofreu com uma concepção binária das coisas, como se a violência fosse exterior a este mesmo elo social, como se este último não se servisse, e mesmo não produzisse, a violência, para cumprir sua intenção de troca, de convivência, de...

  17. Alternativas eficientes para procesamiento y comunicaciones en sistemas de tiempo real

    OpenAIRE

    Romero, Fernando; Méndez, Mariano; Encinas, Diego; De Giusti, Armando Eduardo; Tinetti, Fernando Gustavo; Medina, Santiago; Pi Puig, Martín; Paniego, Juan Manuel; Dell'Oso, Matías

    2017-01-01

    El objetivo de esta línea de investigación es el estudio y desarrollo de Sistemas de Tiempo Real (STR), en particular, la planificación de tareas y la comunicación en Sistemas Distribuidos de Tiempo Real (SDTR), experimentando con microcontroladores y simulaciones para la adquisición y control de las variables del sistema.

  18. Ritual folklórico y representaciones colectivas. Modelo de Análisis Comunicacional

    Directory of Open Access Journals (Sweden)

    ANTONIO MUÑOZ CARRIÓN

    1986-01-01

    Full Text Available Se definen los materiales folclóricos de acuerdo a sus elementos constitutivos (acciones, personas, objetos, valores y normas; se atribuye a las funciones de cada elemento presente en el contexto de una celebración la determinación de relaciones constantes y variables. Se emplea un análisis estructural-formal para investigar el orden interno que rige el carnaval tradicional Ru, el cual se celebra anualmente en un pueblo de Galicia, en el noroeste de España. Se concluye que en el interior del carnaval mencionado, cuyo desarrollo es aparentemente caótico e incontrolable, existe una estructura aceptada de normas que lo condiciona y lo inmoviliza. Este repertorio de "normas carnavalísticas" opera como una sintaxis en los márgenes del significado que posee cada norma para el grupo y para el individuo. Esta perspectiva teórica rechaza aquellos enfoques que estudian los rituales folclóricos sólo en tanto que productos del sistema social; antes bien, los sistemas de reglas vigentes en el ritual merecen un estudio específico.

  19. Empoderamiento comunicacional: competencias narrativas de los sujetos Communicative Empowerment: Narrative Skills of the Subjects

    Directory of Open Access Journals (Sweden)

    Claudio Avendaño Ruz

    2011-03-01

    Full Text Available El presente trabajo analiza las consecuencias educomunicativas de las transformaciones en la comunicación mediada por el proceso de digitalización. Se presenta una constatación empírica de carácter cualitativo en el uso de los medios masivos y las tecnologías digitales desde la convergencia digital de los soportes, la industria y la consecuente complementariedad de los formatos. En este sentido la televisión ha vivido un proceso de cambios de sus continentes y contenidos expresivos, entre otros aspectos al entregar interactividad, facilita la expresión de los sujetos, desde los distintos dispositivos tecnológicos. Así a nivel de los sujetos se observa que los nuevos dispositivos tecnológicos y sus nuevas gramáticas son usados en la medida que asumen un sentido en sus prácticas cotidianas y trayectorias biográficas. No obstante, las políticas de inclusión digital solo se han centrado en la maximización del acceso a equipamiento y en una alfabetización digital asociada a aplicaciones y no a las competencias narrativas de los sujetos. Por tanto, es necesario generar nuevas conceptualizaciones que permitan nuevas orientaciones metodológicas formativas en comunicación y educación que promuevan el uso de los nuevos espacios digitales emergentes como ciudadanos empoderados comunicacionalmente, es decir, competentes para relatar (habilidades expresivas más específicamente relatarse (como individuo y relatarnos (colectivamente. Finalmente, estos serán los espacios expresivos de la nueva televisión con sus expresiones ciudadanas, propiciados por los elementos convergentes de la tecnología digital.This paper analyzes the educommunicational consequences of the transformations of mediated communication in the process of digitization. We present qualitative empirical evidence on the use of mass media and digital technologies from the digital convergence of media, the industry and the resulting complementary formats. Television, in particular, has experienced a process of changing its formats and expressive content by delivering interactivity, facilitating the expression of subjects by means of different technological devices. So from the perspective of the subject, it is observed that the new technological devices and their new grammars are utilized provided they contribute with meaning to his daily practice and biographical trajectory. Nevertheless, digital inclusion policies have focused only on maximizing access to equipment and digital literacy associated to technology applications and not to the narrative skills of the subjects. It is therefore necessary to generate new concepts that allow new methodological guidelines, in communication and education academic processes, to promote the use of new emerging digital spaces for communicational empowered citizens, that is, from competent to tell (expressive skills to more specifically, tell oneself (as an individual and tell us (collectively. Finally, these will be the expressive spaces of the new television with citizen´s expressions, fostered by converging elements of digital technology.

  20. Enlace de reconectadores a un sistema SCADA mediante una red de comunicaciones

    Directory of Open Access Journals (Sweden)

    Juan Ortega Castro

    2016-12-01

    Abstract The following paper details the link methodology from a communications network for the SCADA system at Azogues Power Company (EEA, starting from the need to implement electric reconnectors in the short and medium term; using automatic reconnectors OSM for their versatility and endurance when used outdoors, IEC 870 DNP3 communications protocols and ModBus for SCADA systems and remote terminal units. This way there is an improvement in the quality of the power supply service that is distributed in Azogues and its parishes. For this task, an implementation design of a communications network was done, in order to link the new reconnectors that were acquired by the company; setting a priority of the infrastructure and resources that it already had, achieving the placement of eight of these devices that were distributed in different areas of the city, using optic fiber in some cases and radio links in other situations when the network infrastructure didn’t allow the physical access to the facility; everything backed up with the correspondent technical and financial studies

  1. La centralidad en las comunicaciones y la influencia percibida en los pequeños grupos

    Directory of Open Access Journals (Sweden)

    Nancy Noemi Terroni

    Full Text Available Este trabajo reporta los resultados de medidas del análisis de redes en la comunicación de pequeños grupos que resuelven una tarea de recuperación de memoria y su asociación con la influencia percibida. El reactivo empleado es una historia y los 65 participantes, alumnos de la Universidad Nacional de Mar del Plata, debieron reconstruir la misma primero en forma individual, luego grupal colaborativa y nuevamente en forma individual. Se registraron las interacciones grupales con comunicación cara a cara y mediada por computadora; se analizaron las medidas de prominencia, la centralidad y el prestigio de la comunicación y el tipo de alocución, orientado a la gestión grupal o hacia la tarea. Se observaron asociaciones significativas entre las medidas reticulares y la influencia percibida para ambos medios de comunicación y se hallaron diferencias en la comunicación de gestión grupal. Se discuten estos resultados con relación a las restricciones que imponen los canales de comunicación mediados.

  2. EL PROBLEMA DE LA CIUDADANIA: UNA APROXIMACION DESDE EL CAMPO DE LA COMUNICACION-EDUCACION

    Directory of Open Access Journals (Sweden)

    Humberto J. Cubides C.

    1998-01-01

    Full Text Available Diversos autores en su análisis de la sociedad contemporánea intentan resignificar el concepto de ciudadanía para responder a la pregunta de cómo lograr en nuestras sociedades complejas idear una base común de solidaridad social, respetando el pluralismo. El autor, acogiendo el término de ciudadanía contestable, y a partir de la revisión de las teorías clásicas de ciudadanía (liberal, comunitarista y neorrepublicana respecto de los rasgos básicos que definen el concepto, realiza un abordaje novedoso y sugerente al tema desde las categorías en construcción del campo de comunicación-educación, campo que define como estratégico.

  3. Problemas psicologicos en la comunicacion lingüistica en el Perú

    Directory of Open Access Journals (Sweden)

    Raúl Gonzales Moreyra

    1983-06-01

    Full Text Available Sustentándose en una hipótesis socio-lingüística de Alberto Escobar sobre la existencia de siete formas dialectales del español en el Perú, sehan explorado siete grupos representativos de dichos dialectos en áreas psicolingüísticas relacionadas con la percepción y producción delhabla, la memoria, las asociaciones verbales, la lectura de la redundancia. El autor halló que a las formas dialectales corresponden procesos psicológicos estadísticamente diferenciados que muestran pérdidas en el tratamiento de la información proveniente de una fuente que se expresa en la norma culta limeña. Se discute, además de los aspectos comunicacionales y psicológicos,algunas implicancias sociales y pedagógicas de estos hechos.

  4. La Comunicacion (Communication). Latino Family Life Education Curriculum Series. Curriculum Unit [and] Student Workbook.

    Science.gov (United States)

    Chavez, Gene T.

    This 10-lesson curriculum unit provides teachers with some basic tools to help Latino students improve their communication skills. Primary goals are to help students analyze how a person's belief system affects the communication process, and to develop and improve decision-making and communication skills. The following key components are included…

  5. Linea abierta -- Comunicacion en Espanol. Edicion del maestro (Open Line -- Communication in Spanish. Teacher's Edition).

    Science.gov (United States)

    Dissemination and Assessment Center for Bilingual Education, Austin, TX.

    This teacher's guide corresponds to the text that is the first of a series of four units concerning language skills for Spanish speakers of limited English-speaking ability in grades 6-9. The text includes a variety of learning experiences designed to develop competence in the student's cognitive and affective skills derived from the following…

  6. Linea abierta -- Comunicacion en espanol. Nivel Uno (Open Line -- Communication in Spanish. Level One).

    Science.gov (United States)

    Dissemination and Assessment Center for Bilingual Education, Austin, TX.

    This text is the first of a series of four units concerning language skills for Spanish speakers of limited English-speaking ability in grades 6-9. The text includes a variety of learning experiences designed to develop competence in the student's cognitive and affective skills derived from the following basic areas: listening, speaking, reading,…

  7. COMUNICACION PRELIMINAR SOBRE EL EFECTO DEL MICROELEMENTO MOLIBDENO EN EL RINDE DEL ALGODONERO

    Directory of Open Access Journals (Sweden)

    Isidoro Mogilner

    1960-01-01

    Full Text Available Se trataron semillas de algodonero de la variedad Stoneville 2B, con soluciones de distinta concentración de (NH42 Mo O4, durante 24 horas, a dos temperaturas distintas. Tratadas las semillas se sembraron dos ensayos, cada uno con las 8 variantes y utilizando dos testigos (H20 destilada para la variante 1; Y H20 corriente para la variante 2.Los dos ensayos ocuparon un terreno contiguo y similar, cuyo suelo es arcilloso, relativamente pobre en Ca, muy pobre en P, y de una reacción ácida (pH de 5,09 a 5,85. Para los dos ensayos se utilizó la misma disposición experimental, con la diferencia de que el segundo ensayo se sembró con previo abonado de una mezcla comercial (Amino-Phos-Ko, 10-20-20; la siembra se efectuó en el mismo día. Se alcanzó a realizar tres cosechas. Los resultados obtenidos en el segundo ensayo (con abono no fueron tan válidos como en el primero (sin abono, porque no pudimos saber si el abono agregado contenía como impurezas el Mo, presente en muchas fuentes del fósforo utilizados en la preparación de abonos (ej.: fosforita. Del primer ensayo, en suelo no abonado, se extrajeron como conclusiones: 1 que en tipos de suelos como en el que se realizaron los ensayos, el suministro de dosis adecuadas de molibdeno incide satisfactoriamente sobre un aumento de los rindes del algodonero, tanto como de 300 Kgfha; 2 que aunque no podemos decir exactamente cual es la dosis óptima para el tratamiento de la semilla antes de la siembra, parecería que se encuentra entre 0,05 % y 0,02 % de molibdato de amonio; 3 que la temperatura a la que se realice el tratamiento de la semila, parece tener importancia; y en los ensayos realizados fueron superiores los rindes con el tratamiento a 30°C, que a 21°C.

  8. Comunicaciones romanas del ámbito provincial de Toledo en las antiguas fuentes itinerarias

    Directory of Open Access Journals (Sweden)

    Gregorio Carrasco Serrano

    1995-01-01

    Full Text Available Sin duda alguna uno de ios elementos más destacables en el fenómeno de la romanización, viene a estar representado por las vías de comunicación de ahí la cada vez mayor importancia y relieve que los estudios al respecto han llegado a adquirir últimamente. En la actualidad la investigación sobre vías de comunicación romanas, presenta una complejidad derivada de la conjunción de trabajos de tipo arqueológico, histórico-geográfico y filológico que necesariamente requieren. Partiendo de este hecho, nuestro propósito en el presente estudio ha consistido básicamente en analizar aquellas vías y sus respectivas mansiones del área territorial correspondiente al ámbito provincial de Toledo, constatadas en las fuentes antiguas itinerarias, punto de partida obligado en toda investigación sobre viaria romana, dejando aparte por tanto, aquellos trazados no citados en dichas fuentes.

  9. Um gênero comunicacional: os boatos e as lendas urbanas

    OpenAIRE

    Université Paul Valéry/Montpelier III, Jean-Bruno Renard - Université Paul Valé

    2008-01-01

    Neste artigo, o autor pontua que é preciso analisar o grau de um boato na sociedade e estudar os mecanismos de distorção de fatos ou informações factuais. Para ele, no entanto, é muito importante entender como e por que são espalhadas notícias falsas que passam a merecer crédito. Renard acredita que boatos e narrativas populares contemporâneas são os equivalentes modernos de lendas antigas ao expressarem um pensamento social ou simbólico.

  10. COMUNICACIONES, EDUCACIÓN y CULTURA (INTRODUCCIÓN AL TEMA

    Directory of Open Access Journals (Sweden)

    Amador Neghme R.

    1982-12-01

    Full Text Available

    Entre las estrategias que podrían proponerse, entre muchas otras, estarían las siguientes:


    1. Llevar a cabo a nivel de nuestros continentes una evaluación de las deficiencias y repercusiones sociales de los diversos medios de comunicación y establecer directrices y financiamientos que tiendan a modificar sus consecuencias negativas, favoreciendo la participación de los universitarios y de las intelectualidades nacionales.

    2. Impulsar las medidas de corrección y estimular la producción de programas educativos, especialmente acerca del aprendizaje innovador, que deberían ocupar, por lo menos, la tercera parte del tiempo de transmisión diaria en los horarios de mayor audiencia juvenil.

    3. A través de equipos multidisciplinarios de profesionales universitarios, que incluyan
    médicos, psiquiatras y psicólogos, educadores y sociólogos, investigar nuevos programas de televisión infantil y elaborar normas que sirvan de base para un código de conducta aplicable a la producción de programas para los niños.

    4. Establecer directrices precisas sobre distribución del tiempo destinado a los diferentes
    programas, de modo que se destine un tercio, por lo menos, a la educación; otro tercio, a
    programas culturales -producidos de preferencia en cada país- y el resto, a los entretenimientos, debidamente encuadrados en un contexto cultural y social, que favorezca el incremento de la indentidad nacional...

  11. Field Model: An Object-Oriented Data Model for Fields

    Science.gov (United States)

    Moran, Patrick J.

    2001-01-01

    We present an extensible, object-oriented data model designed for field data entitled Field Model (FM). FM objects can represent a wide variety of fields, including fields of arbitrary dimension and node type. FM can also handle time-series data. FM achieves generality through carefully selected topological primitives and through an implementation that leverages the potential of templated C++. FM supports fields where the nodes values are paired with any cell type. Thus FM can represent data where the field nodes are paired with the vertices ("vertex-centered" data), fields where the nodes are paired with the D-dimensional cells in R(sup D) (often called "cell-centered" data), as well as fields where nodes are paired with edges or other cell types. FM is designed to effectively handle very large data sets; in particular FM employs a demand-driven evaluation strategy that works especially well with large field data. Finally, the interfaces developed for FM have the potential to effectively abstract field data based on adaptive meshes. We present initial results with a triangular adaptive grid in R(sup 2) and discuss how the same design abstractions would work equally well with other adaptive-grid variations, including meshes in R(sup 3).

  12. Neural fields theory and applications

    CERN Document Server

    Graben, Peter; Potthast, Roland; Wright, James

    2014-01-01

    With this book, the editors present the first comprehensive collection in neural field studies, authored by leading scientists in the field - among them are two of the founding-fathers of neural field theory. Up to now, research results in the field have been disseminated across a number of distinct journals from mathematics, computational neuroscience, biophysics, cognitive science and others. Starting with a tutorial for novices in neural field studies, the book comprises chapters on emergent patterns, their phase transitions and evolution, on stochastic approaches, cortical development, cognition, robotics and computation, large-scale numerical simulations, the coupling of neural fields to the electroencephalogram and phase transitions in anesthesia. The intended readership are students and scientists in applied mathematics, theoretical physics, theoretical biology, and computational neuroscience. Neural field theory and its applications have a long-standing tradition in the mathematical and computational ...

  13. Error field considerations for BPX

    International Nuclear Information System (INIS)

    LaHaye, R.J.

    1992-01-01

    Irregularities in the position of poloidal and/or toroidal field coils in tokamaks produce resonant toroidal asymmetries in the vacuum magnetic fields. Otherwise stable tokamak discharges become non-linearly unstable to disruptive locked modes when subjected to low level error fields. Because of the field errors, magnetic islands are produced which would not otherwise occur in tearing mode table configurations; a concomitant reduction of the total confinement can result. Poloidal and toroidal asymmetries arise in the heat flux to the divertor target. In this paper, the field errors from perturbed BPX coils are used in a field line tracing code of the BPX equilibrium to study these deleterious effects. Limits on coil irregularities for device design and fabrication are computed along with possible correcting coils for reducing such field errors

  14. Chameleons with Field Dependent Couplings

    CERN Document Server

    Brax, Philippe; Mota, David F; Nunes, Nelson J; Winther, Hans A

    2010-01-01

    Certain scalar-tensor theories exhibit the so-called chameleon mechanism, whereby observational signatures of scalar fields are hidden by a combination of self-interactions and interactions with ambient matter. Not all scalar-tensor theories exhibit such a chameleon mechanism, which has been originally found in models with inverse power run-away potentials and field independent couplings to matter. In this paper we investigate field-theories with field-dependent couplings and a power-law potential for the scalar field. We show that the theory indeed is a chameleon field theory. We find the thin-shell solution for a spherical body and investigate the consequences for E\\"ot-Wash experiments, fifth-force searches and Casimir force experiments. Requiring that the scalar-field evades gravitational tests, we find that the coupling is sensitive to a mass-scale which is of order of the Hubble scale today.

  15. Hyperbolic-symmetry vector fields.

    Science.gov (United States)

    Gao, Xu-Zhen; Pan, Yue; Cai, Meng-Qiang; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian

    2015-12-14

    We present and construct a new kind of orthogonal coordinate system, hyperbolic coordinate system. We present and design a new kind of local linearly polarized vector fields, which is defined as the hyperbolic-symmetry vector fields because the points with the same polarization form a series of hyperbolae. We experimentally demonstrate the generation of such a kind of hyperbolic-symmetry vector optical fields. In particular, we also study the modified hyperbolic-symmetry vector optical fields with the twofold and fourfold symmetric states of polarization when introducing the mirror symmetry. The tight focusing behaviors of these vector fields are also investigated. In addition, we also fabricate micro-structures on the K9 glass surfaces by several tightly focused (modified) hyperbolic-symmetry vector fields patterns, which demonstrate that the simulated tightly focused fields are in good agreement with the fabricated micro-structures.

  16. ATLAS cavern magnetic field calculations

    International Nuclear Information System (INIS)

    Vorojtsov, S.B.; Vorozhtsov, A.S.; Butin, F.; Price, M.

    2000-01-01

    A new approach has been adopted in an attempt to produce a complete ATLAS cavern B-field map using a more precise methodological approach (variable magnetisation, depending on the external field) and the latest design taking into account of the structural elements. The basic idea was to produce a dedicated basic TOSCA model and then to insert a series of ferromagnetic structure elements to monitor the perturbative effect on the basic field map. Eventually, it was found: the bedplate field perturbation is an order of magnitude above the permissible level; manufacturing of the bedplates from nonmagnetic material or careful evaluation of their field contribution in the event reconstruction codes is required; the field value at the rack positions is higher than the permissible one; the final position of racks should be chosen taking into account the detailed magnetic field distribution

  17. The logarithmic conformal field theories

    International Nuclear Information System (INIS)

    Rahimi Tabar, M.R.; Aghamohammadi, A.; Khorrami, M.

    1997-01-01

    We study the correlation functions of logarithmic conformal field theories. First, assuming conformal invariance, we explicitly calculate two- and three-point functions. This calculation is done for the general case of more than one logarithmic field in a block, and more than one set of logarithmic fields. Then we show that one can regard the logarithmic field as a formal derivative of the ordinary field with respect to its conformal weight. This enables one to calculate any n-point function containing the logarithmic field in terms of ordinary n-point functions. Finally, we calculate the operator product expansion (OPE) coefficients of a logarithmic conformal field theory, and show that these can be obtained from the corresponding coefficients of ordinary conformal theory by a simple derivation. (orig.)

  18. The Swarm Initial Field Model for the 2014 Geomagnetic Field

    Science.gov (United States)

    Olsen, Nils; Hulot, Gauthier; Lesur, Vincent; Finlay, Christopher C.; Beggan, Ciaran; Chulliat, Arnaud; Sabaka, Terence J.; Floberghagen, Rune; Friis-Christensen, Eigil; Haagmans, Roger

    2015-01-01

    Data from the first year of ESA's Swarm constellation mission are used to derive the Swarm Initial Field Model (SIFM), a new model of the Earth's magnetic field and its time variation. In addition to the conventional magnetic field observations provided by each of the three Swarm satellites, explicit advantage is taken of the constellation aspect by including east-west magnetic intensity gradient information from the lower satellite pair. Along-track differences in magnetic intensity provide further information concerning the north-south gradient. The SIFM static field shows excellent agreement (up to at least degree 60) with recent field models derived from CHAMP data, providing an initial validation of the quality of the Swarm magnetic measurements. Use of gradient data improves the determination of both the static field and its secular variation, with the mean misfit for east-west intensity differences between the lower satellite pair being only 0.12 nT.

  19. Field Science--the Nature and Utility of Scientific Fields.

    Science.gov (United States)

    Casadevall, Arturo; Fang, Ferric C

    2015-09-08

    Fields are the fundamental sociological units of science. Despite their importance, relatively little has been written about their emergence, composition, structure, and function in the scientific enterprise. This essay considers the nature of fields and their important role in maintaining information and providing normative standards for scientific work. We suggest that fields arise naturally as a consequence of increasing information and scientific specialization. New fields tend to emerge as research communities grow, which may reflect biologically determined optima for the size of human groups. The benefits of fields include the organization of scientists with similar interests into communities that collectively define the next important problems to pursue. In the discipline of microbiology, fields are often organized on the basis of phylogenetic differences between microorganisms being studied. Although fields are essential to the proper functioning of science, their emergence can restrict access by outsiders and sustain dogmas that hinder progress. We suggest mechanisms to improve the functioning of scientific fields and to promote interdisciplinary interaction between fields. Copyright © 2015 Casadevall and Fang.

  20. The gravity field and GGOS

    DEFF Research Database (Denmark)

    Forsberg, René; Sideris, M.G.; Shum, C.K.

    2005-01-01

    The gravity field of the earth is a natural element of the Global Geodetic Observing System (GGOS). Gravity field quantities are like spatial geodetic observations of potential very high accuracy, with measurements, currently at part-per-billion (ppb) accuracy, but gravity field quantities are also...... unique as they can be globally represented by harmonic functions (long-wavelength geopotential model primarily from satellite gravity field missions), or based on point sampling (airborne and in situ absolute and superconducting gravimetry). From a GGOS global perspective, one of the main challenges...... is to ensure the consistency of the global and regional geopotential and geoid models, and the temporal changes of the gravity field at large spatial scales. The International Gravity Field Service, an umbrella "level-2" IAG service (incorporating the International Gravity Bureau, International Geoid Service...

  1. Introduction to gauge field theory

    International Nuclear Information System (INIS)

    Bailin, D.; Love, A.

    1986-01-01

    This book provides a postgraduate level introduction to gauge field theory entirely from a path integral standpoint without any reliance on the more traditional method of canonical quantisation. The ideas are developed by quantising the self-interacting scalar field theory, and are then used to deal with all the gauge field theories relevant to particle physics, quantum electrodynamics, quantum chromodynamics, electroweak theory, grand unified theories, and field theories at non-zero temperature. The use of these theories to make precise experimental predictions requires the development of the renormalised theories. This book provides a knowledge of relativistic quantum mechanics, but not of quantum field theory. The topics covered form a foundation for a knowledge of modern relativistic quantum field theory, providing a comprehensive coverage with emphasis on the details of actual calculations rather than the phenomenology of the applications

  2. Gauge invariant fractional electromagnetic fields

    International Nuclear Information System (INIS)

    Lazo, Matheus Jatkoske

    2011-01-01

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators. -- Highlights: → We propose a fractional Lagrangian formulation for fractional Maxwell's fields. → We obtain gauge invariant fractional electromagnetic fields. → Our generalized fractional Maxwell's field is spatially symmetrical. → We discuss the non-causality of the theory.

  3. Gauge invariant fractional electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Lazo, Matheus Jatkoske, E-mail: matheuslazo@furg.br [Instituto de Matematica, Estatistica e Fisica - FURG, Rio Grande, RS (Brazil)

    2011-09-26

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators. -- Highlights: → We propose a fractional Lagrangian formulation for fractional Maxwell's fields. → We obtain gauge invariant fractional electromagnetic fields. → Our generalized fractional Maxwell's field is spatially symmetrical. → We discuss the non-causality of the theory.

  4. Acoustic field modulation in regenerators

    Science.gov (United States)

    Hu, J. Y.; Wang, W.; Luo, E. C.; Chen, Y. Y.

    2016-12-01

    The regenerator is a key component that transfers energy between heat and work. The conversion efficiency is significantly influenced by the acoustic field in the regenerator. Much effort has been spent to quantitatively determine this influence, but few comprehensive experimental verifications have been performed because of difficulties in modulating and measuring the acoustic field. In this paper, a method requiring two compressors is introduced and theoretically investigated that achieves acoustic field modulation in the regenerator. One compressor outputs the acoustic power for the regenerator; the other acts as a phase shifter. A RC load dissipates the acoustic power out of both the regenerator and the latter compressor. The acoustic field can be modulated by adjusting the current in the two compressors and opening the RC load. The acoustic field is measured with pressure sensors instead of flow-field imaging equipment, thereby greatly simplifying the experiment.

  5. Local fields and their extensions

    CERN Document Server

    Fesenko, I B

    2002-01-01

    This book offers a modern presentation of local fields whose spectacular development was initiated almost one hundred years ago by K. Hensel. The volume consists of nine chapters divided into four parts: arithmetic properties of local fields, class field theory for various types of local fields and generalizations, explicit formulas for the Hilbert pairing, and Milnor K-groups of fields and of local fields. The first three parts essentially simplify, revise, and update the first edition. This second edition contains about sixty additional pages reflecting several aspects of the developments in local number theory in the last ten years. Exercises point to many other paths for exploration. The book is designed for graduate students and research mathematicians interested in local number theory and its applications in arithmetic algebraic geometry.

  6. Partially massless fields during inflation

    Science.gov (United States)

    Baumann, Daniel; Goon, Garrett; Lee, Hayden; Pimentel, Guilherme L.

    2018-04-01

    The representation theory of de Sitter space allows for a category of partially massless particles which have no flat space analog, but could have existed during inflation. We study the couplings of these exotic particles to inflationary perturbations and determine the resulting signatures in cosmological correlators. When inflationary perturbations interact through the exchange of these fields, their correlation functions inherit scalings that cannot be mimicked by extra massive fields. We discuss in detail the squeezed limit of the tensor-scalar-scalar bispectrum, and show that certain partially massless fields can violate the tensor consistency relation of single-field inflation. We also consider the collapsed limit of the scalar trispectrum, and find that the exchange of partially massless fields enhances its magnitude, while giving no contribution to the scalar bispectrum. These characteristic signatures provide clean detection channels for partially massless fields during inflation.

  7. Computers in field ion microscopy

    International Nuclear Information System (INIS)

    Suvorov, A.L.; Razinkova, T.L.; Sokolov, A.G.

    1980-01-01

    A review is presented of computer applications in field ion microscopy (FIM). The following topics are discussed in detail: (1) modeling field ion images in perfect crystals, (2) a general scheme of modeling, (3) modeling of the process of field evaporation, (4) crystal structure defects, (5) alloys, and (6) automation of FIM experiments and computer-assisted processing of real images. 146 references are given

  8. Mercury's magnetic field and interior

    International Nuclear Information System (INIS)

    Connerney, J.E.P.; Ness, N.F.

    1988-01-01

    The magnetic-field data collected on Mercury by the Mariner-10 spacecraft present substantial evidence for an intrinsic global magnetic field. However, studies of Mercury's thermal evolution show that it is most likely that the inner core region of Mercury solidified or froze early in the planet's history. Thus, the explanation of Mercury's magnetic field in the framework of the traditional planetary dynamo is less than certain

  9. In praise of quantum fields

    International Nuclear Information System (INIS)

    Shirkov, D.V.

    1989-08-01

    A comprehensive discussion of several topics vital for the structure of a modern Quantum Field Theory are discussed, namely: physical content of the notion of a Quantum Field; meaning of infinite renormalization; renormalizability as quantizability; the influence of several principles of quantum nature (quantizability, gauge dynamics, supersymmetry) on quantum fields dynamics; main trends of QFT evolution; present status of QFT and its frontier role in physics. (author). 15 refs, 1 fig

  10. The Emerging Field of Neuroepigenetics

    OpenAIRE

    Sweatt, J. David

    2013-01-01

    Over the past 25 years the broad field of epigenetics, and over the past decade in particular the emerging field of neuroepigenetics, have begun to have tremendous impact in the areas of learned behavior, neurotoxicology, CNS development, cognition, addiction, and psychopathology. However, epigenetics is such a new field that in most of these areas the impact is more in the category of fascinating implications as opposed to established facts. In this brief commentary I will attempt to address...

  11. Considerations on field problem structure

    International Nuclear Information System (INIS)

    Pavelescu, M.

    1977-01-01

    A survey of the three field problem types known today: equilibrium, eigen value and propagation problems is presented. The place occupied by neutron field in the nuclear reactor systems both statics and dynamics is shown. The special class of approximate solution method concerning the solving of field and boundary equations is analysed. The residual and variational method and the finite element method which presents a special interest are examined as well. (author)

  12. Quantum field theory of fluids.

    Science.gov (United States)

    Gripaios, Ben; Sutherland, Dave

    2015-02-20

    The quantum theory of fields is largely based on studying perturbations around noninteracting, or free, field theories, which correspond to a collection of quantum-mechanical harmonic oscillators. The quantum theory of an ordinary fluid is "freer", in the sense that the noninteracting theory also contains an infinite collection of quantum-mechanical free particles, corresponding to vortex modes. By computing a variety of correlation functions at tree and loop level, we give evidence that a quantum perfect fluid can be consistently formulated as a low-energy, effective field theory. We speculate that the quantum behavior is radically different from both classical fluids and quantum fields.

  13. Introduction to quantum field theory

    CERN Document Server

    Alvarez-Gaumé, Luís

    1994-01-01

    The purpose of this lecture is to review some elementary aspects of Quantum Field Theory. From the necessity to introduce quantum fields once quantum mechanics and special relativity are put together, to some of the basic practical computational tools in the subject, including the canonical quantization of simple field theories, the derivation of Feynman rules, computation of cross sections and decay rates, some introductory remarks on the treatment of unstable states and the possible realization of symmetries in a general field theory. The audience is required to have a working knowledge of quantum mechanics and special relativity and it would also be desirable to know the rudiments of relativistic quantum mechanics.

  14. Multiple fields in stochastic inflation

    Energy Technology Data Exchange (ETDEWEB)

    Assadullahi, Hooshyar [Institute of Cosmology & Gravitation, University of Portsmouth,Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom); Firouzjahi, Hassan [School of Astronomy, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Noorbala, Mahdiyar [Department of Physics, University of Tehran,P.O. Box 14395-547, Tehran (Iran, Islamic Republic of); School of Astronomy, Institute for Research in Fundamental Sciences (IPM),P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Vennin, Vincent; Wands, David [Institute of Cosmology & Gravitation, University of Portsmouth,Dennis Sciama Building, Burnaby Road, Portsmouth, PO1 3FX (United Kingdom)

    2016-06-24

    Stochastic effects in multi-field inflationary scenarios are investigated. A hierarchy of diffusion equations is derived, the solutions of which yield moments of the numbers of inflationary e-folds. Solving the resulting partial differential equations in multi-dimensional field space is more challenging than the single-field case. A few tractable examples are discussed, which show that the number of fields is, in general, a critical parameter. When more than two fields are present for instance, the probability to explore arbitrarily large-field regions of the potential, otherwise inaccessible to single-field dynamics, becomes non-zero. In some configurations, this gives rise to an infinite mean number of e-folds, regardless of the initial conditions. Another difference with respect to single-field scenarios is that multi-field stochastic effects can be large even at sub-Planckian energy. This opens interesting new possibilities for probing quantum effects in inflationary dynamics, since the moments of the numbers of e-folds can be used to calculate the distribution of primordial density perturbations in the stochastic-δN formalism.

  15. The Nonlinear Field Space Theory

    Energy Technology Data Exchange (ETDEWEB)

    Mielczarek, Jakub, E-mail: jakub.mielczarek@uj.edu.pl [Institute of Physics, Jagiellonian University, ul. Łojasiewicza 11, 30-348 Kraków (Poland); Trześniewski, Tomasz, E-mail: tbwbt@ift.uni.wroc.pl [Institute of Physics, Jagiellonian University, ul. Łojasiewicza 11, 30-348 Kraków (Poland); Institute for Theoretical Physics, University of Wrocław, pl. Borna 9, 50-204 Wrocław (Poland)

    2016-08-10

    In recent years the idea that not only the configuration space of particles, i.e. spacetime, but also the corresponding momentum space may have nontrivial geometry has attracted significant attention, especially in the context of quantum gravity. The aim of this letter is to extend this concept to the domain of field theories, by introducing field spaces (i.e. phase spaces of field values) that are not affine spaces. After discussing the motivation and general aspects of our approach we present a detailed analysis of the prototype (quantum) Nonlinear Field Space Theory of a scalar field on the Minkowski background. We show that the nonlinear structure of a field space leads to numerous interesting predictions, including: non-locality, generalization of the uncertainty relations, algebra deformations, constraining of the maximal occupation number, shifting of the vacuum energy and renormalization of the charge and speed of propagation of field excitations. Furthermore, a compact field space is a natural way to implement the “Principle of finiteness” of physical theories, which once motivated the Born–Infeld theory. Thus the presented framework has a variety of potential applications in the theories of fundamental interactions (e.g. quantum gravity), as well as in condensed matter physics (e.g. continuous spin chains), and can shed new light on the issue of divergences in quantum field theories.

  16. The Nonlinear Field Space Theory

    International Nuclear Information System (INIS)

    Mielczarek, Jakub; Trześniewski, Tomasz

    2016-01-01

    In recent years the idea that not only the configuration space of particles, i.e. spacetime, but also the corresponding momentum space may have nontrivial geometry has attracted significant attention, especially in the context of quantum gravity. The aim of this letter is to extend this concept to the domain of field theories, by introducing field spaces (i.e. phase spaces of field values) that are not affine spaces. After discussing the motivation and general aspects of our approach we present a detailed analysis of the prototype (quantum) Nonlinear Field Space Theory of a scalar field on the Minkowski background. We show that the nonlinear structure of a field space leads to numerous interesting predictions, including: non-locality, generalization of the uncertainty relations, algebra deformations, constraining of the maximal occupation number, shifting of the vacuum energy and renormalization of the charge and speed of propagation of field excitations. Furthermore, a compact field space is a natural way to implement the “Principle of finiteness” of physical theories, which once motivated the Born–Infeld theory. Thus the presented framework has a variety of potential applications in the theories of fundamental interactions (e.g. quantum gravity), as well as in condensed matter physics (e.g. continuous spin chains), and can shed new light on the issue of divergences in quantum field theories.

  17. Resonant helical fields in tokamaks

    International Nuclear Information System (INIS)

    Okano, V.

    1990-01-01

    Poincare maps of magnetic field lines of a toroidal helical system were made. The magnetic field is a linear superposition of the magnetic fields produced by a toroidal plasma in equilibrium and by external helical currents. Analytical expression for the Poincare maps was no obtained since the magnetic field do not have symmetry. In order to obtain the maps, the equation minus derivative of l vector times B vector = 0 was numerically integrated. In the Poincare maps, the principal and the secondary magnetic island were observed. (author)

  18. The Capacitive Magnetic Field Sensor

    Science.gov (United States)

    Zyatkov, D. O.; Yurchenko, A. V.; Balashov, V. B.; Yurchenko, V. I.

    2016-01-01

    The results of a study of sensitive element magnetic field sensor are represented in this paper. The sensor is based on the change of the capacitance with an active dielectric (ferrofluid) due to the magnitude of magnetic field. To prepare the ferrofluid magnetic particles are used, which have a followingdispersion equal to 50 brand 5BDSR. The dependence of the sensitivity of the capacitive element from the ferrofluid with different dispersion of magnetic particles is considered. The threshold of sensitivity and sensitivity of a measuring cell with ferrofluid by a magnetic field was determined. The experimental graphs of capacitance change of the magnitude of magnetic field are presented.

  19. K Basins Field Verification Program

    International Nuclear Information System (INIS)

    Booth, H.W.

    1994-01-01

    The Field Verification Program establishes a uniform and systematic process to ensure that technical information depicted on selected engineering drawings accurately reflects the actual existing physical configuration. This document defines the Field Verification Program necessary to perform the field walkdown and inspection process that identifies the physical configuration of the systems required to support the mission objectives of K Basins. This program is intended to provide an accurate accounting of the actual field configuration by documenting the as-found information on a controlled drawing

  20. Generalized field-transforming metamaterials

    International Nuclear Information System (INIS)

    Tretyakov, Sergei A; Nefedov, Igor S; Alitalo, Pekka

    2008-01-01

    In this paper, we introduce a generalized concept of field-transforming metamaterials, which perform field transformations defined as linear relations between the original and transformed fields. These artificial media change the fields in a prescribed fashion in the volume occupied by the medium. We show what electromagnetic properties of transforming medium are required. The coefficients of these linear functions can be arbitrary scalar functions of position and frequency, which makes the approach quite general and opens a possibility to realize various unusual devices.

  1. Field testing a soil site field guide for Allegheny hardwoods

    Science.gov (United States)

    S.B. Jones

    1991-01-01

    A site quality evaluation decision model, developed for Allegheny hardwoods on the non-glaciated Allegheny Plateau of Pennsylvania and New York, was field tested by International Paper (IP) foresters and the author, on sites within the region of derivation and on glaciated sites north and west of the Wisconsin drift line. Results from the field testing are presented...

  2. Towers of Function Fields over Non-prime Finite Fields

    DEFF Research Database (Denmark)

    Bassa, Alp; Beelen, Peter; Garcia, Arnaldo

    2015-01-01

    Over all non-prime finite fields, we construct some recursive towers of function fields with many rational places. Thus we obtain a substantial improvement on all known lower bounds for Ihara’s quantity A(ℓ), for ℓ = pn with p prime and n > 3 odd. We relate the explicit equations to Drinfeld modu...

  3. The Swarm Initial Field Model for the 2014 geomagnetic field

    DEFF Research Database (Denmark)

    Olsen, Nils; Hulot, Gauthier; Lesur, Vincent

    2015-01-01

    agreement (up to at least degree 60) with recent field models derived from CHAMP data, providing an initial validation of the quality of the Swarm magnetic measurements. Use of gradient data improves the determination of both the static field and its secular variation, with the mean misfit for East...

  4. Magnetic response to applied electrostatic field in external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, T.C. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, SP (Brazil); University of Florida, Department of Physics, Gainesville, FL (United States); Gitman, D.M. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, SP (Brazil); Tomsk State University, Department of Physics, Tomsk (Russian Federation); Shabad, A.E. [P. N. Lebedev Physics Institute, Moscow (Russian Federation)

    2014-04-15

    We show, within QED and other possible nonlinear theories, that a static charge localized in a finite domain of space becomes a magnetic dipole, if it is placed in an external (constant and homogeneous) magnetic field in the vacuum. The magnetic moment is quadratic in the charge, depends on its size and is parallel to the external field, provided the charge distribution is at least cylindrically symmetric. This magneto-electric effect is a nonlinear response of the magnetized vacuum to an applied electrostatic field. Referring to the simple example of a spherically symmetric applied field, the nonlinearly induced current and its magnetic field are found explicitly throughout the space; the pattern of the lines of force is depicted, both inside and outside the charge, which resembles that of a standard solenoid of classical magnetostatics. (orig.)

  5. Superconductivity in Strong Magnetic Field (Greater Than Upper Critical Field)

    International Nuclear Information System (INIS)

    Tessema, G.X.; Gamble, B.K.; Skove, M.J.; Lacerda, A.H.; Mielke, C.H.

    1998-01-01

    The National High Magnetic Field Laboratory, funded by the National Science Foundation and other US federal Agencies, has in recent years built a wide range of magnetic fields, DC 25 to 35 Tesla, short pulse 50 - 60 Tesla, and quasi-continuous 60 Tesla. Future plans are to push the frontiers to 45 Tesla DC and 70 to 100 Tesla pulse. This user facility, is open for national and international users, and creates an excellent tool for materials research (metals, semiconductors, superconductors, biological systems ..., etc). Here we present results of a systematic study of the upper critical field of a novel superconducting material which is considered a promising candidate for the search for superconductivity beyond H c2 as proposed by several new theories. These theories predict that superconductors with low carrier density can reenter the superconducting phase beyond the conventional upper critical field H c2 . This negates the conventional thinking that superconductivity and magnetic fields are antagonistic

  6. Field observations and lessons learned

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Joh B [Los Alamos National Laboratory

    2010-01-01

    This presentation outlines observations and lessons learned from the Megaports program. It provides: (1) details of field and technical observations collected during LANL field activities at ports around the world and details of observations collected during radiation detections system testing at Los Alamos National Laboratory; (2) provides suggestions for improvement and efficiency; and (3) discusses possible program execution changes for more effective operations.

  7. Depletion field focusing in semiconductors

    NARCIS (Netherlands)

    Prins, M.W.J.; Gelder, Van A.P.

    1996-01-01

    We calculate the three-dimensional depletion field profile in a semiconductor, for a planar semiconductor material with a spatially varying potential upon the surface, and for a tip-shaped semiconductor with a constant surface potential. The nonuniform electric field gives rise to focusing or

  8. Simplified Representation of Vector Fields

    NARCIS (Netherlands)

    Telea, Alexandru; Wijk, Jarke J. van

    1999-01-01

    Vector field visualization remains a difficult task. Although many local and global visualization methods for vector fields such as flow data exist, they usually require extensive user experience on setting the visualization parameters in order to produce images communicating the desired insight. We

  9. NMR in pulsed magnetic field

    KAUST Repository

    Abou-Hamad, Edy; Bontemps, P.; Rikken, Geert L J A

    2011-01-01

    Nuclear magnetic resonance (NMR) experiments in pulsed magnetic fields up to 30.4 T focused on 1H and 93Nb nuclei are reported. Here we discuss the advantage and limitation of pulsed field NMR and why this technique is able to become a promising research tool. © 2011 Elsevier Inc. All Rights Reserved.

  10. Bell inequalities for random fields

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, Peter [Physics Department, Yale University, CT 06520 (United States)

    2006-06-09

    The assumptions required for the derivation of Bell inequalities are not satisfied for random field models in which there are any thermal or quantum fluctuations, in contrast to the general satisfaction of the assumptions for classical two point particle models. Classical random field models that explicitly include the effects of quantum fluctuations on measurement are possible for experiments that violate Bell inequalities.

  11. Bell inequalities for random fields

    OpenAIRE

    Morgan, Peter

    2004-01-01

    The assumptions required for the derivation of Bell inequalities are not usually satisfied for random fields in which there are any thermal or quantum fluctuations, in contrast to the general satisfaction of the assumptions for classical two point particle models. Classical random field models that explicitly include the effects of quantum fluctuations on measurement are possible for experiments that violate Bell inequalities.

  12. Entendue invariance in speckle fields

    International Nuclear Information System (INIS)

    Medina, F.F.; Garcia-Sucerquia, J.; Henao, R.; Trivi, M.

    2000-04-01

    Experimental evidence is shown that confirms the Entendue invariance in speckle fields. Because of this condition, the coherence patch of the speckle field can be significantly greater than the mean size of the speckles, as is shown by double exposure speckle interferometry. (author)

  13. Low frequency electromagnetic field sensor

    International Nuclear Information System (INIS)

    Zhu Min; Zhou Yan; He Yicheng; Zheng Zhenxing; Liu Sunkun

    2000-01-01

    The measurement technique of low frequency electromagnetic field is reported. According to this principle, the authors have designed a sensor, which is used to measure the natural electromagnetic field, SLEMP and electromagnetic signals generated by some explosions. The frequency band of this sensor is from 0.08 Hz to 2 MHz

  14. Fast superconducting magnetic field switch

    Science.gov (United States)

    Goren, Yehuda; Mahale, Narayan K.

    1996-01-01

    The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles.

  15. Electric field gradients in metals

    International Nuclear Information System (INIS)

    Schatz, G.

    1979-01-01

    A review of the recent works on electric field gradient in metals is given. The main emphasis is put on the temperature dependence of the electric field gradient in nonmagnetic metals. Some methods of investigation of this effect using nuclear probes are described. One of them is nuclear accoustic resonance method. (S.B.)

  16. Particles, fields, and now strings

    International Nuclear Information System (INIS)

    Weinberg, S.

    1986-01-01

    The author traces the history of the struggle between two views of the world: a world of particles or a world of fields. These positions were crystallised as quantum field theory and S-matrix theory and now by the reintroduction of string theories. (Auth.)

  17. Interdisciplinary in the Information Field

    DEFF Research Database (Denmark)

    Madsen, Dorte

    2012-01-01

    Interdisciplinarity and its implications for developing a conceptual framework for the Information Field is discussed, and Zhang & Benjamin’s (2007) paper Understanding Information Related Fields: A Conceptual Framework is examined. It is argued that the fundamental components of a framework must...

  18. Visualizing the Computational Intelligence Field

    NARCIS (Netherlands)

    L. Waltman (Ludo); J.H. van den Berg (Jan); U. Kaymak (Uzay); N.J.P. van Eck (Nees Jan)

    2006-01-01

    textabstractIn this paper, we visualize the structure and the evolution of the computational intelligence (CI) field. Based on our visualizations, we analyze the way in which the CI field is divided into several subfields. The visualizations provide insight into the characteristics of each subfield

  19. Field Lab on the Rocks.

    Science.gov (United States)

    King, David T., Jr.; Abbott-King, Janet P.

    1985-01-01

    Advocates taking students on field trips to highway roadcuts to illustrate various geological principles. Photographs of three roadcuts (with sample objectives and questions/answers for students to answer) are included. Also included are suggestions for preparation, safety, and activities during such field trips. (DH)

  20. Visualization of induced electric fields

    NARCIS (Netherlands)

    Deursen, van A.P.J.

    2005-01-01

    A cylindrical electrolytic tank between a set of Helmholtz coils provides a classroom demonstration of induced, nonconservative electric fields. The field strength is measured by a sensor consisting of a pair of tiny spheres immersed in the liquid. The sensor signal depends on position, frequency,

  1. Review of WAG Field Experience

    DEFF Research Database (Denmark)

    Christensen, Jes Reimer; Stenby, Erling Halfdan; Skauge, A.

    2001-01-01

    well spacing is in the order of 1000 m. For the fields reviewed, a common trend for the successful injections is an increased oil recovery in the range of 5 to 10% of the oil initially in place (OIIP). Very few field trials have been reported as unsuccessful, but operational problems are often noted...

  2. Fast superconducting magnetic field switch

    International Nuclear Information System (INIS)

    Goren, Y.; Mahale, N.K.

    1996-01-01

    The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles. 6 figs

  3. Mean-field lattice trees

    NARCIS (Netherlands)

    Borgs, C.; Chayes, J.T.; Hofstad, van der R.W.; Slade, G.

    1999-01-01

    We introduce a mean-field model of lattice trees based on embeddings into d of abstract trees having a critical Poisson offspring distribution. This model provides a combinatorial interpretation for the self-consistent mean-field model introduced previously by Derbez and Slade [9], and provides an

  4. NMR in pulsed magnetic field

    KAUST Repository

    Abou-Hamad, Edy

    2011-09-01

    Nuclear magnetic resonance (NMR) experiments in pulsed magnetic fields up to 30.4 T focused on 1H and 93Nb nuclei are reported. Here we discuss the advantage and limitation of pulsed field NMR and why this technique is able to become a promising research tool. © 2011 Elsevier Inc. All Rights Reserved.

  5. Strings, fields and critical phenomena

    International Nuclear Information System (INIS)

    Ambjoern, J.

    1987-07-01

    The connection between field theory and critical phenomena is reviewed. Emphasis is put on the use of Monte Carlo methods in the study of non-perturbative aspects of field theory. String theory is then described as a statistical theory of random surfaces and the critical behaviour is analyzed both by analytical and numerical methods. (orig.)

  6. Massive Yang-Mills fields

    NARCIS (Netherlands)

    Veltman, M.J.G.; Reiff, J.

    1969-01-01

    Two problems are studied in the paper: (i) the relation between Lagrangian and Feynman rules if the Lagrangian contains derivative couplings and/or vector meson fields and (ii) the behaviour of certain two closed loop diagrams in the perturbation theory of Yang-Mills fields. With respect to ( i ) .

  7. Quantum theory of noncommutative fields

    International Nuclear Information System (INIS)

    Carmona, J.M.; Cortes, J.L.; Gamboa, J.; Mendez, F.

    2003-01-01

    Generalizing the noncommutative harmonic oscillator construction, we propose a new extension of quantum field theory based on the concept of 'noncommutative fields'. Our description permits to break the usual particle-antiparticle degeneracy at the dispersion relation level and introduces naturally an ultraviolet and an infrared cutoff. Phenomenological bounds for these new energy scales are given. (author)

  8. Optimal field splitting for large intensity-modulated fields

    International Nuclear Information System (INIS)

    Kamath, Srijit; Sahni, Sartaj; Ranka, Sanjay; Li, Jonathan; Palta, Jatinder

    2004-01-01

    The multileaf travel range limitations on some linear accelerators require the splitting of a large intensity-modulated field into two or more adjacent abutting intensity-modulated subfields. The abutting subfields are then delivered as separate treatment fields. This workaround not only increases the treatment delivery time but it also increases the total monitor units (MU) delivered to the patient for a given prescribed dose. It is imperative that the cumulative intensity map of the subfields is exactly the same as the intensity map of the large field generated by the dose optimization algorithm, while satisfying hardware constraints of the delivery system. In this work, we describe field splitting algorithms that split a large intensity-modulated field into two or more intensity-modulated subfields with and without feathering, with optimal MU efficiency while satisfying the hardware constraints. Compared to a field splitting technique (without feathering) used in a commercial planning system, our field splitting algorithm (without feathering) shows a decrease in total MU of up to 26% on clinical cases and up to 63% on synthetic cases

  9. ) Ima Field: A Type Marginal Field-Challenges and Prospects

    International Nuclear Information System (INIS)

    Afolabi, T. J.

    2003-01-01

    The IMA Field is located in the south-eastern Niger Delta in approximately 30' of water. Discovered in 1972 by Japan Petroleum, commercial accumulation was not established until 1994 by the AMNI/Abacan Joint Venture, with the drilling of ima-3 well, which discovered the major reservoirs in the C and D sands. Recoverable Reserve of 48MMBO. Ten wells have been drilled on the IMA structure to date, with a cumulative production of 16 Million barrels of condensates.The IMA Field is a typical Niger Delta rollover anticlinal structure trending northeast southwest with a regional tilt to the northeast. The major trapping mechanism is the anticline.The sediments of IMA Field are Miocene Agbada Fm. They are deltaic deposits with high sand/shale ratio. The reservoirs are loosely compacted sandstones with porosity values ranging from 21% to 27% while permeability is generally measured in darcies.The development of IMA Field posed financial and logistical challenges since the partners had decided to fast track this process, and since neither had the resources to drill the development wells, assemble/install the crude processing and storage facilities; a mixture of debt financing and contractor financing arrangements were made.The prospects in IMA Field are to be found in early realisation of the limitations of a marginal field, particularly the management of cash flow. Workers and field development funding is financed by current production. Appraisal and exploration drilling within the same lease have required equity financing (participation)

  10. Theory of interacting quantum fields

    International Nuclear Information System (INIS)

    Rebenko, Alexei L.

    2012-01-01

    This monograph is devoted to the systematic presentation of foundations of the quantum field theory. Unlike numerous monographs devoted to this topic, a wide range of problems covered in this book are accompanied by their sufficiently clear interpretations and applications. An important significant feature of this monograph is the desire of the author to present mathematical problems of the quantum field theory with regard to new methods of the constructive and Euclidean field theory that appeared in the last thirty years of the 20 th century and are based on the rigorous mathematical apparatus of functional analysis, the theory of operators, and the theory of generalized functions. The monograph is useful for students, post-graduate students, and young scientists who desire to understand not only the formality of construction of the quantum field theory but also its essence and connection with the classical mechanics, relativistic classical field theory, quantum mechanics, group theory, and the theory of path integral formalism.

  11. Naturality in conformal field theory

    International Nuclear Information System (INIS)

    Moore, G.; Seiberg, N.

    1989-01-01

    We discuss constraints on the operator product coefficients in diagonal and nondiagonal rational conformal field theories. Nondiagonal modular invariants always arise from automorphisms of the fusion rule algebra or from extensions of the chiral algebra. Moreover, when the chiral algebra has been maximally extended a strong form of the naturality principle of field theory can be proven for rational conformal field theory: operator product coefficients vanish if and only if the corresponding fusion rules vanish; that is, if and only if the vanishing can be understood in terms of a symmetry. We illustrate these ideas with several examples. We also generalize our ideas about rational conformal field theories to a larger class of theories: 'quasi-rational conformal field theories' and we explore some of their properties. (orig.)

  12. Magnetic field induced dynamical chaos.

    Science.gov (United States)

    Ray, Somrita; Baura, Alendu; Bag, Bidhan Chandra

    2013-12-01

    In this article, we have studied the dynamics of a particle having charge in the presence of a magnetic field. The motion of the particle is confined in the x-y plane under a two dimensional nonlinear potential. We have shown that constant magnetic field induced dynamical chaos is possible even for a force which is derived from a simple potential. For a given strength of the magnetic field, initial position, and velocity of the particle, the dynamics may be regular, but it may become chaotic when the field is time dependent. Chaotic dynamics is very often if the field is time dependent. Origin of chaos has been explored using the Hamiltonian function of the dynamics in terms of action and angle variables. Applicability of the present study has been discussed with a few examples.

  13. Plasma production via field ionization

    Directory of Open Access Journals (Sweden)

    C. L. O’Connell

    2006-10-01

    Full Text Available Plasma production via field ionization occurs when an incoming particle beam is sufficiently dense that the electric field associated with the beam ionizes a neutral vapor or gas. Experiments conducted at the Stanford Linear Accelerator Center explore the threshold conditions necessary to induce field ionization by an electron beam in a neutral lithium vapor. By independently varying the transverse beam size, number of electrons per bunch, or bunch length, the radial component of the electric field is controlled to be above or below the threshold for field ionization. Additional experiments ionized neutral xenon and neutral nitric oxide by varying the incoming beam’s bunch length. A self-ionized plasma is an essential step for the viability of plasma-based accelerators for future high-energy experiments.

  14. Ideal flux field dielectric concentrators.

    Science.gov (United States)

    García-Botella, Angel

    2011-10-01

    The concept of the vector flux field was first introduced as a photometrical theory and later developed in the field of nonimaging optics; it has provided new perspectives in the design of concentrators, overcoming standard ray tracing techniques. The flux field method has shown that reflective concentrators with the geometry of the field lines achieve the theoretical limit of concentration. In this paper we study the role of surfaces orthogonal to the field vector J. For rotationally symmetric systems J is orthogonal to its curl, and then a family of surfaces orthogonal to the lines of J exists, which can be called the family of surfaces of constant pseudopotential. Using the concept of the flux tube, it is possible to demonstrate that refractive concentrators with the shape of these pseudopotential surfaces achieve the theoretical limit of concentration.

  15. Blockspin transformations for finite temperature field theories with gauge fields

    International Nuclear Information System (INIS)

    Kerres, U.

    1996-08-01

    A procedure is proposed to study quantum field theories at zero or at finite temperature by a sequence of real space renormalization group (RG) or blockspin transformations. They transform to effective theories on coarser and coarser lattices. The ultimate aim is to compute constraint effective potentials, i.e. the free energy as a function of suitable order parameters. From the free energy one can read off the thermodynamic behaviour of the theory, in particular the existence and nature of phase transitions. In a finite temperature field theory one begins with either one or a sequence of transformations which transform the original theory into an effective theory on a three-dimensional lattice. Its effective action has temperature dependent coefficients. Thereafter one may proceed with further blockspin transformations of the three-dimensional theory. Assuming a finite volume, this can in principle be continued until one ends with a lattice with a single site. Its effective action is the constraint effective potential. In each RG-step, an integral over the high frequency part of the field, also called the fluctuation field, has to be performed. This is done by perturbation theory. It requires the knowledge of bare fluctuation field propagators and of interpolation operators which enter into the vertices. A detailed examination of these quantities is presented for scalar fields, abelian gauge fields and for Higgs fields, finite temperature is admitted. The lattice perturbation theory is complicated because the bare lattice propagators are complicated. This is due to a partial loss of translation invariance in each step. Therefore the use of translation invariant cutoffs in place of a lattice is also discussed. In case of gauge fields this is only possible as a continuum version of the blockspin method. (orig.)

  16. Working in the magnetic field of ultrahigh field MRI

    International Nuclear Information System (INIS)

    Leitgeb, N.; Gombotz, H.

    2013-01-01

    Development of magnetic resonance imaging (MRI) device technology continues to increase the static magnetic flux densities applied and consequently leads to considerably increased occupational exposure. This has already made it necessary to review limits of occupational exposure and to postpone European legal regulations for occupational exposure to electromagnetic fields. This raises the question whether and if so which adverse health effects and health risks might be associated with occupational exposure to MRI ultra-high static magnetic fields. Based on a survey on interaction mechanisms recommendations and safety rules are presented to help minimize adverse health effects of emerging ultra-high field MRI. (orig.) [de

  17. Quantized Dirac field interacting with a classical Maxwell field

    International Nuclear Information System (INIS)

    Kolsrud, M.

    1987-10-01

    The S operator for the quantized and the s matrix for the unquantized Dirac field, both fields interacting with an unquantized Maxwell field, are shown to be related in the following way: S=exp(-ic†kc) and s=exp(-ik). Here c is the column matrix of the particle operators, and k is a Hermitian matrix. With splitting of c into an electron and a positron part, a corresponding factorization of S is performed. Exact expressions for the probability amplitude for various electron and/or positron processes are then obtained

  18. Thermo field dynamics: a quantum field theory at finite temperature

    International Nuclear Information System (INIS)

    Mancini, F.; Marinaro, M.; Matsumoto, H.

    1988-01-01

    A brief review of the theory of thermo field dynamics (TFD) is presented. TFD is introduced and developed by Umezawa and his coworkers at finite temperature. The most significant concept in TFD is that of a thermal vacuum which satisfies some conditions denoted as thermal state conditions. The TFD permits to reformulate theories at finite temperature. There is no need in an additional principle to determine particle distributions at T ≠ 0. Temperature and other macroscopic parameters are introduced in the definition of the vacuum state. All operator formalisms used in quantum field theory at T=0 are preserved, although the field degrees of freedom are doubled. 8 refs

  19. Black holes, magnetic fields and particle creation. [Quantum field theory

    Energy Technology Data Exchange (ETDEWEB)

    Gibbons, G W [Cambridge Univ. (UK). Dept. of Applied Mathematics and Theoretical Physics

    1976-10-01

    Wald has given a classical argument suggesting that a rotating black hole immersed in a uniform magnetic field B will acquire a charge Q = 2JB where J is the angular momentum of the hole. The note contains a quantum field theoretic treatment of this process. For fields B greater than B/sub 0/ = 4 x 10/sup 13/ G the black hole will rapidly emit charged particles to achieve the equilibrium value. If B is less than the critical value the charge will remain zero.

  20. Quantized fields in interaction with external fields. Pt. 1

    International Nuclear Information System (INIS)

    Bellissard, J.

    1975-01-01

    We consider a massive, charged, scalar quantized field interacting with an external classical field. Guided by renormalized perturbation theory we show that whenever the integral equations defining the Feynman or retarded or advanced interaction kernel possess non perturbative solutions, there exists an S-operator which satisfies, up to a phase, the axioms of Bogoliubov, and is given for small external fields by a power series which converges on coherent states. Furthermore this construction is shown to be equivalent to the one based on the Yang-Kaellen-Feldman equation. This is a consequence of the relations between chronological and retarded Green's functions which are described in detail. (orig.) [de

  1. Dynamical Mean Field Approximation Applied to Quantum Field Theory

    CERN Document Server

    Akerlund, Oscar; Georges, Antoine; Werner, Philipp

    2013-12-04

    We apply the Dynamical Mean Field (DMFT) approximation to the real, scalar phi^4 quantum field theory. By comparing to lattice Monte Carlo calculations, perturbation theory and standard mean field theory, we test the quality of the approximation in two, three, four and five dimensions. The quantities considered in these tests are the critical coupling for the transition to the ordered phase and the associated critical exponents nu and beta. We also map out the phase diagram in four dimensions. In two and three dimensions, DMFT incorrectly predicts a first order phase transition for all bare quartic couplings, which is problematic, because the second order nature of the phase transition of lattice phi^4-theory is crucial for taking the continuum limit. Nevertheless, by extrapolating the behaviour away from the phase transition, one can obtain critical couplings and critical exponents. They differ from those of mean field theory and are much closer to the correct values. In four dimensions the transition is sec...

  2. Detection of electric field around field-reversed configuration plasma

    International Nuclear Information System (INIS)

    Ikeyama, Taeko; Hiroi, Masanori; Nogi, Yasuyuki; Ohkuma, Yasunori

    2010-01-01

    Electric-field probes consisting of copper plates are developed to measure electric fields in a vacuum region around a plasma. The probes detect oscillating electric fields with a maximum strength of approximately 100 V/m through a discharge. Reproducible signals from the probes are obtained with an unstable phase dominated by a rotational instability. It is found that the azimuthal structure of the electric field can be explained by the sum of an n=2 mode charge distribution and a convex-surface electron distribution on the deformed separatrix at the unstable phase. The former distribution agrees with that anticipated from the diamagnetic drift motions of plasma when the rotational instability occurs. The latter distribution suggests that an electron-rich plasma covers the separatrix.

  3. Effective theories of single field inflation when heavy fields matter

    CERN Document Server

    Achucarro, Ana; Hardeman, Sjoerd; Palma, Gonzalo A; Patil, Subodh P

    2012-01-01

    We compute the low energy effective field theory (EFT) expansion for single-field inflationary models that descend from a parent theory containing multiple other scalar fields. By assuming that all other degrees of freedom in the parent theory are sufficiently massive relative to the inflaton, it is possible to derive an EFT valid to arbitrary order in perturbations, provided certain generalized adiabaticity conditions are respected. These conditions permit a consistent low energy EFT description even when the inflaton deviates off its adiabatic minimum along its slowly rolling trajectory. By generalizing the formalism that identifies the adiabatic mode with the Goldstone boson of this spontaneously broken time translational symmetry prior to the integration of the heavy fields, we show that this invariance of the parent theory dictates the entire non-perturbative structure of the descendent EFT. The couplings of this theory can be written entirely in terms of the reduced speed of sound of adiabatic perturbat...

  4. Magnetic field effects in proteins

    Science.gov (United States)

    Jones, Alex R.

    2016-06-01

    Many animals can sense the geomagnetic field, which appears to aid in behaviours such as migration. The influence of man-made magnetic fields on biology, however, is potentially more sinister, with adverse health effects being claimed from exposure to fields from mobile phones or high voltage power lines. Do these phenomena have a common, biophysical origin, and is it even plausible that such weak fields can profoundly impact noisy biological systems? Radical pair intermediates are widespread in protein reaction mechanisms, and the radical pair mechanism has risen to prominence as perhaps the most plausible means by which even very weak fields might impact biology. In this New Views article, I will discuss the literature over the past 40 years that has investigated the topic of magnetic field effects in proteins. The lack of reproducible results has cast a shadow over the area. However, magnetic field and spin effects have proven to be useful mechanistic tools for radical mechanism in biology. Moreover, if a magnetic effect on a radical pair mechanism in a protein were to influence a biological system, the conditions necessary for it to do so appear increasing unlikely to have come about by chance.

  5. Stable piecewise polynomial vector fields

    Directory of Open Access Journals (Sweden)

    Claudio Pessoa

    2012-09-01

    Full Text Available Let $N={y>0}$ and $S={y<0}$ be the semi-planes of $mathbb{R}^2$ having as common boundary the line $D={y=0}$. Let $X$ and $Y$ be polynomial vector fields defined in $N$ and $S$, respectively, leading to a discontinuous piecewise polynomial vector field $Z=(X,Y$. This work pursues the stability and the transition analysis of solutions of $Z$ between $N$ and $S$, started by Filippov (1988 and Kozlova (1984 and reformulated by Sotomayor-Teixeira (1995 in terms of the regularization method. This method consists in analyzing a one parameter family of continuous vector fields $Z_{epsilon}$, defined by averaging $X$ and $Y$. This family approaches $Z$ when the parameter goes to zero. The results of Sotomayor-Teixeira and Sotomayor-Machado (2002 providing conditions on $(X,Y$ for the regularized vector fields to be structurally stable on planar compact connected regions are extended to discontinuous piecewise polynomial vector fields on $mathbb{R}^2$. Pertinent genericity results for vector fields satisfying the above stability conditions are also extended to the present case. A procedure for the study of discontinuous piecewise vector fields at infinity through a compactification is proposed here.

  6. Quality of radiation field imaging

    International Nuclear Information System (INIS)

    Petr, I.

    1988-01-01

    The questions were studied of the quality of imaging the gamma radiation field and of the limits of the quality in directional detector scanning. A resolution angle was introduced to quantify the imaging quality, and its relation was sought with the detection effective half-angle of the directional detector. The resolution angle was defined for the simplest configuration of the radiation field consisting of two monoenergetic gamma beams in one plane. It was shown that the resolution angle decreases, i.e., resolution in imaging the radiation field is better, with the effective half-angle of the directional detector. It was also found that resolution of both gamma beams deteriorated when the beams were surrounded with an isotropic background field. If the beams are surrounded with a background field showing general distribution, the angle size will be affected not only by the properties of the detector but also by the distribution of the ambient radiation field and the method of its scanning. The method described can be applied in designing a directional detector necessary for imaging the presumed radiation field in the required quality. (Z.M.). 4 figs., 3 refs

  7. Electric fields in the magnetosphere

    International Nuclear Information System (INIS)

    Faelthammar, C.G.

    1989-12-01

    The electric field plays an important role in the complex plasma system called the magnetosphere. In spite of this, direct measurement of this quantity are still scarce except in its lowest-altitude part, i.e. the ionosphere. The large scale ionospheric electric field has been determined from measurement on the ground and in low satellite orbit. For most of the magnetosphere, our concepts of the electric field have mostly been based on theoretical considerations and extrapolations of the ionspheric electric field. Direct, in situ, electric field measurements in the outer parts of the magnetosphere have been made only relatively recently. A few satellite missions. most recently the Viking mission, have extended the direct empirical knowledge so as to include major parts of the magnetosphere. These measurements have revealed a number of unexpected features. The actual electric field has been found to have unexpectedly strong space and time variations, which reflect the dynamic nature of the system. Examples are give of measured electric fields in the plasmasphere, the plasmasheet, the neutral sheet, the magnetotail, the flanks of the magnetosphere, the dayside magnetopause and the auroral acceleration region. (author)

  8. Free bosonic string field theory without supplementary fields

    International Nuclear Information System (INIS)

    Embacher, F.

    1987-01-01

    A covariant local action for free bosonic string fields is constructed without the use of supplementary fields. The open string case is treated in detail. Up to a mathematical conjecture which is likely to hold it is shown that the Virasoro constraints arise as a special choice of gauge. The kinetic operator turns out to be extremely simple, the gauge transformation law arising rather implicitly. The case of closed strings is briefly discussed. 25 refs. (Author)

  9. Field electron emission spectrometer combined with field ion/electron microscope as a field emission laboratory

    International Nuclear Information System (INIS)

    Shkuratov, S.I.; Ivanov, S.N.; Shilimanov, S.N.

    1996-01-01

    The facility, combining the field ion microscope, field electron emission microscope and field electron emission spectrometer, is described. Combination of three methodologies makes it possible to carry out the complete cycle of emission studies. Atom-plane and clean surface of the studied samples is prepared by means of field evaporation of the material atom layers without any thermal and radiation impact. This enables the study of atom and electron structure of clean surface of the wide range materials, the study whereof through the field emission methods was previously rather difficult. The temperature of the samples under study changes from 75 up to 2500 K. The energy resolution of the electron analyzer equals 30 MeV. 19 refs., 10 figs

  10. MAGNETIC FIELD MEASUREMENTS FOR FAST-CHANGING MAGNETIC FIELDS

    International Nuclear Information System (INIS)

    2004-01-01

    Several recent applications for fast ramped magnets have been found that require rapid measurement of the field quality during the ramp. (In one instance, accelerator dipoles will be ramped at 1 T/sec, with measurements needed to the accuracy typically required for accelerators.) We have built and tested a new type of magnetic field measuring system to meet this need. The system consists of 16 stationary pickup windings mounted on a cylinder. The signals induced in the windings in a changing magnetic field are sampled and analyzed to obtain the field harmonics. To minimize costs, printed circuit boards were used for the pickup windings and a combination of amplifiers and ADPs used for the voltage readout system. New software was developed for the analysis. Magnetic field measurements of a model dipole developed for the SIS200 accelerator at GSI are presented. The measurements are needed to insure that eddy currents induced by the fast ramps do not impact the field quality needed for successful accelerator operation

  11. Impact of local electrostatic field rearrangement on field ionization

    Science.gov (United States)

    Katnagallu, Shyam; Dagan, Michal; Parviainen, Stefan; Nematollahi, Ali; Grabowski, Blazej; Bagot, Paul A. J.; Rolland, Nicolas; Neugebauer, Jörg; Raabe, Dierk; Vurpillot, François; Moody, Michael P.; Gault, Baptiste

    2018-03-01

    Field ion microscopy allows for direct imaging of surfaces with true atomic resolution. The high charge density distribution on the surface generates an intense electric field that can induce ionization of gas atoms. We investigate the dynamic nature of the charge and the consequent electrostatic field redistribution following the departure of atoms initially constituting the surface in the form of an ion, a process known as field evaporation. We report on a new algorithm for image processing and tracking of individual atoms on the specimen surface enabling quantitative assessment of shifts in the imaged atomic positions. By combining experimental investigations with molecular dynamics simulations, which include the full electric charge, we confirm that change is directly associated with the rearrangement of the electrostatic field that modifies the imaging gas ionization zone. We derive important considerations for future developments of data reconstruction in 3D field ion microscopy, in particular for precise quantification of lattice strains and characterization of crystalline defects at the atomic scale.

  12. Twisted condensates of quantized fields

    International Nuclear Information System (INIS)

    Gallone, F.; Sparzani, A.; Ubertone, G.; Streater, R.F.

    We construct some quasi-free pure states of free quantized fields in 1+1 dimensions, that are localized in the sense of Knight. We consider massless or massive Dirac fields forming a U(n), n >= 1, multiplet and subject it to a local gauge transformation. We also subject a doublet of massive Klein-Gordon fields to local SO(2) transformations. We find the conditions that the resulting automorphism is spatial in Fock space. In some cases the conditions turn out to require that certain parameters, identified as the winding numbers of the gauge, are integers. It is argued that this integer labels states of various charge. (orig.)

  13. Magnetic fields and scintillator performance

    International Nuclear Information System (INIS)

    Green, D.; Ronzhin, A.; Hagopian, V.

    1995-06-01

    Experimental data have shown that the light output of a scintillator depends on the magnitude of the externally applied magnetic fields, and that this variation can affect the calorimeter calibration and possibly resolution. The goal of the measurements presented here is to study the light yield of scintillators in high magnetic fields in conditions that are similar to those anticipated for the LHC CMS detector. Two independent measurements were performed, the first at Fermilab and the second at the National High Magnetic Field Laboratory at Florida State University

  14. Gauge invariant fractional electromagnetic fields

    Science.gov (United States)

    Lazo, Matheus Jatkoske

    2011-09-01

    Fractional derivatives and integrations of non-integers orders was introduced more than three centuries ago but only recently gained more attention due to its application on nonlocal phenomenas. In this context, several formulations of fractional electromagnetic fields was proposed, but all these theories suffer from the absence of an effective fractional vector calculus, and in general are non-causal or spatially asymmetric. In order to deal with these difficulties, we propose a spatially symmetric and causal gauge invariant fractional electromagnetic field from a Lagrangian formulation. From our fractional Maxwell's fields arose a definition for the fractional gradient, divergent and curl operators.

  15. Good Towers of Function Fields

    DEFF Research Database (Denmark)

    Bassa, Alp; Beelen, Peter; Nguyen, Nhut

    2014-01-01

    In this paper, we will give an overview of known and new techniques on how one can obtain explicit equations for candidates of good towers of function fields. The techniques are founded in modular theory (both the classical modular theory and the Drinfeld modular theory). In the classical modular...... setup, optimal towers can be obtained, while in the Drinfeld modular setup, good towers over any non-prime field may be found. We illustrate the theory with several examples, thus explaining some known towers as well as giving new examples of good explicitly defined towers of function fields....

  16. Field Flows of Dark Energy

    Energy Technology Data Exchange (ETDEWEB)

    Cahn, Robert N.; de Putter, Roland; Linder, Eric V.

    2008-07-08

    Scalar field dark energy evolving from a long radiation- or matter-dominated epoch has characteristic dynamics. While slow-roll approximations are invalid, a well defined field expansion captures the key aspects of the dark energy evolution during much of the matter-dominated epoch. Since this behavior is determined, it is not faithfully represented if priors for dynamical quantities are chosen at random. We demonstrate these features for both thawing and freezing fields, and for some modified gravity models, and unify several special cases in the literature.

  17. Integrated solution for field operations

    Energy Technology Data Exchange (ETDEWEB)

    Aubin, Renaud; Dionis, Francois [EDF, Chatou (France)

    2014-08-15

    This document presents our approach to design and to implement mobile applications for field operations. Internal on-field studies yield to the fact that the value added by mobile solutions is correlated with the easiness of their integration with each other and with the underlying information systems. Moreover, the fast-growing mobile market brings new concepts to the mass and industrial applications design can benefit from these. As a consequence, a simple components-based approach has been applied to design and develop mobile applications for field operations and on-site experiments of the resulting applications have been conducted.

  18. Measurements of magnetic field alignment

    International Nuclear Information System (INIS)

    Kuchnir, M.; Schmidt, E.E.

    1987-01-01

    The procedure for installing Superconducting Super Collider (SSC) dipoles in their respective cryostats involves aligning the average direction of their field with the vertical to an accuracy of 0.5 mrad. The equipment developed for carrying on these measurements is described and the measurements performed on the first few prototypes SSC magnets are presented. The field angle as a function of position in these 16.6 m long magnets is a characteristic of the individual magnet with possible feedback information to its manufacturing procedure. A comparison of this vertical alignment characteristic with a magnetic field intensity (by NMR) characteristic for one of the prototypes is also presented. 5 refs., 7 figs

  19. Atom dynamics in laser fields

    International Nuclear Information System (INIS)

    Jang, Su; Mi, No Gin

    2004-12-01

    This book introduces coherent dynamics of internal state, spread of atoms wave speed, semiclassical atoms density matrix such as dynamics equation in both still and moving atoms, excitation of atoms in movement by light, dipole radiating power, quantum statistical mechanics by atoms in movement, semiclassical atoms in movement, atoms in movement in the uniform magnetic field including effects of uniform magnetic field, atom cooling using laser such as Doppler cooling, atom traps using laser and mirrors, radiant heat which particles receive, and near field interactions among atoms in laser light.

  20. The emerging field of neuroepigenetics.

    Science.gov (United States)

    Sweatt, J David

    2013-10-30

    Over the past 25 years, the broad field of epigenetics and, over the past decade in particular, the emerging field of neuroepigenetics have begun to have tremendous impact in the areas of learned behavior, neurotoxicology, CNS development, cognition, addiction, and psychopathology. However, epigenetics is such a new field that in most of these areas the impact is more in the category of fascinating implications as opposed to established facts. In this brief commentary, I will attempt to address and delineate some of the open questions and areas of opportunity that discoveries in epigenetics are providing to the discipline of neuroscience. Copyright © 2013 Elsevier Inc. All rights reserved.