Innovaciones farmacéuticas para la administración de medicamentos

OpenAIRE

Rius Alarcó, Fernando

2012-01-01

Tras algo más de treinta años dedicados a la docencia del medicamento he considerado oportuno referirme, en mi exposición, a Innovaciones farmacéuticas para la administración de medicamentos. La innovación implica la ruptura del estado estacionario y el inicio de un proceso de desarrollo. Actualmente, gracias a los espectaculares avances tecnológicos experimentados en los últimos años, las innovaciones han sido constantes prácticamente en todas las ciencias y la Medicina no ha sido una excepc...

Algoritmo PSO para identificación de parámetros en un motor DC

Directory of Open Access Journals (Sweden)

César Duarte

2010-01-01

Full Text Available En este artículo se presenta la aplicación del algoritmo Particle Swarm Optimization (PSO como estrategia de búsqueda para determinar los parámetros de un sistema tipo caja gris. Este proceso de identificación se ilustra utilizando la respuesta a un escalón de un motor DC en lazo abierto. Para agilizar la identificación del sistema a través del uso de PSO, se limita el espacio de búsqueda usando la información que puede extraerse de la respuesta en el dominio del tiempo del sistema a identificar. Los resultados del proceso de identificación de los parámetros del motor se obtienen utilizando la herramienta PSOt disponible para entorno Matlab® desarrollada por Brian Birge.

Ley de Coulomb y simulación de trayectorias de partículas cargadas en campos eléctricos estacionarios

OpenAIRE

Barco Ríos, Héctor; Rojas Calderón, Edilberto

2001-01-01

Se presenta una descripción del programa de computador "Ley de Coulomb y simulación de trayectorias de partículas cargadas en campos eléctricos estacionarios" creado por el profesor H. Barco Ríos con la colaboración del profesor E. Rojas C., y que ha sido utilizado como complemento del curso de Física II que en la actualidad se desarrolla en la Universidad Nacional de Colombia Sede Manizales. Este programa hace parte de una serie de trabajos que se han venido realizando con el propósito de...

Estratégias para o desenvolvimento motor, intelectual e social para beneficiários de APAES

Directory of Open Access Journals (Sweden)

Byanca Eugênia Duarte Silva

2016-09-01

Full Text Available A APAE é uma entidade filantrópica que desenvolve atividades de sensibilização, conscientização, prevenção, habilitação, reabilitação e inserção no mercado de trabalho. Dentro dessa perspectiva as atividades lúdicas são recurso pedagógico bastante importante, uma vez que além desenvolver as regras de comportamento pode desenvolver sua coordenação motora, suas habilidades visuais e auditivas, e seu raciocínio criativo e cognitivo.  Logo, o estudo objetivou evidenciar a importância das atividades lúdicas pedagógicas para o desenvolvimento da pessoa com deficiência, apresentando sugestões que propiciam este desenvolvimento em diferentes esferas. O presente estudo trata-se de um relato de experiência a partir do estágio realizado na Associação de Pais e Amigos dos Excepcionais (APAE da cidade de Cajazeiras-PB, em detrimento de um trabalho psicoterapêutico realizado com cinco adolescentes beneficiários, no período de outubro à novembro de 2015. Para este trabalho psicoterapêutico utilizou-se da sugestão de 10 atividades lúdicas pedagógicas que trabalham aspectos motores, cognitivos e sociais dos beneficiários. Este leque de atividades mostra as várias formas de possibilidades para que a pessoa com deficiência aperfeiçoe e/ou desenvolva sua capacidade intelectual, motora e social. Como também aumente sua apropriação do real através do simbólico, que são os objetos. Portanto as atividades lúdicas pedagógicas é um valioso recurso para impulsionar o desenvolvimento das pessoas com deficiência.Strategies for motor development, intellectual and social for beneficiaries of APAESAbstract: APAE is a philanthropic organization that develops awareness activities, awareness, prevention, habilitation, rehabilitation and integration into the labor market. Within this perspective the play activities are very important educational resource, as well develop the rules of behavior can develop their motor skills

Cálculo de un sistema de inyección multifuel para motores Diesel

OpenAIRE

PAVÍA PARRA, MARC

2015-01-01

[ES] Los nuevos diseños de motores buscan como estrategia la combinación de propiedades de los combustibles Diesel y gasolina convencionales, por sus ventajas en cuanto a rendimiento y emisiones. El presente proyecto calculará el impacto que estos cambios pueden tener sobre la mezcla combustible-aire, y cómo se quema el combustible en el motor. Para ello se empleará un código de cálculo 1D de chorros, en el cual se definen las condiciones de contorno en el cilindro del motor y se puede predec...

Diseño y construcción de un banco didáctico para pruebas de motores monofásicos.

OpenAIRE

Cornejo Ponce, Erick Alexander; Tinajero Guerra, Jorge Oswaldo

2015-01-01

El presente proyecto de grado sirve como guía didáctica del laboratorio donde se muestran los distintos tipos de motores monofásicos más comunes para aplicaciones residenciales, comerciales e industriales. El banco se conforma de una infraestructura metálica donde se instalan bloques de controles, protecciones y equipos de medición para analizar el funcionamiento en vacío de los motores; motor monofásico de fase partida o arranque por devanado auxiliar, motor monofásico de arranque por capac...

A discreet control of sliding ways of an induction motor; Control discreto de modos deslizantes de un motor de induccion

Energy Technology Data Exchange (ETDEWEB)

Rivera Dominguez, Jorge

2001-12-15

son aplicadas al modelo discreto no lineal de un motor de induccion que se encontro aqui, que posee dinamicas electricas y mecanicas, en donde el par de carga se considera una perturbacion desconocida. Con mediciones completas de los estados, se satisfacen objetivos de seguimiento de la velocidad del rotor y de la amplitud del flujo magnetico del rotor, en donde la carga desconocida no afecta la regulacion de la velocidad. Luego, es implementado un observador de orden reducido en donde las mediciones de velocidad y de corriente se emplean para estimar el par de carga y los flujos que son muy dificiles de medir. El metodo propuesto tiene un diseno y procedimiento de estabilidad de analisis directos, conservando una estructura simple de la ley de control. Las simulaciones predicen que el sistema es robusto con respecto a varios tipos de pares de carga. Las respuestas de velocidad y de amplitud del flujo del rotor a las referencias de entrada se desempenaron muy bien. Estas referencias tienen una dinamica lineal de segundo orden con constantes de tiempo que pueden ser elegidas por el usuario del motor. Se consideran los aspectos practicos para una futura implementacion digital de la ley de control, incluyendo los sensores de velocidad y corrientes, el acondicionamiento de senales, la transformacion de la corriente al marco de referencia estacionario, PWM y modulos inversores, los cuales fueron vistos con detalle. Los resultados experimentales se dejan como trabajo futuro.

Estimación de propiedades hidráulicas de suelos por mediciones a campo y el uso de modelos de flujo estacionario y transitorio Estimation of soil hydraulic properties by field measurement and use of steady- and transient-flow models

Directory of Open Access Journals (Sweden)

Roberto R Filgueira

2006-07-01

Full Text Available El manejo del suelo influencia las propiedades físicas del mismo, con marcado énfasis en las hidráulicas. La medición de estas últimas se ha vuelto uno de los temas predilectos de investigación en la Física de Suelos. El infiltrómetro de disco a tensión se ha convertido en un valioso instrumento para la medición in-situ de propiedades hidráulicas del suelo. La mayoría de los métodos de análisis de la información obtenida con este instrumento, se basa en la obtención de la tasa de flujo estacionario para tiempos largos, aunque actualmente se encuentran disponibles también expresiones analíticas aproximadas para el flujo transitorio desde un infiltrómetro de disco en tres dimensiones y no confinado. En este trabajo se realizaron mediciones con este instrumento en un suelo franco arcilloso con diferente historia de uso. A partir de los datos obtenidos se estimaron la conductividad hidráulica saturada y la sortividad, mediante modelos que utilizan la aproximación de flujo estacionario y de flujo transitorio. A partir del modelo del flujo estacionario, los resultados obtenidos de sortividad (S0 variaron entre 26,8 y 58,5 mm h-1/2 y los de conductividad hidráulica saturada (K0 entre 41,7 y 78,2 mm h-1, para los sitios de labranza convencional y pastura, mientras que S0 varió entre 23,9 y 51,2 mm h-1/2 y K0 entre 19,0 y 45,7 mm h-1 para el sitio compactado. Los valores medios de sortividad no difirieron estadísticamente entre los tratamientos, mientras que para la conductividad hidráulica saturada no hubo diferencia estadística entre la medias en labranza convencional y pastura, pero ambas fueron significativamente diferentes a la media del sitio compactado. A partir del modelo de flujo transitorio los valores de S0 variaron entre 10,9 y 36,6 mm h-1/2 y los de K0 entre 58,6 y 189,3 mm h-1 para labranza convencional y pastura, y entre 15,8 y 33,9 mm h-1/2 para S0 y entre 13,6 y 71,5 mm h-1 para K0 del sitio compactado. No se

Diseño y optimización para plataformas de un dron multirrotor

OpenAIRE

Camacho Puig, Rafael

2016-01-01

El objeto principal del proyecto es el diseño y la optimización de la estructura de un dron disminuyendo su peso para aumentar el tiempo de vuelo o la carga de pago. Este proyecto se centra en el diseño y optimización de la estructura de un dron multirrotor fabricado mediante impresión 3D. El dron será del tipo hexacóptero y tendrá la capacidad de mantener en el aire una carga de 6kg en régimen estacionario. Ingeniería Mecánica

Influencia del porcentaje de mezcla del aceite de higuerilla en la obtención de combustible alternativo para motores diesel

OpenAIRE

Arnoldo Emilio Delgado; Willian Aperador Chaparro; Jorge Réne Silva Gonzalez

2011-01-01

En el presente artículo se describe el uso del aceite de higuerilla como combustible alternativo en motores diesel. Para este fi n, se obtiene biodiesel a partir de aceite de higuerilla mediante el proceso de transesterifi cación. Se prueban tres mezclas de biodiesel (B5%, B10% y B20%) en un motor diesel, para el cual se midieron los siguientes parámetros: la potencia, el consumo de combustible, la temperatura del motor, y los gases de combustión;las mezclas fueron caracterizadas mediante la ...

Comparison of standards to determine the efficiency of three-phase induction motors; Comparacion de normas para determinar la eficiencia de motores de induccion trifasicos

Energy Technology Data Exchange (ETDEWEB)

Renier, B and others [IEEE, (United States)

2001-09-01

The Mexican industry often acquires from different countries, complete systems of production or auxiliaries, most of them impelled by squirrel cage electric motors, whose efficiency stated by the manufacturer is calculated by applying regional or local standards. For this reason, for the accomplishment of an energy balance -one of the first steps to follow is to determine the saving potential of a plant- it is important to know how the mentioned motor saving potentials were evaluated. It is worthwhile to indicate that an incorrect estimation could get to modify the economics of the applied measures. [Spanish] La industria mexicana a menudo adquiere de distintos paises, sistemas completos de produccion o auxiliares, la mayor parte de los cuales estan impulsados por motores electricos tipo aula de ardilla cuya eficiencia declarada por el fabricante se calcula aplicando normas regionales o locales. Por tal motivo, para la realizacion de un balance de energia -uno de los primeros pasos a seguir para determinar los potenciales de ahorro de una planta- resulta importante conocer como fueron evaluadas los mencionados motores. Cabe senalar que una estimacion incorrecta pudiera llegar a modificar la rentabilidad de la medida aplicada.

Diseño preliminar de un rotor de onda para motores con microturbina

Directory of Open Access Journals (Sweden)

Gina P. Pérez B.

2009-01-01

Full Text Available Este trabajo presenta un analisis preliminar sobre los beneficios de ia implementacion de un rotor de onda en una micro-turbina convencional. Este estudio se enfoca en la consecución de un punto de disefio por medio de cálculos térmicos para así lograr una geometría adecuada, la cual podra ser evaluada por medio de Dinámica de Flujo Computacional CFD para determinar la viabilidad de la implementacion de este dispositive en un motor con micro-turbina a gas de 30 lb, de empuje.

Modelado y control en vuelo estacionario de helicópteros autónomos con cable de fijación a tierra

Directory of Open Access Journals (Sweden)

Luis A. Sandino

2013-10-01

Full Text Available Resumen: Los helicópteros son conocidos por sus capacidades de vuelo estacionario (maniobra conocida como hovering, despegue y aterrizaje vertical. Sin embargo, la ejecución de la maniobra de hovering puede verse afectada seriamente por perturbaciones como ráfagas de viento. Lo anterior es más significativo en el caso de helicópteros a escala, que son comúnmente adoptados como plataformas para el desarrollo de vehículos aéreos no tripulados. Para solventar las dificultades anteriores y conseguir maniobras de hovering más estables es posible emplear una configuración consistente en un helicóptero autónomo, un cable de fijación a tierra y un sistema de control que ajusta la tensión en el cable. En este artículo, además de incluir los pasos necesarios para obtener un modelo detallado del sistema, se presenta un análisis de los beneficios inherentes a la configuración con cable, así como el esquema general para el diseño de estrategias de control. A manera de ilustración, se incluyen simulaciones comparativas con perturbaciones de viento generadas artificialmente. Abstract: Helicopters are well-known by their hovering and vertical take-off and landing capabilities. However, the performance of the valuable feature of hovering can be seriously affected by external disturbances such as wind effect. The latter could be even more significant when dealing with small-size helicopters, which are commonly adopted as base platforms for developing unmanned aerial vehicles. In order to address the aforementioned instabilities in hovering maneuvers, it is possible to use an augmented configuration that consists of the unmanned helicopter itself, a tether connecting the helicopter to the ground, and a system in charge of adjusting the tether tension. In this paper, in addition to a detailed model of the system, an analysis on the inherent benefits to the augmented configuration is presented, as well as a general scheme for control design. By

SIMULACIÓN ESTACIONARIA DE UN EVAPORADOR DE DOBLE EFECTO PARA JUGO DE TOMATE

Directory of Open Access Journals (Sweden)

Álvaro Núñez

2012-01-01

Full Text Available En este trabajo se desarrolló un modelo estacionario para simular un sistema evaporador de doble efecto destinado a la concentración de jugo de tomate. Debido a que el licopeno muestra capacidad antioxidante, es deseable que su concentración sea máxima en la pasta de tomate. Ello se logra optimizando tanto el diseño como las condiciones de operación del equipo concentrador de jugo. Para alcanzar ese objetivo, se incorporó al modelo la cinética de degradación del licopeno, y se realizó un estudio de sensibilidad para determinar las relaciones que vinculan las variables de proceso. El estudio determinó que el contenido de licopeno en el producto es altamente sensible al tiempo de residencia; mientras que el consumo de vapor está determinado por la presión del vapor de servicio y las presiones de los efectos.

El biodiesel de aceite de higuerilla como combustible alternativo para motores diesel

Directory of Open Access Journals (Sweden)

ALIRIO BENAVIDES

2007-01-01

Full Text Available En este artículo se presenta un estudio experimental sobre la producción y utilización del biodiesel de aceite de higuerilla. El máximo rendimiento de metilésteres en la reacción de transesterificación del aceite de higuerilla usado se obtiene bajo las siguientes condiciones: temperatura ambiente, una relación molar metanol/aceite de 9 y una concentración de catalizador de 0.8%. El biodiesel de aceite de higuerilla puede ser mezclado con el combustible diesel convencional derivado del petróleo en proporciones hasta del 15%, sin que la mezcla resultante se salga de las especificaciones de calidad estipuladas en los estándares nacionales e internacionales para combustibles diesel. La mayor dificultad para el uso del biodiesel de aceite de higuerilla en motores es su alta viscosidad. Sin embargo este biocombustible presenta excelentes propiedades de flujo a baja temperatura (valores bajos para los puntos de nube y fluidez. Las pruebas en motor con mezclas biodiesel de higuerilla/diesel convencional, en el rango de proporciones de biodiesel ensayadas, muestran que ha medida que se incrementa la proporción de biodiesel en la mezcla aumenta el consumo específico de combustible, disminuye el dosado relativo, la opacidad de humos se disminuye levemente, mientras que el rendimiento efectivo y las emisiones de CO y CO2 prácticamente permanecen constantes

Diseño de una sala de pruebas para motores alternativos de combustión interna

OpenAIRE

García Pamplona, Jesús

2007-01-01

Los bancos de ensayos para motores son de vital importancia para el desarrollo de éstos (o el de alguno de sus componentes) ya que permiten tener un registro de su comportamiento tanto en las condiciones normales de funcionamiento como en situaciones extremas a las que puedan verse obligados a trabajar. Es importante definir la finalidad del banco de ensayos (para producción, investigación, rectificación,…); el tipo de pruebas a realizar (ensayo de potencia, emisión de conta...

Interfaz Gráfica Computacional para Destilación Multicomponente utilizando Métodos Cortos

OpenAIRE

A. Osorio Mirón; Gloria Dominguez Hernández

2011-01-01

En este trabajo, se elaboró una interfaz gráfica que determina por medio de simulación en estado estacionario el número de platos necesarios en el proceso de destilación multicomponente, así como la composición en el flujo de destilado y fondos de una torre de destilación utilizando métodos cortos. La interfaz gráfica de usuario, se construyó en el lenguaje de programación Python 2.5, permite presentar los datos de entrada y salida para el caso de columnas de destilación operando en régimen p...

The Effectiveness of four Motor Games for the Abdominal Conditioning Eficacia de cuatro juegos motores para el acondicionamiento de los músculos del abdomen

Directory of Open Access Journals (Sweden)

B. Flores

2010-09-01

Full Text Available

The purpose of this study was to determine the effectiveness of four traditional motor games (“the tunnel”, “the chicken battle”, “the drunk” and “the wheelbarrow race” for strengthening the abdominal muscles. Electromyography (EMG was collected from rectus abdominis (RA, external oblique (EO, and internal oblique (IO from twelve healthy volunteers during the performance of the games and the trunk curl-up exercise. The EMG amplitude was averaged and normalized using maximal voluntary isometric contractions. A two-way ANOVA (muscle / task was used to compare the level of contraction activity and the way the abdominal muscles co-activated during the different tasks. For EO and IO, the EMG amplitudes during the games were equal or greater than the EMG amplitudes of the curl up. The wheelbarrow race produced the highest intensity of contraction for all muscles. The curl up principally activated RA and IO. On the other hand, the games activated the oblique muscles with higher intensity than RA. On the basis of these results, the motor games are effective for abdominal conditioning.
KEY WORDS: motor games, exercises, training, abdominal muscles, electromyography.

El objetivo de este estudio fue determinar la eficacia de cuatro juegos motores (“el túnel”, “la pelea de gallinas”, “el tentetieso” y “la carretilla” para el fortalecimiento de los músculos del abdomen. Para ello, se registró la electromiografía de los músculos rectus (RA, obliquus externus (OE y obliquus internus abdominis (OI de 12 voluntarios sanos durante la ejecución de los juegos y del ejercicio de encorvamiento del tronco. La amplitud electromiográfica fue promediada y normalizada respecto a la contracción voluntaria isométrica máxima. Posteriormente, se realizó un ANOVA de dos factores (músculo / tarea para comparar la intensidad de la activación muscular y

Influencia del porcentaje de mezcla del aceite de higuerilla en la obtención de combustible alternativo para motores diesel

Directory of Open Access Journals (Sweden)

Arnoldo Emilio Delgado

2011-01-01

Full Text Available En el presente artículo se describe el uso del aceite de higuerilla como combustible alternativo en motores diesel. Para este fi n, se obtiene biodiesel a partir de aceite de higuerilla mediante el proceso de transesterifi cación. Se prueban tres mezclas de biodiesel (B5%, B10% y B20% en un motor diesel, para el cual se midieron los siguientes parámetros: la potencia, el consumo de combustible, la temperatura del motor, y los gases de combustión;las mezclas fueron caracterizadas mediante la densidad, viscosidad, índice de refracción y calor de combustión. Se determinó que el uso del aceite de higuerilla en la mezcla genera un aumento en la viscosidad y el consumo de combustible, además también infl uye en la reducción del poder calorífico, potencia del motor, los gases de combustión como el CO y CO2, los óxidos de azufre, los hidrocarburos, la opacidad en los humos del escape del motor y ocasiona un equilibrio en el rendimiento observado en el motor diesel, manifi esto en las temperaturas del motor.

Desarrollo de un drive para motores paso a paso y aplicación del filtro de Kalman para el sistema de colimación del LHC = Development of a stepper motor drive and Kalman Filter application for the LHC collimation system

OpenAIRE

Picatoste Ruilope, Ricardo

2010-01-01

Este proyecto describe el trabajo realizado durante 14 meses en una estancia en prácticas para estudiantes del CERN. El trabajo consiste en el desarrollo, implementación y testeo de un drive para motores paso a paso que se utilizará en el sistema de colimación del LHC. Se propone así mismo la utilización del filtro de Kalman para obtener una estimación del ángulo, desarrollandose una implementación del mismo aplicable en tiempo real.

Microcomputer based sliding regime discrete control for synchronous AC motors Control discreto por microordenador basado en regímenes deslizantes para motores de corriente alterna síncronos

Directory of Open Access Journals (Sweden)

Eduardo Palomar–Lever

2007-12-01

Full Text Available The basic ideas to design discrete algorithms used to calculate unmeasured mechanical or electrical variables, in order to control electrical motors in mechanical systems are presented. The main point of the paper is to simplify the algorithms by using a linear discrete time model without any variable limitations and to reduce the computing capacity requirements of the controller. Limited references, based on the discrete sliding mode for the exception of the influences of variable limitations, are proposed and designed. The main advantage of the controller presented in this paper is that a large control error does not bestow any problems. In such a case, the system always works in an area without the limitations. Original observation algorithms of both position and rotational velocity for exterior permanent magnet synchronous motors are designed. A computer simulation was performed and the results are presented, showing high dynamic accuracy.Se presentan las ideas básicas para diseñar algoritmos discretos para calcular las variables mecánicas o eléctricas, no medidas sino estimadas, para controlar motores eléctricos en sistemas mecánicos. El objetivo principal de este artículo es simplificar los algoritmos usando un modelo de tiempo discreto lineal sin ninguna limitación en las variables y reducir los requisitos de capacidad informática del controlador. Las referencias limitadas, basadas en el modo deslizante discreto para la excepción de las influencias de limitaciones de las variables, se proponen y diseñan. La ventaja principal del controlador presentada en este artículo es que un error de control grande no causa ningún problema. En dicho caso, el sistema trabaja siempre en un área sin limitaciones. Se diseñan los algoritmos de la observación originales de la posición y de la velocidad rotatoria para el imán permanente exterior de motores síncronos. Se llevó a cabo una simulación en computadora y se presentan los

High efficiency motors; Motores de alta eficiencia

Energy Technology Data Exchange (ETDEWEB)

Uranga Favela, Ivan Jaime [Energia Controlada de Mexico, S. A. de C. V., Mexico, D. F. (Mexico)

1993-12-31

This paper is a technical-financial study of the high efficiency and super-premium motors. As it is widely known, more than 60% of the electrical energy generated in the country is used for the operation of motors, in industry as well as in commerce. Therefore the importance that the motors have in the efficient energy use. [Espanol] El presente trabajo es un estudio tecnico-financiero de los motores de alta eficiencia y los motores super premium. Como es ampliamente conocido, mas del 60% de la energia electrica generada en el pais, es utilizada para accionar motores, dentro de la industria y el comercio. De alli la importancia que los motores tienen en el uso eficiente de la energia.

High efficiency motors; Motores de alta eficiencia

Energy Technology Data Exchange (ETDEWEB)

Uranga Favela, Ivan Jaime [Energia Controlada de Mexico, S. A. de C. V., Mexico, D. F. (Mexico)

1992-12-31

This paper is a technical-financial study of the high efficiency and super-premium motors. As it is widely known, more than 60% of the electrical energy generated in the country is used for the operation of motors, in industry as well as in commerce. Therefore the importance that the motors have in the efficient energy use. [Espanol] El presente trabajo es un estudio tecnico-financiero de los motores de alta eficiencia y los motores super premium. Como es ampliamente conocido, mas del 60% de la energia electrica generada en el pais, es utilizada para accionar motores, dentro de la industria y el comercio. De alli la importancia que los motores tienen en el uso eficiente de la energia.

Desarrollo de un controlador para motores DC brushless basado en CompactRIO y LabVIEW de National Instruments para el estudio de nuevos algoritmos de control

OpenAIRE

García Haro, Juan Miguel

2011-01-01

Este proyecto que el CAR inició hace pocos años tiene como objetivo principal el estudio y desarrollo de nuevas tecnologías en el campo de actuación y control automático, que servirá de base para otras futuras investigaciones dentro del centro. La tecnología a la que se hace mención se refiere al control de actuadores basados en motores DC brushless (BLDC Motors) empleando el sistema de hardware embebido CompactRIO y programación LabVIEW de National Instruments. Tradicionalmente se emplea en ...

Elementos teórico-prácticos útiles para comprender el uso de los motores de búsqueda en Internet

OpenAIRE

Oller Gómez, Jorge

2003-01-01

Con el objetivo de presentar un conjunto de elementos teóricos y prácticos, útiles para conocer el funcionamiento de los llamados motores de búsqueda en Internet, se revisó la literatura existente en la red sobre el tema mediante los conocidos buscadores Google, Infoseek, WebCrawler, entre otros. Se presentan las características generales de los motores de búsqueda y sus componentes, con un énfasis especial en el empleo de los operadores booleanos y su utilización en cada uno de los motores e...

"Desarrollo software de un módulo de cinética química en fase gaseosa para simulación 3D de motores de Combustión interna"

OpenAIRE

Forigua Rodriguez, Carlos Felipe

2015-01-01

Un reactor a volumen constante para (RVC) fue implementado utilizando Cantera dentro de KIVA-4 en un acople multifísico con el fin de simular varios motores. Se simuló un motor de encendido por compresión de carga homogénea (HCCI), un motor Diesel de inyección directa y un motor encendido por chispa. Sólo densidades parciales se intercambian entre KIVA y Cantera. Una densidad parcial inicial se calcula en KIVA para Cantera. Nuevas densidades son generadas por Cantera usando el ...

Expansión estacionaria del plasma producido por un pulso de láser sobre una microesfera

OpenAIRE

Sanz Recio, Javier

1981-01-01

Para obtener energía de fusión mediante el láser, es necesario comprimir una microesfera a densidades muy altas (diez mil veces la densidad inicial), calentando al mismo tiempo un pequeño núcleo central del blanco a temperaturas del orden de 10 KeV. El problema queda dividido en dos partes bien diferenciadas cuando existe una superficie de ablación que separa el problema interior que es no estacionario y el problema exterior,, el cual se puede tomar cuasi estacionario si la densidad crítica d...

Software efical para la gestión eficiente de motores en la industria; Software Efical for Efficient Management of Motors in the Industry

Directory of Open Access Journals (Sweden)

Elías V de la Rosa Masdueño

2011-02-01

Full Text Available En este trabajo se explica el diseño, e implementación de una herramienta capaz de controlar y gestionareficientemente los motores eléctricos de una industria. Para ello se elaboró un software de fácil manejoque resolviera el problema y que además brindara otras opciones a los usuarios que hicieran uso delmismo. EFICAL®, controla el inventario de los motores y sus equipos accionados, sus parámetrosnominales, mantenimientos y ensayos, permite calcular la eficiencia por distintos métodos y brinda ademásdatos de catálogos de diversos fabricantes.  This work explains the developing and application of a software tool for efficient management of electricmotors in the industry. For this it was develop friendly software that solve the problem and more over givesanother option to users. EFICAL®, controls the motor inventory and the equipment that they drive, theirnominal parameters, maintenance, and testing; also allow the efficiency calculations by various methodsand gives the catalog data of some manufacturers.

Algoritmo para la determinación de los parámetros del motor de inducción por datos nominales; Algorithm for the determination of the parameters of the induction motor for nominal data

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Ignacio Romero Rueda

2011-02-01

Full Text Available El trabajo presenta un nuevo enfoque para el cálculo de los parámetros del circuito equivalente para régimennominal, utilizando el teorema de Thevenin y las expresiones deducidas del mismo. Se comparan losresultados obtenidos por esta metodología con varias vías, existentes en la literatura y a través de losensayos típicos (vacío, rotor bloqueado y CD para el motor de inducción de rotor en jaula. La metodologíase aplica a dos motores y muestra efectividad en este campo.  Presently article is carried out an analysis from the experimental point of view of the variables of diagnosisstate (Opacity of the gases, temperatura of the gases of the escape, consumption of fuel for the determinationof the technical state or condition the injection apparatus of a diesel motive installation.

Diseño y construcción de un prototipo digital para diagnósticar fallas en motores de inducción

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FERNANDO VILLADA DUQUE

2007-01-01

Full Text Available En este trabajo se presenta el desarrollo de un prototipo digital utilizando un procesador de señales digitales DSP, al cual se le han incorporado dos algoritmos para diagnosticar fallas en el estator de motores de inducción. El primer algoritmo utiliza las redes neuronales artificiales para estimar la corriente de secuencia negativa, la cual es utilizada como indicador de falla. El segundo algoritmo utiliza la impedancia de secuencia inversa como indicador de falla. Se presenta la estructura general del prototipo y su implementación. Se incluyen los resultados obtenidos experimentalmente en un motor de 3 HP utilizando medida en línea a través del prototipo digital

Diseño y construcción del múltiple de escape para el motor Yamaha FZR600 de la formula SAE

OpenAIRE

Calle Solís, Eloy Tarquino; Rivas Macero, Dorian Alberto

2014-01-01

El documento consiste en la búsqueda de un diseño óptimo de múltiple de escape para implementarlo en el motor Yamaha FZR600 del prototipo Formula SAE. Este elemento debe brindar un buen funcionamiento del motor, cumplir con las normas del reglamento en cuanto a: ubicación dentro del chasis del monoplaza, niveles de ruido del motor, costo y medidas de seguridad que impone la competencia Formula Student. The document consists in the way to search an optimal design of the exhaust system in th...

Oportunidades do ambiente domiciliar e fatores associados para o desenvolvimento motor entre três e 18 meses de idade

OpenAIRE

Defilipo, Érica Cesário

2011-01-01

O ambiente domiciliar tem sido apontado na literatura como um dos fatores extrínsecos que mais influencia o desenvolvimento, pois proporciona à criança oportunidades para a exploração que permitem que o comportamento motor seja estimulado de forma natural. A interação com os pais, a variabilidade de estimulação e a disponibilidade de brinquedos são indicadores críticos para a qualidade do ambiente familiar. Os objetivos do presente estudo foram avaliar as oportunidades prese...

Revision of the standards in the application of high efficiency induction motors; Revision de la normatividad en la aplicacionon de motores, de induccion, de eficiencia alta

Energy Technology Data Exchange (ETDEWEB)

Acoltzi Acoltzi, Higinio [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

2001-07-01

In this work the elements contained in the national and international standards to obtain the benefits in the application of high efficiency electrical motors are presented. A table of associated normal and minimum efficiency is presented, and one with values of nominal efficiency at full load for totally enclosed motors of standard efficiency, for opened motors of standard efficiency and high efficiency. Graphs are given where the comparison of nominal efficiencies is shown for AC induction motors to closed and opened poles. [Spanish] En este trabajo se presentan los elementos contenidos en las normas nacionales e internacionales para conseguir los beneficios en la aplicacion de motores electricos de eficiencia alta. Se muestra una tabla de eficiencia normal y minima asociados, y una con valores de eficiencia nominal a plena carga para motores cerrados de eficiencia estandar, para motores abiertos de eficiencia estandar y de eficiencia alta. Se da graficas donde se muestra la comparacion de eficiencias nominales, para motores de CA de induccion, a polos cerrados y a polos abiertos.

Motores sincrónicos de reluctancia controlados con variadores de frecuencia: una aplicación para ahorrar energía ;Synchronous reluctance motors controlled by variable frequency converters: an application to save energy

Directory of Open Access Journals (Sweden)

Percy Rafael Viego Felipe

2015-04-01

Full Text Available Se presenta un estudio sobre aplicaciones de los motores sincrónicos de reluctancia (MSR controlados por accionamientos de frecuencia variable (AFV, que posibilitan el ahorro de energía. Se realizó una comparación entre las características constructivas de los MSR y los motores asincrónicos de jaula (MA, evaluando las ventajas y limitaciones que aquellos presentan. Una ventaja notable del MSR es que las pérdidas en el rotor se eliminan prácticamente. Una comparación experimental evidenció que para igual momento, el MSR presenta una mayor eficiencia; y que para igual incremento de temperatura, con las mismas dimensiones IEC, se logra más potencia. Por comparaciones entre datos de un fabricante, se demostró las ventajas de utilizar, con el mismo AFV y para cargas centrífugas, un MSR de mayor clase de eficiencia que la de un MA. Un análisis económico con técnicas de descuento, evidenció una atractiva recuperación de la inversión cuando se opera todo el año. A study on applications of synchronous reluctance motor (SynRM controlled by variable frequency drives (VFD for energy saving is presented. A comparison between the basic construction elements of the SynRM and the squirrel cage induction motor (IM is carried out, evaluating advantages and disadvantages. A nearly complete elimination of rotor losses is a significant asset of the SynRM. An experimental comparison showed that at the same torque, the SynRM presents a higher efficiency than the IM; and that at the same temperature rise, more power is obtained with the same IEC frame for both motor types. Comparing data from a manufacturer, the advantages of using, with the same VFD and for centrifugal loads, a higher efficiency class SynRM than that of a lower efficiency IM was demonstrated. An economical study using discount techniques, made evident an attractive pay back when operating all year around.

Selection of electric motors for industrial processes with the rational energy use criteria; Seleccion de motores electricos para procesos industriales con criterios de uso racional de la energia

Energy Technology Data Exchange (ETDEWEB)

Morales Collantes, Arturo [Universidad Nacional Autonoma de Mexico, Mexico, D. F. (Mexico)

1993-12-31

Under the energy and ecological crisis we are now going through, but fundamentally because as human beings we can not keep on acting in such a thoughtless way, I write these notes, with the intention that we take more into consideration that whatever we do to improve the ways of energy consumption, will ease the human life preservation. The electric motors selection, plays an important roll in this respect, since it represents the highest percentage of electric energy consumption at national level. Therefore I will point out some basic criteria for an adequate selection. [Espanol] Ante la crisis energetica y ecologica por la que actualmente pasamos, pero fundamentalmente porque como seres humanos no podemos seguir actuando en forma tan irreflexiva, escribo estas notas, con la intencion de que tomemos mas en cuenta, que lo que hagamos para mejorar las formas de consumo de energia, facilitara la preservacion de la vida humana. La seleccion de motores electricos, juega un importante papel al respecto, ya que representa el mayor porcentaje del consumo de energia electrica a nivel nacional, por lo tanto senalare algunos criterios basicos para una adecuada seleccion.

Selection of electric motors for industrial processes with the rational energy use criteria; Seleccion de motores electricos para procesos industriales con criterios de uso racional de la energia

Energy Technology Data Exchange (ETDEWEB)

Morales Collantes, Arturo [Universidad Nacional Autonoma de Mexico, Mexico, D. F. (Mexico)

1992-12-31

Under the energy and ecological crisis we are now going through, but fundamentally because as human beings we can not keep on acting in such a thoughtless way, I write these notes, with the intention that we take more into consideration that whatever we do to improve the ways of energy consumption, will ease the human life preservation. The electric motors selection, plays an important roll in this respect, since it represents the highest percentage of electric energy consumption at national level. Therefore I will point out some basic criteria for an adequate selection. [Espanol] Ante la crisis energetica y ecologica por la que actualmente pasamos, pero fundamentalmente porque como seres humanos no podemos seguir actuando en forma tan irreflexiva, escribo estas notas, con la intencion de que tomemos mas en cuenta, que lo que hagamos para mejorar las formas de consumo de energia, facilitara la preservacion de la vida humana. La seleccion de motores electricos, juega un importante papel al respecto, ya que representa el mayor porcentaje del consumo de energia electrica a nivel nacional, por lo tanto senalare algunos criterios basicos para una adecuada seleccion.

Eletroerosão por fio em metal duro para ferramentas de estampagem de lâminas de motores elétricos

OpenAIRE

Hespanhol, Heber de Carvalho

2009-01-01

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Mecânica. O processo de eletroerosão por fio é utilizado atualmente na fabricação da maioria das matrizes e punções de metal duro (carbeto de tungstênio), usados em ferramentas de estampagem de aços para motores elétricos. As indústrias de eletrodomésticos, motores elétricos industriais, transformadores e compressores herméticos, utilizam ferramentas progressivas de...

Diseño y construcción de un motor virtual, para el diagnóstico de la ECU de un vehículo Chevrolet Spark

OpenAIRE

Mora Campoverde, José Enrique; Niola Barbecho, Fausto Lizandro

2013-01-01

Con la propuesta de este Motor Virtual se busca bajar los tiempos en el diagnóstico y eliminar la contaminación ambiental al comprobar el buen funcionamiento de la ECU del Vehículo Chevrolet Spark debido a que con este Motor Virtual se elimina encender el vehículo ya que el mismo consta de todos los sensores del motor y sus respectivos actuadores para saber si estos están funcionando en correctas condiciones o existe algún daño en los mismos. With Virtual Motor proposal this time is lookin...

Consumo de combustível e emissões de poluentes em um motor Diesel convertido a etanol para geração térmica de energia elétrica

Directory of Open Access Journals (Sweden)

Vinícius Rückert Roso

2016-03-01

Full Text Available Nos esforços globais para a minimização nas emissões de gases do efeito estufa e redução da pegada de carbono, combustíveis renováveis têm sido extensivamente utilizados em substituição aos combustíveis fósseis nos motores de combustão interna. Particularmente para geração de energia elétrica local, motores diesel são os mais utilizados devido à elevada eficiência térmica e a robustez, se comparado a motores de ignição por centelha. Entretanto, estes sistemas apresentam elevados níveis de emissões de óxido de nitrogênio (NOx e material particulado, trazendo sérias consequências para o meio ambiente. Assim, esta pesquisa combina simulação computacional e resultados experimentais da conversão de um motor diesel para a operação com etanol, sendo sua utilização na geração de energia elétrica. Como este combustível renovável é largamente produzido no Brasil utilizando a cana-de-açúcar, acaba por possuir seu custo reduzido em especial próximo à produtores e refinarias. Dados experimentais foram utilizados na validação do modelo computacional unidimensional desenvolvido para a conversão, onde resultados foram analisados para a comparação de ambos combustíveis. Análises econômicas para diferentes condições de carga forneceram informações de custos operacionais em locais próximos às fontes de produção de etanol. Os resultados apontam as vantagens no uso do combustível renovável para a geração de energia elétrica, como o custo reduzido e a menor emissão de NOx ao longo de toda a gama de operação.

Ajuste de las simulaciones de flujos continuados para el cálculo del Límite de Potencia Eólica; Calculation of Wind Power Limit adjusting the Continuation Power Flow

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Ariel Santos Fuentefria

2012-07-01

Full Text Available La integración de la energía eólica en los sistemas eléctricos puede provocar problemas de estabilidad ligados fundamentalmente a la variación aleatoria del viento y que se reflejan en la tensión y la frecuencia del sistema. Por lo que conocer el Límite de Potencia Eólica (LPE que puede insertarse en la red sin que esta pierda la estabilidad es un aspecto de extrema importancia, en el cual se han realizando métodos de cálculo para encontrar dicho límite. Estos métodos se desarrollan teniendo en cuenta las restricciones del sistema en estado estacionario, en estado dinámico o ambos. En el siguiente trabajo se desarrolla un método para el cálculo de LPE teniendo en cuenta las restricciones en estado estacionario del sistema. El método propuesto se basa en un análisis de flujo continuado, complementado con el método de Producción Mínima de Potencia Activa, desarrollado en la bibliografía. Se prueba en el sistema eléctrico de la Isla de la Juventud, Cuba y se usa elsoftware libre PSAT para la realización de estos estudios.  The wind power insertion in the power system is an important issue and can create some instability problems in voltage and system frequency due to stochastic origin of wind. Know the Wind Power Limit is a very importantmatter. Existing In bibliography a few methods for calculation of wind power limit. The calculation is based in static constrains, dynamic constraints or both. In this paper is developed a method for the calculation of wind power limit using some adjust in the continuation power flow, and having into account the static constrains. The method is complemented with Minimal Power Production Criterion. The method is proved in the Isla de la Juventud Electric System. The software used in the simulations was the Power System Analysis Toolbox (PSAT.

Investigación en Progreso: Sistemas Inteligentes en Arquitecturas de Motores para Videojuegos

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Hernan Merlino

2013-02-01

Full Text Available La industria de productos lúdicos informatizados (más conocidos como videojuegos es una de las actividades económicas de mayor crecimiento en los últimos años. Durante el 2006, en los Estados Unidos los ingresos por videojuegos excedieron por primera vez en la historia a los del cine. Sin embargo, a pesar del auge en este mercado, todavía existen más ofertas de empleo que personas preparadas para ocuparlos. Para lograr el desarrollo de un videojuego se requiere de diversos conocimientos, como ser, diseño multimedial, manejo de lenguajes de programación especifica, uso de plataformas de actividades lúdicas, entre otros; sumado a estas actividades es necesario dotar al videojuego con un grado de inteligencia que lo haga no determinista; logrando que los jugadores mantengan durante una mayor cantidad de tiempo el interés por el mismo, pues de no ser así, los jugadores solo lo utilizarían hasta llegar hasta comprender la lógica de funcionamiento y perderian el interés por el videojuego. Es por esto que es de interés para la industria del video juego el desarrollo de motores basados en sistemas inteligentes tomando la experiencia adquirida en otros dominios, como ser, robótica, minería de datos y control de procesos, haciendo las adaptaciones necesarias al dominio en cuestión..

Modelo integral de motores alternativos con aplicaciones docentes: motores diesel de inyección directa

OpenAIRE

Torres García, Miguel; Chacartegui, R.; Ruiz Marín, Juan José

2002-01-01

Con fines docentes se ha desarrollado un programa en MATLAB que simula el comportamiento de un MDID utilizando un modelo de combustión de una zona incluyendo renovación de la carga, de fugas y perdidas mecánicas. Para la validación del modelo se han comparado los resultados con los reales de varios motores a pesar de la falta de información detallada del motor. Las mayores diferencias aparecen para régimen de giro alto donde los efectos dinámicos, que este modelo no considera, son...

Diseño de un método para controlar la combustión en un motor 2T de gasolina basado en la medida del régimen instantáneo

OpenAIRE

PÉREZ PÉREZ, JUAN CARLOS

2016-01-01

[ES] En determinadas condiciones de operación los motores de 2T de gasolina operan con autoencendido de la mezcla, lo cual hace perder el control tradicional a través de la bujía. En esos casos es preciso conocer cuándo está teniendo lugar ese autoencendido, para así determinar si es necesario llevar a cabo alguna acción correctora para controlar que éste tenga lugar en el momento adecuado. El alumno explorará la posibilidad de utilizar la medida del régimen instantáneo del motor para consegu...

On the Existence of a Free Boundary for a Class of Reaction-Diffusion Systems.

Science.gov (United States)

1982-02-01

I. Diaz. "Soluciones con soporte compacto para alguno. problemas semilineales". Collect. Math. 30 (1979), 141-179. -26- [121 J. I. Diaz. Tecnica de ...supersoluciones locales para problemas estacionarios no lineales: applicacion al estudio de flujoe subsonicos. Memory of the Real Academia de Ciencias...nonlinearity, nonlinear boundary conditions, dead core set, chemical reactions Work Unit Number I - Applied Analysis (1) Seccion de Matematicas

Desigualdad y crecimiento en México: un análisis por entidad federativa

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Jesús SALGADO-VEGA

2012-01-01

Full Text Available Utilizamos un modelo de generaciones superpuestas desarrollado por Castelló-Climent y Doménech (2008 que consideran la dinámica del capital humano en dos generaciones 1982 y 2007 para las entidades federativas de la República Mexicana. Encontramos varios estados estacionarios que dependen de las condiciones iniciales de la distribución de la educación. El estado estacionario más bajo es una trampa de pobreza en la cual los niños de familias pobres tienen esperanza de vida baja y laboran como trabajadores no calificados, tal es el caso del estado de Chiapas. La evidencia empírica sugiere que el mecanismo de la esperanza de vida explica una mayor parte de las relaciones entre la desigualdad y la acumulación del capital humano. El análisis desarrollado explica porqué la desigualdad en la distribución de la renta percápita puede ser dañina para la acumulación del capital humano. Hacemos una simulación de las generaciones para las entidades federativas de México para calcular los años que tardarán en conseguir un alto nivel de educación o para alcanzar un mejor nivel educativo.

Utilización de la zeolita para disminuir los gases tóxicos de los motores de combustión interna. // The utilization of Cuban zeolites in the decrease of toxic gases emissions of internal combustion engines.

Directory of Open Access Journals (Sweden)

J. L. Reyes González

2003-01-01

Full Text Available En el trabajo se presentan los resultados obtenidos al utilizar la zeolita natural cubana para la disminución de los gasestóxicos que los motores de combustión interna MCI. envían a la atmósfera. Los experimentos fueron realizados en bancosde pruebas de MCI. tanto para motores de carburación como para motores diesel. Obteniéndose eficiencias de disminucióndel CO del 80 %, del CnHm del 50% y el humo negro en un 90%. Se demuestra la importancia de la granulometría de lazeolita para esta eliminación y para mantener la potencia del motor dentro de rangos aceptables.Palabras claves: Toxicidad, zeolita, medio ambiente, filtros, gases de escape._______________________________________________________________________________Abstract.In this paper are presented the results of the utilization of Cuban zeolites in the decrease of toxic gas emissions toatmosphere of internal combustion engines, (MCI. The experiments were carried out in test bank for gasoline and dieselengines. The efficiency in the decrement of CO was of 80%, CnHm in 50%, and 90 % in soot. The size of the zeolitesparticle importance in the efficiency is demonstrated.Key words: Toxicity, zeolite, enviroment, filters, gas emissions.

Recursos materiales para el desarrollo motor grueso en escolares de 6-9 años

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José Manuel Cenizo Benjumea

2017-11-01

Full Text Available El objetivo de la investigación ha sido conocer los recursos materiales de educación física más eficaces para mejorar el desarrollo motor grueso del alumnado de 6 a 9 años, en función de su sexo y edad. La muestra de 982 escolares estuvo dividida en tres grupos experimentales según el tipo de material fungible y un grupo de control. Se empleó el test TGM-2, mediante un pretest y un postest tras una intervención de 14 sesiones. La diferencia de puntuaciones directas en los dos ámbitos (locomotor y control de objetos fue mayor en los grupos experimentales (p-valor<0,05. Dicha diferencia resulta más elevada con el uso de materiales alternativos, seguido de “solo balones” y “no balones” en ambos ciclos educativos y en los dos sexos, excepto para las niñas de segundo ciclo, donde los mejores resultados se producen en el grupo experimental de materiales “solo balones”.

Propiedades de las distribuciones beta y Dirichlet de matrices complejas

OpenAIRE

Bedoya Macías, Elizabeth

2007-01-01

Las distribuciones multivariadas complejas juegan un papel importante en varios campos de investigación. La distribución Gaussiana compleja fue introducida por Wooding [66], Turin [61], y Goodman [16]. La distribución Wishart fue definida por Goodman [16] para aproximar la distribución de un estimativo de la matriz de densidad espectral para un proceso Gaussiano estacionario vectorial. En análisis de series de tiempo las distribuciones complejas se usan para describir estimadores de parámetro...

Condiciones de monitoreo para sistema de control de motores de combustión interna

Directory of Open Access Journals (Sweden)

Elio Rafael Hidalgo-Batista

2016-01-01

Full Text Available En el presente trabajo se presentan las insuficiencias existentes en el sistema de control de los motores de combustión interna pertenecientes a los grupos electrógenos, estas insuficiencias se determinaron luego de un análisis realizado al surgimiento de las fallas y a este sistema. Para la mejora del mismo se da a conocer un procedimiento que permite el seguimiento y procesamiento de las condiciones de monitoreo de estos equipos, el uso de este procedimiento ha permitido: definir los patrones de fallo de las tres variables (de ocho que se estudian que con mayor probabilidad se relacionan con el surgimiento de los fallos, mejorar el método comparativo y dos insuficiencias del sistema de control.

BIORREACTORES DE MEMBRANA ANAEROBIOS PARA TRATAMIENTO DE AGUAS RESIDUALES DOMÉSTICAS. ESTUDIO PRELIMINAR

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Luisa Vera

2014-01-01

Full Text Available La o peración de biorreactores anaerobios de membrana sumergida (BRMSAn para tratamiento de aguas residuales domésticas ha sido estudiad a a escala laboratorio , con el objeto de definir las condiciones d e filtra ción sostenibles de l as suspensiones generadas a lo largo del proceso . Durante la experimentación desarrollada, la deg radación de materia orgánica por vía anaerobia ha logrado rendimientos de eliminación de DQO T entre el 85 y el 93%. Además dicha degradación ha originado biogás tras 12 días de operación y su c omposición relativa en metano ha sido del 60% tras 25 días de operación . También se ha realizado una comparación del comportamiento entre biorreactores de membrana ( BRMs opera do s en condiciones aerobias y anaerobias en términos de filtrabilidad , encontrándose que ambos sistemas se comportan de manera similar una vez alcanzado el estado estacionario .

Caracterización reológica en estado estacionario de pastas para detergentes que contienen tripolifosfato pentasódico

OpenAIRE

Guerrero Conejo, Antonio Francisco

1988-01-01

Las propiedades detersivas de los detergentes dependen de la concentración de iones alcalino-térreos en el medio de lavado. Para su eliminación por secuestro o precipitación se incluyen en sus formulaciones compuestos que actúan como coadyuvantes, de los cuales el más empleado es el tripolifosfato pentasódico. No obstante, a pesar de sus indudables ventajas y de que en la actualidad, la casi totalidad de los procesos de fabricación de detergentes se apoyan en la utilización de este compuesto,...

Modelacion del Efecto del Día de la Semana para los Indices Accionarios de Colombia mediante un Modelo STAR GARCH.

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David Mauricio Rivera Palacio

2010-05-01

Full Text Available En este trabajo se estudia el comportamiento de los retornos de los tres principales índices bursátiles de Colombia: el IBB de la Bolsa de Bogotá, el IBOMED de la Bolsa de Medellin, y el IGBC de Bolsa de Valores de Colombia. A través de un modelo STAR GARCH se identifican dos estados o regiones extremos; mientras en el primero los rendimientos de los índices son, en términos absolutos, bajos y los procesos son estacionarios, en el segundo se tienen grandes pérdidas o ganancias, donde los efectos de los choques son permanentes. Aunque en cada uno de los regímenes el efecto del día de la semana es diferente, los resultados indican que para los tres índices existe un efecto del día de la semana en la media, y un efecto del día en la varianza para la Bolsa de Bogotá y Bolsa de Valores de Colombia. Los resultados contradicen la hipótesis de un mercado de acciones efciente en información.

Motor development of kindergarten in 13 months interval

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Lilian Teresa Bucken Gobbi

2005-12-01

da Escala de Desenvolvimento Motor, que compreende uma bateria de testes envolvendo tarefas específicas por idade nos itens motricidade fina, motricidade global, equilíbrio, esquema corporal/rapidez e organização espacial. Foram realizadas comparações do desempenho motor intra e entre os grupos, para cada item da bateria. Os resultados mostraram que o desempenho motor nas tarefas de equilíbrio melhorou após 13 meses para todos os grupos etários; para motricidade fina, motricidade global e esquema corporal as crianças de 3, 4 e 5 anos melhoraram seu desempenho entre as avaliações; para organização espacial somente as crianças de 3 e 5 anos melhoraram seu desempenho quando re-avaliadas. Estes resultados sugerem que o desenvolvimento nesta faixa etária ocorre de forma não homogênea, ou seja, apresenta ritmos diferentes para os itens da motricidade. Fatores do ambiente, do indivíduo e da tarefa podem explicar as mudanças desenvolvimentistas ocorridas em um período de 13 meses. Conclui-se que o processo de desenvolvimento de cada componente da motricidade é dinâmico e apresenta aspectos de não linearidade.

Tratamiento catalítico de las emisiones de NOx en motores diesel

OpenAIRE

Córdoba, Luis Fernando; Montes de Correa, Consuelo

2002-01-01

Se presenta una revisión sobre algunos aspectos del funcionamiento de los motores diesel, las emisiones contaminantes producidas, así como las tecnologías catalíticas disponibles para el tratamiento de dichas emisiones. Se introduce además, el desempeño de un catalizador desarrollado en el grupo Catálisis Ambiental para la reducción de NOx en mezclas sintéticas que simulan las emisiones de motores diesel. Palabras clave: motor diesel, emisiones, tratamiento, catalizadores.

Freno de corrientes parásitas para ensayo de motores eléctricos

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Omar D. Gallo

2017-01-01

Full Text Available Este trabajo trata distintos aspectos referidos al diseño, construcción y puesta en marcha de un freno dinamométrico de corrientes parásitas, destinado al ensayo de motores eléctricos. La introducción aborda los antecedentes y las experiencias previas con máquinas similares, además de precisiones constructivas sobre el freno y su fuente de alimentación. La sección de ensayos describe los valores de temperaturas de bobinas y discos y las pruebas bajo estados de carga. Los parámetros tales como fuerzas magnetomotrices, corrientes en discos, momentos y pérdidas, se calculan en la sección referida a valores de funcionamiento. Finalmente, en las conclusiones, se abordan las ventajas y desventajas de este tipo constructivo, y las mejoras que deberían realizarse para mejorar el desempeño de la máquina.

Diseño e implmentación de maletas didácticas con los Mini PLCS LOGO y ZELIO para aplicaciones en secuencia de motores.

OpenAIRE

Mestanza Ortiz, Joan Jorge; Cruz Lindao, Bolivar Geovanny

2015-01-01

El presente trabajo de tesis contempla el diseño e implementación de módulos didácticos utilizando los mini PLCS LOGO y ZELIO, para aplicaciones en secuencia de motores de manera manual o automática, el cual tendrá como tarea única y primordial, las aplicaciones de arranque de motores existentes en la industria, de forma manual o automática los cuales serán implementados por los estudiantes de la carrera Ingeniería Electrónica e Ingeniería Eléctrica de la Universidad Politécnica Salesiana se...

Curvas de referência da Escala Motora Infantil de Alberta: percentis para descrição clínica e acompanhamento do desempenho motor ao longo do tempo

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Raquel Saccani

2012-02-01

Full Text Available OBJETIVOS: Comparar os dados de infantes brasileiros com a normativa canadense e estabelecer as curvas de referência e percentis do desenvolvimento motor da Escala Motora Infantil de Alberta segundo sexo. MÉTODOS: Participaram da pesquisa, 795 crianças com idade entre 0 e 18 meses provenientes de diferentes cidades de uma região do Brasil. Os participantes foram avaliados com a Escala Motora Infantil de Alberta, em uma sala silenciosa, por um experiente pesquisador. Foi realizada análise dos percentis (P5, P10, P25, P50, P75, P90 por faixa etária da escala e sexo. RESULTADOS: Não foram encontradas diferenças significativas (p > 0,05 entre meninos e meninas na maioria das diferentes faixas etárias. Apenas aos 14 meses, foi encontrada superioridade das meninas no escore total de desempenho motor (p = 0,015 e no percentil de desenvolvimento (0,021. Verificou-se, para ambos os sexos e para crianças típicas e atípicas, uma tendência de desenvolvimento motor alinear nas curvas desenvolvimentistas. Observou-se variação reduzida das aquisições motoras nos limites etários, nos dois primeiros meses de vida e a partir dos 15 meses. CONCLUSÕES: A Escala Motora Infantil de Alberta, embora seja um instrumento amplamente utilizado em clínica e pesquisa, possui restrições considerando a diferenciação comportamental até os 2 meses e depois dos 15 meses. Essa reduzida sensibilidade da escala nas extremidades etárias pode estar relacionada com o número e dificuldade dos itens motores avaliados nessas idades. Sugere-se a utilização de outros instrumentos de triagem para crianças acima dos 15 meses de idade.

Mezclas gasolina-etanol en motores de combustión interna en Colombia

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Juan Mantilla

2016-06-01

Full Text Available En este trabajo se analiza el cambio sobre el desempeño y las emisiones de los motores encendidos por chispa cuando la gasolina es reemplazada por una mezcla de gasolina y etanol. Inicialmente se investiga la diferencia en las propiedades fisicoquímicas del combustible, y sus posibles efectos sobre el motor. Posteriormente se examina el efecto documentado del cambio de combustible en el desempeño y las emisiones del motor. Para llevar a cabo estos objetivos se realizó una revisión bibliográfica profunda de estos temas que sirve para proponer nuevas preguntas de acuerdo con el entorno colombiano. Los resultados de todos los puntos considerados indican que para que el cambio de combustible se convierta en una política efectiva, diferentes modificaciones deben realizarse al combustible y a los motores. Las inquietudes planteadas, junto con los resultados del análisis llevado a cabo, pueden utilizarse además como insumo para continuar con el desarrollo de trabajos de investigación e innovación tendientes a aprovechar el potencial del etanol como combustible.

Limitations of the Neurological Evolutional Exam (ENE as a motor assessment for first graders Limitações do Exame Neurológico Evolutivo (ENE como um instrumento de avaliação motora para crianças da primeira série

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Priscila M. Caçola

2010-10-01

Full Text Available BACKGROUND: Many clinicians and researchers in Brazil consider the Neurological Developmental Exam (NDE, a valid and reliable assessment for Brazilian school-aged children. However, since its inception, several tests have emerged that, according to some researchers, provide more in-depth evaluation of motor ability and go beyond the detection of general motor status (soft neurological signs. OBJECTIVES: To highlight the limitations of the NDE as a motor skill assessment for first graders. METHODS: Thirty-five children were compared on seven selected items of the NDE, seven of the Bruininks-Oseretsky Test (BOT, and seven of the Visual-Motor Integration test (VMI. Participants received a "pass" or "fail" score for each item, as prescribed by the respective test manual. RESULTS: Chi-square and ANOVA results indicated that the vast majority of children (74% passed the NDE items, whereas values for the other tests were 29% (BOT and 20% (VMI. Analysis of specific categories (e.g. visual, fine, and gross motor coordination revealed a similar outcome. CONCLUSIONS: Our data suggest that while the NDE may be a valid and reliable test for the detection of general motor status, its use as a diagnostic/remedial tool for identifying motor ability is questionable. One of our recommendations is the consideration of a revised NDE in light of the current needs of clinicians and researchers.CONTEXTUALIZAÇÃO: Muitos clínicos e pesquisadores brasileiros consideram o Exame Neurológico Evolutivo (ENE, um instrumento válido e confiável para crianças brasileiras em idade escolar. Entretanto, desde a sua criação, surgiram outros testes para uma avaliação mais profunda de habilidade motora, os quais vão além de detectar status motor geral em forma de sinais neurológicos leves. OBJETIVOS: Demonstrar os pontos fracos do ENE como teste de avaliação de habilidade motora para crianças de primeira série. MÉTODOS: Trinta e cinco crianças realizaram 7 itens

La neuroplasticidad: una vía para elevar el desarrollo somestésico motor en las esgrimistas escolares villaclareñas

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Erlys Álvarez Leal

2007-03-01

Full Text Available Formar una esgrimista con un alto desarrollo somestésico motor, implicaría que esta atleta logre una rapidez de reacción, de movimiento, un grado de coordinación y una efectividad en sus toques que se expresen en la mayor calidad del trabajo motor de ambos hemicuerpos. En este informe de investigación, el cual se encuentra en su tercer macrociclo de experimentación. Para esta investigación se utilizan un conjunto de tests específicos de la esgrima que se le aplican a las atletas con ambos hemicuerpos, al inicio, intermedio y final del macrociclo de entrenamiento estudiado 2004 – 2005, con el fin de caracterizar, comparar y valorar sus comportamientos y las principales influencias neurofisiológicas que tuvo este complejo de ejercicios sobre la actividad sensomotora de estas atletas en su desempeño deportivo.

Jidosha's Motors

OpenAIRE

Shirakawa Okuma, Rosely; Calderón Orejuela, Javier

2016-01-01

La tesis narra la situación de una empresa concesionaria de vehículos nuevos, Jidosha's Motors, perteneciente a una corporación japonesa que cuenta con una cultura muy arraigada de ética y de cumplimiento. Se plantean respuestas, se identifican problemas y sus alternativas de solución para una toma adecuada de decisiones por parte de los directivos, siguiendo una estructura de análisis de situaciones de negocios (ASN). Tesis

DANÇA E O DESENVOLVIMENTO MOTOR DE PORTADORES DE NECESSIDADES EDUCATIVAS ESPECIAIS - PNEEs

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Liliane de Oliveira

2012-04-01

Full Text Available O estudo objetivou verificar as modificações nos padrões de desenvolvimento motor de PNEEs mediante prática da dança. Participaram 14 PNEEs do CIEP/Cruz Alta. O instrumento foi a Escala de Desenvolvimento Motor (Rosa Neto, 1996. Utilizou-se a estatística descritiva e teste “t” para análise dos dados. Observou-se diferenças estatisticamente significativas (p<0,05 entre pré e pós-testes nas variáveis idade cronológica, motora geral, motricidade ampla e equilíbrio. Concluiu-se que o programa de dança contribuiu significativamente para o desenvolvimento motor de PNEEs. Palavras chave: dança, motor, desenvolvimento, especial, educação.

New petroleum lifting concept - tubular asynchronous motor application for onshore petroleum exploitation - (MATAEOS); Nova concepcao para bombeamento de petroleo - motor assincrono tubular para aplicacao na extracao de oleo (petroleo) subterraneo - MATAEOS

Energy Technology Data Exchange (ETDEWEB)

Rossini, Wagner Marques; Cruz, Jose Jaime da; Sales, Roberto Moura [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Lab. de Automacao e Controle (LAC)], e-mail: freddie@lac.usp.br, e-mail: jaime@lac.usp.br, e-mail: roberto@lac.usp.br; Alvarenga, Bernardo Pinheiro de; Chabu, Ivan Eduardo; Cardoso, Jose Roberto [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica. Lab.de Eletromagnetismo Aplicado (LMAG)], e-mail: bernardo@eee.ufg.br, e-mail: ichabu@pea.usp.br, e-mail: cardoso@pea.usp.br

2008-06-15

This study presents the development of a prototype Tubular Asynchronous Motor Application for Onshore Petroleum Exploitation - (MATAEOS). The principal function of the motor is to directly drive a suction pump installed in the down hole of an onshore well. Considering the installation and operational difficulties and costs of a traditional production system, known as a ''the walking beam and rod string system'', the developed prototype is intended to be a technical and economically viable alternative. The results obtained show that the motor develops a constant lift force throughout the movement (or pumping) cycle, according to the dynamometric charts. The motor also presented an electro-mechanical performance higher than the traditional systems. Furthermore, the motor completely eliminates the need for the actual system's set of hoists. Generally, the results indicate that the motor can advantageously substitute surface mechanical systems. (author)

Diseño y optimización del sistema de renovación de la carga de un motor dual fuel para transporte pesado mediante sobrealimentación en doble etapa

OpenAIRE

SIRVENT SANJOSÉ, ROBERTO ANDRÉS

2016-01-01

El trabajo consiste en el diseño del sistema de admisión y escape de un motor dual-fuel para transporte pesado. Se deberá seleccionar la arquitectura adecuada para poder conseguir las condiciones de deseadas en el interior del cilindro (sistema de sobrealimentación, producción de EGR). Se deberá también seleccionar la estrategia adecuada para el control de cada uno de los elementos utilizados. Sirvent Sanjosé, RA. (2016). Diseño y optimización del sistema de renovación de la carga de un mo...

Estudio e implementación de un sistema Dual para optimizar la combustión de un motor Otto mediante el uso de gas de Brown (HHO)

OpenAIRE

Cujilema Cujilema, José Sebastián; Ramírez Gonzaga, Carlos Manuel

2011-01-01

La implementación de un sistema Dual para optimizar la combustión de un motor Otto surge debido a que existen millones de vehículos a gasolina circulando por el mundo y cada uno de ellos es una fuente de contaminación y consumo. En ciudades grandes la contaminación de estos vehículos presentan altos índices de gases nocivos para la salud y el medio ambiente. Los altos índices de emisiones contaminantes están determinados por algunos factores como la mala calidad del combustible, la falta d...

Contribución al modelado unidimensional en motores de dos tiempos de altas prestaciones

OpenAIRE

JIMENEZ MACEDO, VICTOR DANIEL

2013-01-01

Un modelo de simulación presenta muchas ventajas en el campo del desarrollo de motores de combustión interna alternativos. Su utilidad es doble. Por un lado, para entender la naturaleza de los fenómenos físicos que suceden en el interior del motor, y por otro, con el fin de optimizar el diseño de los sistemas que integran el mismo. El principal objetivo de esta tesis es desarrollar un modelo de un motor de dos tiempos de 125 cc de altas prestaciones para caracterizar la fluidodinámica interna...

Entrenamiento motor en el continuo de la realidad a la virtualidad

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Martha Torres-Narváez

2018-01-01

Full Text Available Introducción. La trasformación de la capacidad de movimiento de las personas es un reto que el fisioterapeuta asume como estrategia de aprendizaje motor. Objetivo. Plantear los referentes teóricos y prácticos más relevantes en el uso de ambientes terapéuticos en el continuo de la realidad a la virtualidad en el entrenamiento motor de pacientes con accidente cerebrovascular y enfermedad de Parkinson. Materiales y métodos. Revisión de la literatura que analiza y aporta de manera conceptual, en el área de la rehabilitación y la fisioterapia, información sobre entrenamiento y aprendizaje motor. Resultados. Se evidencia potencial en el uso de la realidad virtual para la rehabilitación de alteraciones del movimiento debidas a disfunciones neurológicas. Las herramientas tecnológicas propias de la realidad virtual permiten un mayor conocimiento de los resultados con respecto a las características del movimiento, lo cual ayuda a mejorar el aprendizaje motor, en comparación con el entrenamiento tradicional. Conclusiones. Se requiere objetivar el proceso de rehabilitación para medir con precisión los cambios que producen estrategias de aprendizaje en las capacidades de movimiento de las personas con deficiencias del sistema neuromuscular para generar evidencia del impacto que tienen los programas de entrenamiento motor en el continuo de la realidad a la virtualidad.

Efeito da intervenção em esteira motorizada na aquisição da marcha independente e desenvolvimento motor em bebês de risco para atraso desenvolvimental Efecto de la intervención en caminadora automática en la adquisición de la marcha independiente y desarrollo motor en bebés de riesgo para retraso de desarrollo Treadmill training effects on walking acquisition and motor development in infants at risk of developmental delay

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Diana Xavier C. Schlittler

2011-03-01

Full Text Available OBJETIVO: Examinar o efeito de intervenção em esteira motorizada na idade de aquisição da marcha independente em bebês de risco para atraso de desenvolvimento. MÉTODOS: Estudo experimental com 15 lactentes a partir do 5º mês de idade, sendo cinco deles com risco de atraso de desenvolvimento submetidos a sessões de fisioterapia e intervenção em esteira motorizada (Grupo Experimental; cinco com risco de atraso de desenvolvimento submetidos apenas a sessões de fisioterapia (Grupo Controle de Risco; e cinco bebês sem risco de atraso (Grupo Controle Típico. As sessões de fisioterapia ocorreram duas vezes por semana, seguidas de intervenção em esteira motorizada para o grupo experimental. Todos os bebês foram avaliados mensalmente pela Alberta Infant Motor Scale e os participantes do grupo experimental foram filmados durante a realização das passadas na esteira. Comparações entre os grupos ao longo do tempo foram realizadas por análise de variância (ANOVA e de multivariância (MANOVA. RESULTADOS: Os bebês do Grupo Experimental adquiriram a marcha independente aos 12,8 meses e os do Grupo Controle de Risco aos 13,8 meses de idade corrigida, sendo que a aquisição do Grupo Controle de Risco ocorreu mais tarde em relação ao Grupo Controle Típico (1,1 meses; pOBJETIVO: Examinar el efecto de intervención en caminadora automática en la edad de adquisición de la marcha independiente en bebés de riesgo para retraso de desarrollo. MÉTODOS: Estudio experimental de 15 lactantes a partir del 5º mes de edad, siendo 5 con riesgo de retraso de desarrollo sometidos a sesiones de fisioterapia e intervención en caminadora automática (grupo experimental; 5 de riesgo de retraso de desarrollo sometidos solamente a sesiones de fisioterapia (grupo control de riesgo; y 5 bebés sin riesgo de retraso (grupo control típico. Las sesiones de fisioterapia ocurrieron 2 veces en la semana, seguidas de intervención en caminadora autom

Evaluación de motores de búsqueda en Internet

OpenAIRE

Motz, Regina; Val Perrone, Mario

2000-01-01

El presente artículo incluye documentación de Motores de Búsqueda obtenida de distintas fuentes y detalla las principales características de ellos, así como también cuáles son los mejores métodos a emplear para la inclusión de sitios web en las bases de datos de estos, de la forma más eficiente. El principal fundamento y aplicación del presente artículo, será el explicar el funcionamiento de los motores de búsqueda y el servir de guía para el desarrollo de sitios web con el fin que atraiga...

Una estrategia basada en modelos para el diagnóstico de fallas en el estator del motor de inducción

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Cristian H. De Angelo

2007-07-01

Full Text Available Resumen: Se presenta una estrategia para el diagnóstico de fallas en el estator de los motores de inducción mediante la información contenida en las tensiones y corrientes de alimentación. La estrategia propuesta está basada en la generación de un vector de residuos específicos por medio de un observador de estados, el cual permite detectar la fase dañada y cuantificar el ńumero de espiras en cortocircuito. La estrategia de diagnóstico es muy poco sensible a los cambios de carga o perturbaciones de la red de alimentación tales como armónicos o desbalances. Palabras clave: Diagnóstico de fallas, fallas en el estator, motor de inducción

Criterio no asintótico para el diseño de sistemas Bonus-Malus mediante GPBM

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Antonio Heras Martínez

2002-01-01

Full Text Available El diseño de sistemas Bonus-Malus habitualmente está basado en la distribución estacionaria de la probabilidad. Se supone que una póliza ha alcanzado el estado estacionario (n0 cuando la probabilidad de que dicha póliza pertenezca a la clase Ci es constante para todo n mayor o igual que n0 . Esta distribución estacionaria de probabilidad es sencilla de calcular. Su cálculo está basado en la Teoría de Cadenas de Markov y requiere que el sistema cumpla ciertas condiciones (sea Cadena de Markov irreducible y todos sus estados sean recurrentes en tiempo esperado finito. Podría ocurrir que estas condiciones no se cumplan y en este caso no se podría utilizar la distribución estacionaria. Por otra parte, los criterios basados en la distribución estacionaria no tienen en cuenta a las pólizas nuevas en la empresa ni a las que llevan poco tiempo. Por estos motivos, se propone un nuevo criterio que tenga en cuenta la edad de las pólizas de la cartera.

Métodos para el cálculo de los autovalores de una matriz.

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Palomar Anguas, Juan Manuel

2004-01-01

Full Text Available En la presente exposición se van a describir todas aquellas ideas que aun siguen en vigor para resolver el cálculo de los autovalores de una matriz, contribuyendo en el desarrollo de potentes algoritmos numéricos. Mediante la teoría de autovalores se posibilita la diagonalización de una matriz o la reducción a la forma de Jordan cuando la diagonalización no es posible. Dicho procedimiento facilita el análisis de un endomorfismo eligiendo de entre las matrices semejantes que lo representan, la más sencilla. Algunas aplicaciones del cálculo de los autovalores se refieren a la resolución de ecuaciones diferenciales. Sistemas lineales de ecuaciones en diferencias y potencias de una matriz. Comportamiento a largo plazo de las soluciones: estabilidad, estabilidad asintótica e inestabilidad. Matrices estocásticas y cadenas de Markov: estabilidad y vectores estacionarios Análisis de series temporales. Estudio de los sistemas dinámicos. Tales tipos de aplicaciones y muchas otras más, hacen del problema de autovalores una técnica básica con aplicación en todas las ramas científicas, entre ellas la economía.

APRENDIZAJE MOTOR Y SÍNDROME GENERAL DE ADAPTACIÓN

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F. J. Moreno

2010-09-01

Full Text Available

RESUMEN

Este trabajo examina las posibilidades del Síndrome General de Adaptación como un marco de referencia para explicar y predecir los cambios producidos por el Aprendizaje Motor. Se parte de la consideración del ser humano como un sistema complejo en continua interacción con su entorno y el aprendizaje como un proceso de adaptación a las condiciones impuestas por la tarea. Se propone el concepto de carga de práctica análogo al de carga de entrenamiento, considerando que la práctica, vehículo del aprendizaje, debe aplicarse como una estimulación suficiente como para desencadenar en el aprendiz una adaptación a un nuevo nivel de rendimiento. En base a esta propuesta, se relacionan los principios del entrenamiento deportivo con el aprendizaje de habilidades motrices. Se formula una perspectiva teórica que trata de explicar de forma común los procesos de modificación de los patrones motores independientemente del nivel de complejidad, conllevando los mismos principios relacionados con la adaptación a una carga y aportando criterios para elaborar unos principios generales de actuación que deberían ayudar a diseñar las tareas de aprendizaje.
Palabras Clave:Aprendizaje Motor, adaptación, sistemas complejos, entrenamiento, técnica.

ABSTRACT

This work examines the General Adaptation Syndrome like a suitable framework to explain motor learning processes. Human motor behaviour is viewed like a complex system continuously interacting in the environment. Motor learning is proposed as an adaptation process to the tasks constraints. Training loads and practice load are also considered analogous. Practice is the

Diseño e implementación de maletas didácticas con los mini PLCS logo y Zelio para aplicaciones de arranque e inversión de giro de motores.

OpenAIRE

Hermenegildo Cedeño, Byron Jose; Orellana Apolinario, Andrés Octavio

2015-01-01

La presente tesis: “Diseño e implementación de maletas didácticas con mini plc logo para aplicaciones de arranque e inversión de giro de motores” representa el desarrollo de tres módulos didácticos de pruebas para que los estudiantes fortalezcan sus conocimientos teóricos en la parte práctica implemantando y reconociendo el comportamiento de diferentes tipos de actuadores existentes en el mercado como lo son: contactares, guarda motores, temporizadores, LOGOs programables. Este trabajo b...

Variability and practice load in motor learning. [Variabilidad y carga de práctica en el aprendizaje motor].

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Francisco Javier Moreno

2015-01-01

Full Text Available Previous studies have pointed out the convenience of taking the characteristics of the skill to be learned and the intrinsic characteristics of the learners into account when designing practice tasks. Nevertheless, few studies have manipulated the amount of variable practice. The ability to adapt, as an inherent feature of biological systems, can be an adequate framework to explain and predict motor learning processes. This paper is based on adaption processes explained under the theory of allostasis and the general adaption syndrome and shares the background of the Dynamic Systems Theory, to propose the concept of practice load as a useful tool to quantify variability of practice in motor learning. From this standpoint, the conditions of variable practice are reviewed to be a stimulus in an adequate magnitude and direction to take the learner to a higher level of performance and hence to optimize motor learning. Resumen Muchos autores han recomendado la conveniencia de ajustar los niveles de práctica variable teniendo en cuenta las características de la tarea y la variabilidad intrínseca que muestra el aprendiz en la ejecución de la habilidad. Sin embargo, no son numerosos los trabajos que han manipulado varios niveles de cantidad de variabilidad al practicar. La capacidad de adaptación, como rasgo de los sistemas biológicos puede resultar un marco adecuado para afrontar esta cuestión. En este trabajo, apoyado en los procesos de adaptación explicados bajo las teorías de alostasis y el síndrome general de adaptación (GAS, y bajo presupuestos compartidos por la Teoría General de Sistemas Dinámicos, propondrá el concepto de carga de práctica como una herramienta para cuantificar la práctica en el aprendizaje motor. Bajo esta perspectiva se revisan las condiciones en las que la práctica en variabilidad debe modularse, para suponer una estimulación que facilite al aprendiz una adaptación a un nivel de rendimiento superior y con

Implantación del TPM en líneas semiautomáticas de motores eléctricos para la industria automovilística

OpenAIRE

Viñolo Serrano, Jorge

2004-01-01

El Proyecto final de carrera que desarrollo en el grupo Bosch, por medio del programa “Educació en Alternança” está encaminado a implantar el sistema o filosofía TPM (Mantenimiento Productivo Total) en unas líneas de producción de motores eléctricos para la industria automovilística, partiendo de un sistema de producción y mantenimiento “tradicional”, queriendo obtener finalmente un sistema tanto de producción como de mantenimiento “moderno”. El fin de implantar dicho sistema es, en primer lu...

A IMPORTÂNCIA DA MANUTENÇÃO EM MOTORES DIESEL

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Mário Lucas Santana Silva

2013-12-01

Full Text Available Deve-se tomar medidas necessárias para o bom funcionamento de motores e máquinas, medidas estas que devem levar em conta a conservação e a preservação da situação inicial. O conjunto destas medidas é chamado de manutenção, e com este objetivo, este artigo apresenta os tipos de manutenção, seu histórico, a importância da manutenção em motores a diesel e a forma desta manutenção, informando e classificando as vantagens e desvantagens apresentadas para os sistemas de injeção. Palavras-chave:

RANCANG BANGUN SIMULASI PEWARNAAN SEPEDA MOTOR BERBASIS KOMPUTER

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Hotmian Sitohang

2016-10-01

Full Text Available Belakang ini bisnis pewarnaan atau air brush motor sangat disukai. Setiap toko pengecatan atau pemasangan stiker selalu dipadati motor-motor yang baru maupun yang lama untuk  diwarnai atau di beri sticker agar warna asli tidak rusak dan pudar. Pewarnaan yang dilakukan pada sepeda motor meliputi pewarnaan body, tebeng depan, tebeng belakang, kaca lampu, spion, pelang dan bagian lainnya. Rata-rata para penggemar  pewarnaan kendaraan bermotor melakukan proses pewarnaan untuk tujuan  tertentu, misalnya motornya agar lebih menarik atau hanya ingin sekedar tampil beda.  Dari hasil observasi di Kota Palangka Raya terlihat setiap toko pewarnaan sepeda motor sangat diminati bahkan hampir setiap hari toko-toko pewarnaan penuh, sehingga membuat customer ngantri. Terkadang juga customer mau mewarnai tapi bingung menentukan warna apa yang sesuai dengan motornya. Sering kali juga terjadi sudah diwarnai ternyata tidak sesuai dengan cat awal motor atau warna nyorak. Penulis tertarik membuat simulasi pewarnaan motor berbasis komputer yang dimana nantinya akan dimasukkan gambar motor dan tinggal menyesuaikan seperti apa yang mau diwarnai. Bahkan disiapkan macam-macam pewarnaan motor yang populer saat ini. Aplikasi ini juga menyiapkan pewarnaan sebagian motor. Dimana kadang kala customer hanya mau mewarnai spion atau pelang, maka aplikasi ini akan memilih sesuai dengan yang mau diwarnai saja. Tujuan dari penelitian ini supaya mempermudah customer dalam menentukan pewarnaan motor, sedangkan manfaatnya untuk customer adalah lebih singkat waktu dan penyesuaian  warna motor.

Estimador de la carga (aire-GNC) aspirada por el motor de combustión interna duranrte condiciones transitorias de operación.

OpenAIRE

Barbieri, Andrés; Samat, David; Molina, Héctor

2005-01-01

Durante las operaciones transitorias de un motor, se requiere de una exacta relación aire combustible, a los efectos de optimizar la eficiencia y reducir las emisiones. Motores que de fabrica no están acondicionados para funcionar con gas y son transformados para funcionar con combustibles gaseosos (GNC) en los que se utiliza para su dosado mezcladores tipo Venturi, no brindan una respuesta satisfactoria para las condiciones antes expuestas. El presente trabajo describe y desarrol...

Procedimiento para el cálculo de los parámetros de un modelo térmico simplificado del motor asincrónico Parameter estimation procedure for an asynchronous motor simplified thermal model

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Julio R Gómez Sarduy

2011-06-01

Full Text Available En este trabajo se presenta un método para estimar las conductancias y capacitancias de un modelo térmico simplificado del motor asincrónico, utilizando una técnica de baja invasividad. El procedimiento permite predecir el incremento de temperatura del estator del motor asincrónico, tanto para régimen dinámico como en condiciones de estabilidad térmica. Se basa en la estimación paramétrica mediante un modelo de referencia, utilizando como optimizador un algoritmo genético (AG. Se logra en definitiva obtener los parámetros del modelo térmico con un ensayo más sencillo que lo requerido por otros métodos experimentales complejos o cálculos analíticos basados en datos de diseño. El procedimiento propuesto se puede llevar a cabo en condiciones propias de la industria y resulta atractivo su empleo en el análisis de calentamiento de estas máquinas. El método se valida a partir de un estudio de caso reportado en la literatura y se aplica a un caso real en la industria, lográndose una buena precisión.In this paper, an asynchronous motor simplified thermal model method for conductances and capacitances estimation is presented. A low invasive technique is used. The developed procedure allows the stator temperature rise prediction, not only for dynamic regimes, but also in case of thermal stability. A parametric estimation is done through a reference model, using a genetic algorithm (GA as optimizing method. The thermal model parameters are finally obtained with an easer experimental work, than the required by other complex experimental methods or by analytical calculations based on design data. The proposed procedure can be carry out in the particular conditions of industrial environment. Its application is specially useful for asynchronous machine thermal analysis. Using the data of a study case reported in literature, the method validation is done, and is applied in an industrial real case, with good precision resulted from it.

Modelación de un colector solar para calentamiento de aire; Modelling ofa solar collector for air heating

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Amadou Koulibaly

2015-09-01

Full Text Available En este trabajo es desarrollada la modelación de un colector solar plano para calentamiento de aire operado con convección natural. El análisis del colector mediante balances de masa y energía no estacionarios aplicados a cada uno de los elementos componentes del colector permitió desarrollar un programa en Visual Basic que simula el comportamiento dinámico del colector ante variaciones de las condiciones de operación y variaciones de los parámetros de diseño (dimensiones del colector, tipo de material de cubierta y dimensiones, material de la placa absorbedora y sus dimensiones, eficiencia óptica y tipo y espesor de aislamiento. Los resultados muestran que el software puede ser empleado para el diseño de colectores para calentamiento de aire, además de poder ser empleado para obtener las temperaturas de cada componente del colector y el rendimiento térmico instantáneo. El software también ofrece los elementos para determinar la constante de tiempo que caracteriza la dinámica del colector.In this paper the modeling of a flat solar collector for air heating was developed. This collector works with natural convection. The analysis of the collector was made using unsteady mass and energy balances applied to each component of collector. The equations were solved usinga Visual Basic code with the target to simulate the dynamics performance of the collector when the operating conditions and the design parameters are modified. The dimensions of the collector, the material and dimensions of the covert, the material and dimensions of the absorber plate, the optic efficiency and the type and thin of the insulator are the fundamentals design parameters that can be varied. The results of the simulation show that the software can be used for the design of collectors for heating air. Additionally, the software permits to determine the temperature of each component, the instantaneous efficiency of the collector and offers the elements to obtain

Modelo matemático en Simulink de un Motor de Reluctancia Conmutada con configuración 4/2; Mathematical Model of a 4/2 Switched Reluctance Motor in Simulink

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Luis Manuel Álvarez Tapia

2015-09-01

Full Text Available En el presente trabajo se creó un modelo matemático para el motor de reluctancia conmutada WEKA SR-30102 bifásico irregular de fabricación alemana utilizando la herramienta de diseño Simulink. Para la correcta descripción de los fenómenos eléctricos y mecánicos que ocurren dentro de la máquina se utilizaron las ecuaciones eléctricas y mecánicas, tomando en consideración las características no lineales del motor y la influencia a altas velocidades de fenómenos mecánicos. Dicho modelo se utilizó para la implementación de dos estrategias de control, dígase, control a lazo cerrado de la velocidad mediante modulación de ancho de pulso y con control por histéresis. Estas estrategias fueron aplicadas a un convertidor electrónico de potencia con una configuración 2q, que posteriormente aplica las señales de potencia al motor de reluctancia conmutada. Mediante la comparación de los resultados obtenidos en la simulación y de modo experimental se validó la precisión del modelo obtenido.In the present paper a mathematical model for the WEKA SR-30102 switched reluctance motor was created using the Simulink development suite. In order to accurately model its behavior, the non-linearity of the motor was taken into account. The mathematical equations that describe the mechanical and electrical properties of the motor were used in order to accurately model the corresponding effects that occur inside the machine. Two different control strategies were created, that is, a closed loop using pulse width modulation and another one using hysteresis control. The mathematical model was validated comparing the experimental and the simulation results.

Anthropometric and motor performance profile of elite futsal athletes

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Leandro Ricardo Altimari

2008-01-01

Full Text Available The purpose of the present study was to identify the anthropometric and motor performance profile of futsal (indoor soccer athletes in the second and third-placed teams in the Parana state championships (Brazil. Anthropometric (body mass, stature and skinfolds thickness and motor performance (modified abdominal test, shuttle run, race of 30 m and 40 s measures were obtained from twenty-seven male athletes (24.7 ± 6.4 years; 73.6 ± 7.6 kg; 174.8 ± 6.6 cm. For data analysis, athletes were grouped according to game positions. ANOVA one-way was used for comparisons between different positions, followed by Scheffé’s post hoc test, with p ABSTRACT Este estudo objetivou identificar o perfil antropométrico e o desempenho motor de atletas de futsal masculino, pertencentes às equipes finalistas do campeonato paranaense da categoria adulto, chave ouro. Para tanto, coletou-se medidas antropométricas (massa corporal, estatura e espessura de dobras cutâneas e de desempenho motor (testes abdominal modificado, shuttle run, corrida de 30 m e corrida de 40 s de vinte e sete atletas (24,7 ± 6,4 anos; 73,6 ± 7,6 kg; 174,8 ± 6,6 cm, do sexo masculino. Para a análise dos dados, agrupou-se os atletas de acordo com a posição de jogo. Anova one-way foi empregada para as comparações entre os jogadores das diferentes posições, seguida pelo teste post hoc de Scheffé, com P < 0,05. Verificou-se diferença signifi cante entre os jogadores de diferentes posições de jogo nas variáveis: massa corporal (alas < goleiros, P < 0,01, estatura (alas < pivôs e goleiros, P < 0,01 e massa corporal magra (alas < goleiros, P < 0,01. Não foram observadas diferenças significantes entre os jogadores das diferentes posições de jogo nas variáveis de desempenho motor. Os resultados encontrados no presente estudo sugerem que atletas de futsal apresentam, na maioria das variáveis analisadas, características antropométricas e de desempenho motor semelhantes entre

Adaptación de un motor de combustión interna alternativo de gasolina para su funcionamiento con hidrógeno como combustible. Aplicaciones energética y de automoción

OpenAIRE

Sáinz Casas, David

2016-01-01

En esta tesis doctoral se presentan los trabajos de investigación realizados recientemente en la Universidad Pública de Navarra sobre la conversión de motores de gasolina para su funcionamiento con hidrógeno, así como el desarrollo de aplicaciones demostrativas prácticas empleando estos motores. Esta línea de investigación es continuación de la producción electrolítica de hidrógeno con energía eólica [15-17]. El objetivo principal de esta tesis es la demostración práctica de la viabilidad de ...

Programa de intervenção motora para escolares com indicativo de transtorno do desenvolvimento da coordenação - TDC Motor intervention program for school children with signs of developmental coordination disorder - DCD

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Eva Vilma Alves da Silva

2011-04-01

Full Text Available Este estudo objetivou verificar os efeitos de um programa de intervenção motora para escolares com indicativo de Transtorno do Desenvolvimento da Coordenação. Participaram do estudo seis escolares na faixa etária de 10 anos, do gênero feminino e masculino, matriculados em uma escola municipal no interior do Estado de Santa Catarina. A avaliação motora foi mensurada por meio do Movement Assessement Battery for Children (MABC-2. O teste abrange as faixas etárias de três a 16 anos dentro de cada faixa etária são agrupadas oito tarefas em três categorias de habilidades: destreza manual, lançar e receber, equilíbrio. As intervenções foram baseadas na abordagem da Educação Física Desenvolvimentista em ambiente escolar. As sessões foram realizadas individualmente com 20 sessões de intervenção motora para cada escolar, num total de 120 sessões, com frequência de duas aulas semanais e com duração de 45 minutos. Para interpretação dos dados foi utilizado o teste Wilcoxon no pacote estatístico SPSS 13.0 for Windows. Os resultados evidenciaram diferenças estatisticamente significativas após a intervenção motora (pThis study aimed to verify the effects of a motor intervention program for students with signs of DCD. Six 10 year-old students, both male and female, who were registered at a municipal school in the interior of the state of Santa Catarina participated in the study. Motor capacity was measured using the Movement Assessment Battery for Children (MABC-2, one of the most commonly used instruments for assessing children's movement difficulties. The test encompasses the age groups of 3 to 16 years; for each age group, eight tasks are grouped into three skill categories: manual skill, throw and catch, balance. The interventions were based on the Developmental Physical Education approach in school environments. The sessions were done individually with 20 motor intervention sessions for each student, in a total of 120

Algoritmos genéticos locales

OpenAIRE

García-Martínez, Carlos; Lozano, Manuel

2007-01-01

Los Algoritmos Genéticos Locales son procedimientos que iterativamente re nan soluciones dadas. Su diferencia con procedimientos de mejora iterativa clásicos reside en el uso de operadores genéticos para realizar el re namiento. En este estudio presentamos un nuevo Algoritmo Genético Local Binario basado en un Algoritmo Genético Estacionario. Hemos comparado el Algoritmo Genético Local Binario con otros procedimientos de mejora iterativa de la literatura. Los res...

Determinación IN-SITU del factor de potencia y la eficiencia de motores asincrónicos a cargas parciales; Induction motor power factor and efficiency IN-SITU determination under partial loads.

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Percy Rafael Viego Felipe

2015-04-01

Full Text Available Los motores asincrónicos trifásicos no siempre operan a plena carga y por lo tanto, el factor de potencia y la eficiencia se ven afectados. Determinar estos valores a diferentes cargas, es la base para programas ahorro en la industria y los servicios. En este trabajo se presentan procedimientos para la estimación del factor de potencia y la eficiencia a cargas parciales, con una precisión acorde a los propósitos ingenieriles, baja invasividad y sin implicar para el usuario complejidades de equipamiento o de adquisición y procesamiento de datos. Se ofrecen distintas variantes para la estimación del factor de potencia y la eficiencia, según los datos con que se cuente. Se comparan los resultados de los métodos propuestos con la información de catálogos comerciales. Se realiza un análisis con motores de distinta potencia y velocidad, que demuestra que se logra buena precisión para los propósitos señalados. Three phase induction motors are rarely operating at full load and, in consequence, power factor and efficiency are affected. Determining these values for different partial loads is needed for energy saving programs in industrial and service enterprises. In this work, procedures are given for power factor and efficiency estimation at different loads. These procedures are low or not-invasive, have a good precision for engineering purposes, and do not require neither complex equipment nor complicated acquisition and processing data systems Different ways for estimating the before mentioned parameters, depending on the known data, are given. The results of the proposed procedures are compared with those of manufacturer catalogs. A comparative analysis considering motors of different output power and speed is done, and it shows that the results are enough accurate for the established purposes.

Diagnosis on line and off line of induction motors of low, medium and high voltage; Diagnostico en linea y fuera de linea de motores de induccion de baja, mediana y alta tension

Energy Technology Data Exchange (ETDEWEB)

Carvajal, Francisco Antonio; Ramirez, Jose Manuel; Arcos, Luis Fernando [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

1999-07-01

The induction motors of low, medium and high voltage are the electrical equipment of greatest application in industry. The importance which they have in the different productive processes does necessary to assure its operative continuity. The anticipated detection of a possible cause of fault allows to plan, with maintenance aims, the programmed removal of the motor. In this article are presented the results of the activities nowadays performed by Management of Electrical Equipment of the Instituto de Investigaciones Electricas (IIE) for the development and application of online diagnosis techniques for induction motors up to 13.8 kV. [Spanish] Los motores de induccion de baja, mediana y alta tension son los equipos eletricos de mayor aplicacion en la industria. La importancia que tienen en los diferentes procesos productivos hace necesario asegurar su continuidad operativa. La deteccion anticipada de una posible causa de falla permite planear, con fines de mantenimiento, la remocion programada del motor. En este articulo se presentan los resultados de las actividades que realiza actualmente la Gerencia de equipos Electricos del Instituto de investigaciones Electricas (IIE) para el desarrollo y la aplicacion de tecnicas de diagnostico en linea para motores de induccion de hasta 13.8 kV.

Modelo computacional para la liofilización de alimentos de geometría finita

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Héctor E. Gómez H.

2003-01-01

Full Text Available La liofilización es una técnica de conservación por deshidratación aplicada a productos químicos, farmacéuticos, médicos, biológicos y alimenticios. El proceso es también llamado criodesecación porque consiste primero en congelar un producto húmedo y luego en vaporizar directamente el hielo a baja presión. Este fenómeno es conocido como sublimación y era ya practicado por los incas del Perú, desde el siglo XIII, para conservar papas. Los productos liofilizados, a diferencia de los deshidratados por otras técnicas de secado, conservan prácticamente en 100% su forma y propiedades naturales, tienen mayor vida de anaquel y son fácilmente rehidratables. En el presente trabajo la liofilización es estudiada experimentalmente y caracterizada por medio de un modelo matemático y computacional. Para ello fue utilizada una hortaliza: la papa Solanum tuberosum, variedad blanca, como material para el modelado de la liofilización por contacto. Se prepararon muestras individuales en forma de placas y cilindros finitos a tres espesores diferentes. Se operó a dos presiones de vacío y tres temperaturas de calentamiento. Se obtuvieron así 36 cinéticas de deshidratación y de temperatura del producto en monocapa, con 8 repeticiones cada una. Se propone un modelo de liofilización que considera tres frentes de sublimación que se retiran uniformemente pero a velocidades interdependientes. Para el estudio se recurrió a las leyes de Fick y de Fourier en estado cuasi-estacionario, considerando despreciable el colapso en el producto. Las temperaturas de cada frente de sublimación se consideran variables. El modelo dinámico resultante es un sistema de tres ecuaciones algebraicas no lineales y tres ecuaciones diferenciales ordinarias. Para la solución del sistema de ecuaciones diferenciales-algebraicas se recurrió a los algoritmos acoplados de Runge-Kutta y Newton-Raphson. Para la estimación de los parámetros de transporte o coeficientes

Criterios y metodología para la determinación de los parámetros dinámicos y cinemáticos para la remotorización.

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M. Cárdenas Garnier

2008-05-01

Full Text Available La remotorización, ha significado una valiosa opción para solucionar los problemas que se presentan en los medios de transporte para alargar la vida útil a los equipos existentes, para disminuir los altos consumos de combustible, o bien porque en ocasiones se hace imposible adquirir el motor y la caja de velocidades originales del vehículo. En el presente trabajo se discuten los criterios mínimos y necesarios, así como la metodología para el cálculo de los parámetros o indicadores que se han seleccionado como criterio para la comparación de las variantes entre si (motor original y motor nuevo, se llega a resultados sobre la propuesta y se presentan conclusiones y recomendaciones al respecto. Title: Criteria and methodology for the determination of dynamic and cinematic parameters for engine exchange.Engine exchange is a valuable option to solve the problems that show up in the means of transportation to increase the useful life of the existent vehicles in order to decrease the high consumptions of fuel, or because to acquire the original engine and gearbox of vehicle sometimes becomes impossible. Present paper discussed minimal and necessary criteria, as well as the methodology for the calculation of the parameters or indicators that are been selected as a comparison criteria among the considered variants (original and new engine, this allows reach results about proposal, conclusions are presented.

Comparação do desenvolvimento motor de lactentes de mães adolescentes e adultas Motor development comparison between infants of adolescent and adult mothers

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Naiane Sartori

2010-12-01

Full Text Available Este estudo objetivou caracterizar o desempenho motor de bebês de 0 a 16 meses, comparando o de bebês nascidos de mães adolescentes ao de bebês de mães adultas. Participaram 80 bebês, sendo 40 de mães adolescentes e 40 de mães adultas. Os instrumentos avaliativos foram a escala motora infantil de Alberta AIMS (Alberta infant motor scale e questionário para identificar as características biológicas. Os dados foram analisados estatisticamente. Os resultados da AIMS mostram pior desempenho motor dos bebês de mães adolescentes (p=0,002; p=0,001, além de suas inadequadas aquisições motoras nas posturas prono e em pé. Não foi encontrada associação significativa entre a maioria dos fatores biológicos analisados e o desenvolvimento motor dos bebês. Os resultados sugerem que a idade materna pode ser considerada fator de risco para atraso motor em crianças, porém ressalta-se a interação de diferentes fatores, aqui não controlados, influenciando as aquisições motoras de crianças, tais como as demandas da tarefa e as condições do ambiente.The purpose of the study was to compare motor development of infants aged 0 to 16 months born of teenage mothers to those of adult mothers. Eighty babies were assessed, 40 of which the children of teenage mothers, and 40 of adult mothers. Instruments used were the Alberta infant motor scale (AIMS and a questionnaire to collect biological information. Data were statistically analysed. Results show teenage mothers' infants to have delayed motor development as compared to adult mothers' ones (p=0.002; p=0.001, as well as their poor motor acquisitions in prone and standing positions. No association was found between infants' motor development and most of the biological factors analysed. Results hence suggest that early maternal age may be considered a risk factor to motor delay in infants, but attention should be paid to other factors such as task requirements and environmental conditions (here

Control de velocidad del motor de indución empleando linealización por realimentación de estados Speed control of induction motor using state feedback linearization

OpenAIRE

Eduardo Giraldo Suárez; Santiago Sánchez Acevedo

2009-01-01

Este documento presenta la aplicación de la técnica de control no lineal clásica llamada linealización por realimentación de variables de estado. Se hace una aplicación en el motor de inducción, la variable a controlar es la velocidad del eje del motor, el sistema emplea el esquema de control vectorial para máquinas de corriente alterna desarrollado en las últimas décadas; este método es análogo a la técnica de control del motor de corriente directa. El modelo del motor de inducción se descri...

Pre-diseño de un motor eléctrico para el accionamiento de un automotor

OpenAIRE

Pernia Nieto, Carlos

2017-01-01

El presente proyecto versa sobre el pre-diseño de un motor síncrono de imanes permanentes. La motivación que ha llevado al planteamiento y realización de este trabajo es la necesidad actual de mejorar los motores eléctricos utilizados en tracción ferroviaria. Estos motores son en su mayor parte motores trifásicos de tipo asíncrono, seguidos en número por motores trifásicos síncronos y, en muy pocos casos, de corriente continua, siendo la mayoría de estos últimos usados en ferrocarriles antig...

Diseño de un sistema de análisis temporal y espectral para detectar fallas por vibración en motores eléctricos

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Francisco Ernesto Moreno-García

2014-12-01

Full Text Available El documento se basa en el desarrollo experimental de un sistema de medición y análisis de vibraciones para brindar un estudio de las más relevantes variables utilizadas en el análisis espectral de motores eléctricos, con el fin de detectar posibles fallas. Dicho sistema de análisis fue implementado en un banco de pruebas elaborado por el Grupo de Investigación en Automatización y Control (GIAC, de la Universidad Francisco de Paula Santander.

Uso de un nuevo modelo CFD para la simulación de inyectores y chorros en condiciones de motor. Mejora y puesta en marcha

OpenAIRE

SOÑES BORI, JAVIER

2016-01-01

[ES] El estudio del proceso de inyección de combustible en los MCIA es fundamental para mejorar la eficiencia de la combustión, sobre todo en los motores de inyección directa. Debido a las duras condiciones de operación, realizar experimentos en condiciones reales es difícil y costoso, por eso se utilizan a menudo modelos computacionales. En este trabajo se propone usar un nuevo modelo capaz de simular el flujo en el interior de las toberas y en la cámara de combustión a la vez, un nuevo mode...

Desempenho motor fino e funcionalidade em crianças com síndrome de Down Fine motor performance and functionality in children with Down syndrome

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Aline Cirelli Coppede

2012-12-01

Full Text Available O objetivo do estudo foi comparar crianças com síndrome de Down (SD e crianças típicas quanto ao desempenho motor fino, avaliado pela Bayley Scales of Infant and Toddler Development - Third Edition (BSITD-III, e o desempenho em autocuidado segundo o Inventário Pediátrico de Avaliação de Incapacidade (PEDI; e investigar associação entre ambos os domínios. Participaram 12 crianças típicas e 12 crianças com SD, avaliadas na idade de 2 anos. As crianças com SD apresentaram desempenho motor fino e funcionalidade inferior às crianças típicas, possivelmente por dificuldades em desempenhar tarefas que exijam destreza e coordenação manual, como as que compõem a BSITD-III. Apesar disso, sua pontuação em autocuidado foi adequada para a faixa etária, possivelmente porque as habilidades funcionais exigidas nesse período, como retirar calçados/vestimenta, impõem menor demanda motora fina do que tarefas da BSITD-III. Esse fato pode ter contribuído para o bom desempenho funcional das crianças com SD, e para a ausência de associação entre os domínios. Fatores como os cuidados oferecidos à criança pelos cuidadores, bem como ambientes estimuladores provavelmente também contribuíram para os resultados.The aim of study was to compare typically-developing children and children with Down syndrome (DS for their fine motor performance, measured by the Bayley Scales of Infant and Toddler Development - Third Edition (BSITD-III, and for their functional performance in self-care, measured by the Pediatric Evaluation of Disability Inventory (PEDI. Associations between these areas were also investigated. Twelve typically-developing children and 12 children with DS were assessed at the age of 2 years. The children with DS performed poorly in fine motor skills when compared with typical children, which may be explained by the complex motor skills involved in the BSITD-III's tasks. Their self-care scores were also lower in comparison with the

Electrical energy saving in motors and frequency variators; Ahorro de energia electrica en motores y variadores de frecuencia

Energy Technology Data Exchange (ETDEWEB)

Garcia Neri, Roger [Comision Federal de Electricidad (CFE) (Mexico)

2005-07-01

The necessity of saving energy is urgent and undeniable. We must already begin with the rational use of energy. Which is obtaining the maximum benefit of the consumed energy and of the necessary facilities for its generation, transmission and use. Guaranteeing at the same time an operation free of interferences or interruptions for the users. The electricity in alternating current does not allow its storage, reason why it is necessary to generate and distribute it at the precise moment when it is required. This forces to determine the proportions of the generation facilities, to be able to feed the periods of maximum demand called {sup p}eaks{sup .} It is this very point where the problem of the inappropriate use of the electrical energy starts. The energy waste is self-evident during the periods of low demand because of the low efficiency of the sub-utilized facilities. Electrical motors of the induction type use approximately more than 60% of the energy in the industry. If we use high efficiency motors instead of standard motors, a better advantage of the energy demanded from Comision Federal de Electricidad (CFE) is obtained. [Spanish] Es impostergable e innegable la necesidad de ahorrar energia. Tenemos que empezar ya con el uso racional de la energia: Obtener el maximo beneficio de la energia consumida y de las instalaciones necesarias para su generacion, transmision y utilizacion. Garantizando a los usuarios un funcionamiento sin interferencias o interrupciones. La electricidad en corriente alterna no permite su almacenamiento, por lo que es necesario generarla y distribuirla en el momento preciso en que es requerida. Esto obliga a dimensionar las instalaciones de generacion, para poder alimentar los periodos de maxima demanda llamados pico. Desde esta parte inicia el problema de la mala utilizacion de la energia electrica. Ya que en los periodos de baja demanda, las instalaciones se encuentran subutilizadas y si su eficiencia es muy baja, el desperdicio de

Mezclas gasolina-etanol en motores de combustión interna en Colombia

OpenAIRE

Juan Mantilla; Carlos Galeano; Alejandro Muñoz

2016-01-01

En este trabajo se analiza el cambio sobre el desempeño y las emisiones de los motores encendidos por chispa cuando la gasolina es reemplazada por una mezcla de gasolina y etanol. Inicialmente se investiga la diferencia en las propiedades fisicoquímicas del combustible, y sus posibles efectos sobre el motor. Posteriormente se examina el efecto documentado del cambio de combustible en el desempeño y las emisiones del motor. Para llevar a cabo estos objetivos se realizó una revisión bibliográfi...

Diagnóstico diferencial dos distúrbios motores esofagianos pelas características da disfagia Differential diagnosis of esophageal motor disorders based in characteristics of dysphagia

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Gerson R. DOMINGUES

2001-01-01

Full Text Available Racional -- A disfagia é um dos principais sintomas das doenças do esôfago e sua caracterização é importante para formulação de hipóteses diagnósticas e condução da propedêutica. A anamnese freqüentemente permite diferenciar as disfagias orgânicas das funcionais, porém a literatura carece de dados caracterizando este sintoma entre os diferentes distúrbios motores do esôfago. Objetivo - Avaliar se é possível a distinção entre os diferentes distúrbios motores diagnosticados pela esofagomanometria, tomando-se por base as características da disfagia. Métodos - Foram analisadas de forma retrospectiva, as características da disfagia (relação com a consistência do bolo alimentar, caráter e localização em 133 pacientes que realizaram esofagomanometria para esclarecimento diagnóstico. Resultados - A esofagomanometria foi anormal em 85% dos pacientes. As características da disfagia foram comparadas nos grupos de pacientes com acalásia, alterações espáticas do esôfago, distúrbios motores inespecíficos e exame normal. A distinção precisa entre os diferentes diagnósticos não foi possível, porém algumas características da disfagia puderam apontar para um ou outro grupo. Assim, nos pacientes com acalásia, a disfagia concomitante para sólidos e líquidos, de caráter constante e de localização baixa foi mais prevalente em relação a todos os outros grupos. Disfagia intermitente foi encontrada com maior freqüência nos portadores de alterações espáticas. As características da disfagia dos distúrbios motores inespecíficos se assemelharam às observadas nos pacientes com exame manométrico normal, sendo freqüentemente referida na região cervical. Conclusões - As características da disfagia podem auxiliar no diagnóstico presuntivo dos distúrbios motores, porém o estudo manométrico é necessário para o diagnóstico definitivo.Background - Dysphagia is one of principal symptoms of esophageal

Caracterización, obtención y validación del modelo dinámico de un motor de inducción con rótor devanado para su utilización como DFIG

OpenAIRE

Bañón Martín, José Miguel

2016-01-01

En este proyecto se pretende realizar la caracterización de un motor trifásico de inducción de rotor devanado. Siguiendo los pasos y especificaciones que nos indique la norma UNE. Las máquinas eléctricas juegan un papel muy importante en la actualidad, tanto como generador como motor. Nuestro trabajo irá enfocado a una máquina de inducción ampliamente utilizada en la industria. Para entrar en contacto con el mundo de las máquinas eléctricas utilizaremos una serie de libros básicos sobre es...

MODELO PARA DETERMINAR FUNÇÕES TRANSFERÊNCIA PARA ANÁLISE DE ESTABILIDADE DE VANTS

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Igor Mayer Soares

2017-01-01

Full Text Available Neste trabalho foi apresentado um modelo para determinar as funções de transferência para análise da estabilidade longitudinal de Veículos Aéreos Não Tripulados (VANT através do desenvolvimento simplificado das equações do movimento de aeronaves. O sistema foi simplificado considerando que o motor e o arrasto na superfície de comando não influenciam na dinâmica do veículo, pois o mesmo é significativamente menor que um avião. Analisamos também a resposta em função do tempo para as deflexões das superfícies de comando. Nos resultados apresentados é possível perceber que mesmo simples, o modelo oferece uma boa aproximação para análise dinâmica de VANTs e predizer sua estabilidade e qualidade de voo.

Control of Position for a Telescope with Stepping Motors

OpenAIRE

Quintero Salazar, Edwin Andrés; Gallego Becerra, Hugo Armando; Gallego Orozco, Hoover

2008-01-01

En este documento se muestran los resultados obtenidos al construir un control electrónico de posición para un telescopio reflector de 15 cm de objetivo, con motores paso a paso manejados desde un microcontrolador. También se ilustra el diseño circuital realizado, la simulación obtenida en la herramienta informática Proteus, el software desarrollado en lenguaje ensamblador para el microcontrolador, y el circuito final resultante montado sobre protoboard. In this paper the obtained resul...

Desarrollo de un videojuego para dispositivos móviles

OpenAIRE

Ruiz Pérez, Francisco

2016-01-01

Los dispositivos móviles se han convertido en una de las principales plataformas para videojuegos. Una de las principales problemáticas al desarrollar aplicaciones para estos dispositivos es la alta fragmentación que existe en cuanto a sistemas operativos y características de la interfaz. Existen determinadas librerías y motores, tanto nativas como multiplataforma, dirigidas a resolver este problema.

Core y sistema de control neuro-motor: mecanismos básicos para la estabilidad del raquis lumbar

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Víctor SEGARRA

2014-09-01

Full Text Available El "CORE" es un concepto funcional que engloba la integración de tres sistemas cuyo óptimo funcionamiento garantiza la realización de tareas con una mayor eficacia y seguridad a nivel raquídeo, permitiendo adecuados niveles de estabilidad y control del movimiento. En este sentido, a fin de afrontar con éxito retos que demanden un control dinámico de la columna y la pelvis, el SNC debe aplicar estrategias diferentes, sopesando as fuerzas internas y externas con el fin de proporcionar una respuesta muscular que permita un movimiento óptimo y resista cualquier posible perturbación. En el presente manuscrito se revisa de forma aplicada, las bases, atendiendo a la información disponible actualmente, de los mecanismos básicos de control motor y las posibles alteraciones en los mismos a ser considerados por los especialistas en ejercicio respecto a su intervención mediante programas de ejercicio para la mejora de la capacidad de estabilización raquídea.

Comparison the programs of energy efficiency for industrial electric motors; Comparacao de programas de eficiencia energetica para motores eletricos industriais

Energy Technology Data Exchange (ETDEWEB)

Mariotoni, Carlos Alberto; Naturesa, Jim Silva; Santos Junior, Joubert Rodrigues dos; Demanboro, Antonio Carlos [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo. Nucleo Interdisciplinar de Planejamento Energetico (NIPE)]. E-mail: cam@fec.unicamp.br; jimnaturesa@yahoo.com; joubert@fec.unicamp.br; anto1810@fec.unicamp.br

2006-07-01

This paper aims to present a comparison among the existing programs of energy efficiency for industrial electric motors in Brazil, in the United States of America and in the European Community. The analysis is restricted to the action of each program, considering that the mentioned countries present distinct economical, political and social characteristics. Therefore, it is intended to discuss the main barriers existing in the Brazilian industrial context which cause difficulties to develop a program of electric motors efficiency and to indicate some ways to overcome those barriers. (author)

Evaluación del funcionamiento de motores de combustión interna trabajando con biodiesel.

OpenAIRE

R. Piloto Rodríguez; R. Sierens; S. Verhelst; N. Ferrer Frontela

2008-01-01

En el presente trabajo se determinó la característica exterior de velocidad para dos motores de combustión interna trabajando con combustible biodiesel procedente de varias fuentes naturales y se comparó con la característica exterior de velocidad de los motores originalmente trabajando con combustible diesel. Los motores fueron evaluados con variaciones de carga y velocidad. En uno de los motores ensayados fue determinada la presión en el interior de la cámara de combustión con el objetivo d...

Qualification of electric motors class 1E for supply of motors and its repair; Calificacion de motores electricos clase 1E para el suministro de motores alternativos a los orginales y su reparacion

Energy Technology Data Exchange (ETDEWEB)

Perez, E.; Gonzalez, J. J.; Fernandez, A.; Garcia, D.

2005-07-01

Different original suppliers of nuclear grade equipment have either disappeared or discontinued the manufacture of this kind equipment. Under this situation nuclear plants are experiencing difficulties when dealing with the substitution or maintenance of these equipment. Tecnatom and Cantarey have developed a new line of Class 1E qualified electric low voltage motors which can be used as an alternative to originally installed safety-related motors or for its repair and maintenance. (Author)

Difusividad térmica de mezclas de ldpe y pp en estado fundido

OpenAIRE

Yánez, Genhli; Rodríguez Pérez, Miguel Ángel; Almanza, Ovidio

2012-01-01

Se reportan los resultados experimentales de la medición de la difusividad térmica de dos especies poliméricas: polietileno de baja densidad (LDPE) y polipropileno (PP). Las medidas fueron realizadas en condiciones de flujo de calor no estacionario, usando un dispositivo especialmente construido para ello y a temperatura alrededor de la de fusión de los materiales. Los resultados experi-mentales del perfil de temperatura a través de las muestras, producto de la existencia de un gradiente de t...

The application of frequency converters and/or high efficiency motors in fans; Aplicacion de convertidores de frecuencia y/o motores de alta eficiencia en ventiladores

Energy Technology Data Exchange (ETDEWEB)

Delmar S, A. [Eficiencia Energetica, S.A. de C.V., Mexico, D. F. (Mexico)

1995-12-31

In this paper the characteristic curves of fans will be analyzed, some of the opportunities for energy conservation that can be applied and the precautions that have to be taken when a high efficiency motor is selected for this type of equipment. [Espanol] En este articulo se describiran las curvas caracteristicas de los ventiladores, algunas de las oportunidades de ahorro de energia que se pueden aplicar y las precauciones que hay que tomar cuando se seleccione un motor de alta eficiencia para estos equipos

The application of frequency converters and/or high efficiency motors in fans; Aplicacion de convertidores de frecuencia y/o motores de alta eficiencia en ventiladores

Energy Technology Data Exchange (ETDEWEB)

Delmar S, A [Eficiencia Energetica, S.A. de C.V., Mexico, D. F. (Mexico)

1996-12-31

In this paper the characteristic curves of fans will be analyzed, some of the opportunities for energy conservation that can be applied and the precautions that have to be taken when a high efficiency motor is selected for this type of equipment. [Espanol] En este articulo se describiran las curvas caracteristicas de los ventiladores, algunas de las oportunidades de ahorro de energia que se pueden aplicar y las precauciones que hay que tomar cuando se seleccione un motor de alta eficiencia para estos equipos

O ensino do esporte para crianças e jovens: considerações sobre uma fase do processo de desenvolvimento motor esquecida La enseñanza del deporte para niños y jóvenes: consideraciones sobre una etapa olvidada del desarrollo motor The teaching of sport to chidren and youth: considerations about a forgotten phase of motor development

Directory of Open Access Journals (Sweden)

Go Tani

2012-06-01

Full Text Available O processo ensino-aprendizagem pode ser visto como um sistema constituído pela interação de três componentes - professor, aluno e matéria - que tem por meta promover mudanças efetivas nos comportamentos, capacidades e competências do aluno. Como numa visão sistêmica do processo ensino-aprendizagem, a função de um determinado componente implica sempre o estabelecimento de relação entre os dois componentes que restam, o papel principal do professor é estabelecer relação entre o aluno e a matéria. Neste contexto, a questão central é saber em que se basear para estabelecer essa relação. O presente ensaio parte da assunção de que o conhecimento sobre o desenvolvimento motor constitui um elemento fundamental quando a matéria de ensino é o esporte, discute uma fase desse processo que tem sido sistematicamente esquecida procurando identificar as suas possíveis causas e consequências e apresenta algumas sugestões para trabalhar com essa fase.The teaching-learning process can be viewed as a system constituted by the interaction of three components - teacher, learner and subject matter - whose goal is to promote the effective changes in the learner´s behaviors, capacities and competences. In a systemic view of the teaching-learning process the role played by a given component always implies the establishment of relations between the two remaining components. Thus, the role of the teacher is to establish relations between learner and subject matter. The main question to the teacher is on what to rely upon to establish these relations. The present essay departs from the assumption that knowledge about motor development constitutes a fundamental element when sport is the subject matter. It discusses a phase of that process that has been systematically forgotten in the teaching of sports trying to identify possible causes and consequences, and presents some suggestions of procedures to work with that phase.

Desenvolvimento motor de crianças pré-termo moderadas aos sete e oito anos de idade Motor development of moderate preterm children at seven and eight years of age

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Ana Cristina Resende Camargos

2011-06-01

Full Text Available Crianças pré-termo podem apresentar distúrbios leves do desenvolvimento motor, que podem ser imperceptíveis até a idade pré-escolar ou escolar. O objetivo desse estudo foi comparar o desenvolvimento motor de crianças pré-termo moderadas com crianças a termo aos sete e oito anos de idade. Foram coletados dados de 13 crianças pré-termo e 13 crianças a termo de uma escola da rede municipal de Betim. Foi utilizada a Escala de Desenvolvimento Motor para avaliar motricidade fina, motricidade global, equilíbrio, esquema corporal, organização espacial e organização temporal, bem como a idade motora geral e o quociente motor geral. O teste Mann-Whitney foi utilizado para comparar as idades motoras e os quocientes motores entre os grupos. Foi encontrada diferença significativa somente nos valores da motricidade fina entre os grupos (p=0,01, sendo que o grupo pré-termo apresentou desempenho inferior. Dessa forma, crianças pré-termo moderadas que não apresentam características de alto risco biológico ao nascimento também podem necessitar de acompanhamento ambulatorial até a idade escolar.Preterm children may have light motor developmental impairments, which may be imperceptible until pre-school age or even school age. The aim of this study was to compare the motor development of moderate preterm children with full-term ones at seven and eight years of age. Data from 13 preterm and 13 full-term children were collected from a public school in Betim-MG. The Motor Development Scale was used to access fine and global motricity, balance, body scheme, spatial organization, time organization, as well as general motor age and general motor quotient. The Mann-Whitney's Test was used to compare the motor ages and motor quotients between the groups. A significant difference was only found in the fine motricity values between the groups (p=0.01, the preterm group having shown a poorer performance. Therefore, moderate preterm children who do not

Evaluar la Coordinación Motriz Global en Educación Secundaria: El Test Motor SportComp. [Motor co-ordination assessment in Secondary Education: The SportComp Test].

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Luis Miguel Ruiz-Perez

2017-07-01

Full Text Available El objetivo de este estudio fue el desarrollo y evaluación métrica del Test Motor SportComp, instrumento diseñado para ayudar a los profesores de educación física en la evaluación de la coordinación motriz global de sus alumnos de Educación Secundaria. En la actualidad no existen tests que evalúen la coordinación motriz de forma válida y fiable y que puedan ser empleados por el profesorado de educación física en el contexto de sus clases de manera rápida y económica. El presente test se construyó a partir de una revisión de la literatura científica sobre medición motriz entre los 12 y 17 años. La validez de contenido de las pruebas empleadas fue evaluada por expertos y las pruebas seleccionadas fueron aplicadas a 5732 escolares de estas edades. Se analizaron los resultados mediante la técnica de componentes principales que permitió la extracción de un solo factor formado por 5 tareas motrices relacionadas con la coordinación motriz global. El Coeficiente de Correlación Intraclase (CCI permitió obtener una fiabilidad test-retest de (CCI=0,91. Asimismo, mostró una satisfactoria validez criterial con la batería MABC-2 uno de los más reconocidos para la detección de problemas de coordinación motriz. Las propiedades métricas del presente test son muy satisfactorias y ofrecen buenas posibilidades para ser empleado por los profesores de educación física en sus clases por su bajo coste económico, poco tiempo de aplicación reclamado y poseer normas ajustadas por edad y sexo. Asimismo, este test ofrece el potencial de poder servir para detectar a los alumnos con sospecha de poseer problemas de coordinación motriz y por lo tanto contribuir a la mejora de los programas de educación física que palíen esta condición. Abstract The purpose of this study was the development and metric evaluation of the SportComp Motor Test, an instrument designed to aid physical education teachers in the assessment of gross motor

diesel-biogás para generación de electricidad

Directory of Open Access Journals (Sweden)

Iván Darío Bedoya Caro

2007-01-01

Full Text Available En este trabajo se presentan los resultados obtenidos en la caracterización mecánica y ambiental de un motor de encendido por compresión (MEC para generación de electricidad, operando con diesel y en modo dual diesel-biogás. El motor ha sido acoplado a un generador eléctrico y evaluado a un régimen de 1.800 rpm con varios grados de carga, el biogás se ha simulado con una composición típica de 60% metano (CH4 y 40% de dióxido de carbono (CO2. Se han encontrado disminuciones en la eficiencia efectiva al reducir la cantidad de combustible piloto en modo dual, al igual que aumentos considerables en las emisiones de CH4 y monóxido de carbono (CO, la opacidad del humo no varía significativamente en modo dual, pero muestra una reducción drástica al compararla con las medidas para el motor en modo diesel. Los resultados obtenidos confirman la importancia del uso del biogás como alternativa para mecanismos de desarrollo limpio y como aporte a la disminución de la dependencia energética y económica de los combustibles fósiles

Estimación de la característica de Inductancia de fase del Motor de Reluctancia Conmutada MFR 132.1 Estimation of phase inductance profile of MFR 132.1 switched reluctance motor

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Javier Quintana Santos

2011-06-01

Full Text Available En el presente trabajo se enuncia la idea fundamental en la que se basan todos los métodos empleados para la estimación de los parámetros de fase de los motores de reluctancia conmutada. Se describe, además, un algoritmo de división con punto decimal fijo en lenguaje VHDL. El algoritmo descrito se utiliza posteriormente para la estimación de la inductancia de fase del motor de reluctancia conmutada MFR 132.1, mediante el empleo de la técnica invasiva de modulación de amplitud con señales de tensión pulsantes de tres estados. Se diseñó y construyó una instalación experimental sobre la base de un FPGA de Actel, de la familia ProASIC 3 modelo A3P250, para el procesamiento de las señales. Finalmente se exponen y comentan las características de inductancia de fase del motor de reluctancia MFR 132.1, obtenidas.  In the present work is enunciated the fundamental idea of all the methods used for the estimation of phase parameters in the switched reluctance motors. The fixed point division algorithm employed to estimate the inactive phase inductance profile of the MFR 132.1 switched reluctance motor, is described in VHDL programming language. The algorithm implements the intrusive estimation technique of amplitude modulation with three states pulsating signals. The structure of the experimental set up for the digital signal processing, which is based on the Actel FPGA ProAsic 3 A3P250 development kit, is depicted. Finally, the inactive phase’s inductance profiles, which were experimentally obtained, are shown for different voltage values in the Direct Current converter link.

Rehabilitación de un motor de cuatro tiempos y elaboración de guías de laboratorío y de mantenimiento

OpenAIRE

Polit Chica, Javier; Barriga A, Alfredo

2009-01-01

Para empezar este proyecto y ejecutarlo tanto teóricamente como prácticamente, se necesitó rehabilitar el motor y ponerlo a punto, lo que involucró el cambio de algunas piezas que no estaban en funcionamiento y arreglo de otras que lo requerían. Una vez que logramos que el motor funcione perfectamente, se procedió a realizar las pruebas requeridas para poder concluir que el motor estaba funcionando bien, estas prueba involucraban el cambio de algunos parámetros como carga, número de revolucio...

Modelling reaustenitisation in Fe-C steels with concentration-dependent diffusivity of carbon

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Mancini, R.

2002-12-01

Full Text Available A finite difference method used to model reaustenitisation from a ferrite/cementite mixture in Fe-C steels is presented in this paper. Concentration-dependent carbon diffusivity in austenite is taken into account in order to generalize our earlier numerical model. We select some parameters, such as cementite dissolution time, and compare their values as calculated by different approximations available in the literature (in particular at steady state for planar and spherical geometries. When the dependence of diffusivity on concentration or temperature is increased, the steady state approximation fails to predict correctly the above mentioned parameters and the use of numerical techniques becomes indispensable.

En este trabajo se presenta un método numérico de diferencias finitas para modelar la reaustenización en aceros Fe-C a partir de una distribución inicial de ferrita y cementita. Se tiene en cuenta la dependencia de la difusividad en la austenita con la concentración de carbono, a fin de generalizar el propio modelo numérico previo. Se han seleccionado algunos parámetros, como el tiempo de disolución de la cementita, para comparar los valores obtenidos en este caso con los calculados con diferentes aproximaciones (en particular con la de estado estacionario para los casos de geometrías plana y esférica. Los resultados obtenidos muestran que, cuando la difusividad depende fuertemente de la concentración, la aproximación de estado estacionario no predice correctamente los parámetros calculados y se hace imprescindible la aplicación de métodos numéricos.

Robot Saltador y Procedimiento para su Control

OpenAIRE

Akinfiev, Teodor; Armada, Manuel; Fernández, Roemi; Montes, Héctor

2005-01-01

Robot saltador para el movimiento en terrenos con obstáculos, que contiene al menos un resorte (4) con uno de sus extremos unido al cuerpo (1) del robot, y una cadena cinemática entre el motor (5) y el resorte (4) que comprende un cilindro (7) conectado con el eje del motor (5) y una cuerda (8), con uno de sus extremos conectado al cilindro (7) y con el segundo extremo conectado al pie (3). El procedimiento de control se caracteriza porque en el momento en el que el pie (3) pierde el contacto...

Declínio de desempenho motor no envelhecimento é específico à tarefa Caída del desempeño motor en el envejecimiento es específico a la tarea Task-specific performance decline in aging

Directory of Open Access Journals (Sweden)

Luís Augusto Teixeira

2006-12-01

Full Text Available O declínio de desempenho motor característico do envelhecimento tem sido proposto ter como causa um fator único, originário de deterioração da capacidade de processamento central de informação. Por essa proposição, o desempenho motor em diferentes tarefas deveria ser prejudicado similarmente durante o envelhecimento. Para testar essa hipótese, o desempenho sensório-motor de indivíduos fisicamente ativos entre 19 e 73 anos de idade foi estudado em oito tarefas: tempo de reação, tempo de movimento no contato com um alvo, força manual máxima, sincronização, controle de força, toques repetidos com haste vertical, desenhos seqüenciais e toques entre os dedos. A análise dos resultados indicou perfis variáveis de desempenho entre as tarefas motoras na comparação entre as idades, com declínio motor a uma taxa moderada entre 20 e 60 anos para tempo de reação, quedas mais acentuadas de desempenho na transição entre 20 e 40 anos em tarefas requisitando velocidade de execução de movimentos simples ou precisão temporal, quedas mais acentuadas na transição entre 60 e 70 anos para força máxima e habilidade gráfica e manutenção da capacidade de desempenho com o envelhecimento para controle de força manual. Dessa forma, esses resultados revelam-se contraditórios com a hipótese de fator único e oferecem suporte à hipótese alternativa de que a taxa de declínio de desempenho sensório-motor durante o envelhecimento é específica à tarefa.El descenso del desempeño motor, característico del envejecimiento, ha sido propuesto tener como causa un factor único, originario de la deterioración de la capacidad del procesamiento central de información. Por esa proposición, el desempeño motor en diferentes tareas debería ser perjudicado similarmente durante el envejecimiento. Para probar esta hipótesis, el desempeño sensor-motor de individuos físicamente activos entre 19 y 73 años de edad fue estudiado en ocho

Core reactor simulation of the Central Laguna Verde (CLV) reactor in stationary state and an example of the application in the recharge options analysis of cycle 3; Simulacion del nucleo del reactor de la Central Laguna Verde (CLV) en estado estacionario y ejemplo de aplicacion en el analisis de alternativas de recarga del ciclo 3

Energy Technology Data Exchange (ETDEWEB)

Ocampo Mansilla, Hector; Francois Lacouture, Juan Luis; Blanco Lara, Jesus; Cortes Campos, Carlos Cristobal; Esquivias Montoya, Jesus; Esquivel Torres, Jose Luis; Martin del Campo Marquez, Cecilia [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Montes Tadeo, Jose Luis [Instituto Nacional de Investigaciones Nucleares (ININ), Salazar (Mexico); Sanchez Herrera, Luciano; Torres Alvarez, Carlos [Comision Federal de Electricidad (CFE), Mexico, D. F. (Mexico)

1991-12-31

The results are presented of a study requested by Comision Federal de Electricidad (CFE) for the analysis of Cycle 3, of Unit No. 1 of the Laguna Verde Nuclear Power Station (CLNV) and determine the burning effect impact, carried out with the starting tests and the operation of Cycles 1 and 2 on base of the cycle extension known as coastdown. The calculations were realized with the Code Package FMS for fuel managing, using the Code PRESTO-B that analyzes the reactor in detailed form in three dimensions an in stationary state. In the study the schemes of fraction of recharge proposed by General Electric (GE) were analyzed with the effect of cycle extension. The initial design value of 100 assemblies for Cycle 3, GE proposes to increase such fraction from 112 to 120 assemblies. This impacts the cost of the second recharge and the purpose of this investigation is to analyze options with higher fuel enrichment in U-235 to minimize the number of assemblies in this recharge. The analyses effected show that the designs proposed by GE do not fulfill the required energy proposed for the cycle, even using in the recharge only fuel with 3.03% of enrichment. It is proposed, likewise, the fuel enrichment up to 3.25% to satisfy the energy demand with a minimum of assemblies. [Espanol] Se presentan los resultados de un estudio solicitado por la Comision Federal de Electricidad (CFE) para analizar el ciclo 3, de la unidad 1 de la Central Laguna Verde (CLV), y determinar el impacto del efecto de quemado llevado a cabo con las pruebas de arranque y por la operacion de los ciclos 1 y 2 con base en la tecnica de alargamiento del ciclo conocida como coastdown1. Los calculos se realizaron con el paquete de codigos FMS para la administracion de combustible, usando el codigo PRESTO-B que analiza el reactor en forma detallada en tres dimensiones y en estado estacionario. Se analizaron en el estudio los esquemas de fraccion de recarga propuesta por la General Electric (GE) con el efecto de

Core reactor simulation of the Central Laguna Verde (CLV) reactor in stationary state and an example of the application in the recharge options analysis of cycle 3; Simulacion del nucleo del reactor de la Central Laguna Verde (CLV) en estado estacionario y ejemplo de aplicacion en el analisis de alternativas de recarga del ciclo 3

Energy Technology Data Exchange (ETDEWEB)

Ocampo Mansilla, Hector; Francois Lacouture, Juan Luis; Blanco Lara, Jesus; Cortes Campos, Carlos Cristobal; Esquivias Montoya, Jesus; Esquivel Torres, Jose Luis; Martin del Campo Marquez, Cecilia [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Montes Tadeo, Jose Luis [Instituto Nacional de Investigaciones Nucleares (ININ), Salazar (Mexico); Sanchez Herrera, Luciano; Torres Alvarez, Carlos [Comision Federal de Electricidad (CFE), Mexico, D. F. (Mexico)

1992-12-31

The results are presented of a study requested by Comision Federal de Electricidad (CFE) for the analysis of Cycle 3, of Unit No. 1 of the Laguna Verde Nuclear Power Station (CLNV) and determine the burning effect impact, carried out with the starting tests and the operation of Cycles 1 and 2 on base of the cycle extension known as coastdown. The calculations were realized with the Code Package FMS for fuel managing, using the Code PRESTO-B that analyzes the reactor in detailed form in three dimensions an in stationary state. In the study the schemes of fraction of recharge proposed by General Electric (GE) were analyzed with the effect of cycle extension. The initial design value of 100 assemblies for Cycle 3, GE proposes to increase such fraction from 112 to 120 assemblies. This impacts the cost of the second recharge and the purpose of this investigation is to analyze options with higher fuel enrichment in U-235 to minimize the number of assemblies in this recharge. The analyses effected show that the designs proposed by GE do not fulfill the required energy proposed for the cycle, even using in the recharge only fuel with 3.03% of enrichment. It is proposed, likewise, the fuel enrichment up to 3.25% to satisfy the energy demand with a minimum of assemblies. [Espanol] Se presentan los resultados de un estudio solicitado por la Comision Federal de Electricidad (CFE) para analizar el ciclo 3, de la unidad 1 de la Central Laguna Verde (CLV), y determinar el impacto del efecto de quemado llevado a cabo con las pruebas de arranque y por la operacion de los ciclos 1 y 2 con base en la tecnica de alargamiento del ciclo conocida como coastdown1. Los calculos se realizaron con el paquete de codigos FMS para la administracion de combustible, usando el codigo PRESTO-B que analiza el reactor en forma detallada en tres dimensiones y en estado estacionario. Se analizaron en el estudio los esquemas de fraccion de recarga propuesta por la General Electric (GE) con el efecto de

Realidad virtual para el mantenimiento de motores de avión

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Aiert Amundarain

2003-07-01

Full Text Available Exponemos un sistema de realidad virtual para la simulación de procesos de mantenimiento en aeronáutica que se ha desarrollado en el marco del Proyecto REVIMA. Hemos desarrollado un hardware nuevo (háptico y resuelto diversos problemas al elaborar el software que integra el sistema. El nuevo háptico se emplea para realizar el seguimiento del movimiento de las manos, y al mismo tiempo devuelve una fuerza que provoca la sensación de estar trabajando con una maqueta física. Los principales módulos de software son: el módulo de generación de imágenes, el módulo de colisión y el módulo de control. La integración del sistema está basada en dos ordenadores conectados mediante una LAN que comparten diferentes tareas y datos. El módulo de visualización ha sido implementado empleando sistemas gráficos de bajo coste y mediante un estudio exhaustivo se ha logrado una frecuencia válida para las operaciones de simulación. Los modelos consisten en más de dos mil elementos diferentes y emplean alrededor de dos millones de polígonos para describir su geometría. Este trabajo presenta una breve descripción del conjunto y desarrolla de modo específico las técnicas de visualización que se han desarrollado.

Methodology for quantifying the technological level of energy in electric motors; Metodologia para quantificacao do nivel tecnologico energetico de motores eletricos

Energy Technology Data Exchange (ETDEWEB)

Konopatzki, Evandro Andre; Bianchessi, Joel Marcos [Faculdade Assis Gurgacz (FAG), Cascavel, PR (Brazil); Oliveira, Celso Eduardo Lins de [Universidade de Sao Paulo (FZEA-USP), Pirassununga, SP (Brazil). Fac. de Zootecnia e Engenharia de Alimentos; Konopatzki, Angelica da Silva Lima [Faculdade de Ciencias Aplicadas de Cascavel (FACIAP), PR (Brazil). Curso de Ciencia da Computacao; Marim, Cesar [Universidade Estadual do Oeste do Parana (UNIOESTE), Cascavel, PR (Brazil)

2006-07-01

The market competition created in agricultural industry because of its insertion in the domestic and foreign markets, verified by the increase in GDP share of agribusiness in the Brazilian GDP, led us to have better control of costs and inputs. Thus the final value of products sold by these agribusinesses can download increasing the space in the consumer market. Electricity is one of the inputs now being studied and this paper presents a model for determining the coefficients that allow the comparison of different existing technologies for electric motors inserting an indicator of technological innovation called Technological Level Energy (NTE). The NTE was developed and tested in Storage Units of Grain (UAG) in the region of Cascavel - Parana where data were collected in six UAG, analyzed in medium weighted, had levels of different energy technology development. The main elements used to create the NTE are the number of engines installed in UAG, the lifetime of the engine considered from its manufacture and motor plate data such as income and the power factor. As a comparative process, each region can create your NTE and analyze your situation in a national context. The UAG will use the NTE to technological innovation and planning projects such as depreciation, financing and cross-examination of financial resources for the exchange of electric motors. Thus the NTE will aid in comparative indication of the timing for replacement of electric motors. Moment from which the energy demand, according to the obsolescence of equipment, are considered excessive compared to other more modern UAG. (author)

Tests of a numerical algorithm for the linear instability study of flows on a sphere

Energy Technology Data Exchange (ETDEWEB)

Perez Garcia, Ismael; Skiba, Yuri N [Univerisidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

2001-04-01

A numerical algorithm for the normal mode instability of a steady nondivergent flow on a rotating sphere is developed. The algorithm accuracy is tested with zonal solutions of the nonlinear barotropic vorticity equation (Legendre polynomials, zonal Rossby-Harwitz waves and monopole modons). [Spanish] Ha sido desarrollado un algoritmo numerico para estudiar la inestabilidad lineal de un flujo estacionario no divergente en una esfera en rotacion. La precision del algoritmo se prueba con soluciones zonales de la ecuacion no lineal de vorticidad barotropica (polinomios de Legendre, ondas zonales Rossby-Harwitz y modones monopolares).

Avaliação e intervenção no desenvolvimento motor de uma criança com Síndrome de Down Assessment and intervention in the motor development of a child with Down Syndrome

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Ana Paula Maurilia dos Santos

2010-04-01

Full Text Available o objetivo deste estudo foi analisar o desenvolvimento motor de uma criança com síndrome de Down e verificar os efeitos de um programa de intervenção motora específica. Trata-se de uma pesquisa descritiva do tipo estudo de caso. Para a avaliação do desenvolvimento motor foram utilizados os testes da Escala de Desenvolvimento Motor - EDM que analisa as áreas da motricidade fina e global, equilíbrio, esquema corporal, organização espacial e temporal/linguagem, e lateralidade. Essa criança participou, respectivamente, de avaliação motora, intervenção motora (32 sessões, 2 vezes semanais e reavaliação motora. As intervenções motoras mostraram avanços positivos nas áreas da motricidade global, equilíbrio e organização espacial. A motricidade fina, esquema corporal e a organização temporal /linguagem não apresentaram avanços. Verificou-se que a linguagem foi a área de maior prejuízo. O quociente motor em todos os itens foi classificado como muito inferior, o que se caracteriza como déficit motor. Esses dados justificam a relevância de programas de intervenção motora para essa população.the objective of this study was to analyze the motor development of a child with Down syndrome and to verify the effect of a specific motor intervention program. This is a descriptive research case study. Motor development was evaluated using the Motor Development Scale - MDS, which analyzes both fine and gross motor skills as well as balance, body schema, spatial and temporal organization, language, and laterality. This child participated, respectively, of the motor assessment, motor intervention (32 sessions, twice weekly and motor reevaluation. Gains were demonstrated in motor intervention in the areas of the gross motor skills, balance and spatial organization. No improvement was shown in fine motor skills, body schema and temporal organization/ language. Language was found to be the area of lowest achievement. The motor

Indexación y posicionamiento de los repositorios en motores de búsqueda

OpenAIRE

Prieto Jiménez, Antonio Juan

2015-01-01

Taller presentat al XIV Workshop Rebiun de Poyectos Digitales / VI Jornadas OS-Repositorios (Córdoba, 11-13 de març de 2015) En el taller se exponen diversas utilidades, además de aspectos a tener en cuenta para la correcta indexación de los repositorio en motores de búsqueda generales y académicos haciendo especial referencia a los cambios desarrollados en DSpace en las últimas versiones para mejorar este aspecto. A la vez también se repasan conceptos válidos para cualquier repositorio c...

Bases de datos, motores de búsqueda e índices temáticos: herramientas fundamentales para el ejercicio médico

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Jaime A. Castrillón-Estrada

2008-01-01

Full Text Available Con la diseminación del Internet han cambiado las formas tradicionales de transmisión y adquisición del conocimiento en todas sus ramas; y la medicina, como una disciplina de constantes cambios, no ha sido ajena a esta tecnología. Tras el advenimiento de la informática, las ciencias biológicas y médicas han encontrado un medio eficiente para la globalización del conocimiento, lo cual ha mejorado el entrenamiento y la actualización de los estudiantes y profesionales de la medicina, y ha creado la necesidad de aumentar la eficiencia de estos medios de comunicación. Con el objetivo de facilitar el acceso a la información científica a través de medios informáticos han sido desarrolladas plataformas encargadas de recopilar la información en forma de bases de datos, las cuales pueden ser consultadas a través de otra tecnología emergente como los son los motores de búsqueda. Debido a que cada sitio Web tiene características específicas que le confieren ciertas fortalezas y debilidades, tanto el estudiante como el profesional médico deben reconocerlas, para así obtener el mayor provecho de su utilización.

Escala Motora Infantil de Alberta: validação para uma população gaúcha Escala motora infantil de Alberta: validación para una población de Rio Grande do Sul (Brasil Infant Motor Scale of Alberta: validation for a population of Southern Brazil

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Nadia Cristina Valentini

2011-06-01

Full Text Available OBJETIVO: Traduzir, adaptar e verificar a validade de critérios motor e de constructo (consistência interna, validade dis-criminante, correlação com outros testes e validade preditiva da versão em Português da Alberta Motor Infant Scale. MÉTODOS: Estudo de validação transcultural. Participaram 21 profissionais e 561 crianças do Rio Grande do Sul, com idades de zero a 18 meses (291 meninos. Foram utilizados os instrumentos: Alberta Infant Motor Scale, Escala do Desen-volvimento do Comportamento da Criança e um questionário para controle de variáveis. O estudo compreendeu as fases de tradução e adaptação da escala; análise da validade de conteúdo; treinamento de profissionais; coleta de dados no ambiente familiar e em creches; análise da objetividade e fidedignidade, e validade de critério e construto. RESULTADOS: A versão portuguesa da Alberta Infant Motor Scale continha critérios motores claros e pertinentes; apresentou ótima confiabilidade (escore total, p=0,88; prono, p=0,86; supino, p=0,89; sentado, p=0,80 e em pé, p=0,85 e poder discriminativo (desenvolvimento típico versus atípico; escore, pOBJETIVO: Traducir, adaptar y verificar la validez y clareza de criterios motor y constructo (consistencia interna, vali-dez discriminante, correlación con otras pruebas y validez predictiva de la versión en Portugués de la Alberta Motor Infant Scale. MÉTODOS: Estudio de validación transcultural, descriptivo y transversal. Participaron 21 profesionales y 561 niños de Rio Grande do Sul, con edades entre 0 y 18 meses (291 niños y 270 niñas. Se utilizaron los instrumentos: Alberta Infant Motor Scale (AIMS, Escala del Desarrollo del Comportamiento del Niño (EDCC y un cuestionario para control de variables. El estudio comprendió las etapas de traducción y adaptación de la escala; análisis de la validez de contenido; entrenamiento de profesionales; recolección de datos en el ambiente familiar y en guarderías; an

Electromagnetic model of a three phase induction motor using finite elements; Modelo electromagnetico de un motor de induccion trifasico usando elementos finitos

Energy Technology Data Exchange (ETDEWEB)

Ruvalcaba Marquez, Carlos

2003-02-15

This thesis shows a non-linear electromagnetic analysis of a three-phase induction machine using the two-dimensional finite element method (2D FEM). It is necessary to solve the diffusion equation to obtain the average magnetic vector potential of the FE machine model. The solution of this equation gives the induced eddy currents locally or globally inside the FE machine model. The induction machine is rated at 2.2 kw, 220 V, 60 Hz, and it can handle two different speeds, 1750/1150 rpm with a current consumption of 9.6/11.0 A, respectively. This machine is at the Laboratorio de Propulsion of the Instituto Tecnologico de la Laguna. The eddy currents induced in the conducting material appear because the FE model of the machine model is supplied by a sinusoidal current; finally, the depth penetration factor is considered on the FE mesh to achieve a better skin effect representation. [Spanish] En este trabajo de tesis se realiza un analisis electromagnetico no lineal de un motor de induccion trifasico empleando el metodo del elemento finito en dos dimensiones. De manera especifica, se calcula el potencial magnetico vectorial promedio del modelo de elemento finito del motor mediante la solucion de la ecuacion de difusion. Al resolver la ecuacion de difusion se obtiene la densidad de corrientes de eddy que se inducen ya sea en sentido local o global en el modelo del motor. El motor de induccion analizado esta disenado para operar a dos velocidades, 1750/1150 rpm, tiene una capacidad de 2.2 kW, 220 V, 9.6/11.0 A, 60 Hz, y se encuentra instalado en el Laboratorio de Propulsion del Instituto Tecnologico de la Laguna. Debido a que el modelo electromagnetico del motor de induccion es alimentado por una fuente de corriente senoidal, se tiene una induccion de corrientes de eddy en el material conductor. En el diseno de la malla se considero el factor de penetracion para lograr una mejor representacion del efecto piel.

Motor alternativo : aplicación : sistema de locomoción ferroviario

OpenAIRE

Villaescusa Nistal, Jorge

2009-01-01

El siguiente proyecto consiste en el estudio y modelización del ciclo termodinámico de un motor diesel, cuya aplicación es la locomoción de unidades de ferrocarril. Una vez analizado dicho modelo se realizará un estudio sobre la posibilidad de efectuar mejoras sobre el mismo, con la finalidad de optimizar sus prestaciones. Para comenzar este estudio se realizará una descripción física del motor, utilizando los datos característicos que lo definen y en caso de no disponer de alguno de estos da...

Optimización del rendimiento de un motor de 2 tiempos y pequeña cilindrada mediante simulación numérica.

OpenAIRE

DOMINGO ARTIEDA, SONIA

2015-01-01

[ES] El alumno realizará un trabajo de optimización del proceso de combustión de un motor de pequeña cilindrada y arquitectura 2 tiempos de aplicación para vehículos híbridos, utilizando para ello un código de simulación desarrollado en el Departamento de Máquinas y Motores Térmicos. Esta optimización estará centrada en el rendimiento indicado, que es equivalente al consumo de combustible, ya que éste es un tema de interés actual en el ámbito de la investigación en motores de combustión inter...

Política fiscal óptima en un modelo de Lucas con externalidades.

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Seijas Macías, J. Antonio.

2003-01-01

Full Text Available En este trabajo se desarrolla una política fiscal capaz de proporcionar los incentivos adecuados para que el equilibrio competitivo sea óptimo en el modelo de Lucas con externalidades, tanto en el estado estacionario como a lo largo de la transición. A diferencia de trabajos anteriores, supondremos que la función de producción es del tipo CES. El capital humano medio tiene un efecto externo positivo sobre la producción, lo que provoca que la fracción de tiempo dedicada al estudio sea inferior a la óptima. Para corregir el fallo de mercado provocado por la externalidad, se introduce un subsidio al capital humano y se muestra cómo puede ser financiado.

Estrategia de control predictivo sobre un modelo matemático de un evaporador

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Daniel Alonso Giraldo Giraldo

2006-01-01

Full Text Available Se presenta el diseno de una estrategia de control predictivo, sobre un modelo matematico x de un evaporador de pelIcula descendente con recompresión mecanica de vapor, usado en la industria lactea. Para disenar el controlador se utiliza el programa Connoisseur ,a partir de datos recolectados de la simulación de un modelo no lineal. Se emplea una ley de control obtenida de la minimización de una función de costo, suleta a restricciones del proceso, empleando un algoritmo de programación cuadratico (QP. Finalmente, se elecuta un algoritmo de programación lineal (LP que encuentra un punto de operación “subóptimo“ para el proceso en estado estacionario.

Mezclas etanol-gasolina como combustible de motores de encendido por chispa

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Rodríguez Luis Arnoby

1989-12-01

Full Text Available In the Agricultural Mechanics Shop at Texas A&I University in Kingsville (TX, six ethanolgasoline blends (0, 20, 40, 60, 80 and 100% ethanol were used to operated a six-cylinder engine at different operating conditions of air-fuel ratio, timing, load and speed. A main jet the carburator was used for each fuel to obtaining its stoichiometric air-fuel ratio. The main jet diameter was enlarged 1262 times from gasoline to ethanol. To select the optimun timing, timing was varied from Oto 26° BTOC (Before Top Oead Center and the engine tes1ed at maximun power. The optimun advance timings were respectively 6, 6, 10, 14, 18 and 220 BTOC. It was not necessary to introduce modifications to operate the engine with blends containing upto 20 % ethanol. For blends with more than 20% ethanol, the advance timing (V and the ethanol conmnt (X, followed the relation V = 2.0 + 02 X. In the last test, the engine was set at the optimun advance timing for each fuel. All the fuels performed in the same way. They followed the s e characteristic curves for power, torque, specific fuel consumption and efficiency with the following differences from gasoline to straight ethanol: maximun power and torque decreased 10.6% and 8.7% respectively; specific fuel consumption and efficiency increased 49% and 5.2%.
En el Taller de Mecánica Agrícola de Texas A&T University en Kingsville (TX, se usaron seis mezclas etanol-gasolina (0,20,40,60,80 y 100% etanol para operar un motor de seis cilindros variando la razón aire-combustible, avance de encendido, carga y velocidad. Con cada combustible se usó una tobera principal para obtener su razón estequiométrica. De gasolina a etanol el diámetro de la tobera se aumentó 1262 veces. El avance de la chispa se varió entre 0 y 26° APMS (Antes de Punto Muerto Superior. Se seleccionó como óptimo el avance al que el motor desarrolló máxima potencia. Los avances óptimos fueron 6, 6, 10, 14, 18 y 22° APMS. No fue necesario

Desarrollo de un modelo para la estimación de la presión en la cámara de combustión en un motor Robin EY15 en condiciones de vacío y a velocidad constante, a partir de la señal de vibración

OpenAIRE

Grajales Herrera, Jairo Andrés

2016-01-01

Con el propósito de monitorear el funcionamiento de los motores de combustión internar, en este trabajo se presenta un método para la estimación de la presión en la cámara de combustión a partir del procesamiento de la señal de vibración. Se presentan también dos métodos para el diagnóstico de falla de motores de combustión a partir del análisis de las señales de vibración. A partir del uso de estrategias de mantenimiento preventivo y predictivo en las empresas se han logrado reducciones en l...

Nuevo procedimiento para la evaluación de los motores monofásicos de inducción; New approach to single–phase induction motors performance evaluation

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Marcos A.- de Armas Teyra y otros

2013-01-01

Full Text Available En el presente trabajo se desarrolló un algoritmo basado en el método del torque en elentrehierro que evalúa el comportamiento de los motores monofásicos de inducción y determinala potencia desarrollada, la eficiencia y otros parámetros operacionales a partir de las medicionesobtenidas de un analizador de redes instalado en los terminales del motor. Los resultados poseenadecuada precisión independientemente de si existen variaciones de tensión y de frecuencia, o silas tensiones están desfasadas o no e incluso donde la disposición espacial de los devanadospueda ser arbitraria con distinto número de vueltas en las bobinas así como diferentes calibres en los conductores. La solución se alcanza sin necesidad de conocer los parámetros del circuitoequivalente. Como casos de estudio se muestra su aplicación a motores de fase dividida, capacitor permanente y asimétrico comparando los resultados con el método tradicional basado en la teoría de los campos rotatorios.In this paper was developed an algorithm based in air gap torque method to evaluate theperformance of single phase induction motors. The developed shaft power, efficiency and otherparameters are determined using a power analyzer installed in motor terminals in field conditions.Results are adequate independently if there exist voltage or frequency deviation, voltageunbalance or different voltage phase between main and auxiliary winding and different spatial disposition of windings, wire size or winding distribution. The solution is obtained withoutknowledge of motor equivalent circuit’s parameters. As cases its application to split phase, permanent capacitor and asymmetric motors are exposed comparing the results with the classic rotating field theory.

Movimiento y lenguaje: Análisis de las relaciones entre el desarrollo motor y del lenguaje en la infancia. [Movement and language: Analysis of the relationships between motor and language development in children].

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Luis Miguel Ruiz-Pérez

2016-10-01

Full Text Available El estudio del desarrollo del lenguaje y del desarrollo motor ha tenido procesos paralelos e independientes, considerándose al segundo un ámbito secundario que nada tenía que ver con el primero. Las últimas décadas han revitalizado el estudio del desarrollo motor y los enfoques postcognitivos y encarnados (embodiment han mostrado el papel que el cuerpo y la motricidad juegan en el desarrollo humano, e investigadores que antes estuvieron preocupados por otros ámbitos, han dirigido su atención a comprobar la veracidad de estas hipótesis. En el presente trabajo se ha realizado un análisis del estado del arte, revisando investigaciones que han explorado las relaciones existentes entre el desarrollo motor y del lenguaje, con especial atención a los estudios que relacionan los problemas de coordinación motriz y los problemas de desarrollo del leguaje, llegando a la conclusión de que son más las razones para considerar dichas relaciones que para rechazarlas. Abstract The study of language and motor development has had parallel and independent processes. Recently the study of motor development has been revitalized. The post-cognitive and embodiment approaches of cognition have shown that the body and sensomotor behavior are very relevant in the process of human development, and the researchers who were concerned about other areas of development, have turned their attention to check the accuracy of these hypotheses. This paper has reviewed the relationships between motor and language development, with special attention given to those studies about motor co-ordination problems and specific language problems, and concluded that there are more reasons to consider such relationships than to reject them.

1. Jogos Escolares Brasileiros da Confederação Brasileira de Desportos para Cegos : um estudo de caso

OpenAIRE

Regina Matsui

2007-01-01

Resumo: A pessoa com deficiência visual possui um atraso no seu desenvolvimento motor, em decorrência das poucas oportunidades que elas possuem ao longo da vida. Nesse sentido, sabemos da importância da prática de atividade física para essas pessoas, tendo em vista que ela contribui para o desenvolvimento global da pessoa. As informações retiradas do meio e a aprendizagem de gestos e habilidades motoras contribuem na formação e no desenvolvimento motor dessas pessoas. Na busca de possibilitar...

Split-phase motor running as capacitor starts motor and as capacitor run motor

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Yahaya Asizehi ENESI

2016-07-01

Full Text Available In this paper, the input parameters of a single phase split-phase induction motor is taken to investigate and to study the output performance characteristics of capacitor start and capacitor run induction motor. The value of these input parameters are used in the design characteristics of capacitor run and capacitor start motor with each motor connected to rated or standard capacitor in series with auxiliary winding or starting winding respectively for the normal operational condition. The magnitude of capacitor that will develop maximum torque in capacitor start motor and capacitor run motor are investigated and determined by simulation. Each of these capacitors is connected to the auxiliary winding of split-phase motor thereby transforming it into capacitor start or capacitor run motor. The starting current and starting torque of the split-phase motor (SPM, capacitor run motor (CRM and capacitor star motor (CSM are compared for their suitability in their operational performance and applications.

Variation in motor output and motor performance in a centrally generated motor pattern

Science.gov (United States)

Norris, Brian J.; Doloc-Mihu, Anca; Calabrese, Ronald L.

2014-01-01

Central pattern generators (CPGs) produce motor patterns that ultimately drive motor outputs. We studied how functional motor performance is achieved, specifically, whether the variation seen in motor patterns is reflected in motor performance and whether fictive motor patterns differ from those in vivo. We used the leech heartbeat system in which a bilaterally symmetrical CPG coordinates segmental heart motor neurons and two segmented heart tubes into two mutually exclusive coordination modes: rear-to-front peristaltic on one side and nearly synchronous on the other, with regular side-to-side switches. We assessed individual variability of the motor pattern and the beat pattern in vivo. To quantify the beat pattern we imaged intact adults. To quantify the phase relations between motor neurons and heart constrictions we recorded extracellularly from two heart motor neurons and movement from the corresponding heart segments in minimally dissected leeches. Variation in the motor pattern was reflected in motor performance only in the peristaltic mode, where larger intersegmental phase differences in the motor neurons resulted in larger phase differences between heart constrictions. Fictive motor patterns differed from those in vivo only in the synchronous mode, where intersegmental phase differences in vivo had a larger front-to-rear bias and were more constrained. Additionally, load-influenced constriction timing might explain the amplification of the phase differences between heart segments in the peristaltic mode and the higher variability in motor output due to body shape assumed in this soft-bodied animal. The motor pattern determines the beat pattern, peristaltic or synchronous, but heart mechanics influence the phase relations achieved. PMID:24717348

Motor control for a brushless DC motor

Science.gov (United States)

Peterson, William J. (Inventor); Faulkner, Dennis T. (Inventor)

1985-01-01

This invention relates to a motor control system for a brushless DC motor having an inverter responsively coupled to the motor control system and in power transmitting relationship to the motor. The motor control system includes a motor rotor speed detecting unit that provides a pulsed waveform signal proportional to rotor speed. This pulsed waveform signal is delivered to the inverter to thereby cause an inverter fundamental current waveform output to the motor to be switched at a rate proportional to said rotor speed. In addition, the fundamental current waveform is also pulse width modulated at a rate proportional to the rotor speed. A fundamental current waveform phase advance circuit is controllingly coupled to the inverter. The phase advance circuit is coupled to receive the pulsed waveform signal from the motor rotor speed detecting unit and phase advance the pulsed waveform signal as a predetermined function of motor speed to thereby cause the fundamental current waveform to be advanced and thereby compensate for fundamental current waveform lag due to motor winding reactance which allows the motor to operate at higher speeds than the motor is rated while providing optimal torque and therefore increased efficiency.

Recém-nascido pequeno para a idade gestacional: repercussão nas habilidades motoras finas Pequeño para la edad gestacional: repercusión en las habilidades motoras finas Small-for-gestational-age newborn infant: repercussion on fine motor skills

Directory of Open Access Journals (Sweden)

Amabile Vessoni Arias

2011-03-01

aro suspendido" hubo diferencia significativa (p=0,02; prueba Exacta de Fisher, demostrando mayor frecuencia de ejecución para el grupo PEG en el 3er mes de vida. CONCLUSIONES: Se supone que la diferencia encontrada en el ítem "alcanza el aro suspendido" pueda ser atribuida a la gran ocurrencia de movimientos de los brazos observada en el grupo PEG y no a una condición mejor de desarrollo en este grupo.OBJECTIVE: To compare the fine motor skills of full-term small-for-gestational-age (SGA and appropriate-for-gestational-age (AGA infants in the third month of life. METHODS: This observational cross-sectional study enrolled 67 infants (21 SGA and 46 AGA in the third month of life. Infants presenting genetic syndromes, congenital malformations, congenital infections and those who needed neonatal intensive care were excluded. The Bayley Scales of Infant Development-II were used, with emphasis on items that evaluate the fine motor skills. RESULTS: No differences were observed between groups for motor (p=0.21 and mental (p=0.45 scales in the third month. There was a significant difference between the groups on the item "Reaches for Suspended Ring" (Fisher's exact test; p-value=0.02: a higher percentage of SGA infants accomplished this item in the third month of life. CONCLUSIONS: We hypothesize that the difference found in the item "Reaches for Suspended Ring" could be attributed to an increased frequency of arm movements observed in SGA infants and not to a better neurodevelopment of this group.

Prueba de hipótesis sobre la existencia de una raíz fraccional en una serie de tiempo no estacionaria

OpenAIRE

Diego Fernando Lemus Polania; Elkin Cataño Velez

2013-01-01

En este trabajo se propone una modificación de la prueba de hipótesis propuesta por Castaño, Gómez y Gallón (2008) para determinar la existencia de memoria larga en un proceso ARFIMA(p,d,q) estacionario e invertible. En el caso puntual de los procesos ARFIMA(p,d,q), esta modificación permite determinar la existencia de una raíz fraccional en una serie de tiempo no estacionaria cuyo componente ARMA de corto plazo es indeterminado o desconocido. Vía simulaciones de Monte Carlo, se validan los r...

Producción de entropía y ley de enfriamiento de newton

OpenAIRE

Barragán, Daniel

2010-01-01

Para un sistema con una fuente interna de generación de calor se analizan, en el marco de la termodinámica de los procesos irreversibles, las ecuaciones evolutivas que describen la transferencia de calor según la ley de enfriamiento de Newton. A partir del balance de flujo de entropía se muestra que la generación de entropía no es mínima en el estado estacionario descrito por la ley de enfriamiento de Newton. Igualmente, se discute cómo realizar el balance de flujos en el sistema, su conex...

Aplicación de la medida de NOx para el control de motores diesel sobrealimentados

OpenAIRE

Cabrera López, Pedro

2013-01-01

Los motores de combusti'on interna est'an inmersos en una constante evoluci'on tecnol'ogica con el ¿n de mejorar sus prestaciones y satisfacer adem'as las cada vez m'as restrictivas normas anticontaminantes. En el caso de los motores diesel esto concierne especialmente a las emisiones de NOx y part'¿culas. Los sistemas destinados a reducir estas emisiones (inyecci'on directa common-rail, sobrealimentaci'on con geometr'¿a variable, recirculaci'on de gases de escape, trampas de part'¿c...

La inteligencia emocional: una herramienta necesaria para el liderazgo. Concepto y componentes

OpenAIRE

Mart?nez Percy, Armando Martin

2013-01-01

La inteligencia emocional ser? la herramienta y/o recurso m?s importante del siglo XXI para sobrevivir a una ?poca de ?cambio permanente?. Es b?sica para incrementar el rendimiento profesional y el bienestar personal especialmente en profesiones complejas, como las que incluyen las relaciones personales como centro y principal motor de la actividad: educaci?n, recursos humanos, comunicaci?n, etc. Daniel Goleman (1995), conocido como el autor de la inteligencia emocional, arg...

EVALUACIÓN Y CARACTERIZACIÓN MINERALÓGICA DEL PROCESO DE BIOOXIDACIÓN EN UN REACTOR CONTINUO DE TANQUE AGITADO

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DIANA ARROYAVE G.

2010-01-01

Full Text Available La biooxidación del mineral refractario de oro de la mina El Zancudo (TitiribíAntioquia se realizó en un reactor continuo de tanque agitado usando microorganismos nativos acidófilos compatibles con Acidithiobacillus ferrooxidans y Acidithiobacillus thiooxidans. El reactor se operó inicialmente en discontinuo para alcanzar la máxima concentración de hierro férrico en solución, antes de iniciar el proceso en continuo. La caracterización mineralógica se hizo a muestras recolectadas en discontinuo, estado transitorio y estacionario en continuo, usando Microscopia Electrónica de Barrido (SEM y Difracción de Rayos X (DRX. La caracterización mineralógica mostró una oxidación avanzada de la pirita y arsenopirita en discontinuo y parcial en continuo. Adicionalmente, se encontró la formación de silicatos, jarosita y brushita. Los resultados indican que el sistema alcanzó el estado estacionario después de 8 días de operación en continuo, logrando una concentración de hierro férrico en solución de 8.3 g/l, correspondiente a un porcentaje de extracción de oro y plata de 78 y 80 %, respectivamente.

Evaluación del funcionamiento de motores de combustión interna trabajando con biodiesel. // Evaluation of engine performance working with biodiesel.

OpenAIRE

R. Piloto Rodríguez; R. Sierens; S. Verhelst; N. Ferrer Frontela

2008-01-01

En el presente trabajo se determinó la característica exterior de velocidad para dos motores de combustión internatrabajando con combustible biodiesel procedente de varias fuentes naturales y se comparó con la característica exterior develocidad de los motores originalmente trabajando con combustible diesel. Los motores fueron evaluados con variacionesde carga y velocidad. En uno de los motores ensayados fue determinada la presión en el interior de la cámara decombustión con el objetivo de ev...

Adaptação da AMPS-escolar para crianças brasileiras de 4 a 8 anos Adaptación de la AMPS-escolar para niños brasileños de 4 a 8 años Adaptation of the school-AMPS (Assessment of Motor and Process Skills to Brazilian children from 4 to 8 years old

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Maria das Graças Abreu de Faria

2006-12-01

ajuste, pero el instrumento puede ser útil para evaluar la competencia funcional en niños brasileños con necesidades especiales.The objective of this study was to translate, adapt and analyze the item validity of the School-Version of the Assessment of Motor and Process Skills (School-AMPS. The methodology included the translation, simplification of scoring criteria and selection of motor tasks, which are relevant for classroom performance. Thirty typically developing children, ages 4, 6, and 8 years old, were observed individually, when performing the selected tasks. Rasch analysis indicated that the items proposed were easy for the sample, two items in the motor scale and three items in the process scale presented erratic score patterns, which compromised the test construct validity. The children presented valid patterns of response and there was a significant relationship (Pearson r between the measures of motor skills (0,59 and process (0,53 skills and the child’s age. It was concluded that some items needed adjustments, but the instrument could be useful to evaluate the functional competence of Brazilian children with special needs.

Automatización de una línea de montaje de motores para parabrisas

OpenAIRE

Castillero Carmona, Marc

2009-01-01

Este proyecto está enfocado a la automatización de una línea de producción de parabrisas. Donde también se tendrá que realizar la instalación eléctrica para la alimentación de componentes eléctricos. La línea de producción pertenece a la empresa Robert Bosch fábrica de Castellet, donde se fabrican parabrisas traseros y delanteros, y pequeños componentes para automoción. La línea cuenta con varias máquinas automáticas y puestos manuales, de los cuales no se utilizarán todos para la fa...

Identificación y Control Wavenet de un Motor de CA

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L. E. Ramos Velasco

2013-07-01

Full Text Available Resumen: En el presente artículo se muestra un esquema de identificación y control que sintoniza en línea las ganancias proporcional, integral y derivativa de un controlador PID discreto aplicado a un sistema dinámico SISO. Esto se logra empleando una red neuronal de base radial con funciones de activación wavelet hijas Morlet (wavenet adicionalmente en cascada un filtro de respuesta infinita al impulso (IIR. Dicho esquema es aplicado en tiempo real para controlar la velocidad de un motor de inducción de CA trifásico del tipo jaula de ardilla (MIJA alimentado con un variador de frecuencia trifásico, de esta forma se muestra cómo este esquema de identificación y control en línea, puede ser implementado en este tipo de plantas que son ampliamente utilizadas en la industria, sin la necesidad de obtener los parámetros del modelo matemático del conjunto variador de frecuencia-motor de inducción trifásico. Se presentan los resultados obtenidos en simulación numérica y experimentales, empleando para esto la plataforma de LabVIEW. Abstract: This paper presents a control scheme to tune online the proportional, integral and derivative gains of a discrete PID controller, through the identification and control of a SISO stable and minimum phase dynamic system. This is accomplished using a radial basis network neural with daughter Morlet wavelets activation functions in cascaded with an infinite impulse response (IIR filter. This scheme is applied in real time to control the speed of an AC three-phase induction motor supplied with a three-phase inverter. So in this way we show how the identification and control scheme can be implemented in this type of plants that are widely used in industry, without the need of mathematical model parameters of the induction motor. We present numerical simulation and experimental results. Palabras clave: Control de motores, Controlador PID, Redes neuronales wavelets, Algoritmos auto-ajustables, Keywords

New relation to improve the speed and torque characteristics of induction motors

Directory of Open Access Journals (Sweden)

Luis Antonio Mier-Quiroga

2015-01-01

Full Text Available Los motores de inducción jaula de ardilla son empleados en gran variedad de aplicaciones. Ciertas aplicaciones requieren su operación a velocidad constante y en otras se requiere su operación a diferentes velocidades, como es el caso de proveer energía mecánica a vehículos eléctricos. El desempeño de un vehículo eléctrico depende de las características del motor eléctrico. La relación adecuada entre la magnitud del voltaje y la frecuencia de la fuente de alimentación permite que el motor cumpla con los requisitos del vehículo eléctrico. La magnitud del voltaje está en función de la frecuencia de operación. Si es adecuada la relación V - f , se puede mejorar la respuesta en velocidad del motor. Se presenta una nueva relación V - f , definida por un factor de frecuencia, que mejora la respuesta en velocidad del motor de inducción de rotor sencillo de jaula de ardilla. Para velocidades menores a la nominal, se mantiene la capacidad de par del motor con la relación propuesta.

Procesos Alternativos de Combustión en Motores de Combustión Interna. Procesos Alternativos de Combustión en Motores de Combustión Interna

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S. Martínez-Martínez

2012-02-01

Full Text Available La combustión por compresión de una mezcla pobre homogénea, o premezclada, ha surgido en los últimos años como una alternativa para la reducción simultánea de las emisiones de óxidos de nitrógeno (NOx y partículas (PM en los motores de combustión interna. Este novedoso proceso se puede considerar como un híbrido entre los motores de encendido provocado (MEP y los de encendido por compresión (MEC, ya que usa una mezcla homogénea (o altamente premezclada de aire-combustible como en los motores de encendido provocado, pero la mezcla se comprime hasta su auto-ignición, como en los motores de encendido por compresión. Aunque el nombre más usado para identificar este novedoso proceso de combustión ha sido el de HCCI (Homogeneous Charge Compression Ignition, en la literatura han aparecido una gran variedad de sistemas que aplican este concepto. En este trabajo se presenta una revisión de dichos sistemas. Combustion by compression of a lean and homogeneous (or premixed air-fuel mixture has recently emerged as an effective alternative to achieve simultaneous nitrogen oxides (NOx and particulate matter (PM reduction in internal combustion engines. This novel process can be considered as a hybrid between the spark ignition (SI and the compression ignition (CI combustions. To obtain it is necessary to generate a homogeneous (or highly premixed mixture of fuel and air (such as SI combustion, but this mixture is compressed up to its auto ignition limit (such as DI combustion. Even though this process has been identified as Homogeneous Charge Compression Ignition (HCCI, a variety of systems that use this concept have recently appeared. This document presents a review of such systems.

Análisis de eficiencia de motores asincrónicos en presencia de desbalances y armónicos en la tensión; Efficiency analysis of induction motors in the presence of harmonics and unbalance voltage

Directory of Open Access Journals (Sweden)

Vladimir Sousa Santos

2013-06-01

Full Text Available En los sistemas eléctricos de potencia es muy común encontrar problemas de calidad de la energía. La circulación de armónicos de tiempo en las redes de suministro eléctrico industrial junto al desbalance de tensión, afecta considerablemente el funcionamiento de los motores asincrónicos trifásicos y dificulta su caracterización energética. Existen diferentes métodos in situ para la estimación de la eficiencia de los motores. Sin embargo, ninguno ha sido lo suficientemente preciso para el análisis bajo la influencia de armónicos, desviaciones y desbalance de tensión. En este trabajo se presenta un procedimiento basado en los circuitos equivalentes, con segregación de pérdidas y empleando un Algoritmo de Forraje Bacterial (AFB, que permite determinar en condiciones de campo y con baja invasividad, la eficiencia energética de motores asincrónicos trabajando en las condiciones señaladas. El método se probó satisfactoriamente en un motor de 1,5 kW alimentado con niveles significativos de desbalance y armónicos de tensión.  In electric supply systems it is very common to find problems of power quality. The time harmonic flow in industrial electrical grids with voltage deviations and unbalance, significantly affects three phase induction motor operation and makes difficult energy characterization. There are different methods for in situ estimation of motors efficiency. However, none of them have been sufficiently precise for the analysis under non-sinusoidal, deviated and unbalanced voltage conditions. This paper presents a method based on the equivalent circuits, with losses segregation and using Bacterial Foraging Algorithm (BFA. It allows determining under field conditions and low invasiveness, energy efficiency of induction motors operating under the before mentioned conditions. This method was tested successfully on a 1,5 kW motor, fed with significant levels of unbalance and voltage harmonics.

Análisis de eficiencia de motores asincrónicos en presencia de desbalances y armónicos en la tensión: Efficiency analysis of induction motors in the presence of harmonics and unbalance voltage

Directory of Open Access Journals (Sweden)

Vladimir Sousa Santos

2013-06-01

Full Text Available En los sistemas eléctricos de potencia es muy común encontrar problemas de calidad de la energía. La circulación de armónicos de tiempo en las redes de suministro eléctrico industrial junto al desbalance de tensión, afecta considerablemente el funcionamiento de los motores asincrónicos trifásicos y dificulta su caracterización energética. Existen diferentes métodos in situ para la estimación de la eficiencia de los motores. Sin embargo, ninguno ha sido lo suficientemente preciso para el análisis bajo la influencia de armónicos, desviaciones y desbalance de tensión. En este trabajo se presenta un procedimiento basado en los circuitos equivalentes, con segregación de pérdidas y empleando un Algoritmo de Forraje Bacterial (AFB, que permite determinar en condiciones de campo y con baja invasividad, la eficiencia energética de motores asincrónicos trabajando en las condiciones señaladas. El método se probó satisfactoriamente en un motor de 1,5 kW alimentado con niveles significativos de desbalance y armónicos de tensión.In electric supply systems it is very common to find problems of power quality. The time harmonic flow in industrial electrical grids with voltage deviations and unbalance, significantly affects three phase induction motor operation and makes difficult energy characterization. There are different methods for in situ estimation of motors efficiency. However, none of them have been sufficiently precise for the analysis under non-sinusoidal, deviated and unbalanced voltage conditions. This paper presents a method based on the equivalent circuits, with losses segregation and using Bacterial Foraging Algorithm (BFA. It allows determining under field conditions and low invasiveness, energy efficiency of induction motors operating under the before mentioned conditions. This method was tested successfully on a 1,5 kW motor, fed with significant levels of unbalance and voltage harmonics.

Influência da adulteração de combustíveis no desempenho e na vida útil de motores de combustão interna de ignição por faísca de pequeno porte utilizados em motocicletas.

OpenAIRE

Luiz Vicente Figueira de Mello Filho

2009-01-01

Este trabalho tem como principal objetivo mostrar os efeitos do uso de gasolina adulterada em motores de pequena cilindrada em seus desempenhos e durabilidades. Para tanto, foram realizados ensaios comparativos em três motores carburados de aplicação em motocicletas, de mesmas séries. Estes motores consumiram gasolina C, padrão brasileiro de combustível para motores de ignição por faísca, e misturas desta gasolina com etanol hidratado carburante e solvente C-9. Os resultados mostram alteraçõe...

Comportamento motor oral e global de recém-nascidos de mães usuárias de crack e/ou cocaína Oral and general motor behavior of newborns from crack and/or cocaine using mothers

Directory of Open Access Journals (Sweden)

Marisa Gasparin

2012-12-01

Full Text Available OBJETIVO: Analisar o comportamento motor oral e global de recém-nascidos de mães que fizeram uso de crack e/ou cocaína durante a gestação e verificar se há relação entre o desenvolvimento dos sistemas sensório motor oral (SSMO e motor global. MÉTODOS: Estudo transversal, em que foram avaliados 25 recém-nascidos prematuros e a termo de mães usuárias de crack e/ou cocaína, pareados com outro grupo de 25 recém-nascidos sem o fator em estudo. As avaliações do SSMO e motor global foram realizadas por meio do Instrumento de Avaliação da Prontidão do Prematuro para Início da Alimentação Oral e do Test of Infant Motor Performance (TIMP, respectivamente. Os resultados compararam os escores encontrados nas duas escalas e a relação destes com o uso materno do crack e/ou cocaína durante a gestação. RESULTADOS: No TIMP não foi constatada diferença na comparação entre os escores de recém-nascidos de mães usuárias de crack e/ou cocaína e os de mães não usuárias. No Instrumento de Avaliação da Prontidão do Prematuro para Início da Alimentação Oral, os resultados apresentaram diferença. Foi observada associação entre os resultados de bebês que apresentaram atraso no TIMP com menor escore no Instrumento de Avaliação da Prontidão do Prematuro para Início da Alimentação Oral. CONCLUSÃO: O baixo desempenho observado no Instrumento de Avaliação da Prontidão do Prematuro para Início da Alimentação Oral sugere que as respostas motoras orais estão alteradas pelo uso materno das drogas. A correlação entre os dois instrumentos mostra que o desenvolvimento do SSMO pode estar relacionado ao desenvolvimento motor global.PURPOSE: analyzing the oral and general motor behavior of newborns from women who used crack and/or cocaine during pregnancy, and verifying if there is a relation between the development of the oral and general sensory motor system. METHODS: Cross-sectional study with 25 premature and full

To What Extent Can Motor Imagery Replace Motor Execution While Learning a Fine Motor Skill?

NARCIS (Netherlands)

Sobierajewicz, Jagna; Szarkiewicz, Sylwia; Prekoracka-Krawczyk, Anna; Jaskowski, Wojciech; van der Lubbe, Robert Henricus Johannes

2016-01-01

Motor imagery is generally thought to share common mechanisms with motor execution. In the present study, we examined to what extent learning a fine motor skill by motor imagery may substitute physical practice. Learning effects were assessed by manipulating the proportion of motor execution and

Eficiencia de los motores de inducción con carga cíclica; Efficiency of Induction Motors with Cyclic Load

Directory of Open Access Journals (Sweden)

Elías de la Rosa Masdueño

2011-02-01

Full Text Available Se propone un nuevo método para determinar la eficiencia de trabajo de los motores de inducción queaccionan cargas cíclicas tales como bombas reciprocantes, martinetes, etc. El método se basa en lasegregación de pérdidas, y la determinación del gráfico de corriente y la energía total del ciclo. Se muestrauna comprobación experimental basada en un método de Monte Carlo.  A new method for finding the working efficiency of the induction motors moving cyclic loads is proposed.This type of loading is frequent in mechanism like piston pumps, hammers, etc. The method is based inthe losses segregation and the determination of the current graphic and the total energy in the cycle. Anexperimental proof based on Monte Carlo method is shown.

Depressive symptoms and motor performance in the elderly: a population based study Sintomas depressivos e desempenho motor em idosos: estudo de base populacional

Directory of Open Access Journals (Sweden)

Kleyton T. Santos

2012-08-01

intervalo de confiança de 95%. RESULTADOS: Para todos os testes motores, o desempenho motor foi negativamente associado à sintomatologia depressiva, independentemente do sexo, idade, saber ler e escrever, renda familiar per capita e atividade física. Idosos com sintomas depressivos possuem entre 58% e 82% mais limitação funcional, a depender do teste de desempenho motor. CONCLUSÕES: Conclui-se que existe uma relação inversa entre sintomas depressivos e desempenho motor em idosos.

Comparación del funcionamiento mecánico, termodinámico y ambiental de motores operando con gasolina y gas natural de La Guajira

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John R. Agudelo S.

2005-01-01

Full Text Available En este artículo se presentan los resultados experimentales del funcionamiento mecánico y ambiental de un motor Toyota Hilux 2.400 cm3. con relación de compresión 9:1 y el diagnóstico termodinámico de un motor de ensayos normalizado de relación de compresión variable ASTM-CFR monocilíndrico, operando con gasolina y gas natural de La Guajira. Al usar gas natural en el motor Toyota se observó que para mantener la misma potencia se produce un incremento del consumo específico de combustible cercano al 20%, sin embargo el costo específico (pesos/galón equivalente está cercano al 50% a su favor. El rendimiento volumétrico mejoró alrededor del 10% respecto a la gasolina. Las emisiones de CO disminuyeron alrededor del 40%. Al hacer la comparación en términos termodinámicos en el motor CFR para una relación de compresión de 9:1, se observó que al usar gas natural de La Guajira, la potencia indicada disminuyó en 12,5%, la presión máxima de combustión disminuyó alrededor del 17%, lo que implica disminución proporcional en la temperatura instantánea cercana al 20% para las mejores condiciones de operación del motor. El coeficiente convectivo de transferencia de calor disminuyó alrededor del 28%. La primera fase de la combustión se duplica respecto a la gasolina al mantener el mismo ángulo de avance de chispa. Al usar un avance 15º por encima del establecido para gasolina, esta fase se hace similar.

Modelado sólido y análisis por elementos finitos de un cilindro de motor endotérmico de 2 tiempos de altas prestaciones

OpenAIRE

Pérez Ferreirós, Oscar

2005-01-01

El proyecto pretende explicar el proceso de evolución de un cilindro monobloque de motor endotérmico, 2 tiempos de altas prestaciones. El proceso real de evolución del motor consta de los siguientes pasos: - Modelado en 3D del cilindro, de una forma sencilla para que sea fácilmente modificable (modelado con Pro-Engineer WildFire). - Hipótesis de cálculo para realizar un cálculo de esfuerzos sobre los pernos que fijan el culatín y la culata del cilindro (Se proponen 2 estudio...

Técnicas de Inteligencia Artificial en el filtro de contenido web Smart Keeper para la clasificación de información

OpenAIRE

Yurisleidy Hernández Moya; Karel Antonio Verdecia Ortiz; Kiuver Kaddiel Ibañez Castro; Luis Enrique Sánchez Arce; Dovier Antonio Ripoll Méndez

2012-01-01

En los filtros de contenido web resulta importante identificar la temática de la información a la que acceden los usuarios, con el fin de ser capaz de decidir si permitirla o denegarla. El análisis inteligente de contenido es una de las técnicas empleadas por este tipo de software para la clasificación de información. Para el filtro cubano de contenido Smart Keeper se desarrolla el software Motor de Clasificación Inteligente de Contenido. El motor emplea técnicas de Inteligencia Artificial co...

Efeitos de um programa regular de atividade generalizada sobre os distúrbios motores de uma pessoa com doença de Parkinson The Effects of a Regular Physical Activity Program on the Motor Disorders of a Parkinson Patient. Efectos de un programa regular de actividad generalizada sobre los disturbios motores de una persona con enfermedad de parkinson

Directory of Open Access Journals (Sweden)

2006-11-01

Full Text Available O objetivo deste estudo foi analisar os efeitos de seis meses de um programa regular de atividade física sobre os distúrbios motores em uma pessoa idosa com a doença de parkinson. O sujeito pesquisado foi uma pessoa idosa do sexo feminino, sedentária, portadora da doença há dez anos. O programa foi desenvolvido durante seis meses com o apoio do Centro Goiano de Neurologia e Neurocirurgia. Para avaliar o nível de rigidez, a bradicinesia, a capacidade de se levantar da cadeira e se locomover e as alterações posturais foi utilizado um exame motor (BRITO, 1998, com avaliações antes e após o programa. Com dois meses de atividade física houve melhora na rigidez, na bradicinesia e no equilíbrio, contribuindo para a autonomia e independência do sujeito pesquisado. PALAVRAS-CHAVE: Doença de Parkinson – Idoso – Atividade física This study aims at analyzing the effects of a six-month program of regular physical activity upon the motor disorders of an elderly Parkinson patient. The subject was an elderly, physically inactive woman, who has had Parkinson for ten years. The six-month program was developed with the help of the Centro Goiano de Neurologia e Neurocirurgia (The Goianian Center for Neurology and Neuro-surgery. A motor exam (Brito, 1998 was used to evaluate the level of rigidness, bradicinesia, the capacity to raise from a chair and walk, and posture changes. Evaluations were conducted before and after the program. After two months of regular physical activity, improvements were noticed on rigidness, bradicinesia, and balance, which brought autonomy and independence to the subject. KEY-WORDS: Parkinson - elderly - physical activity El objetivo de este estudio fue analizar los efectos de seis meses de un programa regular de actividad física sobre los disturbios motores en una persona mayor con la enfermedad de parkinson. El sujeto investigado fue una persona mayor del sexo femenino, sedentaria portadora de la enfermedad

El retrato de fase como una herramienta de análisis del comportamiento motor

Directory of Open Access Journals (Sweden)

Rosa Angulo-Barroso

2016-04-01

Full Text Available Existe un gran número de investigaciones centradas en la adquisición y perfeccionamiento de habilidades motrices. Estas investigaciones intentan explicar cuál es la fuente y los procesos de cambio de los comportamientos motores que permiten al individuo adquirir o perfeccionar una habilidad. La ventaja de la Teoría de los Sistemas Dinámicos (TSD como marco de referencia es la inclusión de un análisis contextual en el proceso de aprendizaje. El objetivo de este artículo es dar a conocer una metodología llamada retrato de fase, la cual facilita el estudio del comportamiento motor basándose en los principios de la TSD. Datos biomecánicos tratados con una técnica de reducción adecuada constituyen una buena herramienta para describir y entender los cambios que suceden en el comportamiento motor. Los retratos de fase, mediante un gráfico (posición angular, velocidad angular, son capaces de capturar el complejo juego de fuerzas que influyen en el comportamiento motor. En este artículo, las formas de las trayectorias de los gráficos nos indicaron: (1 cómo el organismo se comporta durante la realización de las habilidades motoras analizadas mostrando sus patrones generales; (2 las singularidades poblacionales (con deficiencias y sin deficiencias o individuales; (3 los comportamientos adquiridos en el proceso de aprendizaje (novato y experto; y (4 los cambios producidos por manipulación del entorno. No obstante, los retratos de fase aunque muy útiles para resumir el comportamiento motor, no son representaciones completas del mismo y deberíamos completarlos con otras técnicas de análisis.

Modelo computacional del circuito motor basado en estudios de Resonancia Magnética Nuclear funcional

OpenAIRE

Karla Batista García-Ramó; Rafael Rodríguez-Rojas; Maylén Carballo-Barreda

2012-01-01

Los ganglios basales constituyen una compleja red de núcleos subcorticales implicados en el control motor,en la integración sensorimotora y en los procesos cognitivos. Su funcionamiento e interacción con el resto de las estructurascerebrales permanecen como una gran polémica. Este trabajo tuvo como objetivo modelar la interacción del circuito formado por los ganglios basales, el tálamo y la corteza para la selección de un programa motor, sobre la base del patrón de conectividad funcional ob...

Motor Neurons

DEFF Research Database (Denmark)

Hounsgaard, Jorn

2017-01-01

Motor neurons translate synaptic input from widely distributed premotor networks into patterns of action potentials that orchestrate motor unit force and motor behavior. Intercalated between the CNS and muscles, motor neurons add to and adjust the final motor command. The identity and functional...... in in vitro preparations is far from complete. Nevertheless, a foundation has been provided for pursuing functional significance of intrinsic response properties in motoneurons in vivo during motor behavior at levels from molecules to systems....

Simulación de procesos termodinámicos cuasi ideales orientados a la generación de trabajo mecánico. Evaluación de combinaciones posibles para su aplicación en motores alternativos de combustión o de aportación de calor

OpenAIRE

Llop Garcia, Xavier

2009-01-01

El objetivo del presente proyecto es la obtención de una herramienta informática que, gracias a un modelo matemático, simule los procesos termodinámicos de la fase cerrada de un motor alternativo de combustión interna. El motor que se pretende simular puede seguir un ciclo Otto o un ciclo Diesel y ser alimentado por distintos tipos de combustible. Para la obtención del modelo matemático se aceptaran ciertas hipótesis de simplificación debido a la complejidad de los procesos que tienen luga...

MOTORIC STIMULATION RELATED TO FINE MOTORIC DEVELOPMENT ON CHILD

Directory of Open Access Journals (Sweden)

Mira Triharini

2017-07-01

Full Text Available Introduction: Motor developmental stimulation is an activity undertaken to stimulate the children basic skills and so they can grow and develop optimally. Children who obtain a direct stimulus will grow faster than who get less stimulus. Mother’s behavior of stimulation is very important for children, it is considering as the basic needs of children and it must be fulfilled. Providing good stimulation could optimize fine motor development in children. The purpose of this study was to analyze mother’s behavior about motor stimulation with fine motor development in toddler age 4-5 years old. Method: Design have been  used in this study was cross sectional. Population were mothers and their toddler in Group A of Dharma Wanita Persatuan Driyorejo Gresik Preschool. Sample were 51 respondents recruited by using purposive sampling technique according to inclusion and exclusion criteria. The independent variable was mother’s behavior about motor stimulation whereas dependent variable was fine motor development in toddler. The data were collected using questionnaire and conducting observation on fine motor development based on Denver Development Screening Test (DDST. Data then analyzed using Spearman Rho (r test to find relation between mother’s behaviors about stimulation motor on their toddler fine motor development. Result: Results  of this study showed that there were correlations between mother’s knowledge and fine motor development in toddler (p=0.000, between mother’s attitude and fine motor development in toddler (p=0.000, and between mother’s actions and fine motor development in toddler (p=0.000. Analysis: In sort study found that there were relation between fine motor development and mother’s behavior. Discussion: Therefore mother’s behavior needed to be improved. Further research about stimulation motor and fine motor development aspects in toddler is required.

Generador oxihidrógeno para motor de combustión interna

OpenAIRE

Cebrián López, Héctor

2014-01-01

La pujada de preus dels carburants per la crisi econòmica actual motiva a investigar fonts d'energia alternatives. Les fonts d'energia convencionals com els combustibles fòssils són contaminants i costoses, i l'hidrogen generat a través de l'electròlisi de l'aigua és una solució ecològica i econòmica. En aquest projecte es dissenya un generador d'oxihidrógeno i s'estudien els efectes de l'addició d'aquest gas en 2 motors de combustió interna de 2 temps i 50 cc. Els resultats indiquen que, ...

DESEMPENHO DE MOTOR-GERADOR DE CICLO OTTO OPERADO COM GASOLINA E BIOGÁS PROVENIENTE DE SUINOCULTURA / PERFORMANCE MOTOR-GENERATOR OPERATED WITH OTTO CYCLE GASOLINE AND BIOGAS FROM THE PIG.

Directory of Open Access Journals (Sweden)

C. Rossetto

2014-12-01

Full Text Available A busca por novas fontes energéticas que não poluam o meio ambiente, bem como a mitigação dos impactos ambientais gerados pelo aumento da população, abre uma nova perspectiva no campo da pesquisa do biogás provenientes do resultado de tratamento de efluentes. O processo de transformação de energia gerada pela combustão do biogás para energia em motores no ciclo Otto e posterior transformação em energia elétrica é de fácil realização sendo necessárias algumas adaptações no motor, neste trabalho foi realizada apenas a substituição do carburador por um misturador de ar/combustível tipo Venturi. O objetivo deste trabalho foi avaliar o desempenho de motor-gerador ciclo Otto alimentado com biogás proveniente de suinocultura. Como testemunha foram utilizados ensaios com gasolina, simulando diferentes condições de trabalho, com cargas de 0; 0,250 kW (10 % da carga; 0,500 kW (20 % da carga; 0,750 kW (30 % da carga; 1 kW (40 % da carga; 1,250 kW (50 % da carga; 1,500 kW (60 % da carga; 1,750 kW (70 % da carga; 2 kW (80 % da carga; 2,250 kW (90 % da carga e 2,500 kW (100 % da carga. Onde foram avaliadas as emissões de dióxido de carbono (CO2, monóxido de carbono (CO e oxido de nitrogênio (NOx, e analisado o rendimento do motor-gerador que foi baixo em torno de 76 % menor quando comparado com gasolina, sendo necessários ajustes para o melhor desempenho. 

The electric motor handbook

Energy Technology Data Exchange (ETDEWEB)

Hurst, R.W.; Feltham, P. (eds.)

2004-05-01

This handbook outlines the important role that electric motors play in modern society. It covers the field of motor applications from various motor types to their use and repair. It also presents practical applications of electric motors and methods on motor efficiency. More than half of all electricity generated, and 75 per cent of all industrial electricity consumption is consumed by electric motors. Electrical personnel must be aware of all factors involved in electric motors in order to choose and apply the appropriate size of electric motor. These factors include efficiency, sizing and proper application. The efficient use and maximum life expectancy of electric motors depends on proper motor protection, control and maintenance. This handbook includes articles from leading experts on electric motors in modern electrical systems. The content includes: design considerations; proper electric motor sizing techniques; optimal electric motor application; electric motor protection technology; electric motor control principles; electric motor maintenance and troubleshooting; induction electric motors; electric motor bearing currents; electric motor bearing lubrication; electromagnetism; electric motor enclosures; electric motor testing; electric motor repair; DC electric motor; electric motor starters; electric motor brushes; industrial electric motors; electric motor diagrams; AC electric motors; electric motor wiring; electric motor service; electric motor rewinding; electric motor winding; diagram of electric motor wiring; electric motor kit; and, troubleshooting electric motors. A directory of motor manufacturers and suppliers was also included. refs., tabs., figs.

Facility Bench of Stationary Engines for Study of Emissions (E65-PO) CIEMAT; Instalacion Banco de Motores Estacionarios para Estudio de Emisiones (E65-PO) CIEMAT

Energy Technology Data Exchange (ETDEWEB)

Rojas Garcia, E; Rodriguez Maroto, J J

2007-07-01

The Project of Technology of Aerosols in Generation of Energy, of the Department of Fossil Fuels of the CIEMAT, began in the year 2004, a research activity line, based on the study of the emissions coming from internal combustion engines, particularly of Diesel technology. Activity was continued by the Polluting Emissions Group of the Department of Environment, when becoming the original Project in this Group. From the concession to the Group, of the project GR/AMB/0119/2004 Evaluation of the Emissions of Biodiesel supported by the Autonomous Community of Madrid together with the European Regional Development Fund (ERDF), this activity was encourage, with the design, assembly and to get ready of the facility Bench of stationary engines for study of emissions, located in the building 65 at CIEMAT, Madrid. The present report constitutes a detailed technical description of each one of the elements that the installation Bench of stationary engines for study of emissions it integrated within the framework of the referred project (GR/AMB/0119/2004) and whose capacity includes studies of the effects of the engine, fuel, operation conditions, and methodology of sampling and measurement of emissions (gases and particles). The fundamental parts of facility describes in the present report are: engine test cell (cabin of sound insulation , ventilation and refrigeration system, anti vibrations mounting, engine, dynamometric brake), lines of preconditioning of particles and gases emissions (exhaust line, primary and secondary dilution lines, gases cleaning system...), other general parts of facility (sampling and measurement station, service lines...). The present report not only reflects the characteristics of the systems involved, but rather also in certain cases specified the procedure and reason for their choice. (Author) 10 refs.

Split-phase motor running as capacitor starts motor and as capacitor run motor

OpenAIRE

Yahaya Asizehi ENESI; Jacob TSADO; Mark NWOHU; Usman Abraham USMAN; Odu Ayo IMORU

2016-01-01

In this paper, the input parameters of a single phase split-phase induction motor is taken to investigate and to study the output performance characteristics of capacitor start and capacitor run induction motor. The value of these input parameters are used in the design characteristics of capacitor run and capacitor start motor with each motor connected to rated or standard capacitor in series with auxiliary winding or starting winding respectively for the normal operational condition. The ma...

Segmented motor drive - with multi-phase induction motor

DEFF Research Database (Denmark)

Bendixen, Flemming Buus

of the induction motor is set up. The model is able to calculate dynamical electric, magnetic and mechanic state variables, but initially it is used to calculate static characteristics in motors with different number of phases and different voltage supply shapes. This analysis show i.e. that the efficiency....... The multi-phase motor is selected for further analysis. The project is limited to examine if increasing the number of phases can improve the characteristics for induction motor drives. In the literature it is demonstrated that torque production in a six-phase motor can be increased, if a 3rd harmonic......This PhD project commences in modulation of motor drives, i.e. having the advantage of reducing the number of variants and improves the system reliability at error situations. Four different motor drive topologies with modular construction as common denominator are compared on a general level...

Dinámica neuronal del circuito motor: un estudio de resonancia magnética funcional

Directory of Open Access Journals (Sweden)

Maylen Carballo Barreda

2012-06-01

Full Text Available Normal 0 21 false false false ES X-NONE X-NONE MicrosoftInternetExplorer4 /* 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 modelación de redes neuronales que describan la interacción funcional del circuito cerebral formado por los ganglios basales (GB, el tálamo y la corteza está limitada por las simplificaciones necesarias para reproducir sus propiedades biológicas.  Este trabajo tiene como objetivo general modelar el circuito GB-tálamo-corteza para la selección de un programa motor, sobre la base del patrón de conectividad funcional obtenido por imágenes de resonancia magnética nuclear funcional (RMNf.  Se incluyeron cinco poblaciones neuronales y dos circuitos paralelos en competencia. La determinación de los pesos de las conexiones entre las poblaciones neuronales a partir de imágenes de RMNf, contribuyó a una formulación más realista del modelo, permitiendo describir la participación de los GB en la selección de una acción en estado normal y en la enfermedad de Parkinson (EP. La simulación permitió demostrar que ante una pérdida de dopamina superior al 40%, el circuito GB-tálamo-cortical no es capaz de seleccionar entre dos programas motores; y además reflejó la capacidad de adaptación del sistema para compensar el trastorno funcional del circuito motor en la EP

46 CFR 111.70-3 - Motor controllers and motor-control centers.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Motor controllers and motor-control centers. 111.70-3... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Motor Circuits, Controllers, and Protection § 111.70-3 Motor controllers and motor-control centers. (a) General. The enclosure for each motor controller or motor-control...

Revisión sobre métodos matemáticos para el estudio de la estabilidad del voltaje en los sistemas eléctricos de potencia; A review on mathematics methodo to study the voltage stability on electric power systems

Directory of Open Access Journals (Sweden)

Zaid García Sánchez

2011-05-01

Full Text Available En Cuba desde la década del 70 se empezaron a desarrollar algoritmos para realizar el estudio de los regímenes estacionarios y transitorios del Sistema Eléctrico Nacional (SEN. Particular énfasis se hizo sobre el desarrollo de algoritmos y programas para computadoras para realizar el estudio de la estabilidad transitoria. Actualmente se utiliza ampliamente el programa Power System Explorer (PSX, el que posee amplias facilidades para realizar estudios sobre regímenes estaciones y transitorios de los sistemas eléctricos de potencia. A través de los estudios realizados para la planificación y la experiencia alcanzada sobre la explotación del SEN, con su estructura actual, se ha revelado la necesidad de estudiar en detalles los problemas relacionados con el voltaje, en particular el problema de la estabilidad del voltaje del SEN. En este artículo se realiza una primera revisión sobre algunos de los métodos matemáticos estáticos y dinámicos que se han desarrollado y que recoge la bibliografía sobre el tema de la Estabilidad del Voltaje en los Sistemas Eléctricos de Potencia.  In Cuba, from the seventies of the past century, different algorithms to study stationary and transient regimes of the Cuban Electric System were developed. Those algorithms and computer programs were focused in the study of transient stability. Currently, we use widely the computer program “Power System Explorer” (PSX which have a lot of facilities to make studies about stationary and transient regimes of electric power systems. Due to the studies about planning of electric power systems and the accumulated experience working with Cuban Electric System, the need of study the problems related with voltage stability of Cuban Electric System has arisen. In this paper, we make a first review about some static and dynamic mathematical methods included in bibliography about voltage stability of electric power systems.

Neurons other than motor neurons in motor neuron disease.

Science.gov (United States)

Ruffoli, Riccardo; Biagioni, Francesca; Busceti, Carla L; Gaglione, Anderson; Ryskalin, Larisa; Gambardella, Stefano; Frati, Alessandro; Fornai, Francesco

2017-11-01

Amyotrophic lateral sclerosis (ALS) is typically defined by a loss of motor neurons in the central nervous system. Accordingly, morphological analysis for decades considered motor neurons (in the cortex, brainstem and spinal cord) as the neuronal population selectively involved in ALS. Similarly, this was considered the pathological marker to score disease severity ex vivo both in patients and experimental models. However, the concept of non-autonomous motor neuron death was used recently to indicate the need for additional cell types to produce motor neuron death in ALS. This means that motor neuron loss occurs only when they are connected with other cell types. This concept originally emphasized the need for resident glia as well as non-resident inflammatory cells. Nowadays, the additional role of neurons other than motor neurons emerged in the scenario to induce non-autonomous motor neuron death. In fact, in ALS neurons diverse from motor neurons are involved. These cells play multiple roles in ALS: (i) they participate in the chain of events to produce motor neuron loss; (ii) they may even degenerate more than and before motor neurons. In the present manuscript evidence about multi-neuronal involvement in ALS patients and experimental models is discussed. Specific sub-classes of neurons in the whole spinal cord are reported either to degenerate or to trigger neuronal degeneration, thus portraying ALS as a whole spinal cord disorder rather than a disease affecting motor neurons solely. This is associated with a novel concept in motor neuron disease which recruits abnormal mechanisms of cell to cell communication.

Dinámica neuronal del circuito motor: un estudio de resonancia magnética funcional

OpenAIRE

Batista García-Ramó, Karla; Rodríguez Rojas, Rafael; Carballo Barreda, Maylén

2012-01-01

La modelación de redes neuronales que describan la interacción funcional del circuito cerebral formado por los ganglios basales (GB), el tálamo y la corteza está limitada por las simplificaciones necesarias para reproducir sus propiedades biológicas. Este trabajo tiene como objetivo general modelar el circuito GB-tálamo-corteza para la selección de un programa motor, sobre la base del patrón de conectividad funcional obtenido por imágenes de resonancia magnética nuclear funcional (RMNf). Se i...

Classification of cerebral palsy: association between gender, age, motor type, topography and Gross Motor Function Classificação da paralisia cerebral: associação entre gênero, idade, tipo motor, topografia e Função Motora Grossa

Directory of Open Access Journals (Sweden)

Luzia Iara Pfeifer

2009-12-01

Full Text Available The goal of this study was to assess the relation between gender, age, motor type, topography and gross motor function, based on the Gross Motor Function System of children with cerebral palsy. Trunk control, postural changes and gait of one hundred children between 5 months and 12 years old, were evaluated. There were no significant differences between gender and age groups (p=0.887 or between gender and motor type (p=0.731. In relation to body topography most children (88% were spastic quadriplegic. Most hemiplegics children were rated in motor level I, children with diplegia were rated in motor level III, and quadriplegic children were rated in motor level V. Functional classification is necessary to understand the differences in cerebral palsy and to have the best therapeutic planning since it is a complex disease which depends on several factors.Este estudo teve como objetivo avaliar a relação entre gênero, idade, tipo motor, topografia e Função Motora Grossa, baseado no Sistema de Função Motora Grossa em crianças com paralisia cerebral. Participaram desta pesquisa 100 crianças com idade entre 5 meses a 12 anos que foram observadas em relação ao controle de tronco, trocas posturais e marcha. Não houve diferenças significativas entre gêneros e grupos etários (p=0,887 e entre gênero e tipo motor (p=0,731. Em relação à topografia corporal, houve predomínio de crianças com quadriplegia, sendo que a maioria (88% era do tipo espástico. Quanto ao nível motor, as crianças hemiplégicas pertenciam em sua maioria ao nível I, as diplégicas ao nível III e as quadriplégicas ao nível V. Sendo a paralisia cerebral uma condição complexa que depende de diversos fatores, beneficia-se de classificações funcionais para compreensão da diversidade e melhor planejamento terapêutico.

Equipo comparativo para la medida de conductividad térmica de materiales cerámicos

Directory of Open Access Journals (Sweden)

Barea, R.

2006-04-01

Full Text Available Among the different techniques available for measuring thermal conductivity, the comparative method (ASTM E1225-99 is the most appropriate for porous materials. This method determines the thermal conductivity in steady state conditions in the 100 - 1300 K temperature range and for conductivities between 0.2 and 200 W/mK, respectively, depending on the equipment characteristics. In the present paper, the design and development, as well as the start up process, of an apparatus based on this method is described. Thermal conductivity data on a mullite based refractory, measured by both the laser flash and the comparative methods, are presented and comparatively discussed in order to validate the developed equipment.

Entre las distintas técnicas de medida de la conductividad térmica de materiales, el método comparativo, recogido en la norma ASTM E1225-99, es el más adecuado para muestras porosas o materiales compuestos. Este método permite determinar conductividades térmicas en estado estacionario, en el intervalo de valores de 0,2 a 200 W/mK, y a temperaturas de ensayo en el rango 100-1300 K, dependiendo del diseño del equipo. En este trabajo se expone el diseño, desarrollo y puesta a punto de un equipo de medida de conductividad térmica basado en este método. Paralelamente, se realiza una validación del equipo mediante el estudio comparativo de los resultados obtenidos usando el equipo comparativo y la técnica del pulso láser en materiales porosos de mullita.

Aplicaciones del análisis de aceite usado en motores a diesel de uso marino

OpenAIRE

Muñoz, Carlos Neder; Marin Lopez, Jose Rolando

2009-01-01

El principal parámetro que determina la vida útil de un motor de combustión interna es el lu-bricante, el mismo que está compuesto usualmente de uno o dos tipos de aceites básico más un paquete de aditivos, para seleccionar un aceite de motor, se recomienda guiarse por el manual del fabricante de dicha máquina, en donde se indicará la viscosidad y el nivel de servicio o calidad que deberá tener el lubricante seleccionado. Dependerá de la correcta selección del lubricante que el desgaste de la...

Aberrant supplementary motor complex and limbic activity during motor preparation in motor conversion disorder.

Science.gov (United States)

Voon, Valerie; Brezing, Christina; Gallea, Cecile; Hallett, Mark

2011-11-01

Conversion disorder (CD) is characterized by unexplained neurological symptoms presumed related to psychological issues. The main hypotheses to explain conversion paralysis, characterized by a lack of movement, include impairments in either motor intention or disruption of motor execution, and further, that hyperactive self-monitoring, limbic processing or top-down regulation from higher order frontal regions may interfere with motor execution. We have recently shown that CD with positive abnormal or excessive motor symptoms was associated with greater amygdala activity to arousing stimuli along with greater functional connectivity between the amygdala and supplementary motor area. Here we studied patients with such symptoms focusing on motor initiation. Subjects performed either an internally or externally generated 2-button action selection task in a functional MRI study. Eleven CD patients without major depression and 11 age- and gender-matched normal volunteers were assessed. During both internally and externally generated movement, conversion disorder patients relative to normal volunteers had lower left supplementary motor area (SMA) (implicated in motor initiation) and higher right amygdala, left anterior insula, and bilateral posterior cingulate activity (implicated in assigning emotional salience). These findings were confirmed in a subgroup analysis of patients with tremor symptoms. During internally versus externally generated action in CD patients, the left SMA had lower functional connectivity with bilateral dorsolateral prefrontal cortices. We propose a theory in which previously mapped conversion motor representations may in an arousing context hijack the voluntary action selection system, which is both hypoactive and functionally disconnected from prefrontal top-down regulation. Copyright © 2011 Movement Disorder Society.

Aberrant supplementary motor complex and limbic activity during motor preparation in motor conversion disorder

Science.gov (United States)

Voon, V; Brezing, C; Gallea, C; Hallett, M

2014-01-01

Background Conversion disorder is characterized by unexplained neurological symptoms presumed related to psychological issues. The main hypotheses to explain conversion paralysis, characterized by a lack of movement, include impairments in either motor intention or disruption of motor execution, and further, that hyperactive self-monitoring, limbic processing or top-down regulation from higher order frontal regions may interfere with motor execution. We have recently shown that conversion disorder with positive abnormal or excessive motor symptoms was associated with greater amygdala activity to arousing stimuli along with greater functional connectivity between the amgydala and supplementary motor area. Here we studied patients with such symptoms focusing on motor initiation. Methods Subjects performed either an internally or externally generated two-button action selection task in a functional MRI study. Results Eleven conversion disorder patients without major depression and 11 age- and gender-matched normal volunteers were assessed. During both internally and externally generated movement, conversion disorder patients relative to normal volunteers had lower left supplementary motor area (SMA) (implicated in motor initiation) and higher right amygdala, left anterior insula and bilateral posterior cingulate activity (implicated in assigning emotional salience). These findings were confirmed in a subgroup analysis of patients with tremor symptoms. During internally versus externally generated action in CD patients, the left SMA had lower functional connectivity with bilateral dorsolateral prefrontal cortices. Conclusion We propose a theory in which previously mapped conversion motor representations may in an arousing context hijack the voluntary action selection system which is both hypoactive and functionally disconnected from prefrontal top-down regulation. PMID:21935985

Las principales fallas de motores eléctricos en Costa Rica

Directory of Open Access Journals (Sweden)

Osvaldo Guerreo Castro

2010-10-01

Full Text Available Una de las tareas más importantes en la gestión del mantenimiento de los equipos de producción, y particularmente de los motores eléctricos, es identificar y prevenir las fallas para tomar acciones que eviten la incidencia de las mismas.Mediante una investigación de campo, con visitas a empresas de varios sectoresproductivos y talleres de reparación de motores eléctricos en Costa Rica, se logróobtener una clasificación y distribución porcentual de las fallas más comunes enlos motores trifásicos de inducción, en el rango de 2 a 50 HP.Esta investigación determinó que existen cuatro tipos de fallas más comunes enmotores eléctricos en Costa Rica; estas se concentran en dos sectores productivos.La investigación identificó aspectos relevantes por mejorar en cuanto a la orientación de la formación profesional universitaria y, en el modelo administrativo del mantenimiento de estos equipos, en lasindustrias.

Design and implementation of a system for controlling emission of radiation; Diseno e implementacion de un sistema para el control de emision de radiacion

Energy Technology Data Exchange (ETDEWEB)

Alvarez Alfaro, Luis Diego

2012-07-01

The Centro de Investigacion en Ciencias Atomicas, Nucleares y Moleculares of the Universidad de Costa Rica has seen the need to automate the process of changing filters, so that no person has to be exposed to the radiation emitted by the source, which can be very harmful to health. A graphical interface and a controller is implemented using the LabView software, to manipulate and detect the position of a rotating disk to a radiation source. The rotary disk is used in the Center by means of a microcontroller Arduino UNO and a stepper motor. An actuator and a stepper motor, controlled through signals sent by an Arduino UNO, have been defined and implemented in a first stage, by an integrated module of bridges H and an optical system to locate the position of the filters. The second stage has been the creation in parallel of a virtual instrument in LabView, with routines able to move the stepper motor shaft to a desired position, along with its graphical interface, adaptable to any stepper motor bipolar or unipolar, and simple to use. The program has been validated to verify proper operation, by a routine in which filters are chosen randomly and persons handling the program. The stages have been documented along with the user manual for proper use of virtual instrument and system assembly. (author) [Spanish] El Centro de Investigacion en Ciencias Atomicas, Nucleares y Moleculares de la Universidad de Costa Rica ha visto la necesidad de automatizar el proceso de cambio de filtros, de tal manera que ninguna persona tuviera que estar expuesta a la radiacion emitida por la fuente, que puede resultar muy danina para la salud. Una interfaz grafica y un controlador se ha implementado utilizando el software LabView, para manipular y detectar la posicion de un disco giratorio para una fuente de radiacion. El disco giratorio es utilizado en el Centro por medio de un microcontrolador Arduino UNO y un motor a pasos. Un actuador y un motor a pasos, controlados a traves de senales

Interfaz Gráfica Computacional para Destilación Multicomponente utilizando Métodos Cortos

Directory of Open Access Journals (Sweden)

A. Osorio Mirón

2011-12-01

Full Text Available En este trabajo, se elaboró una interfaz gráfica que determina por medio de simulación en estado estacionario el número de platos necesarios en el proceso de destilación multicomponente, así como la composición en el flujo de destilado y fondos de una torre de destilación utilizando métodos cortos. La interfaz gráfica de usuario, se construyó en el lenguaje de programación Python 2.5, permite presentar los datos de entrada y salida para el caso de columnas de destilación operando en régimen permanente. Los resultados del uso de la interfaz gráfica muestran una forma simple de realizar diseños preliminares de torres de destilación y su potencialidad como material de apoyo para el estudio y comprensión de conceptos básicos en destilación multicomponente. En un trabajo posterior se podrá visualizar el desempeño del modelo dinámico a través de perturbaciones programadas en las condiciones de operación.   Palabras claves: destilación multicomponente; métodos cortos; interfaz gráfica de usuario; Phyton 2.5.In this work, we developed a graphical interface that determines by steady-state simulation the number of plates required for multicomponent distillation process and the composition of distillate and bottoms flow of a distillation tower using short-cut methods. The graphical user interface was built in the programming language Python 2.5, allows to present the input and output data for the case of distillation columns operating in steady state. The results of using the graphical interface shows a simple way to make preliminary designs of distillation towers and its potential as support material for the study and understanding of basic concepts in multicomponent distillation. In a later work it will can display the dynamic model performance through scheduled disturbances in operating conditions.   Keywords: multicomponent distillation; shorcut methods;graphical user interface; Phyton 2.5.

Motor/generator

Science.gov (United States)

Hickam, Christopher Dale [Glasford, IL

2008-05-13

A motor/generator is provided for connecting between a transmission input shaft and an output shaft of a prime mover. The motor/generator may include a motor/generator housing, a stator mounted to the motor/generator housing, a rotor mounted at least partially within the motor/generator housing and rotatable about a rotor rotation axis, and a transmission-shaft coupler drivingly coupled to the rotor. The transmission-shaft coupler may include a clamp, which may include a base attached to the rotor and a plurality of adjustable jaws.

Application of stepping motor

International Nuclear Information System (INIS)

1980-10-01

This book is divided into three parts, which is about practical using of stepping motor. The first part has six chapters. The contents of the first part are about stepping motor, classification of stepping motor, basic theory og stepping motor, characteristic and basic words, types and characteristic of stepping motor in hybrid type and basic control of stepping motor. The second part deals with application of stepping motor with hardware of stepping motor control, stepping motor control by microcomputer and software of stepping motor control. The last part mentions choice of stepping motor system, examples of stepping motor, measurement of stepping motor and practical cases of application of stepping motor.

Critérios técnicos para a seleção de pulverizadores autopropelidos comercializados no mercado brasileiro

Directory of Open Access Journals (Sweden)

Marcelo Silveira de Farias

2015-05-01

Full Text Available Nos últimos anos, a oferta de pulverizadores autopropelidos no mercado brasileiro aumentou, principalmente para suprir a demanda de agricultores que possuem grandes extensões de áreas, nas quais se requer um alto ritmo operacional. Neste trabalho, foram avaliados, em função da potência nominal do motor, os diferentes tipos de transmissões, a capacidade do reservatório de calda, tamanho das barras e vão livre, considerados critérios técnicos importantes para a seleção dessas máquinas. Para tanto, utilizaram-se informações técnicas de 41 modelos de pulverizadores autopropelidos comercializados no mercado brasileiro. Como resultado, classificaram-se os pulverizadores em cinco classes, segundo a potência do motor. Verificou-se que, com o aumento da potência, os pulverizadores são equipados com transmissão hidrostática e a capacidade dos reservatórios de calda são maiores.

A descrição do funcionamento de um motor Homopolar linear e suas aplicações: Ilustrando o funcionamento de um acelerador de partículas

OpenAIRE

Doff, Adriano; Szmoski, Romeu M.

2016-01-01

Neste trabalho exploramos o potencial didático de um motor homopolar linear com o objetivo de ilustrar o princípio de funcionamento de um acelerador de partículas. A fim de estabelecer o mecanismo de funcionamento de um motor homopolar linear, consideramos uma analogia com a descrição de um motor homopolar rotatório, e partir deste apresentamos os princípios de funcionamento deste dispositivo e estabelecemos um limite teórico para a velocidade do motor linear. De posse dos dados gerados exper...

Prospecção de talentos motores para rugby : proposta de modelo a de indicadores somatomotores

OpenAIRE

Eraldo dos Santos Pinheiro

2014-01-01

O objetivo da presente tese foi o de propor um modelo de identificação de características somatomotoras em escolares para a prospecção de possíveis talentos esportivos para o Rugby XV. Para tanto fizeram parte da amostra 195 escolares do sexo masculino com idades entre 16 e 17 anos e 32 atletas do sexo masculino da seleção brasileira de Rugby menores de 18 anos, subdividos em dois grupos Forwards (n=17) e Backs (n=15). Este estudo foi realizado a partir de uma base de dados de medidas e teste...

Propuesta de mejora para el mantenimiento del equipo pesado de la constructora COANDES S.A. basado en un análisis del aceite lubricante usado en los motores de combustión interna diésel

OpenAIRE

Arévalo Avalos, David Alejandro

2015-01-01

Se realiza una propuesta de mejora proactiva-predictiva para el mantenimiento efectuado por COANDES. Primero se efectúa una evaluación de criticidad de los equipos y un estudio del aceite usado en los motores de combustión interna diésel. Finalmente se propone un modelo de análisis de fallas basado en los resultados que incluye un software de interpretación de resultados de análisis de aceite. The investigation performs a proposal for proactive-predictive improvement for the maintenance by...

Uma análise do desenvolvimento motor de crianças com transtorno do déficit de atenção e hiperatividade (TDAH

Directory of Open Access Journals (Sweden)

Lidiane Aparecida Fernandes

2017-04-01

Full Text Available O Transtorno do Déficit de Atenção com Hiperatividade (TDAH é decorrente de alterações em áreas do cérebro que implicam em alterações no controle inibitório, na memória de trabalho, no tempo de reação, além de outras funções. As habilidades motoras globais e finas estão comprometidas nas crianças com TDAH e uma desordem ou desarranjo no desenvolvimento motor (DM pode interferir em diversas fases do desenvolvimento global da criança. O objetivo do estudo foi analisar o DM de crianças com TDAH a partir da avaliação das habilidades motoras fundamentais. A amostra foi composta por oito crianças do sexo masculino com idade média de 10,25 anos. O teste de habilidades motoras foi realizado através do Test of Gross Motor Development (TGMD-2. Os resultados alcançados ficaram dentro do esperado e evidenciaram valores abaixo do esperado tanto para o subteste de atividades locomotoras como também para atividades manipulativas. As crianças com TDAH apresentaram um déficit motor acentuado nas habilidades de controle de objetos. A partir da análise do padrão de movimentos é possível identificar os fatores que tornam o movimento limitado, possibilitando a tomada de decisão sobre que habilidades e/ou critérios motores devem ser enfatizados nos programas; o tempo de prática para cada habilidade e as metas de desempenho da criança. Os resultados evidenciam a necessidade de programas de atividades físicas regulares e sistematizados e permitem concluir que crianças diagnosticadas com TDAH apresentam um atraso no desempenho motor quando comparadas com crianças que estão de acordo com o que é esperado para a faixa etária.

La diversidad cultural en Google y los motores de búsqueda: una aproximación conceptual

OpenAIRE

Abadal, Ernest; Codina, Lluís

2008-01-01

Se analiza una preocupación expresada tanto de forma implícita como explícita en diversos ámbitos, según la cual los motores de búsqueda en general y Google en particular, podrían estar utilizando algún sistema para ocultar determinados contenidos culturales o bien para destacar aquellos que proceden del ámbito anglosajón en detrimento de los de otras culturas y lenguas. Dicho de otro modo, se considera, en una primera aproximación de modo exclusivamente conceptual, la idea de si el uso inten...

Desenvolvimento motor e funcional em crianças nascidas pré-termo e a termo: influência de fatores de risco biológico e ambiental Desarrollo motor y funcional en niños nacidos pretérmino y a término: influencia de factores de riesgo biológico y ambiental Motor and functional development in infants born preterm and full term: influence of biological and environmental risk factors

Directory of Open Access Journals (Sweden)

Edifrance Sá de Souza

2012-12-01

Full Text Available OBJETIVO: Comparar o desenvolvimento motor de crianças de 12 a 18 meses nascidas pré-termo e a termo e investigar sua relação com o desempenho funcional e com a quantidade e qualidade de estímulos ambientais. MÉTODOS: Estudo quantitativo e longitudinal com 30 crianças prematuras (idade gestacional de 30,0±2,3 semanas e peso ao nascimento de 1178±193g e 30 nascidas a termo (idade gestacional de 39,0±1,3 semanas e peso ao nascimento de 3270±400g. O desenvolvimento motor foi avaliado pelos testes Alberta Infant Motor Scale e Peabody Developmental Motor Scales. O ambiente domiciliar foi avaliado com o Home Observation Measurement of the Environment. Com o intuito de examinar as habilidades funcionais, utilizou-se o Pediatric Evaluation of Disability Inventory. RESULTADOS: Houve maior lentidão para aquisição da marcha no grupo pré-termo (p=0,005, embora não tenha sido encontrada diferença significativa entre os grupos no Alberta Infant Motor Scale aos 12 (p=0,19 e aos 15 meses (p=0,80. Aos 18 meses foram encontradas diferenças significativas no desenvolvimento motor grosso (pOBJETIVO: Comparar el desarrollo motor de los 12 a los 18 meses de niños nacidos pretérmino y a término e investigar la relación entre desarrollo motor, desempeño funcional y la cantidad y calidad de estímulos ambientales. MÉTODOS: Estudio cuantitativo, direccional y longitudinal, que incluyó a 30 niños prematuros (edad gestacional: 30,0±2,3 semanas y peso al nacer: 1178±193 gramas y 30 nacidos a término (edad gestacional: 39,0±1,3 semanas y peso al nacer: 3270±400 gramas. El desarrollo motor fue evaluado con el uso de las pruebas Alberta Infant Motor Scale (AIMS y Peabody Developmental Motor Scales (PDMS-2. El ambiente domiciliar fue evaluado con el Home Observation Measurement of the Enviroment (HOME. Para examinar las habilidades funcionales se utilizó el Pediatric Evaluation of Disability Inventory (PEDI. RESULTADOS: Hubo mayor lentitud para

Performance Comparison between a Permanent Magnet Synchronous Motor and an Induction Motor as a Traction Motor for High Speed Train

Science.gov (United States)

Kondo, Minoru; Kawamura, Junya; Terauchi, Nobuo

Performance tests are carried out to demonstrate the superiority of a permanent magnet synchronous motor to an induction motor as a traction motor for high-speed train. A prototype motor was manufactured by replacing the rotor of a conventional induction motor. The test results show that the permanent magnet motor is lighter, efficient and more silent than the induction motor because of the different rotor structure.

Uso de etanol carburado en motores Diesel

Directory of Open Access Journals (Sweden)

Rodríguez Luis Arnoby

1990-06-01

Full Text Available Este trabajo se ejecutó en el Taller de Maquinaria Agrícola de la Facultad de Ciencias Agropecuarias de la Universidad Nacional de Colombia, Seccional Palmira. Un motor diesel de 2 cilindros, 1260 cm3 y relación de comprensión 23:1, fue alimentado mediante un sistema dual formado por el sistema de inyección para ACPM y un sistema de carburación para etanol y mezclas etanol-agua. En primer término se varió el avance de la inyección entre 18 y 26° APMS(Antes de Punto Muerto Superior con el fin de determinar el avance óptimo de inyección en el motor original y el motor alimentado con el sistema dual. Con base en el punto de máxima potencia, se seleccionaron 20 y 22" como avances óptimos. En la segunda prueba, al operar el motor con carga y velocidad variables y alimentarlo con cuatro combustibles (ACPM, etanol y mezclas etanol- agua con 20 y 40 % agua, se incrementaron la velocidad en 10% la potencia máxima en 6.5% ; y el torque máximo en 3.73%, desde el motor original al sistema dual alimentado con la mezcla carburada de 40% agua. La mayor sustitución de combustible se presentó a alta velocidad donde se reemplazó hasta el 32 % de ACPM por etanol. Solo a alta velocidad se justifica la sobrealimentación con etanol carburado. En este rango se presentaron aumentos de potencia, velocidad, par torsor y sustitución de combustible.This work was performed in the Agricultural Mechanics Shop of the Universidad Nacional of Colombia in Palmira. A two-cylinder, 1260 cm3 diesel engine with a compression ratio of 23:1 was fueled by a dual system formed by its injection system for diesel oil and a carburation system for ethanol and ethanol-water blends. In a first test, m e injection advance was varied between 18 and 26 o BTDC (Before Top Dead Center to determine the optimum injection advance in the original engine and the engine fueled with the dual system. According to the maximum power point, 20 and 22° BTDC were selected as the optimum

Prueba de hipótesis sobre la existencia de una raíz fraccional en una serie de tiempo no estacionaria

Directory of Open Access Journals (Sweden)

Diego Fernando Lemus Polania

2013-01-01

Full Text Available Gómez y Gallón (2008 para determinar la existencia de memoria larga en un proceso ARFIMA(p,d,q estacionario e invertible. En el caso puntual de los procesos ARFIMA(p,d,q, esta modificación permite determinar la existencia de una raíz fraccional en una serie de tiempo no estacionaria cuyo componente ARMA de corto plazo es indeterminado o desconocido. Vía simulaciones de Monte Carlo, se validan los resultados analíticos obtenidos en el trabajo y se demuestra el buen comportamiento de la prueba propuesta, en términos de potencia y tamaño, en comparación con otras metodologías disponibles en la literatura.

Active and reactive power flow regulation for a grid connected vsc based on fuzzy controllers

Directory of Open Access Journals (Sweden)

Nelson Díaz Aldana

2013-01-01

bajo diferentes niveles de transferencia de potencia. Este artículo, presenta el análisis, diseño y resultados de la implementación de controladores difusos para la regulación del flujo de potencia activa y reactiva de un VSC conectado a red. Además, se muestra la dependencia de la respuesta transitoria y de estado estacionario con la forma de las funciones de pertenencia del controlador difuso cuando este se aplica a diferentes niveles de transferencia de potencia. El desempeño de los controladores se verifica mediante simulación y mediante implementación física en un prototipo construido de un VSC.

Efecto de los trending topics en el volumen de consultas a los motores de búsqueda

OpenAIRE

Ricci, Santiago; Tolosa, Gabriel Hernán

2013-01-01

Las redes sociales se han convertido en aplicaciones muy populares en Internet, principalmente para publicar información y comunicarse en grupos. Una caso bien conocido es Twitter, considerado un servicio de microblogging. Aquí se generan temas que se vuelven muy populares en la red social en un determinado momento, denominados trending topics (TT). En este trabajo se intenta determinar el efecto de estos temas en cuanto al volumen de consultas enviadas a un motor de búsqueda web. Para ello...

The effect of induction motor shaft diameter on motor performance

Directory of Open Access Journals (Sweden)

Asım Gökhan Yetgin

2017-10-01

Full Text Available Induction motors are used in many areas from the past to the present and in different fields with the development of technology has continued to be used. It is obvious that induction motors as an improvement to the efficiency in terms of energy saving would cause great benefit. In that context, induction motor manufacturers and designers are constantly trying out new methods to improve motor performance and efficiency. In this study, what would be the optimum diameter of the shaft in order to increase the efficiency of the induction motor were investigated. In the study, 5.5 kW, 7.5 kW and 11 kW motors analyzes were also performed. Obtained shaft diameter values were compared with the manufacturer values. In addition, critical points such as the magnetic flux values, weight values and performances of the motors were examined and optimal shaft diameter values for each motor have been determined.

Motor experience with a sport-specific implement affects motor imagery

Science.gov (United States)

Zhu, Hua; Shen, Cheng; Zhang, Jian

2018-01-01

The present study tested whether sport-specific implements facilitate motor imagery, whereas nonspecific implements disrupt motor imagery. We asked a group of basketball players (experts) and a group of healthy controls (novices) to physically perform (motor execution) and mentally simulate (motor imagery) basketball throws. Subjects produced motor imagery when they were holding a basketball, a volleyball, or nothing. Motor imagery performance was measured by temporal congruence, which is the correspondence between imagery and execution times estimated as (imagery time minus execution time) divided by (imagery time plus execution time), as well as the vividness of motor imagery. Results showed that experts produced greater temporal congruence and vividness of kinesthetic imagery while holding a basketball compared to when they were holding nothing, suggesting a facilitation effect from sport-specific implements. In contrast, experts produced lower temporal congruence and vividness of kinesthetic imagery while holding a volleyball compared to when they were holding nothing, suggesting the interference effect of nonspecific implements. Furthermore, we found a negative correlation between temporal congruence and the vividness of kinesthetic imagery in experts while holding a basketball. On the contrary, the implement manipulation did not modulate the temporal congruence of novices. Our findings suggest that motor representation in experts is built on motor experience associated with specific-implement use and thus was subjected to modulation of the implement held. We conclude that sport-specific implements facilitate motor imagery, whereas nonspecific implements could disrupt motor representation in experts. PMID:29719738

Avaliação e intervenção no desenvolvimento motor de uma criança com Síndrome de Down

OpenAIRE

Santos,Ana Paula Maurilia dos; Weiss,Silvio Luiz Indrusiak; Almeida,Geciely Munaretto Fogaça de

2010-01-01

o objetivo deste estudo foi analisar o desenvolvimento motor de uma criança com síndrome de Down e verificar os efeitos de um programa de intervenção motora específica. Trata-se de uma pesquisa descritiva do tipo estudo de caso. Para a avaliação do desenvolvimento motor foram utilizados os testes da Escala de Desenvolvimento Motor - EDM que analisa as áreas da motricidade fina e global, equilíbrio, esquema corporal, organização espacial e temporal/linguagem, e lateralidade. Essa criança parti...

Control de velocidad de un motor de inducción utilizando un controlador Fuzzy

Directory of Open Access Journals (Sweden)

Madelín Lima Álvarez

2011-03-01

Full Text Available Se realiza la simulación del sistema de control de velocidad del motor de inducción. Se parte del enfoquevectorial y de un sistema de coordenadas adecuado a su futura utilización, utilizando para esto el lenguaje desimulación de sistemas dinámicos Simulink. En cuanto a la simulación del método de control vectorial porcampo orientado se ha empleado el denominado método de control vectorial indirecto. El control de la velocidaddel motor se simuló utilizando un controlador Fuzzy, comparándose posteriormente estos resultados con losobtenidos mediante la utilización de un controlador PI digital.  This work carries out the simulation of speed control of induction motor. It is based on the field orientation theoryand on a system of coordinates adapted to its future use. The language that has been used for the simulation ofdynamics systems is Simulink. The indirect method of the field orientation control theory was used in themathematical analysis of the induction motor. The speed control of the induction motor was simulated using aFuzzy controller and these results were compared with those obtained by means of the use of a PI digitalcontroller.

Motor-operated valve (MOV) actuator motor and gearbox testing

International Nuclear Information System (INIS)

DeWall, K.; Watkins, J.C.; Bramwell, D.

1997-07-01

Researchers at the Idaho National Engineering and Environmental Laboratory tested the performance of electric motors and actuator gearboxes typical of the equipment installed on motor-operated valves used in nuclear power plants. Using a test stand that simulates valve closure loads against flow and pressure, the authors tested five electric motors (four ac and one dc) and three gearboxes at conditions a motor might experience in a power plant, including such off-normal conditions as operation at high temperature and reduced voltage. They also monitored the efficiency of the actuator gearbox. All five motors operated at or above their rated starting torque during tests at normal voltages and temperatures. For all five motors, actual torque losses due to voltage degradation were greater than the losses calculated by methods typically used for predicting motor torque at degraded voltage conditions. For the dc motor the actual torque losses due to elevated operating temperatures were greater than the losses calculated by the typical predictive method. The actual efficiencies of the actuator gearboxes were generally lower than the running efficiencies published by the manufacturer and were generally nearer the published pull-out efficiencies. Operation of the gearbox at elevated temperature did not affect the operating efficiency

The change in perceived motor competence and motor task values during elementary school : Gender and motor performance differences

NARCIS (Netherlands)

Noordstar, J.J.; van der Net, J.; Jak, S.; Helders, P.J.M.; Jongmans, M.J.

2016-01-01

Participation in motor activities is essential for social interaction and life satisfaction in children. Self-perceptions and task values have a central position in why children do or do not participate in (motor) activities. Investigating developmental changes in motor self-perceptions and motor

Electric motor handbook

CERN Document Server

Chalmers, B J

2013-01-01

Electric Motor Handbook aims to give practical knowledge in a wide range of capacities such as plant design, equipment specification, commissioning, operation and maintenance. The book covers topics such as the modeling of steady-state motor performance; polyphase induction, synchronous, and a.c. commutator motors; ambient conditions, enclosures, cooling and loss dissipation; and electrical supply systems and motor drives. Also covered are topics such as variable-speed drives and motor control; materials and motor components; insulation types, systems, and techniques; and the installation, sit

Coupling with concentric contact around motor shaft for line start synchronous motor

Science.gov (United States)

Melfi, Michael J.; Burdeshaw, Galen E.

2017-10-03

A method comprises providing a line-start synchronous motor. The motor has a stator, a rotor core disposed within the stator, and a motor shaft. In accordance with a step of the method, a coupling for coupling a load to the motor is provided. The coupling has a motor shaft attachment portion configured to provide substantially concentric contact around the shaft at the end of the motor shaft. The coupling has a load attachment portion configured to operatively connect to a load. In accordance with a step of the method, a load is coupled to the motor with the coupling, and driven from start to at least near synchronous speed during steady state operation of the motor with a load coupled thereto. The motor shaft attachment portion may comprise a bushing assembly with matching and opposed tapered surfaces that cooperate to secure the motor shaft attachment portion around the motor shaft.

Diseño y construcción de un sistema computarizado de alineamiento de neumáticos, revoluciones y puesta a punto del motor para vehículos livianos a gasolina de hasta 8 cilindros

OpenAIRE

Carrasco Timbe, Diego Fernando; Venegas Riera, Klever Fernando

2009-01-01

El correcto desempeño de un vehículo se ve afectado por diversos factores, estos pueden ser fallas en el motor, en la suspensión o el desgaste incorrecto de los neumáticos, la alineación de llantas es esencial para una buena capacidad de manejo del vehículo y juega un rol muy importante en la vida de las llantas. Una alineación incorrecta y una presión de aire inadecuada en las llantas son consideradas las dos principales causas de desgaste prematuro en las llantas. El sistema de alineación c...

Medición de corrientes EDM sobre rodamientos en el conjunto motor de inducción y variador de frecuencia

Directory of Open Access Journals (Sweden)

David Raúl Quintero Sarmiento

2013-07-01

Full Text Available En este artículo se establece una metodología para la medición de corrientes de rodamiento del tipo “Electric Discharge Machining (EDM” en motores de inducción alimentados por variador de velocidad (VSD- Drive. Este artículo hace una introducción a los tipos de corriente de rodamiento causadas por la operación conjunta motor variador de velocidad, y establece una metodología de medición de corriente EDM que incluye el diseño y construcción de una bobina de Rogowski que permite la detección y medida de corrientes de rodamiento EDM. Finalmente se realizan pruebas de laboratorio para el registro, caracterización y validación de la metodología de medición de corrientes de rodamientos “EDM”.

Concurrent word generation and motor performance: further evidence for language-motor interaction.

Directory of Open Access Journals (Sweden)

Amy D Rodriguez

Full Text Available Embodied/modality-specific theories of semantic memory propose that sensorimotor representations play an important role in perception and action. A large body of evidence supports the notion that concepts involving human motor action (i.e., semantic-motor representations are processed in both language and motor regions of the brain. However, most studies have focused on perceptual tasks, leaving unanswered questions about language-motor interaction during production tasks. Thus, we investigated the effects of shared semantic-motor representations on concurrent language and motor production tasks in healthy young adults, manipulating the semantic task (motor-related vs. nonmotor-related words and the motor task (i.e., standing still and finger-tapping. In Experiment 1 (n = 20, we demonstrated that motor-related word generation was sufficient to affect postural control. In Experiment 2 (n = 40, we demonstrated that motor-related word generation was sufficient to facilitate word generation and finger tapping. We conclude that engaging semantic-motor representations can have a reciprocal influence on motor and language production. Our study provides additional support for functional language-motor interaction, as well as embodied/modality-specific theories.

Revisão sistemática das escalas utilizadas para avaliação funcional na doença de Pompe Revisión sistemática de las escalas utilizadas para evaluación funcional en la enfermedad de Pompe Systematic review of functional assessment scales in Pompe disease

Directory of Open Access Journals (Sweden)

Alana Karla Savegnago

2012-06-01

Full Text Available OBJETIVO: Identificar as escalas utilizadas para avaliação funcional na doença de Pompe (DP e descrever seu nível de evidência e recomendação. FONTES DE DADOS: Revisão sistemática sobre as escalas de avaliação funcional na DP. Pesquisa realizada nos bancos de dados Medline, Lilacs, Registro Cochrane de Ensaios Controlados Central (CCTR e SciELO com artigos (exceto artigos de revisão publicados entre 2000 e 2010. As palavras-chave utilizadas nos idiomas português e inglês foram: doença de depósito de glicogênio tipo II, atividades cotidianas, avaliação. Os artigos foram classificados em nível de evidência e recomendação. SÍNTESE DOS DADOS: Foram incluídos 14 estudos que avaliaram desde recém-nascidos a adultos (amostra total=449. Foram encontradas as seguintes escalas na literatura: Pediatric Evaluation of Disability Inventory (PEDI e sua forma adaptada para DP (Pompe-PEDI, Alberta Infant Motor Scale (AIMS, Rotterdam Handiscap Scale (RHS, Functional Independence Measure (FIM, Gross Motor Function Measure (GMFM e Peabody Developmental Motor Scales (PDMS-II. A maioria dos estudos apresentou nível de evidência III, por serem não randomizados. Grau de recomendação das escalas: C para AIMS e Pompe-PEDI; D para GMFM e PDMS-II; E para RHS e FIM. CONCLUSÕES: A maioria das escalas utilizadas para avaliação funcional na DP apresenta baixo nível de evidência e recomendação. As que apresentam melhor grau de recomendação (C são as escalas AIMS e Pompe-PEDI aplicadas em Pediatria.OBJETIVO: Identificar las escalas utilizadas para evaluación funcional en la enfermedad de Pompe (EP y describir su nivel de evidencia y recomendación. FUENTES DE DATOS: Revisión sistemática sobre las escalas de evaluación funcional en la EP. Investigaciones realizadas en las bases de datos Medline, Lilacs, Registro Cochrane de Ensayos Controlados Central (CCTR y SciELO con artículos (excepto artículos de revisión publicados entre 2000

Motor cortex is required for learning but not executing a motor skill

Science.gov (United States)

Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu; Dhawale, Ashesh; Kampff, Adam R.; Ölveczky, Bence P.

2018-01-01

Motor cortex is widely believed to underlie the acquisition and execution of motor skills, yet its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex’s established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in ‘tutoring’ these circuits during learning. PMID:25892304

Estudio Teórico de la Influencia del Uso de Mezclas de Biodiesel de Aceite de Palma con JET a-1 en Motores a Reacción

Directory of Open Access Journals (Sweden)

Luisa Fernanda Mónico Muñoz

2017-02-01

Full Text Available Contexto: al igual que en muchas otras, en la actualidad, la industria aeronáutica se ha visto obligada a implementar métodos para mitigar el daño producido al medio ambiente por la emisión de gases contaminantes, y de esta manera hacerle frente a la problemática del calentamiento global. En este panorama, la investigación sobre la utilización de combustibles alternativos es de suma relevancia, en particular el estudio del rendimiento de motores al usar mezclas de Biodiesel Colombiano a base de aceite de palma con Jet A1.  Método: como punto de partida, se realiza una revisión al estado del arte para la selección del motor a estudiar y los combustibles alternativos a utilizar. Paralelamente, se seleccionó el biodiesel colombiano a base de aceite de palma, ya que ha demostrado tener un buen comportamiento como combustible al ser mezclado en porcentajes de 10% ,20% y 50%. A cada una de las mezclas realizadas se les hicieron pruebas en laboratorio para conocer su valor de viscosidad, densidad y poder calorífico. Para la realización de los análisis, se desarrolló un programa sobre una hoja de cálculo que contempla Propiedades físicas de las mezclas y parámetros del motor, así como emisiones de óxidos nitrosos (NOx, atomización y combustión producida por el uso de las mezclas. Los resultados se contrastaron contra el software de simulación Gas turbine. Resultados: se escogió el CFM 56-5B como motor apropiado para realizar el estudio, debido a que en la actualidad es el más empleado en la industria aeronáutica colombiana.  Por otra parte, ninguna de las mezclas de combustible alternativo genera el mismo rendimiento del motor al emplear Jet A1. Las mezclas E10 y E20 tienen un comportamiento similar, con la novedad de generar menor cantidad de emisiones de NOx y mejorar la atomización del combustible. Conclusiones: al comparar el rendimiento del motor al usar combustible convencional y al emplear las mezclas de Biodiesel

Conceptual design of stepper motor replacing servo motor for control rod controller

International Nuclear Information System (INIS)

Mohd Dzul Aiman Aslan; Mohd Idris Taib; Izhar Abu Hussin; Mohd Khairulezwan Abdul Manan; Mohd Sabri Minhat

2010-01-01

In PUSPATI TRIGA Reactor, current control rod controller are using servo motor to control the movement. Control rod is a very important safety element and measure in every nuclear reactor. So, precision is very important in measurement of security in the nuclear reactor. In this case, there are a few disadvantages when using the servo motor is measurement of the motor is not precise. One solution to overcome this is by shifting servo motor with stepper motor. A stepper motor (or step motor) is a brush less, synchronous electric motor that can divide a full rotation into a large number of steps. (author)

A versatile stepping motor controller for systems with many motors

International Nuclear Information System (INIS)

Feng, S.K.; Siddons, D.P.

1989-01-01

A versatile system for controlling beamlines or complex experimental setups is described. The system as currently configured can control up to 32 motors, with all motors capable of full speed operation concurrently. There are 2 limit switch inputs for each motor, and a further input to accept a reference position marker. The motors can be controlled via a front panel keyboard with display, or by a host computer over an IEEE-488 interface. Both methods can be used together if required. There is an ''emergency stop'' key on the front panel keyboard to stop the motion of all motors without losing track of the motors' position. 3 refs., 4 figs., 1 tab

HTSL massive motor. Project: Motor field calculation. Final report

International Nuclear Information System (INIS)

Gutt, H.J.; Gruener, A.

2003-01-01

HTS motors up to 300 kW were to be developed and optimized. For this, specific calculation methods were enhanced to include superconducting rotor types (hysteresis, reluctance and permanent magnet HTS rotors). The experiments were carried out in a SHM70-45 hysteresis motor. It was shown how static and dynamic trapped field magnetisation of the rotor with YBCO rings will increase flux in the air gap motor, increasing the motor capacity to twice its original level. (orig.) [de

Consideraciones sobre el efecto de los armónicos de tiempo en motores trifásicos asincrónicos; Considerations about the Effect of Time Harmonics on Three Phase Induction Motor

Directory of Open Access Journals (Sweden)

Persy R Viego Felipe

2011-02-01

Full Text Available Se analiza el origen de los armónicos de tiempo en los sistemas eléctricos, tanto de los múltiplos integralescomo de los no integrales de la fundamental (interarmónicos y subarmónicos. Se consideran las causas y losefectos fundamentales de los mismos sobre las pérdidas en los motores asincrónicos. A partir de un estudio decaso, se evalúa el comportamiento de un motor en presencia de los principales armónicos y a partir del espectroarmónico de un circuito del CAI Ciudad Caracas, se ponen en evidencia los efectos negativos que sobre unmotor conectado en el mismo tendría esa distorsión armónica. Se establece, que para evaluar estos efectos,resulta conveniente emplear métodos de inteligencia artificial. The source of time harmonics in electric systems, no only integral multiples, but also non multiples of thefundamental (inter and subharmonics, are analyzed. The main causes and effects on induction motor losses areconsidered. On the base of a case study, the operation of an induction motor considering the most importantharmonics is evaluated. From a harmonic spectrum, the negative effects that would have a motor connected toa circuit of the sugar factory "Ciudad Caracas" are shown. The convenience of using tolls based on artificialintelligence for evaluating these effects is remarked 

A Fábrica Nacional de Motores (FNM e a Pré-história da Implantação da Indústria Automobilística no Brasil do Ponto de Vista da Teoria Ator-Rede

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Eduardo Paiva Nazareth

2004-01-01

Full Text Available La planta nacional de Motores (FNM pertenece a la pre-historia de la tecnología brasileña en el sector de Automotriz. Fue creada para fabricar el motor para los aeroplanos, durante la Segunda Guerra Mundial. Posteriormente fue convertida en una industria de automotriz a través de acuerdos de cooperación tecnológica con los italianos, para la producción de sus camiones y automóviles. Su agotamiento sucedió con su controvertida venta para la alfa de Romeo, en 1968. Con el objetivo de abordar la Teoría del actor red, la investigación se propone delinear e identificar una narrativa histórica capaz de anteponerse a la considerada reputación asimétrica de la FNM.

Handbook on linear motor application

International Nuclear Information System (INIS)

1988-10-01

This book guides the application for Linear motor. It lists classification and speciality of Linear Motor, terms of linear-induction motor, principle of the Motor, types on one-side linear-induction motor, bilateral linear-induction motor, linear-DC Motor on basic of the motor, linear-DC Motor for moving-coil type, linear-DC motor for permanent-magnet moving type, linear-DC motor for electricity non-utility type, linear-pulse motor for variable motor, linear-pulse motor for permanent magneto type, linear-vibration actuator, linear-vibration actuator for moving-coil type, linear synchronous motor, linear electromagnetic motor, linear electromagnetic solenoid, technical organization and magnetic levitation and linear motor and sensor.

Desempenho motor de lactentes frequentadores de berçários em creches públicas Motor performance of infants attending the nurseries of public day care centers

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Letícia Baltieri

2010-09-01

Full Text Available OBJETIVO: Analisar o desempenho motor axial, apendicular e global e sua correlação com as características neonatais, familiares e de tempo de exposição à creche em crianças com idade entre 12-24 meses, frequentadoras de creches públicas. MÉTODOS: Estudo transversal com 40 lactentes (idade média 14,3±2,4 meses frequentadores de creches públicas. Os participantes foram avaliados quanto ao desempenho motor com a Bayley Scales of Infant and Toddler Development-III, a qual possibilita análise do desempenho motor e comparação dos domínios motores axial e apendicular. Foram coletados dados neonatais, familiares e de exposição à creche e pesquisou-se a correlação destes fatores ao desempenho motor. Foi utilizado o teste t pareado para comparar médias e a correlação de Pearson. RESULTADOS: O desempenho motor do grupo esteve, em média, abaixo da referência, com 22,5% das crianças classificadas como suspeitas de atraso nos desempenhos axial e global, contrastando com nenhuma no domínio apendicular. A comparação axial e apendicular apontou diferença significativa, com desempenho axial aquém do apendicular, além de 35% do grupo ter apresentado discrepância significativa entre esses domínios. Não foi encontrada correlação linear entre os domínios motores avaliados e as variáveis neonatais, familiares e de exposição à creche. CONCLUSÕES: O desempenho motor global do grupo esteve abaixo da média de referência, com desempenho motor axial inferior ao apendicular e importante discrepância entre esses. Recomenda-se atenção às habilidades motoras axiais e às oportunidades de exploração que o ambiente em creches pode propiciar, especialmente no decorrer dos dois primeiros anos de vida.OBJECTIVE: To analyze gross, fine and global motor performance and its correlation with neonatal and familial variables and day care exposure among children between 12-24 months of age attending public day care centers. METHODS: This

DEVELOPMENT OF FINE MOTOR COORDINATION AND VISUAL-MOTOR INTEGRATION IN PRESCHOOL CHILDREN

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Haris MEMISEVIC

2013-03-01

Full Text Available Fine motor skills are prerequisite for many everyday activities and they are a good predictor of a child's later academic outcome. The goal of the present study was to assess the effects of age on the development of fine motor coordination and visual-motor integration in preschool children. The sample for this study consisted of 276 preschool children from Canton Sara­jevo, Bosnia and Herzegovina. We assessed children's motor skills with Beery Visual Motor Integration Test and Lafayette Pegboard Test. Data were analyzed with one-way ANOVA, followed by planned com­parisons between the age groups. We also performed a regression analysis to assess the influence of age and motor coordination on visual-motor integration. The results showed that age has a great effect on the development of fine motor skills. Furthermore, the results indicated that there are possible sensitive periods at preschool age in which the development of fine motor skills is accelerated. Early intervention specialists should make a thorough evaluations of fine motor skills in preschool children and make motor (rehabilitation programs for children at risk of fine motor delays.

On-line diagnosis of high power motors based on ultra wide band partial discharge detection; Diagnostico en linea de motores de gran capacidad mediante la deteccion de descargas parciales utilizando tecnicas de banda ultra ancha

Energy Technology Data Exchange (ETDEWEB)

Carvajal M, F. Antonio; Garcia Colon H, Vicente R. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Asiain, Tomas [Instituto Politecnico Nacional, Escuela Superior de Ingenieria Mecanica y Electrica (Mexico)

2009-07-01

In this work a non-standardized method for on-line diagnostic of high capacity motors based on Ultra Wide Band (UWB) Partial Discharge (PD) measuring techniques is theoretically supported, implemented and applied. The method developed is non invasive and consist in the measurement of PD in the main motor power supply cables and its ground shields connection using a near field sensor (Rogowski coil, clamp-on type) with a bandwidth of 2 to 40 MHz. The measured signals by the sensor, are stretched electronically, digitized and fed to a conventional Partial Discharge digital detector. The UWB PD detection system used displays the output in a Pulse repetition frequency-Charge-Phase angle (N-Q-?) PD pattern. The results obtained in thirteen 2500 H.P., 13.8 kV motors performed during operating in an Oil Pumping facility are presented, including its analysis and comparison with values and PD patterns reported in literature. [Spanish] En este trabajo se presentan los fundamentos teoricos, la implementacion y aplicacion de un metodo no normalizado, para el diagnostico en linea de motores de gran capacidad, basado en la deteccion de Descargas Parciales (DP) utilizando tecnicas de medicion de Banda Ultra Ancha. El metodo desarrollado es no invasivo y consiste en la medicion de las DP en los conductores y conexiones a tierra de la pantalla de los cables principales de suministro de energia al motor, utilizando un sensor de campo cercano (bobina Rogowski, tipo gancho) cuyo ancho de banda de medicion es de 2 a 40 MHz. Las senales medidas por el sensor son electronicamente procesadas para ampliar su duracion, digitalizadas y enviadas a un detector digital de Descargas Parciales convencional. El sistema de deteccion de DP en Banda Ultra Ancha despliega la medicion en un patron de DP tipo frecuencia de repeticion de Pulso-Carga-Angulo de fase (N-Q-?). Se presentan los resultados obtenidos de la evaluacion en linea de trece motores de 2500 C.P. a 13.8 kV, instalados y operando en una

41 CFR 102-34.85 - What motor vehicles require motor vehicle identification?

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What motor vehicles require motor vehicle identification? 102-34.85 Section 102-34.85 Public Contracts and Property Management... 34-MOTOR VEHICLE MANAGEMENT Identifying and Registering Motor Vehicles Motor Vehicle Identification...

Torque calculation in the induction motor with the finite element method; Calculo del par en el motor de induccion con el metodo del elemento finito

Energy Technology Data Exchange (ETDEWEB)

Castillo Diaz, Ramon

2002-06-15

In this work the method of the finite element is applied to the bi-dimensional analysis of the induction motor in operation in steady state, excited by sine sources of laminar currents and sine sources of voltage. The analysis is focused mainly in the calculation of the electromagnetic torque. The topics of electromagnetic theory are covered and in an idealized model of the induction motor, analytically and numerically with the method of the finite element, in the variant method of Galerkin, the vectorial potential and the torque are calculated. The results obtained with the analytical and numerical methods are compared. Three formulations are developed to calculate the torque with the method of the finite element, using triangular elements of first order, based in the equation of force of Lorentz, the Maxwell tensor and the principle of the virtual work. Finally, a motor of induction of real characteristics is simulated, assuming it is connected to a three-phase voltage source. In this motor it is analyzed the convergence and the evolution in the results obtained of the torque with different discretions, and the torque-velocity performance curve is calculated. [Spanish] En este trabajo se aplica el metodo del elemento finito al analisis bidimensional del motor de induccion en operacion en estado estable, excitado por fuentes de corriente laminar senoidales y fuentes de voltaje senoidales. El analisis se enfoca principalmente en el calculo del par electromagnetico. Se tratan los topicos de teoria electromagnetica involucrados y en un modelo idealizado del motor de induccion, se calculan analitica y numericamente con el metodo del elemento finito, en la variante metodo de Galerkin, el potencial vectorial y el par. Se comparan resultados obtenidos con los metodos analiticos y numericos. Se desarrollan tres formulaciones para calcular el par con el metodo del elemento finito, utilizando elementos triangulares de primer orden, basadas en la ecuacion de fuerza de

DC Motor control using motor-generator set with controlled generator field

Science.gov (United States)

Belsterling, Charles A.; Stone, John

1982-01-01

A d.c. generator is connected in series opposed to the polarity of a d.c. power source supplying a d.c. drive motor. The generator is part of a motor-generator set, the motor of which is supplied from the power source connected to the motor. A generator field control means varies the field produced by at least one of the generator windings in order to change the effective voltage output. When the generator voltage is exactly equal to the d.c. voltage supply, no voltage is applied across the drive motor. As the field of the generator is reduced, the drive motor is supplied greater voltage until the full voltage of the d.c. power source is supplied when the generator has zero field applied. Additional voltage may be applied across the drive motor by reversing and increasing the reversed field on the generator. The drive motor may be reversed in direction from standstill by increasing the generator field so that a reverse voltage is applied across the d.c. motor.

INICIAÇÃO AO ATLETISMO: UM DIAGNÓSTICO DO PROCESSO DE DESENVOLVIMENTO MOTOR EM CRIANÇAS

OpenAIRE

ZANON, Silmar

2013-01-01

Este estudo descritivo teve como objetivo investigar se crianças praticantes de atletismo na fase de iniciação já apresentam-se em níveis de desenvolvimento motor adequados para especializarem-se. A população deste estudo foi formada por crianças de ambos os sexos, com idade entre 10 e 12 anos que praticam atletismo. Para a seleção da amostra deste estudo escolheu-se intencionalmente o Campeonato Estadual de Atletismo do Rio Grande do Sul de 1998 - categoria mirim e pré-mirim, realizado pela ...

Desempenho de misturas pré-aquecidas de óleo de soja cru e diesel como combustível para motores agrícolas Performance of preheated crude soybean oil-diesel blends as fuel in agricultural engines

Directory of Open Access Journals (Sweden)

José Fernando Schlosser

2007-10-01

Full Text Available O óleo de soja é um dos óleos vegetais que têm potencial de uso como combustível para motores diesel, pois é renovável, seguro e de fácil utilização. Em temperatura ambiente, o óleo cru apresenta uma viscosidade cerca de dez vezes maior que a do óleo diesel. Para reduzir a viscosidade do óleo de soja a níveis aceitáveis, é necessária uma temperatura de aquecimento em torno de aproximadamente 60°C ou misturá-lo com óleo diesel. O objetivo deste estudo foi avaliar o desempenho do óleo de soja cru e suas misturas com óleo diesel, pré-aquecidas antes da bomba injetora entre 57°C e 68°C, como combustível para motores diesel. O desempenho das misturas combustíveis foi avaliado num motor monocilíndrico de injeção indireta e comparado com o obtido pelo óleo diesel. Os ensaios de curta duração foram conduzidos entre 1.800 e 2.800rpm, sob condição de plena carga em dinamômetro hidráulico. Ensaios realizados a 68°C apresentaram sempre os melhores valores para torque, potência e consumo específico de combustível do que a 57°C. Uma mistura composta por 70% de óleo de soja e 30% de óleo diesel, aquecida a 68°C, apresentou os melhores resultados.Crude soybean oil is one of the vegetable oils that have potential for use as fuel for diesel engines. Soybean oil is renewable, and is safe and easy to handle. At room temperature crude oil has a viscosity about ten times higher than that of diesel oil. To lower soybean oil's viscosity to the acceptable levels a heating temperature at least 60°C is needed or blending with diesel fuel. The objective of this study was evaluating the soybean oil and blends performance as a fuel for diesel engines. On both crude soybean oil and soybean oil blends were used pre-heating temperature levels on the range between 57°C and 68°C, before fuel pump. The performance of the fuel blends were evaluated in a single cylinder indirect injection diesel engine and compared with the performance

Non-motor and motor features in LRRK2 transgenic mice.

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Zoë Bichler

Full Text Available Non-motor symptoms are increasingly recognized as important features of Parkinson's disease (PD. LRRK2 mutations are common causes of familial and sporadic PD. Non-motor features have not been yet comprehensively evaluated in LRRK2 transgenic mouse models.Using a transgenic mouse model overexpressing the R1441G mutation of the human LRRK2 gene, we have investigated the longitudinal correlation between motor and non-motor symptoms and determined if specific non-motor phenotypes precede motor symptoms.We investigated the onset of motor and non-motor phenotypes on the LRRK2(R1441G BAC transgenic mice and their littermate controls from 4 to 21 month-old using a battery of behavioral tests. The transgenic mutant mice displayed mild hypokinesia in the open field from 16 months old, with gastrointestinal dysfunctions beginning at 6 months old. Non-motor features such as depression and anxiety-like behaviors, sensorial functions (pain sensitivity and olfaction, and learning and memory abilities in the passive avoidance test were similar in the transgenic animals compared to littermate controls.LRRK2(R1441G BAC transgenic mice displayed gastrointestinal dysfunction at an early stage but did not have abnormalities in fine behaviors, olfaction, pain sensitivity, mood disorders and learning and memory compared to non-transgenic littermate controls. The observations on olfaction and gastrointestinal dysfunction in this model validate findings in human carriers. These mice did recapitulate mild Parkinsonian motor features at late stages but compensatory mechanisms modulating the progression of PD in these models should be further evaluated.

Carcinogenic potential of noxious emissions of diesel engines; Potencial cancerigeno de emisiones nocivas en motores a diesel

Energy Technology Data Exchange (ETDEWEB)

Romero Lopez, Alejandro F [Universidad Nacional Autonoma de Mexico, Mexico, D. F. (Mexico)

1993-12-31

empresas fabricantes de motores han llevado a cabo cambios espectaculares en el diseno interior de los motores a diesel, para disminuir tanto como sea posible, la generacion de particulas dentro del motor mismo. El esfuerzo no puede provenir de una sola parte, tambien las empresas productoras de combustibles en paises desarrollados han llevado a cabo esfuerzos sustanciales para mejorar tanto los combustibles como los lubricantes. El objetivo de todas estas medidas es eliminar practicamente el contenido de azufre en especial en el combustible, puesto que la generacion de particulas parece depender linealmente, entre otros factores, del contenido de este elemento nocivo en el diesel. Finalmente, se incluye una discusion breve de algunos sistemas de tratamiento posterior de los gases de escape, que parecen ser inevitables para poder alcanzar los estandares rigurosos que para 1994 y anos posteriores han sido establecidos por la Agencia de Proteccion al Medio Ambiente de los USA (Environmental Protection Agency, EPA para abreviar en lo sucesivo). Se analiza tambien la legislacion mexicana, a traves de las Normas Tecnicas Ecologicas (NTE), emitidas por la Secretaria de Desarrollo Urbano y Ecologia (SEDUE), ahora Secretaria de Desarrolo Economico y Social (SEDESOL), simplemente para tener una referencia de comparacion con la legislacion internacional.

Carcinogenic potential of noxious emissions of diesel engines; Potencial cancerigeno de emisiones nocivas en motores a diesel

Energy Technology Data Exchange (ETDEWEB)

Romero Lopez, Alejandro F. [Universidad Nacional Autonoma de Mexico, Mexico, D. F. (Mexico)

1992-12-31

empresas fabricantes de motores han llevado a cabo cambios espectaculares en el diseno interior de los motores a diesel, para disminuir tanto como sea posible, la generacion de particulas dentro del motor mismo. El esfuerzo no puede provenir de una sola parte, tambien las empresas productoras de combustibles en paises desarrollados han llevado a cabo esfuerzos sustanciales para mejorar tanto los combustibles como los lubricantes. El objetivo de todas estas medidas es eliminar practicamente el contenido de azufre en especial en el combustible, puesto que la generacion de particulas parece depender linealmente, entre otros factores, del contenido de este elemento nocivo en el diesel. Finalmente, se incluye una discusion breve de algunos sistemas de tratamiento posterior de los gases de escape, que parecen ser inevitables para poder alcanzar los estandares rigurosos que para 1994 y anos posteriores han sido establecidos por la Agencia de Proteccion al Medio Ambiente de los USA (Environmental Protection Agency, EPA para abreviar en lo sucesivo). Se analiza tambien la legislacion mexicana, a traves de las Normas Tecnicas Ecologicas (NTE), emitidas por la Secretaria de Desarrollo Urbano y Ecologia (SEDUE), ahora Secretaria de Desarrolo Economico y Social (SEDESOL), simplemente para tener una referencia de comparacion con la legislacion internacional.

Autoguía para el telescopio 2,15 mts de CASLEO

Science.gov (United States)

Aballay, J. A.; Casagrande, A. R.; Pereyra, P. F.; Marún, A. H.

Se está desarrollando un sistema de autoguía para el telescopio de 2,15 mts. El mismo se realizará aprovechando el Offset Guider. Al ocular móvil de éste se vinculará alguna cámara digital (ST4-ST7-CH250) para lograr la visión del objeto. El funcionamiento del equipo será el siguiente: primero, dadas las coordenadas del objeto a observar, se tomarán las coordenadas del telescopio para que, a través de una base de datos, se determine un campo de objetos que sirvan para la cámara de visión, luego, la PC obtendrá el offset entre la estrella de observación y la estrella seleccionada como guía, este valor será trasladado a los motores que posicionarán en forma automática el ocular. Una vez que la estrella es visualizada en la cámara (monitor de PC ) se correrá el programa que guiará el telescopio automáticamente.

FUZZY LOGIC CONTROL OF ELECTRIC MOTORS AND MOTOR DRIVES: FEASIBILITY STUDY

Science.gov (United States)

The report gives results of a study (part 1) of fuzzy logic motor control (FLMC). The study included: 1) reviews of existing applications of fuzzy logic, of motor operation, and of motor control; 2) a description of motor control schemes that can utilize FLMC; 3) selection of a m...

Documentos para la historio social de Popayán en el Siglo XVIII

Directory of Open Access Journals (Sweden)

Peter Marzalh

1970-01-01

Full Text Available Documentos para la Historia Social de Papayán en el siglo XVIII. Varios/ Archivo Central del Central del Cauca. Fondo: Protocolos Notariales. Años 1616, 1620, 1621, 1629, 1634. Transcripción de Peter Marzahl// En: Anuario No. 5 (1970; p. 143-188. Serie de documentos, testamentos, contratos, etc., en donde se dan datos importantes para reconstruir aspectos de la economía y sociedad del Cauca del siglo XVIII, tales como: número de vecinos, encomenderos, mano de obra indígena y esclava; importancia de la minería como motor económico de la región; relaciones entre encomienda y control de mano de obra; el desarrollo de una economía mercantil con surgimiento de compañías para tal actividad.

Motor-pump unit provided with a lifting appliance of the motor

International Nuclear Information System (INIS)

Veronesi, Luciano; Francis, W.R.

1978-01-01

This invention relates to lifting appliances and particularly concerns a 'pump and motor set' or motor-pump unit fitted with a lifting appliance enabling the motor to be separated from the pump. In nuclear power stations the reactor discharges heat that is carried by the coolant to a distant point away from the reactor to generate steam and electricity conventionally. In order to cause the reactor coolant to flow through the system, coolant motor-pump units are provided in the cooling system. These units are generally of the vertical type with an electric motor fitted vertically on the pump by means of a cylindrical or conical structure called motor support [fr

Chemical and mechanical efficiencies of molecular motors and implications for motor mechanisms

International Nuclear Information System (INIS)

Wang Hongyun

2005-01-01

Molecular motors operate in an environment dominated by viscous friction and thermal fluctuations. The chemical reaction in a motor may produce an active force at the reaction site to directly move the motor forward. Alternatively a molecular motor may generate a unidirectional motion by rectifying thermal fluctuations using free energy barriers established in the chemical reaction. The reaction cycle has many occupancy states, each having a different effect on the motor motion. The average effect of the chemical reaction on the motor motion can be characterized by the motor potential profile. The biggest advantage of studying the motor potential profile is that it can be reconstructed from the time series of motor positions measured in single-molecule experiments. In this paper, we use the motor potential profile to express the Stokes efficiency as the product of the chemical efficiency and the mechanical efficiency. We show that both the chemical and mechanical efficiencies are bounded by 100% and, thus, are properly defined efficiencies. We discuss implications of high efficiencies for motor mechanisms: a mechanical efficiency close to 100% implies that the motor potential profile is close to a constant slope; a chemical efficiency close to 100% implies that (i) the chemical transitions are not slower than the mechanical motion and (ii) the equilibrium constant of each chemical transition is close to one

Prevención de las fallas de los motores trifásicos de inducción mediante una adecuada selección

Directory of Open Access Journals (Sweden)

Osvaldo Guerreo Castro

2010-10-01

Full Text Available En este trabajo se expone los aspectos de mayor importancia a considerar enuna adecuada selección de motores para prevenir las fallas, así como lasrepercusiones que puede tener tanto en la operación del equipo, como en la cantidad, frecuencia y tipo de falla de los motores trifásicos de inducción.Primeramente, se expondrán los aspectos que prevalecen o se usan con mayorfrecuencia en la selección de un motor trifásico de inducción y otros aspectosque se deben analizar con el cuidado correspondiente y que no se consideranpara prevenir las fallas de estos equipos.No se pretende que este trabajo sea una guía en la selección de motores eléctricos, ya que existen otros aspectos a tomar en cuenta que no serán analizados, sin embargo, sirve de complemento, especialmente si se pretende prevenir las fallas de estos equipos desde su compra.En este trabajo se expone los aspectos de mayor importancia a considerar en una adecuada selección de motores para prevenir las fallas, así como las repercusiones que puede tener tanto en la operación del equipo, como en la cantidad, frecuencia y tipo de falla de los motores trifásicos de inducción.Primeramente, se expondrán los aspectos que prevalecen o se usan con mayorfrecuencia en la selección de un motor trifásico de inducción y otros aspectoque se deben analizar con el cuidado correspondiente y que no se consideranpara prevenir las fallas de estos equipos. No se pretende que este trabajo sea una guía en la selección de motores eléctricos, ya que existen otros aspectos a tomar en cuenta que no serán analizados, sin embargo, sirve de complemento, especialmente si se pretende prevenir las fallas de estos equipos desde su compra.

Efectos de la música sobre el rendimiento físico-motor: una revisión sistemática de la literatura científica

OpenAIRE

Montero Herrera, Bryan

2016-01-01

La música para hacer ejercicio se ha convertido en una herramienta de uso regular tanto para deportistas como para personas que llevan a cabo alguna actividad física más o menos ocasional, de ahí el objetivo de indagar sobre los efectos que la música tiene a nivel físico-motor. Para esto se llevó a cabo una búsqueda con la utilización de las palabras claves: “music and exercise” y “music and performance” en la base de datos de SPORTDiscus, donde se obtuvieron 442 artículos de texto completo d...

Substituição de amianto por silicato de alumínio e grafite expansível em compósito de poliuretano utilizado em motor-foguete Substitution of asbestos for aluminosiliacate and expandable graphite in polyurethane composites used in rocket motors

Directory of Open Access Journals (Sweden)

Henrique Crespim

2007-09-01

Full Text Available Compósitos de poliuretano e amianto (liner são utilizados como revestimento interno em paredes de motor-foguete, conferindo proteção térmica e garantindo a adesão entre o propelente e as paredes do motor. No entanto, o uso do amianto tem sido restringido devido à sua toxidade. No presente trabalho, o amianto foi substituído por um silicato de alumínio hidratado (SA e pelo grafite expansível (GE em diferentes teores no liner. Resultados de análise termogravimétrica (TG mostraram que a estabilidade térmica do liner praticamente não é afetada pela substituição das cargas, embora a energia de ativação (Ea obtida para a decomposição tenha mudado, mostrando maiores valores para as amostras contendo as cargas SA e GE. A análise termomecânica (TMA mostrou que o coeficiente de expansão térmica linear do liner contendo SA foi menor que aquele encontrado para o liner contendo amianto. O liner contendo a carga SA também apresentou os maiores valores de tensão nos testes mecânicos de tração.Composites of polyurethane (PU and asbestos (liner are used as internal coating of rocket motors, providing thermal protection and assuring the adhesion between propellant and the motor walls. However, the use of asbestos has been restricted due to its hazardous nature. In the present work, asbestos was replaced by hydrated alumina silicate (SA and expandable graphite (GE in different contents. Thermogravimetric analysis (TG showed that the thermal stability of liners was practically unaffected by the filler replacement although the activation energy obtained for the decomposition has changed. Thermomechanical analysis (TMA showed that coefficients of thermal expansion of SA/liners were lower than asbestos/liner. SA/liners also presented the highest tension values in mechanical tests.

Motor cortex is required for learning but not for executing a motor skill.

Science.gov (United States)

Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu L; Dhawale, Ashesh K; Kampff, Adam R; Ölveczky, Bence P

2015-05-06

Motor cortex is widely believed to underlie the acquisition and execution of motor skills, but its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex's established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in "tutoring" these circuits during learning. Copyright © 2015 Elsevier Inc. All rights reserved.

Modulation of motor performance and motor learning by transcranial direct current stimulation.

Science.gov (United States)

Reis, Janine; Fritsch, Brita

2011-12-01

Transcranial direct current stimulation (tDCS) has shown preliminary success in improving motor performance and motor learning in healthy individuals, and restitution of motor deficits in stroke patients. This brief review highlights some recent work. Within the past years, behavioural studies have confirmed and specified the timing and polarity specific effects of tDCS on motor skill learning and motor adaptation. There is strong evidence that timely co-application of (hand/arm) training and anodal tDCS to the contralateral M1 can improve motor learning. Improvements in motor function as measured by clinical scores have been described for combined tDCS and training in stroke patients. For this purpose, electrode montages have been modified with respect to interhemispheric imbalance after brain injury. Cathodal tDCS applied to the unlesioned M1 or bihemispheric M1 stimulation appears to be well tolerated and useful to induce improvements in motor function. Mechanistic studies in humans and animals are discussed with regard to physiological motor learning. tDCS is well tolerated, easy to use and capable of inducing lasting improvements in motor function. This method holds promise for the rehabilitation of motor disabilities, although acute studies in patients with brain injury are so far lacking.

Motor learning processes: an electrophysiologic perspective Processos de aprendizagem motora: uma perspectiva eletrofisiológica

Directory of Open Access Journals (Sweden)

Bruna Velasques

2007-12-01

Full Text Available The goal of the present study was to investigate electrophysiologic, qEEG, changes when individuals were exposed to a motor task. Subjects’ brain electrical activity was analyzed before and after the typewriting training task. For the neurophysiological variable asymmetry, a paired t-test was performed to compare each moment, pre and post-task, in the beta bands. The findings showed a change for the qEEG variable in each scalp site, F3/F4; C3/C4 and P3/P4. These results suggest an adaptation of pre-frontal, sensory-motor and parietal cortex, as a consequence of the typewriting training.O objetivo do presente estudo foi investigar mudanças eletrofisiológicas através do EEGq quando indivíduos são expostos a uma tarefa motora. A atividade elétrica no córtex dos sujeitos foi analisada antes e após o treinamento da tarefa motora. Para a variável neurofisiológica assimetria, um teste t foi implementado para comparar cada momento, pré e pós-tarefa, na banda beta. Os achados demonstraram mudança em assimetria para as seguintes regiões no escalpo: F3/F4, C3/C4 e P3/P4. Estes resultados sugerem uma adaptação das regiões pré-frontal, somatosensorial e parietal como conseqüência do treinamento de datilografia.

Propriedades termofísicas de suco concentrado de lulo em temperaturas acima do ponto de congelamento

OpenAIRE

Giraldo-Gómez, Glória Ines; Gabas, Ana Lúcia; Telis, Vânia Regina Nicoletti; Telis-Romero, Javier

2010-01-01

En este trabajo fueron determinados experimentalmente el calor específico, conductividad térmica, difusividad térmica y densidad del jugo de lulo en el rango de contenido de agua de 0.55 a 0.90 (p/p en base húmeda) y en temperaturas variando de 4 a 78.6 °C. La conductividad térmica y el calor específico fueron obtenidos utilizando el mismo aparato - una célula constituida de dos cilindros concéntricos - operando en estado estacionario y no- estacionario, respectivamente. La difusividad térmic...

Propiedades termofísicas del jugo concentrado de lulo a temperaturas por encima del punto de congelación

OpenAIRE

Giraldo-Gómez,Glória Ines; Gabas,Ana Lúcia; Telis,Vânia Regina Nicoletti; Telis-Romero,Javier

2010-01-01

En este trabajo fueron determinados experimentalmente el calor específico, conductividad térmica, difusividad térmica y densidad del jugo de lulo en el rango de contenido de agua de 0.55 a 0.90 (p/p en base húmeda) y en temperaturas variando de 4 a 78.6 °C. La conductividad térmica y el calor específico fueron obtenidos utilizando el mismo aparato - una célula constituida de dos cilindros concéntricos - operando en estado estacionario y no- estacionario, respectivamente. La difusividad térmic...

Fundamental motor skill proficiency is necessary for children's motor activity inclusion

Directory of Open Access Journals (Sweden)

José Angelo Barela

2013-09-01

Full Text Available Motor development is influenced by many factors such as practice and appropriate instruction, provided by teachers, even in preschool and elementary school. The goal of this paper was to discuss the misconception that maturation underlies children's motor skill development and to show that physical education, even in early years of our school system, is critical to promote proficiency and enrolment of children's in later motor activities. Motor skill development, as a curricular focus, has been marginalized in many of our physical education proposal and in doing so, we have not promote motor competence in our children who lack proficiency to engage and to participate in later motor activities such as sport-related or recreational.

Proyecto de un autobús urbano eléctrico para el transporte de pasajeros

OpenAIRE

Sacco, Juan; Blanco, Alberto Rubén; Vucetich, Danilo A.; Pierre Castel, Andrea V.; Matera, Román; Bellomo, Daniel

2013-01-01

Se estimó que en los próximos años habrá más de 1.000 millones de vehículos en el mundo. Si todos estos vehículos fuesen equipados con motores de combustión interna convencionales, los niveles de contaminación, en las condiciones actuales, serán inaceptables para el planeta. Basado en esto, han surgido en todo el mundo legislaciones que promueven, hasta exigen, el uso de “vehículos de emisión cero” (VECs) o no contaminantes. La única tecnología disponible, probada, para producir VECs es la...

Proyecto de un autobús urbano híbrido para el transporte de pasajeros

OpenAIRE

Sacco, Juan; Blanco, Alberto Rubén; Vucetich, Danilo A.; Pierre Castel, Andrea V.

2011-01-01

Se estima que en el año 2020 habrá más de 1.000 millones de vehículos en el mundo. Si todos estos vehículos fuesen equipados con motores de combustión interna convencionales, los niveles de contaminación serán inaceptables para el planeta (en las condiciones actuales). Basado en esto, han surgido en todo el mundo legislaciones que promueven, hasta exigen, el uso de “vehículos de emisión cero” (VECs) o no contaminantes. Hasta el momento, la única tecnología disponible, madura, para producir VE...

Skeletal maturation, fundamental motor skills and motor coordination in children 7-10 years.

Science.gov (United States)

Freitas, Duarte L; Lausen, Berthold; Maia, José António; Lefevre, Johan; Gouveia, Élvio Rúbio; Thomis, Martine; Antunes, António Manuel; Claessens, Albrecht L; Beunen, Gaston; Malina, Robert M

2015-01-01

Relationships between skeletal maturation and fundamental motor skills and gross motor coordination were evaluated in 429 children (213 boys and 216 girls) 7-10 years. Skeletal age was assessed (Tanner-Whitehouse 2 method), and stature, body mass, motor coordination (Körperkoordinations Test für Kinder, KTK) and fundamental motor skills (Test of Gross Motor Development, TGMD-2) were measured. Relationships among chronological age, skeletal age (expressed as the standardised residual of skeletal age on chronological age) and body size and fundamental motor skills and motor coordination were analysed with hierarchical multiple regression. Standardised residual of skeletal age on chronological age interacting with stature and body mass explained a maximum of 7.0% of the variance in fundamental motor skills and motor coordination over that attributed to body size per se. Standardised residual of skeletal age on chronological age alone accounted for a maximum of 9.0% of variance in fundamental motor skills, and motor coordination over that attributed to body size per se and interactions between standardised residual of skeletal age on chronological age and body size. In conclusion, skeletal age alone or interacting with body size has a negligible influence on fundamental motor skills and motor coordination in children 7-10 years.

Neuroplasticity & Motor Learning

DEFF Research Database (Denmark)

Jensen, Jesper Lundbye

Practice of a new motor task is usually associated with an improvement in performance. Indeed, if we stop practicing and return the next day to the same task, we find that our performance has been maintained and may even be better than it was at the start of the first day. This improvement...... is a measure of our ability to form and store a motor memory of the task. However, the initial memory of the task is labile and may be subject to interference. During and following motor learning plastic changes occur within the central nervous system. On one hand these changes are driven by motor practice......, on the other hand the changes underlie the formation of motor memory and the retention of improved motor performance. During motor learning changes may occur at many different levels within the central nervous system dependent on the type of task and training. Here, we demonstrate different studies from our...

Uso de óleos vegetais puros como combustíveis para motores diesel

Directory of Open Access Journals (Sweden)

Deny Cesar Moreira

2016-05-01

Full Text Available This article aims to review the productive situation of the domestic industry of vegetable oils, point out what the main sources of raw materials and evaluate the use of these oils as a fuel source diesel engines for motor vehicles and generating electricity. Show the importance of these oils as a fuel source, generation of employment and income and especially social development when their use for provision of electricity to isolated communities. It reaffirms the importance of the use of vegetable oils as another renewable fuel source and its relevance with environmental issues.

Sistema Recomendador para áreas de: Ventas/Mercadotecnia de Yamaha Motor de México

OpenAIRE

Cueva-Morales, Gabriela

2017-01-01

This work is the documentation of the experiment: Recommender System for Sales or Marketing departments of Yamaha Motor de México, which recommends products to offer to the company´s dealers, in this work is the detailed procedure to solve the company's problem using Artificial Intelligence, and it shows the theoretical framework in which this development is encompassed, describes briefly the Neighborhood-Based Collaborative Filtering and analyze the steps to the construction of a Recommender...

DC motors and servo-motors controlled by Raspberry Pi 2B

Directory of Open Access Journals (Sweden)

Šustek Michal

2017-01-01

Full Text Available The expanding capabilities of today’s microcontrollers and other devices lead to an increased utilization of these technologies in diverse fields. The automation and issue of remote control of moving objects belong to these fields. In this project, a microcontroller Raspberry Pi 2B was chosen for controlling DC motors and servo-motors. This paper provides basic insight into issue of controlling DC motors and servo-motors, connection between Raspberry and other components on breadboard and programming syntaxes for controlling motors in Python programming language.

Estudio energético de un motor de encendido por compresión y arquitectura 2-tiempos operando con el concepto de combustión parcialmente premezclada

OpenAIRE

ALCÁZAR LÓPEZ, ANTONIO

2016-01-01

[ES] Dicho proyecto se encuentra dentro de un proyecto de colaboración “Powertrain of future lightduty vehicles (POWERFUL)” cuyo fin es la investigación y desarrollo de futuros motores de vehículos ligeros para transporte terrestre. Está compuesto por los siguientes sub-proyectos:  V1. Motor de 4T MEP caracterizado por bajas emisiones y bajo coste.  V2. Motor de 4TMEC con combustible a medida e integrando el modo LTC (Low Temperature Combustion) al sistema de encendido por co...

Motor Skill Competence and Perceived Motor Competence: Which Best Predicts Physical Activity among Girls?

Science.gov (United States)

Khodaverdi, Zeinab; Bahram, Abbas; Khalaji, Hassan; Kazemnejad, Anoshirvan

2013-10-01

The main purpose of this study was to determine which correlate, perceived motor competence or motor skill competence, best predicts girls' physical activity behavior. A sample of 352 girls (mean age=8.7, SD=0.3 yr) participated in this study. To assess motor skill competence and perceived motor competence, each child completed the Test of Gross Motor Development-2 and Physical Ability sub-scale of Marsh's Self-Description Questionnaire. Children's physical activity was assessed by the Physical Activity Questionnaire for Older Children. Multiple linear regression model was used to determine whether perceived motor competence or motor skill competence best predicts moderate-to-vigorous self-report physical activity. Multiple regression analysis indicated that motor skill competence and perceived motor competence predicted 21% variance in physical activity (R(2)=0.21, F=48.9, P=0.001), and motor skill competence (R(2)=0.15, ᵝ=0.33, P= 0.001) resulted in more variance than perceived motor competence (R(2)=0.06, ᵝ=0.25, P=0.001) in physical activity. Results revealed motor skill competence had more influence in comparison with perceived motor competence on physical activity level. We suggest interventional programs based on motor skill competence and perceived motor competence should be administered or implemented to promote physical activity in young girls.

Motor Cortex Activity During Functional Motor Skills: An fNIRS Study.

Science.gov (United States)

Nishiyori, Ryota; Bisconti, Silvia; Ulrich, Beverly

2016-01-01

Assessments of brain activity during motor task performance have been limited to fine motor movements due to technological constraints presented by traditional neuroimaging techniques, such as functional magnetic resonance imaging. Functional near-infrared spectroscopy (fNIRS) offers a promising method by which to overcome these constraints and investigate motor performance of functional motor tasks. The current study used fNIRS to quantify hemodynamic responses within the primary motor cortex in twelve healthy adults as they performed unimanual right, unimanual left, and bimanual reaching, and stepping in place. Results revealed that during both unimanual reaching tasks, the contralateral hemisphere showed significant activation in channels located approximately 3 cm medial to the C3 (for right-hand reach) and C4 (for left-hand reach) landmarks. Bimanual reaching and stepping showed activation in similar channels, which were located bilaterally across the primary motor cortex. The medial channels, surrounding Cz, showed significantly higher activations during stepping when compared to bimanual reaching. Our results extend the viability of fNIRS to study motor function and build a foundation for future investigation of motor development in infants during nascent functional behaviors and monitor how they may change with age or practice.

Fine motor control

Science.gov (United States)

... gross (large, general) motor control. An example of gross motor control is waving an arm in greeting. Problems ... out the child's developmental age. Children develop fine motor skills over time, by practicing and being taught. To ...

Gene Expression Changes in the Motor Cortex Mediating Motor Skill Learning

Science.gov (United States)

Cheung, Vincent C. K.; DeBoer, Caroline; Hanson, Elizabeth; Tunesi, Marta; D'Onofrio, Mara; Arisi, Ivan; Brandi, Rossella; Cattaneo, Antonino; Goosens, Ki A.

2013-01-01

The primary motor cortex (M1) supports motor skill learning, yet little is known about the genes that contribute to motor cortical plasticity. Such knowledge could identify candidate molecules whose targeting might enable a new understanding of motor cortical functions, and provide new drug targets for the treatment of diseases which impair motor function, such as ischemic stroke. Here, we assess changes in the motor-cortical transcriptome across different stages of motor skill acquisition. Adult rats were trained on a gradually acquired appetitive reach and grasp task that required different strategies for successful pellet retrieval, or a sham version of the task in which the rats received pellet reward without needing to develop the reach and grasp skill. Tissue was harvested from the forelimb motor-cortical area either before training commenced, prior to the initial rise in task performance, or at peak performance. Differential classes of gene expression were observed at the time point immediately preceding motor task improvement. Functional clustering revealed that gene expression changes were related to the synapse, development, intracellular signaling, and the fibroblast growth factor (FGF) family, with many modulated genes known to regulate synaptic plasticity, synaptogenesis, and cytoskeletal dynamics. The modulated expression of synaptic genes likely reflects ongoing network reorganization from commencement of training till the point of task improvement, suggesting that motor performance improves only after sufficient modifications in the cortical circuitry have accumulated. The regulated FGF-related genes may together contribute to M1 remodeling through their roles in synaptic growth and maturation. PMID:23637843

Características del desarrollo motor en niños de 3 a 7 años de la ciudad de Barranquilla

Directory of Open Access Journals (Sweden)

Lilia Angélica Campo Ternera

2011-01-01

Full Text Available Abstract This research paper presents the characteristics of motor development in children 3 to 7 years in the city of Barranquilla. The study was developed from the empirical analytical paradigm correlational design and the measuring of the study variables was made by the Battelle Developmental Inventory. The results revealed the issues in each of the areas assessed (muscle control, body coordination, locomotion, fine motor, perceptual motor skills. Lower performance scores than expected for age were found and therefore reflect greater need for care and stimulation, that aspects is importance because children who do not develop during this period mature motor patterns, would present difficulties in acquiring more complex skills. Resumen El presente artículo de investigación expone las características del desarrollo motor en niños de 3 a 7 años en la ciudad de Barranquilla. El estudio se desarrolló a partir del paradigma empírico analítico con un diseño correlacional y para la medición de las variables de estudio se utilizó el Inventario de Desarrollo Battelle. Los resultados obtenidos revelaron los aspectos en cada una de las áreas evaluadas: (Control muscular, Coordinación corporal, Locomoción, Motricidad fina, Motricidad perceptiva. Se presentaron puntajes de desempeño más bajos de lo esperado para la edad y por lo tanto reflejan mayor necesidad de atención y estimulación, aspectos de suma importancia teniendo en cuenta que aquellos niños que no desarrollen durante este periodo patrones motores maduros, presentarán posteriormente dificultades en la adquisición de habilidades más complejas.

Actions to promote energy efficient electric motors. Motors study group

Energy Technology Data Exchange (ETDEWEB)

Almeida, A.T. de [Coimbra Univ. (PT). Inst. of Systems and Robotics (ISR)

1996-10-01

Motor electricity consumption is influenced by many factors including: motor efficiency, motor speed controls, power supply quality, harmonics, systems oversizing, distribution network, mechanical transmission system, maintenance practices, load management and cycling, and the efficiency of the end-use device (e.g. fan, pump, etc.). Due to their importance, an overview of these factors is presented in this report. This study also describes the electricity use in the industrial and tertiary sectors and the electricity consumption associated with the different types of electric motors systems in the Member States of the European Union, as well as estimated future evolution until 2010. The studies for individual countries were carried out by the different partners of the motors study group at a previous stage. The study has found that there is a lack of accurate information about the motor electricity consumption, installed motor capacity and the motor market in almost all the European Union countries and only some general statistical sources are available. There is little field data, which is mainly available in Denmark, France, Italy and the Netherlands. Due to this lack of primary information, some common assumptions were made, based on the experience of the members of the study group. This lack of end-use characterisation data shows the need for improvement from the point of view of current knowledge. It is therefore recommended that further research is undertaken to arrive at more accurate figures. These could be the basis for a better understanding for motor use in practice and - as a consequence - for a more precise appraisal of potentials and barriers to energy efficiency. (orig.)

Het motorrijwiel : handboek voor motor- en scooterrijders, motor- en scootermonteurs en -technici

NARCIS (Netherlands)

Seyffardt, A.L.W.

1961-01-01

INHOUD: 1. De werking van de motor ; 2. De hoofddelen van de motor ; 3. De kleppen en de klepbeweging ; 4. Balancering, de meercilinder motor ; 5. Bijzonderheden over de werking ; 6. De carburateur ; 7. De smering van de motor ; 8. De tweetaktmotor ; 9. De elektrische installatie ; 10. De

commodity: el caso del mercado internacional del azúcar

Directory of Open Access Journals (Sweden)

Julio César Alonso

2013-01-01

Full Text Available Este trabajo estudia el comportamiento estacional de los precios internacionales del azúcar transados en Nueva York y Londres. Para este caso, empleando pruebas de raíces estacionales y una muestra mensual desde enero de 1989 hasta diciembre de 2010, se encuentra la existencia de un comportamiento estacional estocástico no estacionario. Dicha conducta implica que un “verano” se puede convertir en un “invierno”, resultado que no había sido documentado previamente en estos mercados. Por otro lado, empleando dicho hallazgo, los resultados muestran que es posible construir un modelo autorregresivo de media móvil que se comporta relativamente mejor al pronosticar el precio frente a un modelo que no tiene en cuenta dicho tipo de estacionalidad.

Parkinson's Disease Subtypes Identified from Cluster Analysis of Motor and Non-motor Symptoms.

Science.gov (United States)

Mu, Jesse; Chaudhuri, Kallol R; Bielza, Concha; de Pedro-Cuesta, Jesus; Larrañaga, Pedro; Martinez-Martin, Pablo

2017-01-01

Parkinson's disease is now considered a complex, multi-peptide, central, and peripheral nervous system disorder with considerable clinical heterogeneity. Non-motor symptoms play a key role in the trajectory of Parkinson's disease, from prodromal premotor to end stages. To understand the clinical heterogeneity of Parkinson's disease, this study used cluster analysis to search for subtypes from a large, multi-center, international, and well-characterized cohort of Parkinson's disease patients across all motor stages, using a combination of cardinal motor features (bradykinesia, rigidity, tremor, axial signs) and, for the first time, specific validated rater-based non-motor symptom scales. Two independent international cohort studies were used: (a) the validation study of the Non-Motor Symptoms Scale ( n = 411) and (b) baseline data from the global Non-Motor International Longitudinal Study ( n = 540). k -means cluster analyses were performed on the non-motor and motor domains (domains clustering) and the 30 individual non-motor symptoms alone (symptoms clustering), and hierarchical agglomerative clustering was performed to group symptoms together. Four clusters are identified from the domains clustering supporting previous studies: mild, non-motor dominant, motor-dominant, and severe. In addition, six new smaller clusters are identified from the symptoms clustering, each characterized by clinically-relevant non-motor symptoms. The clusters identified in this study present statistical confirmation of the increasingly important role of non-motor symptoms (NMS) in Parkinson's disease heterogeneity and take steps toward subtype-specific treatment packages.

76 FR 647 - Energy Conservation Program: Test Procedures for Electric Motors and Small Electric Motors

Science.gov (United States)

2011-01-05

... Electric Motors and Small Electric Motors; Proposed Rule #0;#0;Federal Register / Vol. 76, No. 3... Motors and Small Electric Motors AGENCY: Office of Energy Efficiency and Renewable Energy, Department of... motors and small electric motors, clarify the scope of energy conservation standards for electric motors...

Interacting adiabatic quantum motor

Science.gov (United States)

Bruch, Anton; Kusminskiy, Silvia Viola; Refael, Gil; von Oppen, Felix

2018-05-01

We present a field-theoretic treatment of an adiabatic quantum motor. We explicitly discuss a motor called the Thouless motor which is based on a Thouless pump operating in reverse. When a sliding periodic potential is considered to be the motor degree of freedom, a bias voltage applied to the electron channel sets the motor in motion. We investigate a Thouless motor whose electron channel is modeled as a Luttinger liquid. Interactions increase the gap opened by the periodic potential. For an infinite Luttinger liquid the coupling-induced friction is enhanced by electron-electron interactions. When the Luttinger liquid is ultimately coupled to Fermi liquid reservoirs, the dissipation reduces to its value for a noninteracting electron system for a constant motor velocity. Our results can also be applied to a motor based on a nanomagnet coupled to a quantum spin Hall edge.

DEVELOPMENT OF FINE MOTOR COORDINATION AND VISUAL-MOTOR INTEGRATION IN PRESCHOOL CHILDREN

OpenAIRE

MEMISEVIC Haris; HADZIC Selmir

2015-01-01

Fine motor skills are prerequisite for many everyday activities and they are a good predictor of a child's later academic outcome. The goal of the present study was to assess the effects of age on the development of fine motor coordination and visual-motor integration in preschool children. The sample for this study consisted of 276 preschool children from Canton Sara­jevo, Bosnia and Herzegovina. We assessed children's motor skills with Beery Visual Motor Integration Test and Lafayette Pegbo...

Brain Computer Interface: Assessment of Spinal Cord Injury Patient towards Motor Movement through EEG application

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Syam Syahrull Hi-Fi

2017-01-01

Full Text Available Electroencephalography (EEG associated with motor task have been comprehensively investigated and it can also describe the brain activities while spinal cord injury (SCI patient with para/tetraplegia performing movement with their limbs. This paper reviews on conducted research regarding application of brain computer interface (BCI that offer alternative for neural impairments community such as spinal cord injury patient (SCI which include the experimental design, signal analysis of EEG band signal and data processing methods. The findings claim that the EEG signals of SCI patients associated with movement tasks can be stimulated through mental and motor task. Other than that EEG signal component such as alpha and beta frequency bands indicate significance for analysing the brain activity of subjects with SCI during movements.

Princípio de funcionamento do motor elétrico universal: reflexão educacional a partir de explicações de uma versão didática tipo série

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Osmar Henrique Moura da Silva

2013-04-01

Full Text Available http://dx.doi.org/10.5007/2175-7941.2013v30n1p177 É comum a divulgação de determinada versão simples e de baixo custo do motor elétrico tipo série (ou universal para fins pedagógicos que pode ser muito proveitosa. No entanto, devido à sua geometria e disposição das bobinas, percebe-se uma dificuldade para se determinar as direções e os sentidos das forças responsáveis pelo torque no rotor, originando explicações inadequadas ou incompletas do seu princípio de funcionamento. Essa dificuldade se faz presente em divulgações a respeito desse motor sendo ainda corroborada por revelações de uma amostra de professores investigada que se dedicou a estudar o experimento. Considerando isso, este estudo contribui para melhor aclarar a origem do movimento rotacional do rotor da versão didática do motor em série aqui apresentada na medida em que fica ajustada corretamente a aplicação das forças magnéticas ali envolvidas. Finaliza-se com uma reflexão que conscientiza acerca do cuidado educacional a respeito das explicações físicas do funcionamento dos motores elétricos em geral.

Fundamental motor skill proficiency is necessary for children's motor activity inclusion

OpenAIRE

Barela, José Angelo

2013-01-01

Motor development is influenced by many factors such as practice and appropriate instruction, provided by teachers, even in preschool and elementary school. The goal of this paper was to discuss the misconception that maturation underlies children's motor skill development and to show that physical education, even in early years of our school system, is critical to promote proficiency and enrolment of children's in later motor activities. Motor skill development, as a curricular focus, has be...

Estimación del estado del motor de reluctancia conmutada MFR132.5 mediante Filtro Desaromatizado de Kalman. State estimation of the switching reluctance motor MFR132.5 using an Unscented Kalman Filter

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Ariel Omar Cepero Díaz

2015-04-01

Full Text Available La determinación de la posición angular instantánea del rotor es parte integral del control en los accionamientos de Motores de Reluctancia Conmutada. La medición directa de esta variable adiciona complejidad y costo al sistema y no siempre brinda buenos resultados, lo que ha motivado el desarrollo y prueba de algoritmos de estimación de la posición angular del rotor. En este trabajo se presenta el empleo de un Filtro Desaromatizado de Kalman para estimar la velocidad y la posición angular del rotor del motor MFR 132.5, basado en un modelo de caja gris de dicho motor que también es presentado en este trabajo. Los resultados demuestran que este estimador ofrece estimaciones satisfactorias del estado del motor, lo mismo durante el arranque que durante el funcionamiento regular, aún bajo la presencia de perturbaciones en el torque de la carga y errores en la estimación inicial de la posición angular del rotor.  The measure of the instant angular position of the rotor is integral part of the control of Switching Reluctance Motors drivers. The direct measurement of this variable adds complexity and cost to the system and it doesn’t give good results sometimes. That has motivated the development and test of algorithms for estimating the rotor angular position of the motor. In this work is presented the use of an Unscented Kalman Filter for estimating the speed and rotor angular position of the motor MFR 132.5, based on a grey box model of the motor which is also presented in this work. The results show that this kind of estimator gives good estimations of the state of the motor, as well during the starting as during the regular operation, even under the presence of perturbations of the load torque and errors in the initial estimation of the angular position.

Análisis del funcionamiento del motor y de la eficiencia de conducción mediante el uso de sistemas GPS y OBD

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Carlos Guardiola García

2016-01-01

Full Text Available El uso generalizado de los teléfonos inteligentes y la disponibilidad de sensores de diagnóstico de abordo (OBD permite su uso como herramientas para mejorar la forma en que los estudiantes de ingeniería aprenden como los Motores de Combustión Interna Alternativos operan en condiciones de conducción reales. En particular, la metodología de aprendizaje presentada en este artículo se basa en proporcionar a los estudiantes un sensor OBD de bajo coste que en combinación con sus propios teléfonos inteligentes les permite registrar las variables del motor y del vehículo durante sus viajes diarios. Posteriormente, los estudiantes analizan el comportamiento de sus motores, con especial énfasis en el consumo de combustible y la huella de CO2 de sus patrones de conducción, para finalmente  evaluar el potencial de diferentes arquitecturas de sistema de propulsión. La experiencia muestra que el trabajo experimental y el hecho de que los alumnos analicen sus propios hábitos y estilos de conducción despierta su interés en la materia.

Control de velocidad del motor de indución empleando linealización por realimentación de estados Speed control of induction motor using state feedback linearization

Directory of Open Access Journals (Sweden)

Eduardo Giraldo Suárez

2009-01-01

Full Text Available Este documento presenta la aplicación de la técnica de control no lineal clásica llamada linealización por realimentación de variables de estado. Se hace una aplicación en el motor de inducción, la variable a controlar es la velocidad del eje del motor, el sistema emplea el esquema de control vectorial para máquinas de corriente alterna desarrollado en las últimas décadas; este método es análogo a la técnica de control del motor de corriente directa. El modelo del motor de inducción se describe en el sistema de coordenadas de campo orientado del flujo de rotor y se muestra una introducción al producto y la derivada de Lie, empleados en el diseño del controlador no lineal.This articles shows the application of a classic non-linear control technique called "linearization by feedback of status variables." An application on the induction engine is made. Variable to be controlled is speed of the engine shaft. The system employs a vectorial control scheme for AC engines developed during the last decades. This is a method analogous to the DC engine control technique. Induction engine model is described in the guided field coordinate system of rotor flow. Introduction to the product and Lie derivative used for designing the non-linear controller are shown.

Stepping Motor - Hydraulic Motor Servo Drives for an NC Milling ...

African Journals Online (AJOL)

In this paper the retrofit design of the control system of an NC milling machine with a stepping motor and stepping motor - actuated hydraulic motor servo mechanism on the machines X-axis is described. The servo designed in the course of this study was tested practically and shown to be linear - the velocity following errors ...

Motor proteins and molecular motors: how to operate machines at the nanoscale

International Nuclear Information System (INIS)

Kolomeisky, Anatoly B

2013-01-01

Several classes of biological molecules that transform chemical energy into mechanical work are known as motor proteins or molecular motors. These nanometer-sized machines operate in noisy stochastic isothermal environments, strongly supporting fundamental cellular processes such as the transfer of genetic information, transport, organization and functioning. In the past two decades motor proteins have become a subject of intense research efforts, aimed at uncovering the fundamental principles and mechanisms of molecular motor dynamics. In this review, we critically discuss recent progress in experimental and theoretical studies on motor proteins. Our focus is on analyzing fundamental concepts and ideas that have been utilized to explain the non-equilibrium nature and mechanisms of molecular motors. (topical review)

Motor unit recruitment by size does not provide functional advantages for motor performance.

Science.gov (United States)

Dideriksen, Jakob L; Farina, Dario

2013-12-15

It is commonly assumed that the orderly recruitment of motor units by size provides a functional advantage for the performance of movements compared with a random recruitment order. On the other hand, the excitability of a motor neuron depends on its size and this is intrinsically linked to its innervation number. A range of innervation numbers among motor neurons corresponds to a range of sizes and thus to a range of excitabilities ordered by size. Therefore, if the excitation drive is similar among motor neurons, the recruitment by size is inevitably due to the intrinsic properties of motor neurons and may not have arisen to meet functional demands. In this view, we tested the assumption that orderly recruitment is necessarily beneficial by determining if this type of recruitment produces optimal motor output. Using evolutionary algorithms and without any a priori assumptions, the parameters of neuromuscular models were optimized with respect to several criteria for motor performance. Interestingly, the optimized model parameters matched well known neuromuscular properties, but none of the optimization criteria determined a consistent recruitment order by size unless this was imposed by an association between motor neuron size and excitability. Further, when the association between size and excitability was imposed, the resultant model of recruitment did not improve the motor performance with respect to the absence of orderly recruitment. A consistent observation was that optimal solutions for a variety of criteria of motor performance always required a broad range of innervation numbers in the population of motor neurons, skewed towards the small values. These results indicate that orderly recruitment of motor units in itself does not provide substantial functional advantages for motor control. Rather, the reason for its near-universal presence in human movements is that motor functions are optimized by a broad range of innervation numbers.

Análisis por medio de la simulación de un accionamiento con motor de reluctancia conmutada; Analysis by Means of Simulation of a Switched Reluctance Machines Drive

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Javier Muñoz Álvarez

2011-02-01

Full Text Available Se presentan los fundamentos teóricos que modelan el comportamiento de los motores de reluctancia conmutaday sus accionamientos. Se exponen las características constructivas generales, las ecuaciones diferencialesque constituyen el modelo matemático del motor y se describen los bloques en Simulink utilizados para lasimulación. El sistema modular se valida comparando el comportamiento de las variables de salida con señalesobtenidas experimentalmente. Es empleado, además, para realizar diversos estudios sobre la instalación. Losresultados obtenidos en cada corrida son reflejados y se exponen las condiciones de operación y la explicaciónteórica de lo obtenido.  This paper presents the theoretical basis that models the behavior of The switched reluctance machines andtheir drives. The general characteristics, the differential equation system that constitutes the mathematicalmodel of the motor and the Simulink's blocks, which have been built for running the simulation, are outlined. Theresults of the simulation have been shown and compared with those obtained experimentally. The Simulinkmodel is used for studying the Switched Reluctance motor drive behavior under some operation conditions andtheoretical explanations for the simulation's results are given in every case.

A Recommended New Approach on Motorization Ratio Calculations of Stepper Motors

Science.gov (United States)

Nalbandian, Ruben; Blais, Thierry; Horth, Richard

2014-01-01

Stepper motors are widely used on most spacecraft mechanisms requiring repeatable and reliable performance. The unique detent torque characteristics of these type of motors makes them behave differently when subjected to low duty cycle excitations where the applied driving pulses are only energized for a fraction of the pulse duration. This phenomenon is even more pronounced in discrete permanent magnet stepper motors used in the space industry. While the inherent high detent properties of discrete permanent magnets provide desirable unpowered holding performance characteristics, it results in unique behavior especially in low duty cycles. Notably, the running torque reduces quickly to the unpowered holding torque when the duty cycle is reduced. The space industry's accepted methodology of calculating the Motorization Ratio (or Torque Margin) is more applicable to systems where the power is continuously applied to the motor coils like brushless DC motors where the cogging torques are low enough not to affect the linear performance of the motors as a function of applied current. This paper summarizes the theoretical and experimental studies performed on a number of space qualified motors under different pulse rates and duty cycles. It is the intention of this paper to introduce a new approach to calculate the Motorization Ratios for discrete permanent magnet steppers under all full and partial duty cycle regimes. The recommended approach defines two distinct relationships to calculate the Motorization Ratio for 100 percent duty cycle and partial duty cycle, when the motor detent (unpowered holding torque) is the main contributor to holding position. These two computations reflect accurately the stepper motor physical behavior as a function of the command phase (ON versus OFF times of the pulses), pointing out how the torque contributors combine. Important points highlighted under this study are the torque margin computations, in particular for well characterized

Motor skills training promotes motor functional recovery and induces synaptogenesis in the motor cortex and striatum after intracerebral hemorrhage in rats.

Science.gov (United States)

Tamakoshi, Keigo; Ishida, Akimasa; Takamatsu, Yasuyuki; Hamakawa, Michiru; Nakashima, Hiroki; Shimada, Haruka; Ishida, Kazuto

2014-03-01

We investigated the effects of motor skills training on several types of motor function and synaptic plasticity following intracerebral hemorrhage (ICH) in rats. Male Wistar rats were injected with collagenase into the left striatum to induce ICH, and they were randomly assigned to the ICH or sham groups. Each group was divided into the motor skills training (acrobatic training) and control (no exercise) groups. The acrobatic group performed acrobatic training from 4 to 28 days after surgery. Motor functions were assessed by motor deficit score, the horizontal ladder test and the wide or narrow beam walking test at several time points after ICH. The number of ΔFosB-positive cells was counted using immunohistochemistry to examine neuronal activation, and the PSD95 protein levels were analyzed by Western blotting to examine synaptic plasticity in the bilateral sensorimotor cortices and striata at 14 and 29 days after ICH. Motor skills training following ICH significantly improved gross motor function in the early phase after ICH and skilled motor coordinated function in the late phase. The number of ΔFosB-positive cells in the contralateral sensorimotor cortex in the acrobatic group significantly increased compared to the control group. PSD95 protein expression in the motor cortex significantly increased in the late phase, and in the striatum, the protein level significantly increased in the early phase by motor skills training after ICH compared to no training after ICH. We demonstrated that motor skills training improved motor function after ICH in rats and enhanced the neural activity and synaptic plasticity in the striatum and sensorimotor cortex. Copyright © 2013 Elsevier B.V. All rights reserved.

Piezoelectric Motors, an Overview

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Karl Spanner

2016-02-01

Full Text Available Piezoelectric motors are used in many industrial and commercial applications. Various piezoelectric motors are available in the market. All of the piezoelectric motors use the inverse piezoelectric effect, where microscopically small oscillatory motions are converted into continuous or stepping rotary or linear motions. Methods of obtaining long moving distance have various drive and functional principles that make these motors categorized into three groups: resonance-drive (piezoelectric ultrasonic motors, inertia-drive, and piezo-walk-drive. In this review, a comprehensive summary of piezoelectric motors, with their classification from initial idea to recent progress, is presented. This review also includes some of the industrial and commercial applications of piezoelectric motors that are presently available in the market as actuators.

Anthropometric and motor performance characteristics of futsal athletes in different categories

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Edilson Serpeloni Cyrino

2007-09-01

Full Text Available The objective of this study was to analyze the anthropometric characteristics of young futsal (fi ve-a-side soccer players and to make comparisons between different competitive categories. To this end, 232 male athletes aged 8 to 18 years, playing in the following categories: under-9 (8-9 years; n = 56, under-11 (10-11 years; n = 62, under-13 (12-13 years; n = 36, under-15 (14-15 years; n = 29, under-17 (16-17 years; n = 35 and under-19 (18 years; n = 14, underwent anthropometric measurement to obtain body mass (MB, height, middle-upper arm circumference and skin fold thicknesses (triceps and subscapular. Based on these measurements, body mass index (BMI, sum of skin folds thickness (ΣSF, relative body fat (%fat and muscular area of the arm (MAB were all calculated. Motor performance was analyzed based on the results of the following tests: modifi ed 1-minute abdominal (ABD, horizontal impulse (HI, 9/12 minute walk/run (9/12 min and medicine ball throw (MB. Categories were compared using one-way ANOVA, followed by Scheffé’s post hoc test when p ABSTRACT O propósito do presente estudo foi analisar as características antropométricas de jovens atletas de futsal e, posteriormente, estabelecer comparações entre diferentes categorias competitivas. Para tanto, 232 atletas do sexo masculino, de 8 a 18 anos, das categorias sub 9 (8-9 anos; n = 56, sub 11 (10-11 anos; n = 62, sub 13 (12-13 anos; n = 36, sub 15 (14-15 anos; n = 29, sub 17 (16-17 anos; n = 35 e sub 19 (18 anos; n = 14 foram submetidos a medidas antropométricas de massa corporal (MC, estatura, perímetro braquial e espessura de dobras cutâneas (tríceps e subescapular. A partir dessas medidas foram determinados o índice de massa corporal (IMC, o somatório de espessura de dobras cutâneas (ΣDC, a gordura corporal relativa (% gordura e a área muscular do braço (AMB. O desempenho motor foi analisado a partir dos seguintes testes motores: abdominal modifi cado 1 minuto (ABD

Análise do desempenho motor de escolares praticantes de futsal e voleibol

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Ricardo Drews

2013-10-01

Full Text Available O objetivo do presente estudo foi analisar o desempenho motor de escolares a partir da prática regular de futsal e voleibol. A amostra foi constituida por 60 indivíduos do sexo masculino, com idade média de 16 ± 0.4 anos, divididos em dois grupos: praticantes de futsal (GF (n = 32 e praticantes de voleibol (GV (n = 28. Os indivíduos analisados praticavam regularmente 2 aulas semanais de 60 minutos em suas respectivas modalidades esportivas, no período mínimo de 6 meses. Para avaliar as capacidades físico-motoras foram utilizados os protocolos de teste Shuttle Run ou Corrida do Vai-e-Vem de Johnson e Nelson (1979 para agilidade, software de Pereira, Teixeira, Villis, e Corazza (2009 para o tempo de reação simples e escolha, e o cinesiômetro (Paixão, 1981 e goniômetro (Hurley, Rees, & Newham, 1998 para propriocepção de membros superiores e inferiores respectivamente. Para a análise dos dados, fez-se uso da estatística inferencial, com o Teste t para amostras independentes, através do pacote estatístico SPSS versão 14.0, com nível de significância alfa de 5%. Os resultados não apresentaram diferença estatisticamente significativa entre os grupos em nenhuma capacidade físico-motora analisada.

Presentation of electric motor and motor control technology for electric vehicles and hybrid vehicles; Denki jidosha hybrid sha yo motor oyobi motor seigyo gijutsu no shokai

Energy Technology Data Exchange (ETDEWEB)

Matsudaira, N.; Masakik, R.; Tajima, F. [Hitachi, Ltd., Tokyo (Japan)

1999-02-01

The authors have developed a motor drive system for electric vehicles and hybrid vehicles. This system consists of a permanent magnet type synchronous motor, an inverter using insulated gate bipolar transistors (IGBTs) and a controller based on a single-chip microcomputer. To achieve a compact and light weight synchronous motor, an internal permanent magnet type rotor structure was designed. This paper presents motor control technology for electric vehicles, such as an optimization method of field weakening control and a new current control method. (author)

Diseño de un calibrador de calidad para disminuir el desperdicio en el área de ensamble de un componente para automóvil

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Paloma Michelle Torres Hernández

2015-10-01

Full Text Available Esta investigación de tipo aplicada es realizada en una empresa dentro de la industria automotriz en Ciudad Juárez Chihuahua México, en la cual se presenta un problema en el área de preforme para el doblez de los pines de los transistores que son ensamblados en un dispositivo llamado AFC (Automotive Fan Control, por sus siglas en inglés, el cual es utilizado para el funcionamiento del encendido y apagado de los ventiladores de enfriamiento del motor de un vehículo. El propósito de este proyecto es el diseñar un calibrador de calidad (Gage Go no Go, traducido al inglés mediante el método de la función de despliegue de la calidad para verificar el correcto ensamble de estos componentes, debido a que actualmente la empresa no cuenta con dicho calibrador. Los resultados muestran que la función de despliegue de la calidad es una metodología que garantiza el diseño satisfactorio de este tipo de dispositivo.

Diseño de un calibrador de calidad para disminuir el desperdicio en el área de ensamble de un componente para automóvil

Directory of Open Access Journals (Sweden)

Paloma Michelle Torres Hernández

2015-11-01

Full Text Available Esta investigación de tipo aplicada es realizada en una empresa dentro de la industria automotriz en Ciudad Juárez Chihuahua México, en la cual se presenta un problema en el área de preforme para el doblez de los pines de los transistores que son ensamblados en un dispositivo llamado AFC (Automotive Fan Control, por sus siglas en inglés, el cual es utilizado para el funcionamiento del encendido y apagado de los ventiladores de enfriamiento del motor de un vehículo. El propósito de este proyecto es el diseñar un calibrador de calidad (Gage Go no Go, traducido al inglés mediante el método de la función de despliegue de la calidad para verificar el correcto ensamble de estos componentes, debido a que actualmente la empresa no cuenta con dicho calibrador. Los resultados muestran que la función de despliegue de la calidad es una metodología que garantiza el diseño satisfactorio de este tipo de dispositivo.

Reduction of power consumption in motor-driven applications by using PM motors; PM = Permanent Magnet; Reduktion af elforbrug til motordrift ved anvendelse af PM motorer

Energy Technology Data Exchange (ETDEWEB)

Hvenegaard, C.M.; Hansen, Mads P.R.; Groenborg Nikolaisen, C. (Teknologisk Institut, Taastrup (Denmark)); Nielsen, Sandie B. (Teknologisk Institut, AArhus (Denmark)); Ritchie, E.; Leban, K. (Aalborg Univ., Aalborg (Denmark))

2009-12-15

The traditional asynchronous motor with aluminum rotor is today by far the most widespread and sold electric motor, but a new and more energy efficient type of engine - the permanent magnet motor (PM motor) - is expected in the coming years to win larger and larger market shares. Several engine manufacturers in Europe, USA and Asia are now beginning to market the PM motors, which can replace the traditional asynchronous motor. The project aims to uncover the pros and cons of replacing asynchronous motors including EFF1 engines with PM motors, including the price difference. Furthermore, it is identified how the efficiency of PM motors is affected by low load levels and at various forms of control. Finally, the energy savings potential is analysed, by replacing asynchronous motors with PM motors. The study includes laboratory tests of PM motors, made in a test stand at Danish Technological Institute. (ln)

36 CFR 292.45 - Use of motorized and non-motorized rivercraft.

Science.gov (United States)

2010-07-01

... practicable, conflicts between motorized and non-motorized rivercraft users and between both types of...-motorized rivercraft may be permitted subject to restrictions on size, type of craft, numbers, duration... Service where such activity may be permitted subject to restrictions on size, type of craft, numbers...

Energy-saving motor; Energiesparmotor

Energy Technology Data Exchange (ETDEWEB)

Lindegger, M.

2002-07-01

This report for the Swiss Federal Office of Energy (SFOE) describes the development and testing of an advanced electrical motor using a permanent-magnet rotor. The aims of the project - to study the technical feasibility and market potential of the Eco-Motor - are discussed and the three phases of the project described. These include the calculation and realisation of a 250-watt prototype operating at 230 V, the measurement of the motor's characteristics as well as those of a comparable asynchronous motor on the test bed at the University of Applied Science in Lucerne, Switzerland, and a market study to establish if the Eco-Motor and its controller can compete against normal asynchronous motors. Also, the results of an analysis of the energy-savings potential is made, should such Eco-Motors be used. Detailed results of the three phases of the project are presented and the prospects of producing such motors in Switzerland for home use as well as for export are examined.

Capacidades motoras envolvidas na habilidade psicomotora da técnica de ressuscitação cardiopulmonar: subsídios para o processo ensino-aprendizagem Capacidades motoras involucradas en la habilidad psicomotora de la técnica de resucitación cardiopulmonar: subsídios para el proceso ensenanza-aprendizaje Motor capacities involved in the psychomotor skills of the cardiopulmonary resuscitation: subsidies of the teaching-learning process

Directory of Open Access Journals (Sweden)

Ana Maria Kazue Miyadahira

2001-12-01

Full Text Available Trata-se de uma estudo bibliográfico sobre a identificação das capacidades motoras envolvidas na habilidade psicomotora da técnica de ressuscitação cardiopulmonar (RCP cuja finalidade é obter subsídios para o planejamento do processo ensino-aprendizagem desta habilidade. Verificou-se que as capacidades motoras envolvidas na habilidade psicomotora da técnica de RCP são predominantemente cognitivas e motoras, envolvendo 9 capacidades perceptivo-motoras e 8 capacidades de proficiência física. A técnica de RCP é uma habilidade psicomotora classificada como aberta, seriada e categorizada como uma habilidade fina e global e o processo de ensino-aprendizagem da técnica de RCP tem alto grau de complexidade.Se trata de un estudio bibliográfico sobre la identificación de las capacidades motoras involucradas en la habilidad psicomotora de la técnica de resucitación cardiopulmonar (RCP cuya finalidad fue obtener subsidios para la planificación del proceso ensenanza-aprendizaje de esta habilidad. Se verifico que las capacidades motoras involucradas en la habilidad psicomotora de la técnica de RCP son predominantemente cognitivas y motoras, involucrando 9 capacidades perceptivo-motoras y 8 capacidades de proficiencia física. La técnica de RCP es una habilidad psicomotora clasificada como abierta, seriada y categorizada como una habilidad fina y global y el proceso de ensenanza-aprendizaje de la técnica de RCP tiene alto grado de complejidad.It is a bibliographic study about the identification of the motor capacities involved in the psychomotor skills of the cardiopulmonary resuscitation (CPR which aims to obtain subsidies to the planning of the teaching-learning process of this skill. It was found that: the motor capacities involved in the psychomotor skill of the CPR technique are predominantly cognitive and motor, involving 9 perceptive-motor capacities and 8 physical proficiency capacities. The CPR technique is a psychomotor skill

77 FR 26607 - Energy Conservation Program: Test Procedures for Electric Motors and Small Electric Motors

Science.gov (United States)

2012-05-04

... Conservation Program: Test Procedures for Electric Motors and Small Electric Motors; Final Rules #0;#0;Federal... Procedures for Electric Motors and Small Electric Motors AGENCY: Office of Energy Efficiency and Renewable... electric motors and small electric motors. That supplemental proposal, along with an earlier proposal from...

Motor degradation prediction methods

Energy Technology Data Exchange (ETDEWEB)

Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

1996-12-01

Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor`s duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures.

46 CFR 169.684 - Overcurrent protection for motors and motor branch circuits.

Science.gov (United States)

2010-10-01

...) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Electrical Installations Operating at... motor that is responsive to motor current or to both motor current and temperature may be used. (b) The...

Neuronal mechanisms of motor learning and motor memory consolidation in healthy old adults

NARCIS (Netherlands)

Berghuis, K. M. M.; Veldman, M. P.; Solnik, S.; Koch, G.; Zijdewind, I.; Hortobagyi, T.

It is controversial whether or not old adults are capable of learning new motor skills and consolidate the performance gains into motor memory in the offline period. The underlying neuronal mechanisms are equally unclear. We determined the magnitude of motor learning and motor memory consolidation

Microprocessor controller for stepping motors

International Nuclear Information System (INIS)

Strait, B.G.; Thuot, M.E.

1977-01-01

A new concept for digital computer control of multiple stepping motors which operate in a severe electromagnetic pulse environment is presented. The motors position mirrors in the beam-alignment system of a 100-kJ CO 2 laser. An asynchronous communications channel of a computer is used to send coded messages, containing the motor address and stepping-command information, to the stepping-motor controller in a bit serial format over a fiber-optics communications link. The addressed controller responds by transmitting to the computer its address and other motor information, thus confirming the received message. Each controller is capable of controlling three stepping motors. The controller contains the fiber-optics interface, a microprocessor, and the stepping-motor driven circuits. The microprocessor program, which resides in an EPROM, decodes the received messages, transmits responses, performs the stepping-motor sequence logic, maintains motor-position information, and monitors the motor's reference switch. For multiple stepping-motor application, the controllers are connected in a daisy chain providing control of many motors from one asynchronous communications channel of the computer

Neuronal mechanisms of motor learning and motor memory consolidation in healthy old adults.

Science.gov (United States)

Berghuis, K M M; Veldman, M P; Solnik, S; Koch, G; Zijdewind, I; Hortobágyi, T

2015-06-01

It is controversial whether or not old adults are capable of learning new motor skills and consolidate the performance gains into motor memory in the offline period. The underlying neuronal mechanisms are equally unclear. We determined the magnitude of motor learning and motor memory consolidation in healthy old adults and examined if specific metrics of neuronal excitability measured by magnetic brain stimulation mediate the practice and retention effects. Eleven healthy old adults practiced a wrist extension-flexion visuomotor skill for 20 min (MP, 71.3 years), while a second group only watched the templates without movements (attentional control, AC, n = 11, 70.5 years). There was 40 % motor learning in MP but none in AC (interaction, p learn a new motor skill and consolidate the learned skill into motor memory, processes that are most likely mediated by disinhibitory mechanisms. These results are relevant for the increasing number of old adults who need to learn and relearn movements during motor rehabilitation.

What happens to the motor theory of perception when the motor system is damaged?

Science.gov (United States)

Stasenko, Alena; Garcea, Frank E; Mahon, Bradford Z

2013-09-01

Motor theories of perception posit that motor information is necessary for successful recognition of actions. Perhaps the most well known of this class of proposals is the motor theory of speech perception, which argues that speech recognition is fundamentally a process of identifying the articulatory gestures (i.e. motor representations) that were used to produce the speech signal. Here we review neuropsychological evidence from patients with damage to the motor system, in the context of motor theories of perception applied to both manual actions and speech. Motor theories of perception predict that patients with motor impairments will have impairments for action recognition. Contrary to that prediction, the available neuropsychological evidence indicates that recognition can be spared despite profound impairments to production. These data falsify strong forms of the motor theory of perception, and frame new questions about the dynamical interactions that govern how information is exchanged between input and output systems.

Permanent magnet DC motor control by using arduino and motor drive module BTS7960

Science.gov (United States)

Syukriyadin, S.; Syahrizal, S.; Mansur, G.; Ramadhan, H. P.

2018-05-01

This study proposes a control system for permanent magnet DC (PMDC) motor. PMDC drive control system has two critical parameters: control and monitoring. Control system includes rotation speed control and direction of rotation of motor using motor drive module BTS7960. The PWM signal has a fixed frequency of waves with varying duty cycles (between 0% and 100%), so the motor rotation can be regulated gradually using a potentiometer already programmed on the Arduino Uno board. The motor rotation direction setting uses the H-bridge circuit method using a 3-way switch to set the direction of forward-reverse rotation of the motor. The monitoring system includes measurements of rotational speed, current, and voltage. Motor rotation speed can be adjusted from the armature voltage settings through the duty cycle PWM setting so that the motor speed can be increased or decreased by the desired duty cycle. From the unload PMDC motor test results it has also been shown that the torque of the motor is relatively constant when there is a change in speed from low rpm to high rpm or vice versa.

Phrenic motor neuron adenosine 2A receptors elicit phrenic motor facilitation.

Science.gov (United States)

Seven, Yasin B; Perim, Raphael R; Hobson, Orinda R; Simon, Alec K; Tadjalli, Arash; Mitchell, Gordon S

2018-04-15

Although adenosine 2A (A 2A ) receptor activation triggers specific cell signalling cascades, the ensuing physiological outcomes depend on the specific cell type expressing these receptors. Cervical spinal adenosine 2A (A 2A ) receptor activation elicits a prolonged facilitation in phrenic nerve activity, which was nearly abolished following intrapleural A 2A receptor siRNA injections. A 2A receptor siRNA injections selectively knocked down A 2A receptors in cholera toxin B-subunit-identified phrenic motor neurons, sparing cervical non-phrenic motor neurons. Collectively, our results support the hypothesis that phrenic motor neurons express the A 2A receptors relevant to A 2A receptor-induced phrenic motor facilitation. Upregulation of A 2A receptor expression in the phrenic motor neurons per se may potentially be a useful approach to increase phrenic motor neuron excitability in conditions such as spinal cord injury. Cervical spinal adenosine 2A (A 2A ) receptor activation elicits a prolonged increase in phrenic nerve activity, an effect known as phrenic motor facilitation (pMF). The specific cervical spinal cells expressing the relevant A 2A receptors for pMF are unknown. This is an important question since the physiological outcome of A 2A receptor activation is highly cell type specific. Thus, we tested the hypothesis that the relevant A 2A receptors for pMF are expressed in phrenic motor neurons per se versus non-phrenic neurons of the cervical spinal cord. A 2A receptor immunostaining significantly colocalized with NeuN-positive neurons (89 ± 2%). Intrapleural siRNA injections were used to selectively knock down A 2A receptors in cholera toxin B-subunit-labelled phrenic motor neurons. A 2A receptor knock-down was verified by a ∼45% decrease in A 2A receptor immunoreactivity within phrenic motor neurons versus non-targeting siRNAs (siNT; P phrenic motor neurons. In rats that were anaesthetized, subjected to neuromuscular blockade and ventilated, p

Cerebellar motor learning versus cerebellar motor timing: the climbing fibre story

Science.gov (United States)

Llinás, Rodolfo R

2011-01-01

Abstract Theories concerning the role of the climbing fibre system in motor learning, as opposed to those addressing the olivocerebellar system in the organization of motor timing, are briefly contrasted. The electrophysiological basis for the motor timing hypothesis in relation to the olivocerebellar system is treated in detail. PMID:21486816

Physical capacity and the motor tests relative for the health promotion in children and adolescents

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Roberto Jerônimo dos Santos Silva

2003-06-01

Full Text Available This article discusses physical capacity and health-promotion-oriented motor tests in children and adolescents, in order to provide a foundation for future studies that intend to debate this topic. The idea of evaluating physical activity levels in a population is aimed to determine the level of physical fi tness, and to verify that this is in line with criteria for good health. From a functional point of view, .good health is defined by the following components: body composition (not considered in this article, strength, muscular endurance capacity and fl exibility. These components are measured by test batteries that are intended to measure the health of individuals and/or populations. The starting point for this debate is the published reference literature that classifi es motor tests as either norm-referenced or criterion-referenced standards. RESUMO Este artigo discute as capacidades físicas e os testes motores voltados à promoção da saúde em crianças e adolescentes, de forma a subsidiar trabalhos em que este tema esteja em voga. A idéia de avaliar a atividade física em uma população é baseada no desejo de determinar o estado de atividade atual da mesma, e verifi car se ela está de acordo com os critérios apropriados para uma boa saúde. Do ponto de vista morfofuncional, uma boa “saúde relatada” é defi nida a partir dos componentes: composição corporal (não abordado neste trabalho, força e resistência muscular e fl exibilidade, componentes estes que são verifi cados a partir da aplicação de testes ou baterias de testes que pretendem medir e verifi car os níveis individuais e/ou populacionais de saúde relatada. A literatura de referência, que classifi ca os testes motores como referenciados a partir de normas ou critérios é o ponto de partida para esse debate.

A influência do desempenho motor no “status” social percebido por crianças

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Pâmella MEDEIROS

Full Text Available Resumo Este estudo teve como objetivos descrever o desempenho motor de crianças e adolescentes em relação ao “status” social dos mesmos segundo a percepção dos colegas nos diferentes sexos, além de verificar se há o efeito sexo nessa possível associação. Participaram desta pesquisa 300 crianças e adolescentes do 3º ao 5º ano e da 4a a 6a série do Ensino Fundamental de duas escolas públicas, com idades entre oito e 14 anos. Os instrumentos utilizados foram a Bateria motora TGMD-2 e a Escala Subjetiva de Status Social. As meninas apresentaram melhor desempenho motor que os meninos, no entanto, apenas os meninos com melhor desempenho motor também apresentaram maior “status” social percebido. Tal situação nos indica que os meninos estão mais suscetíveis a avaliações sociais positivas pautadas em competências físicas que as meninas, podendo fazer uso do seu melhor nível de desempenho motor para elevar a sua popularidade na escola através de práticas esportivas.

Desempenho motor e sensorial de lactentes com e sem síndrome de Down: estudo piloto Motor and sensory performance of infants with and without Down syndrome: a pilot study

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Ana Carolina de Campos

2010-09-01

Full Text Available O estudo visou avaliar o desempenho motor e sensorial de lactentes com e sem síndrome de Down (SD aos seis meses de vida. Foram avaliados oito lactentes, sendo quatro com SD e quatro típicos, com 24 semanas de vida. Para verificar o desempenho motor foi utilizada a escala motora infantil de Alberta (AIMS, nas posturas supina, prona, sentada e em pé. O desempenho sensorial foi avaliado por meio de entrevista com o cuidador da criança utilizando o perfil sensorial infantil ITSP (infant/toddler sensory profile, que classifica comportamentos sensoriais como de"baixo registro" (dificuldade em registrar estímulos sensoriais, busca de estímulos, excessiva sensibilidade a estímulos e comportamentos de evitar estímulos. Os resultados no ITSP mostram que os lactentes com SD obtiveram piores escores em baixo registro, possivelmente por apresentarem altos limiares neurológicos, demorando mais para responder aos estímulos. Na AIMS os lactentes com SD tiveram um desempenho inferior quando comparados aos típicos na subescala prono, o que pode advir de dificuldades no controle postural e antigravitacional. Não foi encontrada correlação entre os escores do ITSP e da AIMS. Os resultados sugerem que os lactentes com SD podem se engajar com menos freqüência em atividades de interação com o ambiente, tanto por dificuldade em registrar estímulos cotidianos (como diferentes sons e pessoas, quanto por dificuldade em explorar o meio utilizando habilidades motoras.The study aimed at assessing motor and sensory performance of infants with Down syndrome (DS comparing them to typical infants at the age of six months. Eight infants - 4 with typical development, 4 with DS - were assessed as to motor performance by the Alberta infant motor scale (AIMS at supine, prone, sitting, and standing positions. Sensory performance was assessed by using the Infant/toddler sensory profile (ITSP, which classifies sensorial behaviours as"low registration" (difficulty in

Comparison of Linear Induction Motor Theories for the LIMRV and TLRV Motors

Science.gov (United States)

1978-01-01

The Oberretl, Yamamura, and Mosebach theories of the linear induction motor are described and also applied to predict performance characteristics of the TLRV & LIMRV linear induction motors. The effect of finite motor width and length on performance ...

Recruitment of rat diaphragm motor units across motor behaviors with different levels of diaphragm activation.

Science.gov (United States)

Seven, Yasin B; Mantilla, Carlos B; Sieck, Gary C

2014-12-01

Phrenic motor neurons are recruited across a range of motor behaviors to generate varying levels of diaphragm muscle (DIAm) force. We hypothesized that DIAm motor units are recruited in a fixed order across a range of motor behaviors of varying force levels, consistent with the Henneman Size Principle. Single motor unit action potentials and compound DIAm EMG activities were recorded in anesthetized, neurally intact rats across different motor behaviors, i.e., eupnea, hypoxia-hypercapnia (10% O2 and 5% CO2), deep breaths, sustained airway occlusion, and sneezing. Central drive [estimated by root-mean-squared (RMS) EMG value 75 ms after the onset of EMG activity (RMS75)], recruitment delay, and onset discharge frequencies were similar during eupnea and hypoxia-hypercapnia. Compared with eupnea, central drive increased (∼25%) during deep breaths, and motor units were recruited ∼12 ms earlier (P motor units were recruited ∼30 ms earlier (P motor unit onset discharge frequencies were significantly higher (P Recruitment order of motor unit pairs observed during eupnea was maintained for 98%, 87%, and 84% of the same pairs recorded during hypoxia-hypercapnia, deep breaths, and airway occlusion, respectively. Reversals in motor unit recruitment order were observed primarily if motor unit pairs were recruited motor unit recruitment order being determined primarily by the intrinsic size-dependent electrophysiological properties of phrenic motor neurons. Copyright © 2014 the American Physiological Society.

Cryogenic Electric Motor Tested

Science.gov (United States)

Brown, Gerald V.

2004-01-01

Technology for pollution-free "electric flight" is being evaluated in a number of NASA Glenn Research Center programs. One approach is to drive propulsive fans or propellers with electric motors powered by fuel cells running on hydrogen. For large transport aircraft, conventional electric motors are far too heavy to be feasible. However, since hydrogen fuel would almost surely be carried as liquid, a propulsive electric motor could be cooled to near liquid hydrogen temperature (-423 F) by using the fuel for cooling before it goes to the fuel cells. Motor windings could be either superconducting or high purity normal copper or aluminum. The electrical resistance of pure metals can drop to 1/100th or less of their room-temperature resistance at liquid hydrogen temperature. In either case, super or normal, much higher current density is possible in motor windings. This leads to more compact motors that are projected to produce 20 hp/lb or more in large sizes, in comparison to on the order of 2 hp/lb for large conventional motors. High power density is the major goal. To support cryogenic motor development, we have designed and built in-house a small motor (7-in. outside diameter) for operation in liquid nitrogen.

Aspectos motores corporais e orais em um grupo de crianças com transtorno/atraso fonológico Body and oral motor aspects in a group of children with phonological delay/disorder

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Ana Paula Ramos de Souza

2010-01-01

Full Text Available OBJETIVO: Comparar o desenvolvimento motor e aspectos orofaciais em crianças com transtorno e atraso fonológico. MÉTODOS: Participaram da pesquisa 80 crianças de cinco a 11 anos de idade pertencentes à rede escolar regular de um município da Grande Porto Alegre com alterações fonológicas. Foi realizada uma entrevista com os pais através de um questionário semi-estruturado. Em seguida, foram avaliados o sistema estomatognático e a fala das crianças, e o diagnóstico de transtorno ou atraso fonológico foi confirmado para cada sujeito. Para a análise estatística, foram utilizados os testes de Fisher e o Qui-quadrado com nível de significância de 5% (pPURPOSE: To compare the motor development and orofacial aspects in children with phonological disorder and delay. METHODS: The participants were 80 children with phonological deficits and ages ranging from five to 11 years, who belonged to the regular school system of a city in Rio Grande do Sul, Brazil. An interview with their parents was conducted, using a semi-structured questionnaire. After that, it was carried out the assessment of the subjects' stomatognathic system and speech, and the diagnosis of phonological delay or disorder was confirmed. The Chi-square test and the Fisher test were used for statistical analysis, with significance level of 5% (p<0,05. RESULTS: There were no statistically significant differences between the group with phonological delay and the group with phonological disorder in all aspects examined. CONCLUSION: Phonological delay and disorder do not show significant distinction regarding motor, oral and infectious aspects, together with deleterious oral habits, as shown by the homogeneity between the groups.

Desempenho de motor ciclo Diesel em bancada dinamométrica utilizando misturas diesel/biodiesel Performance of cycle Diesel engine in dynamometer using diesel/biodiesel mixtures

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Marcio Castellanelli

2008-03-01

Full Text Available Diante da previsão de escassez do petróleo, o éster etílico (biodiesel tem-se apresentado como excelente opção de combustível alternativo para motores ciclo Diesel. As características do biodiesel são semelhantes às do diesel em termos de viscosidade e poder calorífico, podendo ser utilizado sem adaptações nos motores. Para a realização deste trabalho, utilizou-se de motor ciclo Diesel, de injeção direta, com quatro cilindros, sem adaptações. O motor foi acoplado a um dinamômetro e sistemas de aquisição de dados auxiliares. Avaliaram-se os desempenhos de torque, de potência e de consumo específico de combustível para as seguintes misturas diesel/éster etílico de soja: B2, B5, B10, B20, B50, B75 e B100. O melhor desempenho registrado deu-se com a mistura B20.Given the prediction of the scarcity of oil, the ethyl ester (biodiesel has presented as an excellent alternative fuel option for cycle diesel engine. The characteristics of biodiesel are similar of diesel in terms of viscosity and the calorific power, being able to be used without adaptations in the engines. For the accomplishment of this work it was used a cycle diesel engine, of direct injection with four cylinders, without adaptations. The engine was connected to a dynamometer and acquisition systems of auxiliary data. The performances of torque, power and specific fuel consumption for the following mixtures diesel/soy ethyl ester had been evaluated: B2, B5, B10, B20, B50, B75 and B100. The best registered performance was given with the B20 mixture.

Assessment of Preschoolers' Gross Motor Proficiency: Revisiting Bruininks-Oseretsky Test of Motor Proficiency

Science.gov (United States)

Lam, Hazel Mei Yung

2011-01-01

Literature reveals that there are very few validated motor proficiency tests for young children. According to Gallahue and Ozmun, the Bruininks-Oseretsky Test of Motor Proficiency is a valid test. However, manipulative skills, which are classified as gross motor skills by most motor development specialists, are only tested in the Upper Limb…

Análisis de modos de falla, efectos y criticidad (AMFEC) del sistema de inyección de un motor de encendido provocado Corsa Evolution 1.4L empleando herramientas de aprendizaje y clasificación para la programación del mantenimiento

OpenAIRE

Aguilar Romero, Angel Yasmany; Tandazo Flores, Luis Fernando

2017-01-01

En este proyecto se desarrolla la técnica de análisis de modos de falla, efectos y criticidad (AMFEC) en el sistema de inyección del motor de un vehículo a raíz de la información obtenida sobre su comportamiento en diferentes estados de funcionamiento, los datos adquiridos son analizados mediante herramientas de aprendizaje y clasificación para la programación del mantenimiento. This project develops the technique of analysis of modes of failure, effects and criticality (AMFEC) in the syst...

Control difuso de un motor de inducción

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Agustín Garzón Carbonell

2011-02-01

Full Text Available Se presenta la simulación de un esquema de control de velocidad de un motor de inducción en coordenadas decampo, con controlador difuso sin la necesidad de realizar las compensaciones en los ejes d-q, lo que simplificasustancialmente el control. La inferencia difusa se implementó por el método de mínimo máximo. Para eldesemborronado, el método del centro de gravedad. Se muestra el comportamiento del sistema de controlsometido a cambios bruscos de carga y referencia, observándose la robustez del control difuso frente a un PIDclásico.  In this article the simulation  of speed control  of  induction motor is presented in field coordinates with fuzzycontroller without the necessity of carrying out the compensations in the d-q axes, simplifying substantially thecontrol. The diffuse inference was implemented by the maximum minimum method. For defuzzification, themethod of the center of gravity is used. The system behaviour is shown from control to abrupt changes of loadand it indexes being observed the robustness of the diffuse control in front of a classic PID.

Auditory-motor interactions in pediatric motor speech disorders: neurocomputational modeling of disordered development.

Science.gov (United States)

Terband, H; Maassen, B; Guenther, F H; Brumberg, J

2014-01-01

Differentiating the symptom complex due to phonological-level disorders, speech delay and pediatric motor speech disorders is a controversial issue in the field of pediatric speech and language pathology. The present study investigated the developmental interaction between neurological deficits in auditory and motor processes using computational modeling with the DIVA model. In a series of computer simulations, we investigated the effect of a motor processing deficit alone (MPD), and the effect of a motor processing deficit in combination with an auditory processing deficit (MPD+APD) on the trajectory and endpoint of speech motor development in the DIVA model. Simulation results showed that a motor programming deficit predominantly leads to deterioration on the phonological level (phonemic mappings) when auditory self-monitoring is intact, and on the systemic level (systemic mapping) if auditory self-monitoring is impaired. These findings suggest a close relation between quality of auditory self-monitoring and the involvement of phonological vs. motor processes in children with pediatric motor speech disorders. It is suggested that MPD+APD might be involved in typically apraxic speech output disorders and MPD in pediatric motor speech disorders that also have a phonological component. Possibilities to verify these hypotheses using empirical data collected from human subjects are discussed. The reader will be able to: (1) identify the difficulties in studying disordered speech motor development; (2) describe the differences in speech motor characteristics between SSD and subtype CAS; (3) describe the different types of learning that occur in the sensory-motor system during babbling and early speech acquisition; (4) identify the neural control subsystems involved in speech production; (5) describe the potential role of auditory self-monitoring in developmental speech disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

Coordenação motora fina de escolares com dislexia e transtorno do déficit de atenção e hiperatividade Fine motor coordination of students with dyslexia and attention deficit disorder with hiperactivity

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Paola Matiko Martins Okuda

2011-10-01

Full Text Available OBJETIVOS: descrever e comparar o desempenho da coordenação motora fina em escolares com dislexia e com transtorno do déficit de atenção e hiperatividade utilizando parâmetros de desempenho motor e idade cronológica da Escala de Desenvolvimento Motor. MÉTODO: participaram 22 escolaresdo ensino fundamental, de ambos os gêneros, na faixa etária de 6 a 11 anos de idade distribuídos em: GI: 11 escolares com transtorno do déficit de atenção e hiperatividade e GII: 11 com dislexia. Como procedimento, provas de motricidade fina da Escala de Desenvolvimento Motor foram aplicadas. RESULTADOS: os resultados revelaram diferença estatisticamente significante entre a idade motora fina e a idade cronológica de GI e GII. Conforme a classificação da Escala do Desenvolvimento Motor, 90% dos escolares de GI e GII apresentaram desenvolvimento motor fino muito inferior ao esperado para a idade e 10% dos escolares com dislexia apresentam desenvolvimento normal baixo ao esperado para a idade e 10% dos escolares com transtorno do déficit de atenção e hiperatividade apresentaram desenvolvimento inferior ao esperado para a idade. CONCLUSÃO: concluímos que tanto os escolares com dislexia como os com TDAH deste estudo apresentam atrasos na coordenação motora fina, demonstrando que os participantes desta pesquisa apresentam dificuldades em atividades que exijam destreza, quadro característico do transtorno do desenvolvimento da coordenação. Estudos complementares estão sendo conduzidos pelos autores deste estudo para poder verificar e comprovar se o perfil motor fino dos escolares encontrados neste estudo se assemelham ou se diferem de acordo com o quadro apresentado pelos mesmos.PURPOSE: to describe and compare the fine motor coordination performance of students with dyslexia and with Attention Deficit and Hyperactivity Disorder. METHOD: the study included 22 elementary school students of both genders, aged from 6 to 11-year old, divided into

Hereditary motor neuropathies and motor neuron diseases: which is which.

Science.gov (United States)

Hanemann, Clemens O; Ludolph, Albert C

2002-12-01

When Charcot first defined amyotrophic lateral sclerosis (ALS) he used the clinical and neuropathological pattern of vulnerability as a guideline. Similarly other motor neuron diseases such as the spinal muscular atrophies (SMA) and the motor neuropathies (MN) were grouped following clinical criteria. However, ever since the etiology of these diseases has started to be disclosed by genetics, we have learnt that the limits of the syndromes are not as well defined as our forefathers thought. A mutation leading to ALS can also be associated with the clinical picture of spinal muscular atrophy; even more unexpected is the overlap of the so-called motor neuropathies with the clinical syndrome of slowly progressive ALS or that primary lateral sclerosis (PLS) can be caused by the same gene as that responsible for some cases of ALS. In this review we summarise recent work showing that there is a considerable overlap between CMT, MN, SMA, ALS and PLS. Insights into these phenotypes should lead to study of the variants of motor neuron disease and possibly to a reclassification. This comprehensive review should help to improve understanding of the pathogenesis of motor neuron degeneration and finally may aid the research for urgently needed new treatment strategies, perhaps with validity for the entire group of motor neuron diseases.

Homopolar dc motor and trapped flux brushless dc motor using high temperature superconductor materials

Science.gov (United States)

Crapo, Alan D.; Lloyd, Jerry D.

1991-03-01

Two motors have been designed and built for use with high-temperature superconductor (HTSC) materials. They are a homopolar dc motor that uses HTSC field windings and a brushless dc motor that uses bulk HTSC materials to trap flux in steel rotor poles. The HTSC field windings of the homopolar dc motor are designed to operate at 1000 A/sq cm in a 0.010-T field. In order to maximize torque in the homopolar dc motor, an iron magnetic circuit with small air gaps gives maximum flux for minimum Ampere turns in the field. A copper field winding version of the homopolar dc motor has been tested while waiting for 575 A turn HTSC coils. The trapped flux brushless dc motor has been built and is ready to test melt textured bulk HTSC rings that are currently being prepared. The stator of the trapped flux motor will impress a magnetic field in the steel rotor poles with warm HTSC bulk rings. The rings are then cooled to 77 K to trap the flux in the rotor. The motor can then operate as a brushless dc motor.

Prototipo de motor de realidad aumentada tridimensional para dispositivos móviles

OpenAIRE

Suárez Canosa, Xoan Iago

2016-01-01

La Realidad Aumentada es la tecnología que nos permite superponer elementos gráficos sobre el mundo real. Para que ésta pueda funcionar adecuadamente es necesario conocer con precisión cuál es la posición de la cámara desde la que vemos el mundo y cómo se conforman las imágenes que nos muestra. En este trabajo mostramos cómo calcular la posición de la cámara a partir de diferentes marcas tanto naturales como artificiales, vemos cual es la mejor forma de proyectar sobre estas ma...

Association Between Gross-Motor and Executive Function Depends on Age and Motor Task Complexity

DEFF Research Database (Denmark)

Spedden, Meaghan E; Malling, Anne Sofie B; Andersen, Ken K

2017-01-01

The objective was to examine associations between motor and executive function across the adult lifespan and to investigate the role of motor complexity in these associations. Young, middle-aged and older adults (n = 82; 19-83y) performed two gross-motor tasks with different levels of complexity...... and a Stroop-like computer task. Performance was decreased in older adults. The association between motor and cognitive performance was significant for older adults in the complex motor task (p = 0.03, rs = -0.41), whereas no significant associations were found for young or middle-aged groups, suggesting...... that the link between gross-motor and executive function emerges with age and depends on motor complexity....

Cerebellar Shaping of Motor Cortical Firing Is Correlated with Timing of Motor Actions

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Abdulraheem Nashef

2018-05-01

Full Text Available Summary: In higher mammals, motor timing is considered to be dictated by cerebellar control of motor cortical activity, relayed through the cerebellar-thalamo-cortical (CTC system. Nonetheless, the way cerebellar information is integrated with motor cortical commands and affects their temporal properties remains unclear. To address this issue, we activated the CTC system in primates and found that it efficiently recruits motor cortical cells; however, the cortical response was dominated by prolonged inhibition that imposed a directional activation across the motor cortex. During task performance, cortical cells that integrated CTC information fired synchronous bursts at movement onset. These cells expressed a stronger correlation with reaction time than non-CTC cells. Thus, the excitation-inhibition interplay triggered by the CTC system facilitates transient recruitment of a cortical subnetwork at movement onset. The CTC system may shape neural firing to produce the required profile to initiate movements and thus plays a pivotal role in timing motor actions. : Nashef et al. identified a motor cortical subnetwork recruited by cerebellar volley that was transiently synchronized at movement onset. Cerebellar control of cortical firing was dominated by inhibition that shaped task-related firing of neurons and may dictate motor timing. Keywords: motor control, primates, cerebellar-thalamo-cortical, synchrony, noise correlation, reaction time

Auditory-Motor Interactions in Pediatric Motor Speech Disorders: Neurocomputational Modeling of Disordered Development

Science.gov (United States)

Terband, H.; Maassen, B.; Guenther, F.H.; Brumberg, J.

2014-01-01

Background/Purpose Differentiating the symptom complex due to phonological-level disorders, speech delay and pediatric motor speech disorders is a controversial issue in the field of pediatric speech and language pathology. The present study investigated the developmental interaction between neurological deficits in auditory and motor processes using computational modeling with the DIVA model. Method In a series of computer simulations, we investigated the effect of a motor processing deficit alone (MPD), and the effect of a motor processing deficit in combination with an auditory processing deficit (MPD+APD) on the trajectory and endpoint of speech motor development in the DIVA model. Results Simulation results showed that a motor programming deficit predominantly leads to deterioration on the phonological level (phonemic mappings) when auditory self-monitoring is intact, and on the systemic level (systemic mapping) if auditory self-monitoring is impaired. Conclusions These findings suggest a close relation between quality of auditory self-monitoring and the involvement of phonological vs. motor processes in children with pediatric motor speech disorders. It is suggested that MPD+APD might be involved in typically apraxic speech output disorders and MPD in pediatric motor speech disorders that also have a phonological component. Possibilities to verify these hypotheses using empirical data collected from human subjects are discussed. PMID:24491630

Behavior of high efficiency electric motors; Comportamiento de motores electricos de alta eficiencia

Energy Technology Data Exchange (ETDEWEB)

Bonett, Austin H. [IEEE, (United States)

2001-09-01

The energy efficiency is one of the main parameters in the design of the industrial motors of general purpose; nevertheless, it is avoided that it is at the cost of the reliability or to the global performance of the motor. Exist user groups of this equipment that consider that, in the search of a greater efficiency, the useful life period is diminished and the characteristics of operation of the motor are affected. During the past last years, the author has studied the aspects of quality and reliability, as well as the operative advantages of the high efficiency motors and written down the increasing interest for these aspects. Also he has detected that a great number of users has realized that, additionally to the obvious energy saving, the efficient motor offers a greater reliability and a longer useful life in most of the industrial applications. The objective of this article is to present the differences in the quality levels, reliability and operation parameters of high efficiency squirrel cage type electrical motors with those of the motors of standard manufacture. [Spanish] La eficiencia energetica es uno de los principales parametros en el diseno de los motores industriales de proposito general; sin embargo, se evita que sea a costa de la confiabilidad o del desempeno global del motor. Existen grupos de usuarios de estos equipos que consideran que, en la busqueda de una mayor eficiencia, se disminuye el periodo de vida util y se afectan las caracteristicas de operacion del motor. Durante los ultimos anos, el autor ha estudiado los aspectos de calidad y confiabilidad, asi como las ventajas operativas de los motores de alta eficiencia y anotado el incremento del interes por estos aspectos. Tambien ha detectado que un gran numero de usuarios se ha dado cuenta que, adicionalmente a los obvios ahorros de energia, el motor eficiente ofrece una mayor confiabilidad y una vida util mas larga en la mayoria de las aplicaciones industriales. El objetivo de este

Comparison of capabilities of reluctance synchronous motor and induction motor

International Nuclear Information System (INIS)

Stumberger, Gorazd; Hadziselimovic, Miralem; Stumberger, Bojan; Miljavec, Damijan; Dolinar, Drago; Zagradisnik, Ivan

2006-01-01

This paper compares the capabilities of a reluctance synchronous motor (RSM) with those of an induction motor (IM). An RSM and IM were designed and made, with the same rated power and speed. They differ only in the rotor portion while their stators, housings and cooling systems are identical. The capabilities of both motors in a variable speed drive are evaluated by comparison of the results obtained by magnetically nonlinear models and by measurements

Perfil do desenvolvimento motor em escolares com excesso de peso

Directory of Open Access Journals (Sweden)

Mayara Moura Alves da Cruz

2017-12-01

Full Text Available Introdução: Diferenças relacionadas ao peso e as habilidades motoras em crianças em idade escolar ainda apresentam controversias. Objetivo: Analisar a relação entre desenvolvimento motor e nível de atividade física com o índice de massa corporal (IMC de escolares com excesso de peso. Métodos: Foram avaliados 85 escolares de ambos os sexos, de 6 a 10 anos, de Presidente Prudente, São Paulo, Brasil. Os instrumentos utilizados foram a classificação do IMC/idade, a Escala de Desenvolvimento Motor e o Questionário do Nível de Atividade Física Modificado e Adaptado. A amostra foi dividida em dois grupos: grupo com excesso de peso (GEP, com 50 escolares com diagnostico nutricional de sobrepeso e obesidade; e grupo com normopeso (GNP, com 35 escolares eutroficos. Para analise dos dados obtidos foram utilizados: Shapiro Wilk (normalidade, teste t de Student não pareado ou Mann Whitney (amostras independentes, teste de Spearman (correlação e teste do χ2 (proporção, com nível de significância p<0,05. Resultados: O GEP apresentou resultados inferiores significantes no desenvolvimento motor geral (91,32±10,68 versus 97,14±9,06; p=0,010, nas áreas de motricidade fina – QM1 (93,21±21,59 versus 103,1±13,12; p=0,0138 e motricidade global – QM2 (90,31±23,54 versus 112,6±16,07; p<0,0001. Observou-se correlação positiva significativa entre o nível de atividade física e o desenvolvimento motor no GEP, nas áreas de equilibrio – QM3 (0,35080; p=0,0125 e organização espacial – QM5 (0,41820; p=0,0025. Conclusão: O GEP, quando comparado com o GNP, demonstrou resultados inferiores no quociente motor geral (QMG, QM1 e QM2.

Motor homopolar

OpenAIRE

Martín Muñoz, Agustín

2007-01-01

Mostramos la construcción de un modelo de motor homopolar, uno de los más antiguos tipos de motores eléctricos. Se caracterizan porque el campo magnético del imán mantiene siempre la misma polaridad (de ahí su nombre, del griego homos, igual), de modo que, cuando una corriente eléctrica atraviesa el campo magnético, aparece una fuerza que hace girar los elementos no fijados mecánicamente. En el sencillísimo motor homopolar colgado (Schlichting y Ucke 2004), el imán puede girar ...

Electric vehicle motors and controllers

Science.gov (United States)

Secunde, R. R.

1981-01-01

Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

IE Information No. 87-08: Degraded motor leads in Limitorque dc motor operators

International Nuclear Information System (INIS)

Jordan, E.L.

1992-01-01

On May 6, 1986 the NRC received from Portland General Electric Company a 10 CFR 21 report concerning a motor failure which occurred at its Trojan Nuclear Power Plant. The failure involved shorting of the motor leads inside a Limitorque motor operator connected to an auxiliary feedwater flow control valve. Upon inspection it was determined that the failure was the result of insulation degradation of the motor leads that had allowed two leads to short together. Recently, the NRC has also learned of a failure at the Turkey Point Nuclear Power Plant in which the steam supply valve for the auxiliary feedwater turbine failed to operate after a Limitorque motor operator experienced a similar motor lead short circuit. The Trojan and the Turkey Point Limitorque operators were found to contain motors manufactured with Nomex-Kapton insulated leads. On January 12--14, 1987, the NRC conducted an inspection at Peerless-Winsmith, Inc., manufacturer of dc motors for Limitorque Co. During this inspection it was determined that the failed Nomex-Kapton leads were different than the leads which were fitted to the motors, tested, and documented in Limitorque Qualification Report B-0009 for dc motor operators. The leads attached to the tested motors were insulated with Nomex plus an epoxy impregnated braided fiberglass sleeve. The NRC knows of no analysis or testing that has been performed to show the Nomex-Kapton leads are acceptable for use in an application requiring environmental qualification. Further, it should be noted that the failures cited above occurred under normal operating conditions, not under the harsh conditions which could occur in areas where environmental qualification is required

Electrodynamic linear motor

Energy Technology Data Exchange (ETDEWEB)

Munehiro, H

1980-05-29

When driving the carriage of a printer through a rotating motor, there are problems regarding the limited accuracy of the carriage position due to rotation or contraction and ageing of the cable. In order to solve the problem, a direct drive system was proposed, in which the printer carriage is driven by a linear motor. If one wants to keep the motor circuit of such a motor compact, then the magnetic flux density in the air gap must be reduced or the motor travel must be reduced. It is the purpose of this invention to create an electrodynamic linear motor, which on the one hand is compact and light and on the other hand has a relatively high constant force over a large travel. The invention is characterised by the fact that magnetic fields of alternating polarity are generated at equal intervals in the magnetic field, and that the coil arrangement has 2 adjacent coils, whose size corresponds to half the length of each magnetic pole. A logic circuit is provided to select one of the two coils and to determine the direction of the current depending on the signals of a magnetic field sensor on the coil arrangement.

Piezoelectric Motors, an Overview

OpenAIRE

Karl Spanner; Burhanettin Koc

2016-01-01

Piezoelectric motors are used in many industrial and commercial applications. Various piezoelectric motors are available in the market. All of the piezoelectric motors use the inverse piezoelectric effect, where microscopically small oscillatory motions are converted into continuous or stepping rotary or linear motions. Methods of obtaining long moving distance have various drive and functional principles that make these motors categorized into three groups: resonance-drive (piezoelectric ult...

Spinal cord: motor neuron diseases.

Science.gov (United States)

Rezania, Kourosh; Roos, Raymond P

2013-02-01

Spinal cord motor neuron diseases affect lower motor neurons in the ventral horn. This article focuses on the most common spinal cord motor neuron disease, amyotrophic lateral sclerosis, which also affects upper motor neurons. Also discussed are other motor neuron diseases that only affect the lower motor neurons. Despite the identification of several genes associated with familial amyotrophic lateral sclerosis, the pathogenesis of this complex disease remains elusive. Copyright © 2013 Elsevier Inc. All rights reserved.

Análisis estocástico de señales vibratorias de motores de inducción para la detección de fallas usando descomposición de modo empírico

Directory of Open Access Journals (Sweden)

Alejandro Rivera Roldán

2015-04-01

Full Text Available En este artículo se presenta un análisis de vibraciones en motores de inducción por medio de Modelos Ocultos de Markov (Hidden Markov Model - HMM aplicado a características obtenidas de la Descomposición de Modo Empírico (Empirical Mode Decomposition - EMD y transformada de Hilbert-Huang de señales de vibración obtenidas en las coordenadas x y y, con el fin de detectar fallas de funcionamiento en rodamientos y barras.  Además se presenta un análisis comparativo de la capacidad de las señales de vibración en dirección x y en dirección y, para aportar información en la detección de fallas. Así, un HMM ergódico inicializado y entrenado por medio del algoritmo de máxima esperanza, con convergencia en 10e-7 y un máximo de iteraciones de 100, se aplicó sobre el espacio de características y su desempeño fue determinado mediante validación cruzada 80-20 con 30 fold, obteniendo un alto desempeño para la detección de fallas en términos de exactitud.

Dimensionamento e análises de sistemas energéticos para irrigação em fazendas no estado de Minas Gerais

Directory of Open Access Journals (Sweden)

Gabriel de Souza Freitas

2017-06-01

Full Text Available O presente estudo consiste em analisar os pontos de vista energéticos, econômicos e ambientais os sistemas de acionamento utilizados para irrigação em áreas agrícolas no estado de Minas Gerais (MG. Realizando-se análises de viabilidade econômica e impactos ambientais de cada forma de acionamento utilizada nos sistemas para irrigação, será avaliado qual o acionador primário mais indicado para o estudo de caso avaliado, em uma área agrícola em Minas Gerais, considerando-se o acionamento do conjunto motobomba diretamente por meio da rede elétrica, motor diesel e energia fotovoltaica, tanto on grid quanto off grid. Será visto que o uso da rede elétrica para acionar o conjunto motobomba do sistema de irrigação é o acionador primário mais indicado para o estudo de caso realizado, por apresentar custos totais anuais muito menores que os demais, e os sistemas fotovoltaicos são os mais benéficos com relação aos impactos ambientais, pois sua utilização não resulta em poluição ambiental. Com relação ao uso do motor diesel, o preço do diesel torna muito caro seu uso, além de gerar altos níveis de emissão de CO2 na atmosfera.

Technical application of current analysis to detect broken bars in three-phase induction motors at ArcelorMittal Tubarao; A aplicacao da tecnica de analise de corrente para deteccao de barras quebradas nos motores e inducao trifasicos na ArcelorMittal Tubarao

Energy Technology Data Exchange (ETDEWEB)

Antunes, Harison Araujo; Rocha, Rogerio Hubner; Oliveira Filho, Jessui de; Spinasse, Amarildo; Calente, Aderaldo [ArcelorMittal Tubarao, ES (Brazil). Dept. de Producao de Gusa e Energia

2009-11-01

Most modern machinery operates from three-phase induction motors that, in time, can develop faults. These faults can cause the machine to stop working or decrease its efficiency level in the productive process. When a motor suffers a fault it generates indication of defects in several ways: changing in vibrating signals, temperature variations, noises, and electromagnetic field alteration. Known as motor current signature analysis, this technique allows fault detection with mechanical and electrical origin in squirrel-cage three-phase induction motors. This technique is used within ArcelorMittal Tubarao to analyze and follow the motor's rotor broken bar tendency. At ArcelorMittal Tubarao, 450 motors are monitored, at 13200, 3300 and 440V and with power rating exceeding 55 KW. This paper will show the results of applying this technique during the last 2 years, as well as the several types of broken bars detected, fault characteristics, the type of load it operates in each fault encountered, and the fault range caused in the productive process. (author)

Higher Efficiency HVAC Motors

Energy Technology Data Exchange (ETDEWEB)

Flynn, Charles Joseph [QM Power, Inc., Kansas City, MO (United States)

2018-02-13

The objective of this project was to design and build a cost competitive, more efficient heating, ventilation, and air conditioning (HVAC) motor than what is currently available on the market. Though different potential motor architectures among QMP’s primary technology platforms were investigated and evaluated, including through the building of numerous prototypes, the project ultimately focused on scaling up QM Power, Inc.’s (QMP) Q-Sync permanent magnet synchronous motors from available sub-fractional horsepower (HP) sizes for commercial refrigeration fan applications to larger fractional horsepower sizes appropriate for HVAC applications, and to add multi-speed functionality. The more specific goal became the research, design, development, and testing of a prototype 1/2 HP Q-Sync motor that has at least two operating speeds and 87% peak efficiency compared to incumbent electronically commutated motors (EC or ECM, also known as brushless direct current (DC) motors), the heretofore highest efficiency HVACR fan motor solution, at approximately 82% peak efficiency. The resulting motor prototype built achieved these goals, hitting 90% efficiency and .95 power factor at full load and speed, and 80% efficiency and .7 power factor at half speed. Q-Sync, developed in part through a DOE SBIR grant (Award # DE-SC0006311), is a novel, patented motor technology that improves on electronically commutated permanent magnet motors through an advanced electronic circuit technology. It allows a motor to “sync” with the alternating current (AC) power flow. It does so by eliminating the constant, wasteful power conversions from AC to DC and back to AC through the synthetic creation of a new AC wave on the primary circuit board (PCB) by a process called pulse width modulation (PWM; aka electronic commutation) that is incessantly required to sustain motor operation in an EC permanent magnet motor. The Q-Sync circuit improves the power factor of the motor by removing all

Retos logísticos en Ssangyong Motor Colombia S.A.

OpenAIRE

CARLOS ENRIQUE RAMÍREZ R.; JULIÁN ANDRÉS PAREDES G.; JOHANNA CARMONA; MARIO ANDRÉS GIL A.

2008-01-01

La revaluación del peso frente al dólar y el importante crecimiento que tuvo la economía colombiana en los años 2005 y 2006, dispararon las ventas de vehículos en Colombia. Para poder aprovechar ese importante aumento de la demanda, SsangYong Motor Colombia S.A., empresa especializada en la importación y comercialización de vehículos diésel de última generación, se enfrentó a grandes retos logísticos, que se presentaron porque a mediados del año 2007 se elevaron los precios de los fl etes mar...

Motor degradation prediction methods

International Nuclear Information System (INIS)

Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

1996-01-01

Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor's duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures

Motor Importance of motor assessment in school children: analysis of the reliability of the motor development scale

Directory of Open Access Journals (Sweden)

Kassandra Nunes Amaro

2010-09-01

Full Text Available The objective of this study was to investigate the motor performance of school chil-dren aged 6 to 10 years without learning difficulties (n=101, and to analyze the reliability of the Motor Development Scale (MDS (Rosa Neto, 2002. Descriptive statistics with calculation of the mean, standard deviation, and range was used for data analysis. The internal consistency of the MDS was assessed using Cronbach’s alpha coefficient, and the correlation between variables was determined by Pearson’s linear correlation, with p<0.05. The results showed (1 that motor development was within normal limits in 96% of the children, and (2 a high correlation betwe-en chronological age and general motor age, indicating good internal consistency. These data demonstrate the logic and structured design of the MDS, confirming its reliability.

Mechanical design of electric motors

CERN Document Server

Tong, Wei

2014-01-01

Rapid increases in energy consumption and emphasis on environmental protection have posed challenges for the motor industry, as has the design and manufacture of highly efficient, reliable, cost-effective, energy-saving, quiet, precisely controlled, and long-lasting electric motors.Suitable for motor designers, engineers, and manufacturers, as well as maintenance personnel, undergraduate and graduate students, and academic researchers, Mechanical Design of Electric Motors provides in-depth knowledge of state-of-the-art design methods and developments of electric motors. From motor classificati

Markov process of muscle motors

International Nuclear Information System (INIS)

Kondratiev, Yu; Pechersky, E; Pirogov, S

2008-01-01

We study a Markov random process describing muscle molecular motor behaviour. Every motor is either bound up with a thin filament or unbound. In the bound state the motor creates a force proportional to its displacement from the neutral position. In both states the motor spends an exponential time depending on the state. The thin filament moves at a velocity proportional to the average of all displacements of all motors. We assume that the time which a motor stays in the bound state does not depend on its displacement. Then one can find an exact solution of a nonlinear equation appearing in the limit of an infinite number of motors

Motor demand-dependent activation of ipsilateral motor cortex.

Science.gov (United States)

Buetefisch, Cathrin M; Revill, Kate Pirog; Shuster, Linda; Hines, Benjamin; Parsons, Michael

2014-08-15

The role of ipsilateral primary motor cortex (M1) in hand motor control during complex task performance remains controversial. Bilateral M1 activation is inconsistently observed in functional (f)MRI studies of unilateral hand performance. Two factors limit the interpretation of these data. As the motor tasks differ qualitatively in these studies, it is conceivable that M1 contributions differ with the demand on skillfulness. Second, most studies lack the verification of a strictly unilateral execution of the motor task during the acquisition of imaging data. Here, we use fMRI to determine whether ipsilateral M1 activity depends on the demand for precision in a pointing task where precision varied quantitatively while movement trajectories remained equal. Thirteen healthy participants used an MRI-compatible joystick to point to targets of four different sizes in a block design. A clustered acquisition technique allowed simultaneous fMRI/EMG data collection and confirmed that movements were strictly unilateral. Accuracy of performance increased with target size. Overall, the pointing task revealed activation in contralateral and ipsilateral M1, extending into contralateral somatosensory and parietal areas. Target size-dependent activation differences were found in ipsilateral M1 extending into the temporal/parietal junction, where activation increased with increasing demand on accuracy. The results suggest that ipsilateral M1 is active during the execution of a unilateral motor task and that its activity is modulated by the demand on precision. Copyright © 2014 the American Physiological Society.

Motor network structure and function are associated with motor performance in Huntington's disease.

Science.gov (United States)

Müller, Hans-Peter; Gorges, Martin; Grön, Georg; Kassubek, Jan; Landwehrmeyer, G Bernhard; Süßmuth, Sigurd D; Wolf, Robert Christian; Orth, Michael

2016-03-01

In Huntington's disease, the relationship of brain structure, brain function and clinical measures remains incompletely understood. We asked how sensory-motor network brain structure and neural activity relate to each other and to motor performance. Thirty-four early stage HD and 32 age- and sex-matched healthy control participants underwent structural magnetic resonance imaging (MRI), diffusion tensor, and intrinsic functional connectivity MRI. Diffusivity patterns were assessed in the cortico-spinal tract and the thalamus-somatosensory cortex tract. For the motor network connectivity analyses the dominant M1 motor cortex region and for the basal ganglia-thalamic network the thalamus were used as seeds. Region to region structural and functional connectivity was examined between thalamus and somatosensory cortex. Fractional anisotropy (FA) was higher in HD than controls in the basal ganglia, and lower in the external and internal capsule, in the thalamus, and in subcortical white matter. Between-group axial and radial diffusivity differences were more prominent than differences in FA, and correlated with motor performance. Within the motor network, the insula was less connected in HD than in controls, with the degree of connection correlating with motor scores. The basal ganglia-thalamic network's connectivity differed in the insula and basal ganglia. Tract specific white matter diffusivity and functional connectivity were not correlated. In HD sensory-motor white matter organization and functional connectivity in a motor network were independently associated with motor performance. The lack of tract-specific association of structure and function suggests that functional adaptation to structural loss differs between participants.

Task-dependent activation of distinct fast and slow(er) motor pathways during motor imagery.

Science.gov (United States)

Keller, Martin; Taube, Wolfgang; Lauber, Benedikt

2018-02-22

Motor imagery and actual movements share overlapping activation of brain areas but little is known about task-specific activation of distinct motor pathways during mental simulation of movements. For real contractions, it was demonstrated that the slow(er) motor pathways are activated differently in ballistic compared to tonic contractions but it is unknown if this also holds true for imagined contractions. The aim of the present study was to assess the activity of fast and slow(er) motor pathways during mentally simulated movements of ballistic and tonic contractions. H-reflexes were conditioned with transcranial magnetic stimulation at different interstimulus intervals to assess the excitability of fast and slow(er) motor pathways during a) the execution of tonic and ballistic contractions, b) motor imagery of these contraction types, and c) at rest. In contrast to the fast motor pathways, the slow(er) pathways displayed a task-specific activation: for imagined ballistic as well as real ballistic contractions, the activation was reduced compared to rest whereas enhanced activation was found for imagined tonic and real tonic contractions. This study provides evidence that the excitability of fast and slow(er) motor pathways during motor imagery resembles the activation pattern observed during real contractions. The findings indicate that motor imagery results in task- and pathway-specific subliminal activation of distinct subsets of neurons in the primary motor cortex. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Survival motor neuron protein in motor neurons determines synaptic integrity in spinal muscular atrophy.

Science.gov (United States)

Martinez, Tara L; Kong, Lingling; Wang, Xueyong; Osborne, Melissa A; Crowder, Melissa E; Van Meerbeke, James P; Xu, Xixi; Davis, Crystal; Wooley, Joe; Goldhamer, David J; Lutz, Cathleen M; Rich, Mark M; Sumner, Charlotte J

2012-06-20

The inherited motor neuron disease spinal muscular atrophy (SMA) is caused by deficient expression of survival motor neuron (SMN) protein and results in severe muscle weakness. In SMA mice, synaptic dysfunction of both neuromuscular junctions (NMJs) and central sensorimotor synapses precedes motor neuron cell death. To address whether this synaptic dysfunction is due to SMN deficiency in motor neurons, muscle, or both, we generated three lines of conditional SMA mice with tissue-specific increases in SMN expression. All three lines of mice showed increased survival, weights, and improved motor behavior. While increased SMN expression in motor neurons prevented synaptic dysfunction at the NMJ and restored motor neuron somal synapses, increased SMN expression in muscle did not affect synaptic function although it did improve myofiber size. Together these data indicate that both peripheral and central synaptic integrity are dependent on motor neurons in SMA, but SMN may have variable roles in the maintenance of these different synapses. At the NMJ, it functions at the presynaptic terminal in a cell-autonomous fashion, but may be necessary for retrograde trophic signaling to presynaptic inputs onto motor neurons. Importantly, SMN also appears to function in muscle growth and/or maintenance independent of motor neurons. Our data suggest that SMN plays distinct roles in muscle, NMJs, and motor neuron somal synapses and that restored function of SMN at all three sites will be necessary for full recovery of muscle power.

Uma versão compacta do motor elétrico de Faraday para demonstração em sala de aula

Directory of Open Access Journals (Sweden)

Osmar Henrique Moura Silva

2013-06-01

Full Text Available http://dx.doi.org/10.5007/2175-7941.2013v30n2p385 O “motor” elétrico de Michael Faraday (1791-1867 é versado como o precursor dos motores elétricos atuais e um equipamento interessante no estudo introdutório do assunto. Um trabalho anterior divulgou uma montagem deste motor mais bem adaptada aos ambientes educativos não formais, abrangendo suas duas variantes: uma, com haste móvel e ímã fixo; outra, com haste fixa e ímã móvel. Apresenta-se aqui uma elaboração desse motor na primeira destas variantes que se diferencia nas dimensões e peso, sendo de fácil transporte e uso em sala de aula por apropriação da energia elétrica padrão de 127V.

Producción de entropía y ley de enfriamiento de Newton

Directory of Open Access Journals (Sweden)

Daniel Barragán

2009-05-01

Full Text Available Para un sistema con una fuente interna de generación de calor se analizan, en el marco de la termodinámica de los procesos irreversibles, las ecuaciones evolutivas que describen la transferencia de calor según la ley de enfriamiento de Newton. A partir del balance de flujo de entropía se muestra que la generación de entropía no es mínima en el estado estacionario descrito por la ley de enfriamiento de Newton. Igualmente, se discute cómo realizar el balance de flujos en el sistema, su conexión con los parámetros de control y su futura aplicación a procesos de optimización basados en la segunda ley de la termodinámica.

Motor Skill Competence and Perceived Motor Competence: Which Best Predicts Physical Activity among Girls?

OpenAIRE

Khodaverdi, Zeinab; Bahram, Abbas; Khalaji, Hassan; Kazemnejad, Anoshirvan

2013-01-01

Abstract Background The main purpose of this study was to determine which correlate, perceived motor competence or motor skill competence, best predicts girls? physical activity behavior. Methods A sample of 352 girls (mean age=8.7, SD=0.3 yr) participated in this study. To assess motor skill competence and perceived motor competence, each child completed the Test of Gross Motor Development-2 and Physical Ability sub-scale of Marsh?s Self-Description Questionnaire. Children?s physical activit...

The influence of motor imagery on the learning of a fine hand motor skill

NARCIS (Netherlands)

Sobierajewicz, Jagna; Przekoracka-Krawczyk, Anna; Jaśkowski, Wojciech; Verwey, Willem B.; van der Lubbe, Rob

2017-01-01

Motor imagery has been argued to affect the acquisition of motor skills. The present study examined the specificity of motor imagery on the learning of a fine hand motor skill by employing a modified discrete sequence production task: the Go/NoGo DSP task. After an informative cue, a response

Deafness and motor abilities level

Directory of Open Access Journals (Sweden)

A Zwierzchowska

2008-09-01

Full Text Available The audition injury hinders some motor motions and the organised coordination at the higher level and may be a cause of disturbances and disorder in some motor abilities adoption. It was assumed that deafness including its aetiology and injury mechanism may significantly influence the motor development of human being. The study aimed in checking if the deafness, as a result of various unfavourable factors, determines the motor development of children and youngsters. Consequently the dependency between qualitative features i.e.: signed motor level and aetiology, audition injury mechanism and the deafness degree was examined. The mechanism and aetiology of hearing correlated with the motor abilities displayed statistically significant dependencies in few motor trials only. Revealed correlations regarded mostly the coordination trials excluding the flexibility one. Statistically significant dependencies between the audition diminution and the motor abilities level were not found.

CONSTRUCCIÓN Y VALIDACIÓN DE UN SECADOR SOLAR PARA MADERA ASERRADA

Directory of Open Access Journals (Sweden)

M. Fuentes-Salinas

2003-01-01

Full Text Available Este trabajo consistió en construir y probar un secador solar para 7.075 m3 de madera aserrada, destinado a los pequeños y medianos productores forestales. Para la construcción se utilizaron materiales disponibles en cualquier región de México y para evaluar su funcionamiento se usó madera de Pinus hartwegii de 2.54 cm de espesor, 2.50 m de largo y anchos variables. La cámara está construida tipo invernadero, con un piso de concreto, estructura metálica para soportar el colector solar, muros a base de bastidores de madera y forro de plástico, y está equipado con dos ventiladores axiales con motor de ½ HP. Para la validación se hicieron dos ensayos de secado, uno en el secador solar y otro secado al aire libre, teniendo como resultado que la madera en el secador solar se secó en el 50 % del tiempo requerido para el secado al aire libre, a un contenido de humedad final del 10 y 12 % respectivamente; además, que la calidad de la madera resultó también mejor en el secador solar. El costo de construcción del secador solar fue de $ 5,227. 25 US Dls. y se estimó un tiempo de construcción de 21 días.

Tribosystems based on multilayered micro/nanocrystalline CVD diamond coatings =

Science.gov (United States)

Shabani, Mohammadmehdi

A combinacao das caracteristicas do diamante microcristalino (MCD) e nanocristalino (NCD), tais como elevada adesao do MCD e a baixa rugosidade superficial e baixo coeficiente de atrito do NCD, e ideal para aplicacoes tribologicas exigentes. Deste modo, o presente trabalho centrou-se no desenvolvimento de revestimentos em multicamada MCD/NCD. Filmes com dez camadas foram depositados em amostras de cerâmicos de Si3N4 pela tecnica de deposicao quimica em fase vapor assistida por filamento quente (HFCVD). A microestrutura, qualidade do diamante e adesao foram investigadas usando tecnicas como SEM, AFM, espectroscopia Raman, DRX, indentacao Brale e perfilometria otica 3D. Diversas geometrias para aplicacoes distintas foram revestidas: discos e esferas para testes tribologicos a escala laboratorial, e para testes em servico, aneis de empanques mecânicos e pastilhas de corte para torneamento. Nos ensaios tribologicos esfera-sobre-plano em movimento reciproco, sob 10-90% de humidade relativa (RH), os valores medios dos coeficientes de atrito maximo e em estado estacionario sao de 0,32 e 0,09, respetivamente. Em relacao aos coeficientes de desgaste, observou-se um valor minimo de cerca de 5,2x10-8 mm3N-1m-1 para valores intermedios de 20-25% de RH. A humidade relativa tem um forte efeito sobre o valor da carga critica que triplica a partir de 40 N a 10% RH para 120 N a 90% de RH. No intervalo de temperaturas 50-100 °C, as cargas criticas sao semelhantes as obtidas em condicoes de baixa RH ( 10-25%). A vida util das ferramentas com revestimento de dez camadas alternadas MCD/NCD e 24 mum de espessura total no torneamento de um composito de matriz metalica Al- 15 vol% Al2O3 (Al-MMC) e melhor do que a maioria das ferramentas de diamante CVD encontradas na literatura, e semelhante a maioria das ferramentas de diamante policristalino (PCD). A formacao de cratera ocorre por desgaste sucessivo das varias camadas, atrasando a delaminacao total do revestimento de diamante do

Motor fuel prices in Turkey

International Nuclear Information System (INIS)

Erdogdu, Erkan

2014-01-01

The world's most expensive motor fuel (gasoline, diesel and LPG) is sold most likely in the Republic of Turkey. This paper investigates the key issues related to the motor fuel prices in Turkey. First of all, the paper analyses the main reason behind high prices, namely motor fuel taxes in Turkey. Then, it estimates the elasticity of motor fuel demand in Turkey using an econometric analysis. The findings indicate that motor fuel demand in Turkey is quite inelastic and, therefore, not responsive to price increases caused by an increase in either pre-tax prices or taxes. Therefore, fuel market in Turkey is open to opportunistic behavior by firms (through excessive profits) and the government (through excessive taxes). Besides, the paper focuses on the impact of high motor fuel prices on road transport associated activities, including the pattern of passenger transportation, motorization rate, fuel use, total kilometers traveled and CO 2 emissions from road transportation. The impact of motor fuel prices on income distribution in Turkey and Turkish public opinion about high motor fuel prices are also among the subjects investigated in the course of the study. - Highlights: • The key issues (e.g. taxes) related to motor fuel prices in Turkey are explored. • Their impact on transport activities and income distribution is also investigated. • An econometric analysis is performed to estimate motor fuel demand in Turkey. • Motor fuel demand in Turkey is found to be quite inelastic. • Turkish fuel market is open to opportunistic behavior by firms and the government

Validade concorrente e confiabilidade da Alberta Infant Motor Scale em lactentes nascidos prematuros Concurrent validity and reliability of the Alberta Infant Motor Scale in premature infants

Directory of Open Access Journals (Sweden)

Kênnea Martins Almeida

2008-10-01

Full Text Available OBJETIVO: Verificar a validade concorrente e a confiabilidade interobservador da Alberta Infant Motor Scale (AIMS em lactentes prematuros acompanhados no ambulatório de seguimento do Instituto Fernandes Figueira, Fundação Oswaldo Cruz (IFF/Fiocruz. MÉTODOS: Foram avaliados 88 lactentes nascidos prematuros no ambulatório de seguimento do IFF/Fiocruz entre fevereiro e dezembro de 2006. No estudo de validade concorrente, 46 lactentes com 6 (n = 26 ou 12 (n = 20 meses de idade corrigida foram avaliados pela AIMS e pela escala motora da Bayley Scales of Infant Development, 2ª edição, por dois observadores diferentes, utilizando-se o coeficiente de correlação de Pearson para análise dos resultados. No estudo de confiabilidade, 42 lactentes entre 0 e 18 meses foram avaliados pela AIMS por dois observadores diferentes, utilizando-se o intraclass correlation coefficient (ICC para análise dos resultados. RESULTADOS: No estudo de validade concorrente, a correlação encontrada entre as duas escalas foi alta (r = 0,95 e estatisticamente significativa (p OBJECTIVE: To verify the concurrent validity and interobserver reliability of the Alberta Infant Motor Scale (AIMS in premature infants followed-up at the outpatient clinic of Instituto Fernandes Figueira, Fundação Oswaldo Cruz (IFF/Fiocruz, in Rio de Janeiro, Brazil. METHODS: A total of 88 premature infants were enrolled at the follow-up clinic at IFF/Fiocruz, between February and December of 2006. For the concurrent validity study, 46 infants were assessed at either 6 (n = 26 or 12 (n = 20 months' corrected age using the AIMS and the second edition of the Bayley Scales of Infant Development, by two different observers, and applying Pearson's correlation coefficient to analyze the results. For the reliability study, 42 infants between 0 and 18 months were assessed using the Alberta Infant Motor Scale, by two different observers and the results analyzed using the intraclass correlation

Increasing Mud Pump Motor Reliability against Malfunctions of DC Motor Excitation System

Science.gov (United States)

Nikulin, O. V.; Shabanov, V. A.

2017-10-01

The most widely used drilling machinery, such as mud pumps, draw-works, and rotors, use direct-current (DC) motors with independent excitation as the electric drive. Drilling machinery drives operate in harsh ambient conditions, including those with the presence of moisture, dust and vibration, which increases the malfunction rate of both drilling equipment and their electric drives. One of the frequently encountered malfunctions are DC motor excitation coil faults, which disrupt the normal functioning of electric drives, often leading to shutdown of the drilling process. In a four-pole DC motor, the malfunction of one coil leads to lack of excitation current in just one coil pair, while the other pair remains functional. In this case, DC motors and drilling equipment can remain operational, which would allow for continuing the drilling process. This paper considers the possibility of operation of a DC motor on a drilling rig in those cases when one pair of excitation coils is non-functional, and describes the device for switching between the excitation coils and the auxiliary winding in a DC motor with independent excitation.

Changes of motor-cortical oscillations associated with motor learning.

Science.gov (United States)

Pollok, B; Latz, D; Krause, V; Butz, M; Schnitzler, A

2014-09-05

Motor learning results from practice but also between practice sessions. After skill acquisition early consolidation results in less interference with other motor tasks and even improved performance of the newly learned skill. A specific significance of the primary motor cortex (M1) for early consolidation has been suggested. Since synchronized oscillatory activity is assumed to facilitate neuronal plasticity, we here investigate alterations of motor-cortical oscillations by means of event-related desynchronization (ERD) at alpha (8-12 Hz) and beta (13-30 Hz) frequencies in healthy humans. Neuromagnetic activity was recorded using a 306-channel whole-head magnetoencephalography (MEG) system. ERD was investigated in 15 subjects during training on a serial reaction time task and 10 min after initial training. The data were compared with performance during a randomly varying sequence serving as control condition. The data reveal a stepwise decline of alpha-band ERD associated with faster reaction times replicating previous findings. The amount of beta-band suppression was significantly correlated with reduction of reaction times. While changes of alpha power have been related to lower cognitive control after initial skill acquisition, the present data suggest that the amount of beta suppression represents a neurophysiological marker of early cortical reorganization associated with motor learning. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Parkinson Disease: The Relationship Between Non-motor Symptoms and Motor Phenotype.

Science.gov (United States)

Ba, Fang; Obaid, Mona; Wieler, Marguerite; Camicioli, Richard; Martin, W R Wayne

2016-03-01

Parkinson disease (PD) presents with motor and non-motor symptoms (NMS). The NMS often precede the onset of motor symptoms, but may progress throughout the disease course. Tremor dominant, postural instability gait difficulty (PIGD), and indeterminate phenotypes can be distinguished using Unified PD Rating scales (UPDRS-III). We hypothesized that the PIGD phenotype would be more likely to develop NMS, and that the non-dopamine-responsive axial signs would correlate with NMS severity. We conducted a retrospective cross-sectional chart review to assess the relationship between NMS and PD motor phenotypes. PD patients were administered the NMS Questionnaire, the UPDRS-III, and the Mini-Mental State Examination score. The relationship between NMS burden and PD subtypes was examined using linear regression models. The prevalence of each NMS among difference PD motor subtypes was analyzed using chi-square test. PD patients with more advanced disease based on their UPDRS-III had higher NMS Questionnaire scores. The axial component of UPDRS-III correlated with higher NMS. There was no correlation between NMS and tremor scores. There was a significant correlation between PIGD score and higher NMS burden. PIGD group had higher prevalence in most NMS domains when compared with tremor dominant and indeterminate groups independent of disease duration and severity. NMS profile and severity vary according to motor phenotype. We conclude that in the PD population, patients with a PIGD phenotype who have more axial involvement, associated with advanced disease and poor motor response, have a higher risk for a higher NMS burden.

System programs design of motors; Sistema de programas de diseno de motores

Energy Technology Data Exchange (ETDEWEB)

Diaz Gonzalez Palomas, Oscar; Ciprian Avila, Fernando [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1988-12-31

This paper describes the objective of creating the program system for induction motors design SIPRODIMO, its scope, its general characteristics, its structure and the results obtained with its application, as well as the service capacity developed by the Motors Area of the Instituto de Investigaciones Elctricas. [Espanol] En este articulo se describe el objetivo de crear el sistema de programas de diseno de motores de induccion, Siprodimo, su alcance, sus caracteristicas generales, su estructura y los resultados obtenidos con su aplicacion, asi como la capacidad de servicio desarrollada por el area de motores, del Instituto de Investigaciones Electricas.

ANÁLISIS DE SENSIBILIDAD POR SIMULACIÓN DEL PROCESO DE DESHIDRATACIÓN DE UNA PLANTA DE ACONDICIONAMIENTO DE GAS NATURAL

Directory of Open Access Journals (Sweden)

Eleonora Erdmann

2012-01-01

Full Text Available Este trabajo describe el desarrollo de un simulador estacionario para los sectores de deshidratación y estabilización de una planta de tratamiento de gas natural. El simulador fue implementado empleando el simulador comercial ASPEN HYSYS®. El gas considerado en la simulación es un gas típico proveniente de yacimientos de la provincia de Salta (Argentina. La configuración de la planta y las condiciones de operación adoptadas para la simulación son las generalmente empleadas en el tratamiento de gas natural en Salta. Con el simulador desarrollado, se llevó a cabo un estudio de sensibilidad paramétrica de las principales variables operativas del proceso. La simulación realizada permite visualizar el proceso de deshidratación, y realizar un análisis de su comportamiento en función de las variables operativas críticas: concentración de la solución de TEG (70% p – 99% p y temperatura del rehervidor (200 – 375 oF.

50 CFR 35.5 - Commercial enterprises, roads, motor vehicles, motorized equipment, motorboats, aircraft...

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Commercial enterprises, roads, motor... Rules § 35.5 Commercial enterprises, roads, motor vehicles, motorized equipment, motorboats, aircraft... private rights, there shall be no commercial enterprise and no permanent road within a wilderness unit...

Parâmetros motores e envelhecimento: um estudo de idosos de 60 a 83 anos de Ivoti, RS = Motor parameters and ageing: a study of elderly aged from 60 to 83 years from Ivoti, RS

Directory of Open Access Journals (Sweden)

Piccoli, João Carlos Jaccottet

2009-01-01

Full Text Available O objetivo deste estudo foi traçar o perfil motor de idosos de 60 a 83 anos, residentes na cidade de Ivoti, RS, estratificados por gêneros e faixa etária (60 a 70 e acima de 70. Na investigação, de tipo descritivo, participaram 202 idosos, 140 do gênero feminino e 62 do masculino, selecionados por conveniência, submetidos à Escala Motora para a Terceira Idade de Rosa Neto (2002, que avaliou as seguintes variáveis: Motricidade Fina, Coordenação Global, Equilíbrio, Esquema Corporal e Rapidez, Organização Espacial e Organização Temporal. A análise estatística foi através do teste “t” de Student a partir do programa SPSS, versão 16. 0 para Windows. Os idosos do gênero masculino entre 60 e 70 anos, classificaram-se, predominantemente, entre os níveis motores “normal baixo” e “alto” e os de maior idade, entre “normal médio” a “muito inferior”. Já as mulheres de ambos os grupos etários se classificaram num nível motor que variou de “normal médio” a “muito inferior”. Comparando-se os resultados médios dos idosos nos testes, entre as faixas etárias, observaram-se resultados superiores no grupo de 60 a 70 anos, quando comparados aos de maior idade (p D 0,05. Concluiu-se que os homens apresentaram resultados superiores aos das mulheres em todos os testes, com exceção do equilíbrio e organização temporal, nos idosos acima de 70 anos

Estudio de uniones en un circuito de engrase de un motor biturbo

OpenAIRE

Clemente, Pasqua

2005-01-01

Un circuito de engrase interviene en un motor biturbo para realizar la conexión entre el cárter y los turbos permitiendo el engrase de éstos mediante la llegada de aceite. Un circuito de engrase está constituido básicamente por dos circuitos: un circuito de alimentación, que permite la llegada de aceite a los turbos, y un circuito de retorno que permite al aceite volver por gravedad al cárter. Los tubos de los dos circuitos, de calidad AISI 304, están conectados a los turbos por medio de d...

Control of non-conventional synchronous motors

CERN Document Server

Louis, Jean-Paul

2013-01-01

Classical synchronous motors are the most effective device to drive industrial production systems and robots with precision and rapidity. However, numerous applications require efficient controls in non-conventional situations. Firstly, this is the case with synchronous motors supplied by thyristor line-commutated inverters, or with synchronous motors with faults on one or several phases. Secondly, many drive systems use non-conventional motors such as polyphase (more than three phases) synchronous motors, synchronous motors with double excitation, permanent magnet linear synchronous motors,

The correlation between motor impairments and event-related desynchronization during motor imagery in ALS patients

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Kasahara Takashi

2012-06-01

Full Text Available Abstract Background The event-related desynchronization (ERD in EEG is known to appear during motor imagery, and is thought to reflect cortical processing for motor preparation. The aim of this study is to examine the modulation of ERD with motor impairment in ALS patients. ERD during hand motor imagery was obtained from 8 ALS patients with a variety of motor impairments. ERD was also obtained from age-matched 11 healthy control subjects with the same motor task. The magnitude and frequency of ERD were compared between groups for characterization of ALS specific changes. Results The ERD of ALS patients were significantly smaller than those of control subjects. Bulbar function and ERD were negatively correlated in ALS patients. Motor function of the upper extremities did was uncorrelated with ERD. Conclusions ALS patients with worsened bulbar scales may show smaller ERD. Motor function of the upper extremities did was uncorrelated with ERD.

Spinal Accessory Motor Neurons in the Mouse: A Special Type of Branchial Motor Neuron?

Science.gov (United States)

Watson, Charles; Tvrdik, Petr

2018-04-16

The spinal accessory nerve arises from motor neurons in the upper cervical spinal cord. The axons of these motor neurons exit dorsal to the ligamentum denticulatum and form the spinal accessory nerve. The nerve ascends in the spinal subarachnoid space to enter the posterior cranial fossa through the foramen magnum. The spinal accessory nerve then turns caudally to exit through the jugular foramen alongside the vagus and glossopharyngeal nerves, and then travels to supply the sternomastoid and trapezius muscles in the neck. The unusual course of the spinal accessory nerve has long prompted speculation that it is not a typical spinal motor nerve and that it might represent a caudal remnant of the branchial motor system. Our cell lineage tracing data, combined with images from public databases, show that the spinal accessory motor neurons in the mouse transiently express Phox2b, a transcription factor that is required for development of brain stem branchial motor nuclei. While this is strong prima facie evidence that the spinal accessory motor neurons should be classified as branchial motor, the evolutionary history of these motor neurons in anamniote vertebrates suggests that they may be considered to be an atypical branchial group that possesses both branchial and somatic characteristics. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Diseño de un equipo de pruebas rápidas para aceites usados

Directory of Open Access Journals (Sweden)

Juan Carlos Delgado Sanabria

2016-01-01

Full Text Available El presente trabajo tiene como objetivo presentar el proceso de diseño y la construcción de un equipo de pruebas rápidas para el análisis de aceites usados de motores. El equipo que permite evaluar el estado de degradación y contaminación de una muestra de aceite usado mediante los ensayos de crepitación, mancha de aceite, viscosidad y contenido de partículas consta de cuatro aparatos: placa de calentamiento, generador de manchas, viscosímetro de caída de bolas y detector de partículas ferrosas. El aporte fundamental del trabajo lo constituyen los dispositivos y métodos ideados tanto para medir con exactitud el tiempo de caída de la esfera del viscosímetro de bolas como para la detección de partículas ferromagnéticas. El equipo ha producido resultados satisfactorios comparados con los obtenidos en pruebas de laboratorio.

3D visualization of movements can amplify motor cortex activation during subsequent motor imagery

Directory of Open Access Journals (Sweden)

Teresa eSollfrank

2015-08-01

Full Text Available A repetitive movement practice by motor imagery (MI can influence motor cortical excitability in the electroencephalogram (EEG. The feedback and the feedback environment should be inherently motivating and relevant for the learner and should have an appeal of novelty, real-world relevance or aesthetic value (Ryan and Deci, 2000; Merrill, 2007. This study investigated if a realistic visualization in 3D of upper and lower limb movements can amplify motor related potentials during motor imagery. We hypothesized that a richer sensory visualization might be more effective during instrumental conditioning, resulting in a more pronounced event related desynchronisation (ERD of the upper alpha band (10-12 Hz over the sensorimotor cortices thereby potentially improving MI based BCI protocols for motor rehabilitation. The results show a strong increase of the characteristic patterns of ERD of the upper alpha band components for left and right limb motor imagery present over the sensorimotor areas in both visualization conditions. Overall, significant differences were observed as a function of visualization modality (2D vs. 3D. The largest upper alpha band power decrease was obtained during motor imagery after a 3-dimensional visualization. In total in 12 out of 20 tasks the end-user of the 3D visualization group showed an enhanced upper alpha ERD relative to 2D visualization modality group, with statistical significance in nine tasks.With a realistic visualization of the limb movements, we tried to increase motor cortex activation during MI. Realistic visual feedback, consistent with the participant’s motor imagery, might be helpful for accomplishing successful motor imagery and the use of such feedback may assist in making BCI a more natural interface for motor imagery based BCI rehabilitation.

Hybrid vehicle motor alignment

Science.gov (United States)

Levin, Michael Benjamin

2001-07-03

A rotor of an electric motor for a motor vehicle is aligned to an axis of rotation for a crankshaft of an internal combustion engine having an internal combustion engine and an electric motor. A locator is provided on the crankshaft, a piloting tool is located radially by the first locator to the crankshaft. A stator of the electric motor is aligned to a second locator provided on the piloting tool. The stator is secured to the engine block. The rotor is aligned to the crankshaft and secured thereto.

Para-Hermitian and para-quaternionic manifolds

International Nuclear Information System (INIS)

Ivanov, S.; Zamkovoy, S.

2003-10-01

A set of canonical para-Hermitian connections on an almost para-Hermitian manifold is defined. A Para-hermitian version of the Apostolov-Gauduchon generalization of the Goldberg-Sachs theorem in General Relativity is given. It is proved that the Nijenhuis tensor of a Nearly para-Kaehler manifolds is parallel with respect to the canonical connection. Salamon's twistor construction on quaternionic manifold is adapted to the para-quaternionic case. A locally conformally hyper-para-Kaehler (hypersymplectic) flat structure with parallel Lee form on the Kodaira-Thurston complex surfaces modeled on S 1 x SL (2, R)-tilde is constructed. Anti-self-dual locally conformally hyper-para-Kaehler (hypersymplectic) neutral metrics with non vanishing Weyl tensor are obtained on the Inoe surfaces. An example of anti-self-dual neutral metric which is not locally conformally hyper-para-Kaehler (hypersymplectic) is constructed. (author)

Para-Hermitian and para-quaternionic manifolds

Energy Technology Data Exchange (ETDEWEB)

Ivanov, S [University of Sofia ' St. Kl. Ohridski' , Faculty of Mathematics and Informatics, Sofia (Bulgaria) and Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Zamkovoy, S [University of Sofia ' St. Kl. Ohridski' , Faculty of Mathematics and Informatics, Sofia (Bulgaria)

2003-10-01

A set of canonical para-Hermitian connections on an almost para-Hermitian manifold is defined. A Para-hermitian version of the Apostolov-Gauduchon generalization of the Goldberg-Sachs theorem in General Relativity is given. It is proved that the Nijenhuis tensor of a Nearly para-Kaehler manifolds is parallel with respect to the canonical connection. Salamon's twistor construction on quaternionic manifold is adapted to the para-quaternionic case. A locally conformally hyper-para-Kaehler (hypersymplectic) flat structure with parallel Lee form on the Kodaira-Thurston complex surfaces modeled on S{sup 1} x SL (2, R)-tilde is constructed. Anti-self-dual locally conformally hyper-para-Kaehler (hypersymplectic) neutral metrics with non vanishing Weyl tensor are obtained on the Inoe surfaces. An example of anti-self-dual neutral metric which is not locally conformally hyper-para-Kaehler (hypersymplectic) is constructed. (author)

Motor imagery beyond the motor repertoire: Activity in the primary visual cortex during kinesthetic motor imagery of difficult whole body movements.

Science.gov (United States)

Mizuguchi, N; Nakata, H; Kanosue, K

2016-02-19

To elucidate the neural substrate associated with capabilities for kinesthetic motor imagery of difficult whole-body movements, we measured brain activity during a trial involving both kinesthetic motor imagery and action observation as well as during a trial with action observation alone. Brain activity was assessed with functional magnetic resonance imaging (fMRI). Nineteen participants imagined three types of whole-body movements with the horizontal bar: the giant swing, kip, and chin-up during action observation. No participant had previously tried to perform the giant swing. The vividness of kinesthetic motor imagery as assessed by questionnaire was highest for the chin-up, less for the kip and lowest for the giant swing. Activity in the primary visual cortex (V1) during kinesthetic motor imagery with action observation minus that during action observation alone was significantly greater in the giant swing condition than in the chin-up condition within participants. Across participants, V1 activity of kinesthetic motor imagery of the kip during action observation minus that during action observation alone was negatively correlated with vividness of the kip imagery. These results suggest that activity in V1 is dependent upon the capability of kinesthetic motor imagery for difficult whole-body movements. Since V1 activity is likely related to the creation of a visual image, we speculate that visual motor imagery is recruited unintentionally for the less vivid kinesthetic motor imagery of difficult whole-body movements. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

A existência de alterações neurofisiológicas pode auxiliar na compreensão do papel da hipotonia no desenvolvimento motor dos indivíduos com síndrome de Down? Existence of neurophysiologic changes can assist in understanding the role of hypotonia in motor development of subjects with Down syndrome?

Directory of Open Access Journals (Sweden)

João Carlos Ferrari Corrêa

2011-12-01

Full Text Available A proposta deste estudo foi analisar e verificar a existência de alterações neurofisiológicas nos indivíduos com síndrome de Down, como a hiporreflexia, estática e dinâmica, que, se presente, pode ocasionar prejuízo no controle sensório-motor dos músculos, e consequentemente a hipotonia, contribuindo para alterações no desenvolvimento motor. O sinal eletromiográfico (EMG, início e término do sinal eletromiográfico, foi coletado de 24 voluntários com diagnóstico de síndrome de Down e 25 voluntários como grupo controle, durante 2 situações distintas: período de latência dinâmico e teste de reflexo monossináptico (estático patelar e aquileu. Em relação aos aspectos neurofisiológicos, observou-se que, para todas as variáveis analisadas, houve diferença estatisticamente significante (pThe purpose of this study was to analyze and verify the existence of neurophysiological changes in individuals with Down syndrome, such as hyporeflexia, static and dynamic, which, if present, may cause impairment in sensory-motor control of muscles, and consequently hypotonia, contributing to changes in motor development. The electromyographic signal (EMG, start and termination electromyographic signal, was collected from 24 volunteers with a diagnosis of Down syndrome and 25 volunteers as controls for 2 different situations: the dynamic latency period and monosynaptic reflex (static patellar and Achilles. For neurophysiological aspects, it was observed that for all variables analyzed, statistical difference (p<0.05 between groups. The existence of neurophysiological changes (delay of the latency period demonstrated in this study originated from an impairment in sensory-motor control, which may account for the decreased muscle tone, presents as one of several possible factors for the changes in motor development of children, which shows important due to neuromuscular disorders that can interfere in functional activities.

Enhanced Multisensory Integration and Motor Reactivation after Active Motor Learning of Audiovisual Associations

Science.gov (United States)

Butler, Andrew J.; James, Thomas W.; James, Karin Harman

2011-01-01

Everyday experience affords us many opportunities to learn about objects through multiple senses using physical interaction. Previous work has shown that active motor learning of unisensory items enhances memory and leads to the involvement of motor systems during subsequent perception. However, the impact of active motor learning on subsequent…

Retos Logísticos En Ssangyong Motor Colombia S.A.1

OpenAIRE

Carlos Enrique Ramírez R

2008-01-01

La revaluación del peso frente al dólar y el importante crecimiento que tuvo la economía colombiana en los años 2005 y 2006, dispararon las ventas de vehículos en Colombia. Para poder aprovechar ese importante aumento de la demanda, SsangYong Motor Colombia S.A., empresa especializada en la importación y comercialización de vehículos diésel de última generación, se enfrentó a grandes retos logísticos, que se presentaron porque a mediados del año 2007 se elevaron los precios de los fletes marí...

Plataforma smartphone para biossensores de espectroscopia de infravermelho próximo

OpenAIRE

Queirós, André Ricardo Cabral

2014-01-01

O tema “Plataforma smartphone para biossensores de Espectroscopia de Infravermelho Próximo”, surge no âmbito da instrumentação médica, na área das BCI – Brain Computer Interfaces, devido à necessidade de encontrar um dispositivo portátil, de custo acessível e elevada performance que permita obter informação acerca da actividade neuronal do córtex motor no decorrer duma determinada tarefa. O objectivo do trabalho consiste no desenvolvimento duma sonda capaz de detectar as alterações hemodin...

Electric Motor Thermal Management

Energy Technology Data Exchange (ETDEWEB)

Bennion, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-09-01

Thermal management enables more efficient and cost-effective motors. This Annual Merit Review presentation describes the technical accomplishments and progress in electric motor thermal management R&D over the last year. This project supports a broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management.

Motor areas of the frontal cortex in patients with motor eloquent brain lesions.

Science.gov (United States)

Bulubas, Lucia; Sabih, Jamil; Wohlschlaeger, Afra; Sollmann, Nico; Hauck, Theresa; Ille, Sebastian; Ringel, Florian; Meyer, Bernhard; Krieg, Sandro M

2016-12-01

OBJECTIVE Because of its huge clinical potential, the importance of premotor areas for motor function itself and plastic reshaping due to tumors or ischemic brain lesions has received increased attention. Thus, in this study the authors used navigated transcranial magnetic stimulation (nTMS) to investigate whether tumorous brain lesions induce a change in motor cortex localization in the human brain. METHODS Between 2010 and 2013, nTMS motor mapping was performed in a prospective cohort of 100 patients with brain tumors in or adjacent to the rolandic cortex. Spatial data analysis was performed by normalization of the individual motor maps and creation of overlays according to tumor location. Analysis of motor evoked potential (MEP) latencies was performed regarding mean overall latencies and potentially polysynaptic latencies, defined as latencies longer than 1 SD above the mean value. Hemispheric dominance, lesion location, and motor-function deficits were also considered. RESULTS Graphical analysis showed that motor areas were not restricted to the precentral gyrus. Instead, they spread widely in the anterior-posterior direction. An analysis of MEP latency showed that mean MEP latencies were shortest in the precentral gyrus and longest in the superior and middle frontal gyri. The percentage of latencies longer than 1 SD differed widely across gyri. The dominant hemisphere showed a greater number of longer latencies than the nondominant hemisphere (p < 0.0001). Moreover, tumor location-dependent changes in distribution of polysynaptic latencies were observed (p = 0.0002). Motor-function deficit did not show any statistically significant effect. CONCLUSIONS The distribution of primary and polysynaptic motor areas changes in patients with brain tumors and highly depends on tumor location. Thus, these data should be considered for resection planning.

Skeletal maturation, fundamental motor skills and motor performance in preschool children.

Science.gov (United States)

Freitas, D L; Lausen, B; Maia, J A; Gouveia, É R; Antunes, A M; Thomis, M; Lefevre, J; Malina, R M

2018-06-01

Relationships among skeletal age (SA), body size and fundamental motor skills (FMS) and motor performance were considered in 155 boys and 159 girls 3-6 years of age. Stature and body mass were measured. SA of the hand-wrist was assessed with the Tanner-Whitehouse II 20 bone method. The Test of Gross Motor Development, 2 nd edition (TGMD-2) and the Preschool Test Battery were used, respectively, to assess FMS and motor performance. Based on hierarchical regression analyses, the standardized residuals of SA on chronological age (SAsr) explained a maximum of 6.1% of the variance in FMS and motor performance in boys (ΔR 2 3 , range 0.0% to 6.1%) and a maximum of 20.4% of the variance in girls (ΔR 2 3 , range 0.0% to 20.4%) over that explained by body size and interactions of SAsr with body size (step 3). The interactions of the SAsr and stature and body mass (step 2) explained a maximum of 28.3% of the variance in boys (ΔR 2 2 , range 0.5% to 28.3%) and 16.7% of the variance in girls (ΔR 2 2 , range 0.7% to 16.7%) over that explained by body size alone. With the exception of balance, relationships among SAsr and FMS or motor performance differed between boys and girls. Overall, SA per se or interacting with body size had a relatively small influence in FMS and motor performance in children 3-6 years of age. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

76 FR 10396 - New United Motor Manufacturing, Inc., Formerly a Joint Venture of General Motors Corporation and...

Science.gov (United States)

2011-02-24

... Manufacturing, Inc., Formerly a Joint Venture of General Motors Corporation and Toyota Motor Corporation, Including On- Site Leased Workers From Corestaff, ABM Janitorial, Toyota Engineering and Manufacturing North... Motor Manufacturing, Inc., formerly a joint venture of General Motors Corporation and Toyota Motor...

Increased motor cortex excitability during motor imagery in brain-computer interface trained subjects

Science.gov (United States)

Mokienko, Olesya A.; Chervyakov, Alexander V.; Kulikova, Sofia N.; Bobrov, Pavel D.; Chernikova, Liudmila A.; Frolov, Alexander A.; Piradov, Mikhail A.

2013-01-01

Background: Motor imagery (MI) is the mental performance of movement without muscle activity. It is generally accepted that MI and motor performance have similar physiological mechanisms. Purpose: To investigate the activity and excitability of cortical motor areas during MI in subjects who were previously trained with an MI-based brain-computer interface (BCI). Subjects and Methods: Eleven healthy volunteers without neurological impairments (mean age, 36 years; range: 24–68 years) were either trained with an MI-based BCI (BCI-trained, n = 5) or received no BCI training (n = 6, controls). Subjects imagined grasping in a blocked paradigm task with alternating rest and task periods. For evaluating the activity and excitability of cortical motor areas we used functional MRI and navigated transcranial magnetic stimulation (nTMS). Results: fMRI revealed activation in Brodmann areas 3 and 6, the cerebellum, and the thalamus during MI in all subjects. The primary motor cortex was activated only in BCI-trained subjects. The associative zones of activation were larger in non-trained subjects. During MI, motor evoked potentials recorded from two of the three targeted muscles were significantly higher only in BCI-trained subjects. The motor threshold decreased (median = 17%) during MI, which was also observed only in BCI-trained subjects. Conclusion: Previous BCI training increased motor cortex excitability during MI. These data may help to improve BCI applications, including rehabilitation of patients with cerebral palsy. PMID:24319425

Increased motor cortex excitability during motor imagery in brain-computer interface trained subjects

Directory of Open Access Journals (Sweden)

Olesya eMokienko

2013-11-01

Full Text Available Background: Motor imagery (MI is the mental performance of movement without muscle activity. It is generally accepted that MI and motor performance have similar physiological mechanisms.Purpose: To investigate the activity and excitability of cortical motor areas during MI in subjects who were previously trained with an MI-based brain-computer interface (BCI.Subjects and methods: Eleven healthy volunteers without neurological impairments (mean age, 36 years; range: 24–68 years were either trained with an MI-based BCI (BCI-trained, n = 5 or received no BCI training (n = 6, controls. Subjects imagined grasping in a blocked paradigm task with alternating rest and task periods. For evaluating the activity and excitability of cortical motor areas we used functional MRI and navigated transcranial magnetic stimulation (nTMS.Results: fMRI revealed activation in Brodmann areas 3 and 6, the cerebellum, and the thalamus during MI in all subjects. The primary motor cortex was activated only in BCI-trained subjects. The associative zones of activation were larger in non-trained subjects. During MI, motor evoked potentials recorded from two of the three targeted muscles were significantly higher only in BCI-trained subjects. The motor threshold decreased (median = 17% during MI, which was also observed only in BCI-trained subjects.Conclusion: Previous BCI training increased motor cortex excitability during MI. These data may help to improve BCI applications, including rehabilitation of patients with cerebral palsy.

Modelo de web semántica para universidades

Directory of Open Access Journals (Sweden)

Karla Abad

2015-12-01

Full Text Available A raíz del estudio de estado actual de micrositios y repositorios en la Universidad Estatal Península de Santa Elena se encontró que su información carecía de semántica óptima y adecuada. Bajo estas circunstancias, se plantea entonces la necesidad de crear un modelo de estructura de web semántica para Universidades, el cual posteriormente fue aplicado a micrositios y repositorio digital de la UPSE, como caso de prueba. Parte de este proyecto incluye la instalación de módulos de software con sus respectivas configuraciones y la utilización de estándares de metadatos como DUBLIN CORE, para la mejora del SEO (optimización en motores de búsqueda; con ello se ha logrado la generación de metadatos estandarizados y la creación de políticas para la subida de información. El uso de metadatos transforma datos simples en estructuras bien organizadas que aportan información y conocimiento para generar resultados en buscadores web. Al culminar la implementación del modelo de web semántica es posible decir que la universidad ha mejorado su presencia y visibilidad en la web a través del indexamiento de información en diferentes motores de búsqueda y posicionamiento en la categorización de universidades y de repositorios de Webometrics (ranking que proporciona clasificación de universidades de todo el mundo.   Abstract After examining the current microsites and repositories situation in University, Peninsula of Santa Elena´s, it was found that information lacked optimal and appropriate semantic. Under these circumstances, there is a need to create a semantic web structure model for Universities, which was subsequently applied to UPSE´s microsites and digital repositories, as a test study case. Part of this project includes the installation of software modules with their respective configurations and the use of metadata standards such as DUBLIN CORE, to improve the SEO (Search Engine Optimization; with these applications, it was

Synchronous motor with soft start element formed between the motor rotor and motor output shaft to successfully synchronize loads that have high inertia and/or high torque

Science.gov (United States)

Umans, Stephen D; Nisley, Donald L; Melfi, Michael J

2014-10-28

A line-start synchronous motor has a housing, a rotor shaft, and an output shaft. A soft-start coupling portion is operatively coupled to the output shaft and the rotor shaft. The soft-start coupling portion is configurable to enable the synchronous motor to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling. The synchronous motor is sufficiently rated to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling.

Desarrollo de una aplicación para gráficos de control de calidad de procesos industriales

OpenAIRE

Flores Sánchez, Miguel Alfonso

2013-01-01

El presente trabajo tiene por objeto crear una aplicación para el control estadístico de la calidad basado en un entorno gráfico cuyo motor de cálculo sea el lenguaje R. Se implementan los gráficos de control de calidad más utilizados en este campo mediante una aplicación específica sobre la base del desarrollo de una librería que utiliza algunas librerías estándar para el control de calidad que se encuentran en R. El nombre de la librería es qcr que corresponde a las siglas Quality Control a...

Efectos del acortamiento de paso en un motor trifásico de inducción con estator plástico

OpenAIRE

Díaz Yépez, John Paúl

2014-01-01

El documento consiste en el diseño, cálculo y construcción de la reducción de paso en el bobinado de un motor trifásico de inducción con estator plástico y una sola espira que sirve como filtro pasivo para la reducción de armónicos, se realizan mediciones de la corriente y la tensión aguas arriba y aguas abajo para mediante programación en el Matlab calcular la distorsión armónica total (THD). The document consists of the design, construction of the calculation and reduction in the winding...

Um estudo sobre Google: questões para uma leitura micropolítica das tecnologias da informação

Directory of Open Access Journals (Sweden)

Cecilia Diaz-Isenrath

2006-10-01

Full Text Available Este artigo descreve um motor de busca, não como ferramenta informacional, mas como dispositivo socio-técnico. Para mapear o meio no qual esse dispositivo toma forma, analisamos um artigo científico sobre o Google e a patente onde o método conhecido como “PageRank

Programmable dc motor controller

Science.gov (United States)

Hopwood, J. E.

1982-11-01

A portable programmable dc motor controller, with features not available on commercial instruments was developed for controlling fixtures during welding processes. The controller can be used to drive any dc motor having tachometer feedback and motor requirements not exceeding 30 volts, 3 amperes. Among the controller's features are delayed start time, upslope time, speed, and downslope time.

75 FR 26794 - New United Motor Manufacturing, Inc., Formerly a Joint Venture of General Motors Corporation and...

Science.gov (United States)

2010-05-12

... Manufacturing, Inc., Formerly a Joint Venture of General Motors Corporation and Toyota Motor Corporation... United Motor Manufacturing, Inc., formerly a joint venture of General Motors Corporation and Toyota Motor... reviewed the certification for workers of the subject firm. The workers assemble the Toyota Corolla and the...

La Gestión del conocimiento en y para la Universidad

Directory of Open Access Journals (Sweden)

Roberto Ismael Vega

2009-06-01

Full Text Available http://dx.doi.org/10.5007/1983-4535.2009v2n1p48   El presente trabajo parte de la hipótesis que la Universidad Latinoamericana ha avanzado en el desarrollo y la aplicación de los conocimientos científicos de los últimos dos siglos, incorporándolos a las diferentes currículas de las carreras que ofrece. Esto es particularmente válido para las disciplinas que sirven a la gestión de las organizaciones, entendiendo por tal desde la fijación de políticas hasta la administración de los medios para implementarlas. No obstante no se verifica que este conocimiento haya sido aplicado en su propia gestión, que sigue moviéndose con gran improvisación y donde no parece que el conocimiento tenga un lugar destacado. Esta carencia conlleva, en una época de grandes mutaciones, a la imposibilidad de contar con estructuras flexibles y cuerpos de gestores calificados que permitan que la Universidad se mantenga acorde a estos cambios y constituya un motor para el desarrollo de nuestras sociedades.

Motor-sensory confluence in tactile perception.

Science.gov (United States)

Saig, Avraham; Gordon, Goren; Assa, Eldad; Arieli, Amos; Ahissar, Ehud

2012-10-03

Perception involves motor control of sensory organs. However, the dynamics underlying emergence of perception from motor-sensory interactions are not yet known. Two extreme possibilities are as follows: (1) motor and sensory signals interact within an open-loop scheme in which motor signals determine sensory sampling but are not affected by sensory processing and (2) motor and sensory signals are affected by each other within a closed-loop scheme. We studied the scheme of motor-sensory interactions in humans using a novel object localization task that enabled monitoring the relevant overt motor and sensory variables. We found that motor variables were dynamically controlled within each perceptual trial, such that they gradually converged to steady values. Training on this task resulted in improvement in perceptual acuity, which was achieved solely by changes in motor variables, without any change in the acuity of sensory readout. The within-trial dynamics is captured by a hierarchical closed-loop model in which lower loops actively maintain constant sensory coding, and higher loops maintain constant sensory update flow. These findings demonstrate interchangeability of motor and sensory variables in perception, motor convergence during perception, and a consistent hierarchical closed-loop perceptual model.

How thoughts give rise to action - conscious motor intention increases the excitability of target-specific motor circuits.

Directory of Open Access Journals (Sweden)

Volker R Zschorlich

Full Text Available The present study shows evidence for conscious motor intention in motor preparation prior to movement execution. We demonstrate that conscious motor intention of directed movement, combined with minimally supra-threshold transcranial magnetic stimulation (TMS of the motor cortex, determines the direction and the force of resulting movements, whilst a lack of intention results in weak and omni-directed muscle activation. We investigated changes of consciously intended goal directed movements by analyzing amplitudes of motor-evoked potentials of the forearm muscle, flexor carpi radialis (FCR, and extensor carpi radialis (ECR, induced by transcranial magnetic stimulation over the right motor cortex and their motor outcome. Right-handed subjects were asked to develop a strong intention to move their left wrist (flexion or extension, without any overt motor output at the wrist, prior to brain stimulation. Our analyses of hand acceleration and electromyography showed that during the strong motor intention of wrist flexion movement, it evoked motor potential responses that were significantly larger in the FCR muscle than in the ECR, whilst the opposite was true for an extension movement. The acceleration data on flexion/extension corresponded to this finding. Under no-intention conditions again, which served as a reference for motor evoked potentials, brain stimulation resulted in undirected and minimally simultaneous extension/flexion innervation and virtually no movement. These results indicate that conscious intentions govern motor function, which in turn shows that a neuronal activation representing an "intention network" in the human brain pre-exists, and that it functionally represents target specific motor circuits. Until today, it was unclear whether conscious motor intention exists prior to movement, or whether the brain constructs such an intention after movement initiation. Our study gives evidence that motor intentions become aware before

How Thoughts Give Rise to Action - Conscious Motor Intention Increases the Excitability of Target-Specific Motor Circuits

Science.gov (United States)

Zschorlich, Volker R.; Köhling, Rüdiger

2013-01-01

The present study shows evidence for conscious motor intention in motor preparation prior to movement execution. We demonstrate that conscious motor intention of directed movement, combined with minimally supra-threshold transcranial magnetic stimulation (TMS) of the motor cortex, determines the direction and the force of resulting movements, whilst a lack of intention results in weak and omni-directed muscle activation. We investigated changes of consciously intended goal directed movements by analyzing amplitudes of motor-evoked potentials of the forearm muscle, flexor carpi radialis (FCR), and extensor carpi radialis (ECR), induced by transcranial magnetic stimulation over the right motor cortex and their motor outcome. Right-handed subjects were asked to develop a strong intention to move their left wrist (flexion or extension), without any overt motor output at the wrist, prior to brain stimulation. Our analyses of hand acceleration and electromyography showed that during the strong motor intention of wrist flexion movement, it evoked motor potential responses that were significantly larger in the FCR muscle than in the ECR, whilst the opposite was true for an extension movement. The acceleration data on flexion/extension corresponded to this finding. Under no-intention conditions again, which served as a reference for motor evoked potentials, brain stimulation resulted in undirected and minimally simultaneous extension/flexion innervation and virtually no movement. These results indicate that conscious intentions govern motor function, which in turn shows that a neuronal activation representing an “intention network” in the human brain pre-exists, and that it functionally represents target specific motor circuits. Until today, it was unclear whether conscious motor intention exists prior to movement, or whether the brain constructs such an intention after movement initiation. Our study gives evidence that motor intentions become aware before any motor

Functional connectivity between somatosensory and motor brain areas predicts individual differences in motor learning by observing.

Science.gov (United States)

McGregor, Heather R; Gribble, Paul L

2017-08-01

Action observation can facilitate the acquisition of novel motor skills; however, there is considerable individual variability in the extent to which observation promotes motor learning. Here we tested the hypothesis that individual differences in brain function or structure can predict subsequent observation-related gains in motor learning. Subjects underwent an anatomical MRI scan and resting-state fMRI scans to assess preobservation gray matter volume and preobservation resting-state functional connectivity (FC), respectively. On the following day, subjects observed a video of a tutor adapting her reaches to a novel force field. After observation, subjects performed reaches in a force field as a behavioral assessment of gains in motor learning resulting from observation. We found that individual differences in resting-state FC, but not gray matter volume, predicted postobservation gains in motor learning. Preobservation resting-state FC between left primary somatosensory cortex and bilateral dorsal premotor cortex, primary motor cortex, and primary somatosensory cortex and left superior parietal lobule was positively correlated with behavioral measures of postobservation motor learning. Sensory-motor resting-state FC can thus predict the extent to which observation will promote subsequent motor learning. NEW & NOTEWORTHY We show that individual differences in preobservation brain function can predict subsequent observation-related gains in motor learning. Preobservation resting-state functional connectivity within a sensory-motor network may be used as a biomarker for the extent to which observation promotes motor learning. This kind of information may be useful if observation is to be used as a way to boost neuroplasticity and sensory-motor recovery for patients undergoing rehabilitation for diseases that impair movement such as stroke. Copyright © 2017 the American Physiological Society.

Modelizacion, control e implementacion de un procesador energetico paralelo para aplicacion en sistemas multisalida

Science.gov (United States)

Ferreres Sabater, Agustin

modelizacion, y aplicacion en convertidores PWM, esta aun por estudiar y valorar. El primer Capitulo consiste en una breve introduccion al problema de la regulacion cruzada y la impedancia cruzada para posteriormente describir las tecnicas de post-regulacion actualmente mas empleadas, con especial atencion al post-regulador con transformador controlado. El Capitulo segundo trata del estudio de las caracteristicas estaticas del postregulador con transformador controlado. Partiendo de los estudios disponibles sobre el postregulador se plantean mejoras en su modo de actuacion y se discuten tres alternativas diferentes para controlar el transformador. Las dos primeras consisten en emplear un convertidor auxiliar Boost en sus dos modos de funcionamiento, continuo y discontinuo. La tercera consiste en controlar el transformador con una tension PWM directamente, sin filtrado. Finalmente se comprueba experimentalmente, para el estado estacionario, el funcionamiento del post-regulador para cada uno de los tres metodos de control. El Capitulo tercero trata de la dinamica de la salida controlada con el post-regulador cuando este emplea un convertidor auxiliar tipo Boost. Mediante la tecnica de promediado de variables de estado se propone el modelo de pequena senal, tanto para el modo continuo como para el modo discontinuo de funcionamiento del convertidor auxiliar. Los resultados mas significativos de esta seccion son las expresiones analiticas de las impedancias cruzadas y de la impedancia de la salida post-regulada. Como complemento al modelo de pequena senal se plantea un modelo de gran senal implementado sobre el simulador Pspice. Con este nuevo modelo se reproducen los resultados obtenidos con el modelo de pequena senal y ademas es posible simular los transitorios en las tensiones de salida ante cambios de carga. La modelizacion del convertidor cuando el transformador se controla con una tension PWM sin filtrar es el objetivo del Capitulo 4. En las secciones siguientes del Capitulo

Heavy metals in locus ceruleus and motor neurons in motor neuron disease.

Science.gov (United States)

Pamphlett, Roger; Kum Jew, Stephen

2013-12-12

The causes of sporadic amyotrophic lateral sclerosis (SALS) and other types of motor neuron disease (MND) remain largely unknown. Heavy metals have long been implicated in MND, and it has recently been shown that inorganic mercury selectively enters human locus ceruleus (LC) and motor neurons. We therefore used silver nitrate autometallography (AMG) to look for AMG-stainable heavy metals (inorganic mercury and bismuth) in LC and motor neurons of 24 patients with MND (18 with SALS and 6 with familial MND) and in the LC of 24 controls. Heavy metals in neurons were found in significantly more MND patients than in controls when comparing: (1) the presence of any versus no heavy metal-containing LC neurons (MND 88%, controls 42%), (2) the median percentage of heavy metal-containing LC neurons (MND 9.5%, control 0.0%), and (3) numbers of individuals with heavy metal-containing LC neurons in the upper half of the percentage range (MND 75%, controls 25%). In MND patients, 67% of remaining spinal motor neurons contained heavy metals; smaller percentages were found in hypoglossal, nucleus ambiguus and oculomotor neurons, but none in cortical motor neurons. The majority of MND patients had heavy metals in both LC and spinal motor neurons. No glia or other neurons, including neuromelanin-containing neurons of the substantia nigra, contained stainable heavy metals. Uptake of heavy metals by LC and lower motor neurons appears to be fairly common in humans, though heavy metal staining in the LC, most likely due to inorganic mercury, was seen significantly more often in MND patients than in controls. The LC innervates many cell types that are affected in MND, and it is possible that MND is triggered by toxicant-induced interactions between LC and motor neurons.

Heavy metals in locus ceruleus and motor neurons in motor neuron disease

Science.gov (United States)

2013-01-01

Background The causes of sporadic amyotrophic lateral sclerosis (SALS) and other types of motor neuron disease (MND) remain largely unknown. Heavy metals have long been implicated in MND, and it has recently been shown that inorganic mercury selectively enters human locus ceruleus (LC) and motor neurons. We therefore used silver nitrate autometallography (AMG) to look for AMG-stainable heavy metals (inorganic mercury and bismuth) in LC and motor neurons of 24 patients with MND (18 with SALS and 6 with familial MND) and in the LC of 24 controls. Results Heavy metals in neurons were found in significantly more MND patients than in controls when comparing: (1) the presence of any versus no heavy metal-containing LC neurons (MND 88%, controls 42%), (2) the median percentage of heavy metal-containing LC neurons (MND 9.5%, control 0.0%), and (3) numbers of individuals with heavy metal-containing LC neurons in the upper half of the percentage range (MND 75%, controls 25%). In MND patients, 67% of remaining spinal motor neurons contained heavy metals; smaller percentages were found in hypoglossal, nucleus ambiguus and oculomotor neurons, but none in cortical motor neurons. The majority of MND patients had heavy metals in both LC and spinal motor neurons. No glia or other neurons, including neuromelanin-containing neurons of the substantia nigra, contained stainable heavy metals. Conclusions Uptake of heavy metals by LC and lower motor neurons appears to be fairly common in humans, though heavy metal staining in the LC, most likely due to inorganic mercury, was seen significantly more often in MND patients than in controls. The LC innervates many cell types that are affected in MND, and it is possible that MND is triggered by toxicant-induced interactions between LC and motor neurons. PMID:24330485

Electric vehicle traction motors - The development of an advanced motor concept

Science.gov (United States)

Campbell, P.

1980-01-01

An axial-field permanent magnet traction motor is described, similar to several advanced motors that are being developed in the United States. This type of machine has several advantages over conventional dc motors, particularly in the electric vehicle application. The rapidly changing cost of magnetic materials, particularly cobalt, makes it important to study the utilization of permanent magnet materials in such machines. The impact of different magnets on machine design is evaluated, and the advantages of using iron powder composites in the armature are assessed.

Formation of model-free motor memories during motor adaptation depends on perturbation schedule.

Science.gov (United States)

Orban de Xivry, Jean-Jacques; Lefèvre, Philippe

2015-04-01

Motor adaptation to an external perturbation relies on several mechanisms such as model-based, model-free, strategic, or repetition-dependent learning. Depending on the experimental conditions, each of these mechanisms has more or less weight in the final adaptation state. Here we focused on the conditions that lead to the formation of a model-free motor memory (Huang VS, Haith AM, Mazzoni P, Krakauer JW. Neuron 70: 787-801, 2011), i.e., a memory that does not depend on an internal model or on the size or direction of the errors experienced during the learning. The formation of such model-free motor memory was hypothesized to depend on the schedule of the perturbation (Orban de Xivry JJ, Ahmadi-Pajouh MA, Harran MD, Salimpour Y, Shadmehr R. J Neurophysiol 109: 124-136, 2013). Here we built on this observation by directly testing the nature of the motor memory after abrupt or gradual introduction of a visuomotor rotation, in an experimental paradigm where the presence of model-free motor memory can be identified (Huang VS, Haith AM, Mazzoni P, Krakauer JW. Neuron 70: 787-801, 2011). We found that relearning was faster after abrupt than gradual perturbation, which suggests that model-free learning is reduced during gradual adaptation to a visuomotor rotation. In addition, the presence of savings after abrupt introduction of the perturbation but gradual extinction of the motor memory suggests that unexpected errors are necessary to induce a model-free motor memory. Overall, these data support the hypothesis that different perturbation schedules do not lead to a more or less stabilized motor memory but to distinct motor memories with different attributes and neural representations. Copyright © 2015 the American Physiological Society.

Non-Motor Symptoms in Patients Suffering from Motor Neuron Diseases.

Science.gov (United States)

Günther, René; Richter, Nicole; Sauerbier, Anna; Chaudhuri, Kallol Ray; Martinez-Martin, Pablo; Storch, Alexander; Hermann, Andreas

2016-01-01

The recently postulated "disease spreading hypothesis" has gained much attention, especially for Parkinson's disease (PD). The various non-motor symptoms (NMS) in neurodegenerative diseases would be much better explained by this hypothesis than by the degeneration of disease-specific cell populations. Motor neuron disease (MND) is primarily known as a group of diseases with a selective loss of motor function. However, recent evidence suggests disease spreading into non-motor brain regions also in MND. The aim of this study was to comprehensively detect NMS in patients suffering from MND. We used a self-rating questionnaire including 30 different items of gastrointestinal, autonomic, neuropsychiatric, and sleep complaints [NMS questionnaire (NMSQuest)], which is an established tool in PD patients. 90 MND patients were included and compared to 96 controls. In total, MND patients reported significantly higher NMS scores (median: 7 points) in comparison to controls (median: 4 points). Dribbling, impaired taste/smelling, impaired swallowing, weight loss, loss of interest, sad/blues, falling, and insomnia were significantly more prevalent in MND patients compared to controls. Interestingly, excessive sweating was more reported in the MND group. Correlation analysis revealed an increase of total NMS score with disease progression. NMS in MND patients seemed to increase with disease progression, which would fit with the recently postulated "disease spreading hypothesis." The total NMS score in the MND group significantly exceeded the score for the control group, but only 8 of the 30 single complaints of the NMSQuest were significantly more often reported by MND patients. Dribbling, impaired swallowing, weight loss, and falling could primarily be connected to motor neuron degeneration and declared as motor symptoms in MND.

Motor-operated gearbox efficiency

International Nuclear Information System (INIS)

DeWall, K.G.; Watkins, J.C.; Bramwell, D.; Weidenhamer, G.H.

1996-01-01

Researchers at the Idaho National Engineering Laboratory recently conducted tests investigating the operating efficiency of the power train (gearbox) in motor-operators typically used in nuclear power plants to power motor-operated valves. Actual efficiency ratios were determined from in-line measurements of electric motor torque (input to the operator gearbox) and valve stem torque (output from the gearbox) while the operators were subjected to gradually increasing loads until the electric motor stalled. The testing included parametric studies under reduced voltage and elevated temperature conditions. As part of the analysis of the results, the authors compared efficiency values determined from testing to the values published by the operator manufacturer and typically used by the industry in calculations for estimating motor-operator capabilities. The operators they tested under load ran at efficiencies lower than the running efficiency (typically 50%) published by the operator manufacturer

Motor-operated gearbox efficiency

Energy Technology Data Exchange (ETDEWEB)

DeWall, K.G.; Watkins, J.C.; Bramwell, D. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Weidenhamer, G.H.

1996-12-01

Researchers at the Idaho National Engineering Laboratory recently conducted tests investigating the operating efficiency of the power train (gearbox) in motor-operators typically used in nuclear power plants to power motor-operated valves. Actual efficiency ratios were determined from in-line measurements of electric motor torque (input to the operator gearbox) and valve stem torque (output from the gearbox) while the operators were subjected to gradually increasing loads until the electric motor stalled. The testing included parametric studies under reduced voltage and elevated temperature conditions. As part of the analysis of the results, the authors compared efficiency values determined from testing to the values published by the operator manufacturer and typically used by the industry in calculations for estimating motor-operator capabilities. The operators they tested under load ran at efficiencies lower than the running efficiency (typically 50%) published by the operator manufacturer.

Motor-operator gearbox efficiency

International Nuclear Information System (INIS)

DeWall, K.G.; Watkins, J.C.; Bramwell, D.

1996-01-01

Researchers at the Idaho National Engineering Laboratory recently conducted tests investigating the operating efficiency of the power train (gearbox) in motor-operators typically used in nuclear power plants to power motor-operated valves. Actual efficiency ratios were determined from in-line measurements of electric motor torque (input to the operator gearbox) and valve stem torque (output from the gearbox) while the operators were subjected to gradually increasing loads until the electric motor stalled. The testing included parametric studies under reduced voltage and elevated temperature conditions. As part of the analysis of the results, we compared efficiency values determined from testing to the values published by the operator manufacturer and typically used by the industry in calculations for estimating motor-operator capabilities. The operators we tested under load ran at efficiencies lower than the running efficiency (typically 50%) published by the operator manufacturer

Two-Phase Induction Motor Drives

Directory of Open Access Journals (Sweden)

Gholam Reza Arab Markadeh

2010-10-01

Full Text Available The lack of variable-speed drives for two (single induction motor is a reality. This article attempts mainly to investigate the reasons for this lack of variable – speed drives. This paper deals with literature survey of various existing converter topologies, which have been proposed for adjustable speed single phase induction motor drives. Various converter topologies have been compared in this paper. Among these converter topologies, the adjustable frequency PWM inverter is the best choice for single-phase induction motor drives. However, adjustable-frequency drives have not been widely used with single-phase Induction motors. The open-loop constant V/F control law cannot be used with the single-phase induction motor drives as it is used with three phase motors. The variation of the operating frequency at lower speed range with constant load torque causes variation in motor's slip. A constant V/F control is suitable only over the upper speed range.

DESARROLLO DE UNA NUEVA TÉCNICA ENDOSCÓPICA PARA EL TRATAMIENTO DE LA ACALASIA: POEM (PER-ORAL ENDOSCOPIC MYOTOMY)

OpenAIRE

Mejía M,Ricardo; León F,Felipe; Donoso D,Andrés; Pimentel M,Fernando; Ibáñez A,Luis; Sharp P,Allan

2014-01-01

La Acalasia es el trastorno motor primario más frecuente del esófago. Existen diversas alternativas para el tratamiento de esta enfermedad, siendo el gold standard actual la miotomía de Heller laparoscópica. Durante los últimos años, con el desarrollo de técnicas endoscópicas avanzadas, se ha desarrollado una nueva técnica endoscópica para el tratamiento de esta patología; la técnica POEM (del inglés: Per Oral Endoscopic Myotomy). Hoy en día pocos centros en el mundo realizan esta técnica, co...

EL HÁNDICAP DEL TRANSPORTE AÉREO PARA EL DESARROLLO INICIAL DEL TURISMO DE MASAS EN LAS ISLAS CANARIAS

Directory of Open Access Journals (Sweden)

José Ángel Hernández Luis

2011-01-01

Full Text Available El transporte aéreo, más aún en un territorio fragmentado y alejado como es el caso del Archipiélago canario, ha jugado un papel trascendental para el desarrollo del turismo de masas en los años sesenta y setenta. En efecto, sin la llegada del motor a reacción a Canarias, no se podría comprender el espectacular desarrollo turístico que las Islas experimentaron en este periodo, siendo el principal objetivo de este trabajo, abordar -aunque de forma sucinta-, este proceso absolutamente decisivo para las Islas.

Echoes on the motor network: how internal motor control structures afford sensory experience.

Science.gov (United States)

Burgess, Jed D; Lum, Jarrad A G; Hohwy, Jakob; Enticott, Peter G

2017-12-01

Often, during daily experiences, hearing peers' actions can activate motor regions of the CNS. This activation is termed auditory-motor resonance (AMR) and is thought to represent an internal simulation of one's motor memories. Currently, AMR is demonstrated at the neuronal level in the Macaque and songbird, in conjunction with evidence on a systems level in humans. Here, we review evidence of AMR development from a motor control perspective. In the context of internal modelling, we consider data that demonstrates sensory-guided motor learning and action maintenance, particularly the notion of sensory comparison seen during songbird vocalisation. We suggest that these comparisons generate accurate sensory-to-motor inverse mappings. Furthermore, given reports of mapping decay after songbird learning, we highlight the proposal that the maintenance of these sensorimotor maps potentially explains why frontoparietal regions are activated upon hearing known sounds (i.e., AMR). In addition, we also recommend that activation of these types of internal models outside of action execution may provide an ecological advantage when encountering known stimuli in ambiguous conditions.

Artificial molecular motors

NARCIS (Netherlands)

Kassem, Salma; van Leeuwen, Thomas; Lubbe, Anouk S.; Wilson, Miriam R.; Feringa, Ben L.; Leigh, David A.

2017-01-01

Motor proteins are nature's solution for directing movement at the molecular level. The field of artificial molecular motors takes inspiration from these tiny but powerful machines. Although directional motion on the nanoscale performed by synthetic molecular machines is a relatively new

CANONICAL RELATIONS BETWEEN BASIC AND MOTOR - SITUATIONAL-MOTOR SKILLS IN SPORT GAMES

Directory of Open Access Journals (Sweden)

Bećir Šabotić

2013-07-01

Full Text Available The aim of this study was to establish the correlation between the predictor-basic motor and situational-motor tests in sports games. On the sample of 62 subjects of the first year of high school was carried out measurements which covered 12 basic and 6 motor variables and situational tests in volleyball and basketball.Based on the results of the canonical correlation analysis, it can be concluded that there is a significant relationship between the predictor variables and a set of criterion variables, situational-motor tests basketball and volleyball. These results are logical given the structure of movements from basketball and volleyball that require a high level of coordination and speed.

How Kinesthetic Motor Imagery works: A predictive-processing theory of visualization in sports and motor expertise

NARCIS (Netherlands)

Ridderinkhof, K.R.; Brass, M.

2015-01-01

Kinesthetic Motor Imagery (KMI) is an important technique to acquire and refine motor skills. KMI is widely used by professional athletes as an effective way to improve motor performance without overt motor output. Despite this obvious relevance, the functional mechanisms and neural circuits

76 FR 12792 - Petition for Exemption From the Federal Motor Vehicle Motor Theft Prevention Standard; General...