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Sample records for vapor las turbinas

  1. Effect of the blades and seals system wear on steam turbine efficiency and power; Efecto del desgaste del sistema de alabes y sellos sobre la eficiencia y potencia de las turbinas de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Campos Amezcua, Alfonso; Kubiak Szyszka, Janusz [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    The implementation of a method for steam turbine evaluation through the measured geometry in the flow channel and its operating conditions, is presented. This method, previously developed, allows the identification and quantification of the power and efficiency loss due to the wear of its elements (worn or bent blades, worn seals, deposits, etc.); the benefit that is obtained is a more precise knowledge on the turbine behavior and a basis is acquired to give priority to the maintenance work, from the stand point of energy utilization. In this paper, the power and efficiency loss of a 300 MW steam turbine is located and evaluated, a sensibility analysis is presented for the typical elements that cause the deterioration of the efficiency in this type of turbines. [Espanol] Se presenta la implementacion de un metodo de evaluacion de turbinas de vapor a partir de la geometria medida del canal de flujo y sus condiciones de operacion. Este metodo, previamente desarrollado, permite identificar y cuantificar las perdidas de potencia y eficiencia debido al desgaste de sus elementos (alabes desgastados o doblados, sellos desgastados, depositos, etcetera); el beneficio que se obtiene es un conocimiento mas preciso del comportamiento de la turbina y que se tiene una base para dar prioridad a los trabajos de mantenimiento desde el punto de vista de aprovechamiento de la energia. En este articulo se localizan y evaluan las perdidas de potencia y eficiencia de una turbina de vapor de 300 MW, ademas, se presenta un analisis de sensibilidad para los elementos tipicos que originan el deterioro de la eficiencia en este tipo de turbinas.

  2. Effect of the blades and seals system wear on steam turbine efficiency and power; Efecto del desgaste del sistema de alabes y sellos sobre la eficiencia y potencia de las turbinas de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Campos Amezcua, Alfonso; Kubiak Szyszka, Janusz [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    The implementation of a method for steam turbine evaluation through the measured geometry in the flow channel and its operating conditions, is presented. This method, previously developed, allows the identification and quantification of the power and efficiency loss due to the wear of its elements (worn or bent blades, worn seals, deposits, etc.); the benefit that is obtained is a more precise knowledge on the turbine behavior and a basis is acquired to give priority to the maintenance work, from the stand point of energy utilization. In this paper, the power and efficiency loss of a 300 MW steam turbine is located and evaluated, a sensibility analysis is presented for the typical elements that cause the deterioration of the efficiency in this type of turbines. [Espanol] Se presenta la implementacion de un metodo de evaluacion de turbinas de vapor a partir de la geometria medida del canal de flujo y sus condiciones de operacion. Este metodo, previamente desarrollado, permite identificar y cuantificar las perdidas de potencia y eficiencia debido al desgaste de sus elementos (alabes desgastados o doblados, sellos desgastados, depositos, etcetera); el beneficio que se obtiene es un conocimiento mas preciso del comportamiento de la turbina y que se tiene una base para dar prioridad a los trabajos de mantenimiento desde el punto de vista de aprovechamiento de la energia. En este articulo se localizan y evaluan las perdidas de potencia y eficiencia de una turbina de vapor de 300 MW, ademas, se presenta un analisis de sensibilidad para los elementos tipicos que originan el deterioro de la eficiencia en este tipo de turbinas.

  3. Influencia de los parámetros de proceso, en el comportamiento del parámetro vibración absoluta en turbinas de vapor.

    Directory of Open Access Journals (Sweden)

    F. de la Torre Silva

    2008-01-01

    Full Text Available Este trabajo muestra el estudio realizado en turbinas de vapor de pequeña capacidad de generación de las centrales termoeléctricas cubanas, relacionadas con la influencia estadística entre parámetros de proceso de la turbina, respecto al parámetro vibración absoluta, medidos en las chumaceras de la turbina. Se utilizan las bases de datos de los sistemas de monitoreado on-line de la turbina. Se exponen las relaciones existentes entre los principales parámetros seleccionados para este estudio.This work show the study in small steam turbine capacity of generation in cubans thermoelectric power station to relative with statistical influence between steam process parameters regarding absolute vibration parameter, in the steam housing measurements. Themselves use database as steam on-line monitoring systems. Expose the existing relation between the principal selection parameters for this study.

  4. Theorical and experimental study of the induced forces by the mixed, divergent, convergent and straight labyrinth of seal systems on the steam turbines, gas turbines and compressor rotors; Estudio teorico-experimental de las fuerzas inducidas por los sistemas de sellos de laberinto rectos, convergentes, divergentes y mixtos sobre los rotores de turbinas de vapor, turbinas de gas y compresores

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    Salazar San Andres, Octavio Ramon

    1991-12-31

    demuestran que el modelo es capaz de dar una vision cualitativa y cuantitativa de las fuerzas y los coeficientes de rigidez y amortiguamiento de los sellos de laberinto con las geometrias antes mencionadas, tanto para el rotor estatico como en operacion. Por otra parte se recomienda llevar a cabo mas experimentacion con equipo instalado en plantas termoelectricas y en especial en turbinas de vapor con capacidades iguales o superiores a los 300 MW, donde las altas presiones y los sellos localizados en la parte superior de los alabes, vuelven mas susceptibles a las maquinas para autoinducir vibraciones subsincronas.

  5. Desenvolvimento de uma ferramenta computacional 1-D para uso em projeto de turbinas a vapor

    OpenAIRE

    Fábio Santos Nascimento

    2012-01-01

    O presente trabalho trata do projeto aerotermodinâmico de turbinas a vapor de múltiplos estágios baseado em uma abordagem de técnicas de modelamento unidimensional. Um programa computacional foi desenvolvido para projeto preliminar de turbinas a vapor de múltiplos estágios escritos em linguagem FORTRAN 90, visando à redução do tempo de projeto preliminar, a independência de programas comerciais e o acesso ao código fonte para modificar e implementar novos modelos para melhorar o potencial da ...

  6. Sistemas de tratamiento del aire de admisión de las turbinas de gas

    OpenAIRE

    Fernández Labella, Francisco

    2016-01-01

    Actualmente, las turbinas de gas están instaladas prácticamente en todas las regiones del mundo. Por este motivo, las condiciones del aire de admisión en las diferentes ubicaciones pueden ser muy distintas. No obstante, las características del aire exterior (temperatura, humedad, partículas en suspensión…) influyen notablemente en el rendimiento, la potencia neta, así como en la vida de la turbina de gas. El objetivo de este trabajo fin de grado es explicar cómo y porqué la calidad del air...

  7. Condensers for measuring steam quality at the inlet of back-pressure units of the Los Azufres, Mich., geothermal field; Condensadores para medir la calidad del vapor a la entrada de las turbinas a contrapresion del campo geotermico de Los Azufres, Mich.

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval Medina, Fernando; Gonzalez Gonzalez, Rubi; Reyes Delgado, Lisette; Medina Martinez, Moises [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia de Los Azufres (Mexico)]. E-mail: fernando.sandoval@cfe.gob.mx

    2007-01-15

    Electrical conductivity is an indirect measurement of the quality of the steam supplied to power units. In the Los Azufres, Mich., geothermal field, the electrical conductivity once was measured in a discrete and periodic way by condensing steam samples through a water-cooled condenser. In an attempt to continuously measure conductivity, conductivity meters were installed where the units discharged, but the values proved unstable and unrepresentative. Thereafter, taking into account that steam quality should be measured at the steam delivery-reception point, equipment was designed and tested for continuously condensing steam. Finally it was possible to get an air-cooled condenser able to condense 500 milliliters per minute, enough to collect a representative flow of the steam and to measure its electrical conductivity. The equipment was installed in all seven back-pressure units operating in the field and to date has been operating in an optimal manner. [Spanish] La conductividad electrica es una medida indirecta de la calidad del vapor que se suministra a las unidades turbogeneradoras. En el campo geotermico de Los Azufres, Mich., la conductividad electrica se media en forma puntual y periodica, condensando muestras de vapor por medio de un serpentin enfriado con agua. Despues, ante la necesidad de medirla en forma continua, se instalaron conductivimetros en las descargas de las unidades, pero los valores resultaron muy inestables y poco representativos. Considerando, ademas, que la calidad del vapor debe medirse en el punto de entrega-recepcion, se disenaron y probaron equipos para condensar vapor de manera continua, lograndose construir un condensador enfriado por aire que logra condensar un flujo de 500 mililitros por minuto, cantidad suficiente para tener un flujo representativo del vapor que alimenta a las turbinas y medirle su conductividad electrica. Se instalaron estos equipos en las siete unidades turbogeneradoras a contrapresion que funcionan en el campo

  8. Influencia de los parámetros de proceso, en el comportamiento del parámetro vibración absoluta en turbinas de vapor. // Influence of process parameters of the behaviour of absolute vibration parameters in steam turbine.

    Directory of Open Access Journals (Sweden)

    F. de la Torre Silva

    2008-01-01

    Full Text Available Este trabajo muestra el estudio realizado en turbinas de vapor de pequeña capacidad de generación de las centralestermoeléctricas cubanas, relacionadas con la influencia estadística entre parámetros de proceso de la turbina, respecto alparámetro vibración absoluta, medidos en las chumaceras de la turbina. Se utilizan las bases de datos de los sistemas demonitoreado on-line de la turbina. Se exponen las relaciones existentes entre los principales parámetros seleccionados paraeste estudio.Palabras claves: Monitorado on-line, Monitorado de la condición, Parámetros de proceso, Vibraciónabsoluta, Turbinas de vapor.______________________________________________________________________________AbstractThis work show the estudy in small steam turbine capacity of generation in cubans thermoelectric power station to relative withstatistical influence between steam process parameters regarding absolute vibration parameter, in the steam housing measurements.Themselves use database as steam on-line monitoring systems. Expose the existing relation between the principal selection parametersfor this study.Key Words: On.line monitoring, Condition monitoring, Process parameters, Absolute vibration, SteamTurbine.

  9. Determination of forces induced by steam flow in turbines; Determinacion de fuerzas inducidas por flujo de vapor en turbinas

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    Garcia Castrejon, Juan Carlos

    2008-09-15

    blades, has a harmonic pattern. The pressure field variation as time function is uniform: the peaks and valleys across the axial clearance are always in phase. However the instant picture of the pressure field it's different: the peaks and valleys are not in phase and the number of peaks and valley changed across the clearance. In the case of the forces acting on blades, a Fourier on the forces calculated was used to determine the coefficients and frequency of a Fourier equation which can be used to calculate the alternating stresses on the blade in order to predict the useful life blades. [Spanish] Las vibraciones inducidas por flujo de vapor en turbinas representan uno de los problemas que enfrenta la operacion de turbinas de vapor cuya capacidad rebasa los 300 MW. Ademas estas constituyen uno de los limites tecnologicos para el desarrollo de turbinas de vapor de mas de 1 GW. Este tipo de fenomeno tiene su origen en la interaccion del rotor con el fluido que se encuentra en sus proximidades. El flujo de vapor dentro de la turbina es complejo, ya que es turbulento e inestable. A medida que el flujo pasa una etapa de estator o de rotor, se generan secundarios, vortices en los filos de salida, estelas con caracteristicas de flujo diferentes al flujo principal en los pasajes. Estas variaciones en el flujo son las que inducen vibraciones forzadas en los alabes. Ademas existen varios factores que contribuyen a la aplicacion de vibraciones en alabes inducidas por flujo como son: inestabilidad del flujo de vapor en los claros de los sellos, secuencia de apertura de las valvulas, estelas de las toberas, obstrucciones en algunas de las toberas y diferente espaciamiento en las toberas. Las vibraciones por flujo pueden ser peligrosas si su frecuencia coincide con la frecuencia natural del sistema, provocando efectos mas nocivos que las vibraciones por desbalance o por desalineamiento, pues tienen amplitudes mas grandes y provocan esfuerzos alternantes en los componentes del

  10. The online diagnosis of steam turbines; El diagnostico en linea de turbinas de vapor

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    Ramirez S, J. Antonio; Rivera G, Juan J; Cristalinas N, Victor M; Marino L, Carlos A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2004-07-01

    de mantenimiento requeridas para retornar la unidad a su mejor condicion de trabajo. En este articulo se describe la metodologia para la evaluacion termica en linea de las turbinas de vapor y de sus equipos auxiliares de transferencia de calor: condensador y calentadores de agua, y se presentan algunos de los resultados obtenidos.

  11. Automatic diagnosis of steam turbines in line; Diagnostico automatico de turbinas de vapor en linea

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    Pensado Vassallo, Enlai

    2008-05-15

    o confiabilidad. De esta manera, siendo la energia nuclear la unica alternativa viable para sustituir la quema de combustibles fosiles en plantas termoelectricas, con antecedentes como el accidente de Three Mile Island en 1979 o el desastre de Chernobil en 1986, han llevado a no despreciar los riesgos relacionados. Lo cual complica su manejo y en consecuencia ha limitado la proliferacion de mas centrales nucleares. Bajo esta realidad, la problematica se concentra en dos tares: aumentar el rendimiento de las plantas termoelectricas y reducir la emision de contaminantes, tanto gases como liquidos. Por todo esto, y en cumplimiento con los valores expresados en la mision y vision del Instituto de Investigaciones Electrica (IIE), se ha seleccionado desarrollar una herramienta de apoyo para el estudio del estado de equipos rotativos remotos. Para ello, tomando como base la experiencia del IIE en el diagnostico de turbinas de vapor, se ha desarrollado una plataforma capaz de determinar la presencia de fallas a traves del modelado de la turbina y sus elementos, se representa el comportamiento esperado y, mediante la transformacion de las senales recolectadas del sistema, se calcula el comportamiento real del equipo. Con ambos resultados se procede a aplicar una tecnica de diagnostico que permita detectar las desviaciones e inferir los desperfectos existentes. Buscando mejorar la certeza y calidad de los resultados del analisis, como complemento, se ejecuta revision de las reglas de diagnostico, con base en el registro historico de diagnosis realizada y empleando un algoritmo genetico para la inclusion de reglas nuevas, las cuales se evaluan como candidatas para la mejora del producto. Este documento representa los esfuerzos de mas de un ano en el area de diagnostico, en busca de la adecuada arquitectura para una infraestructura de diagnostico remoto que permita la deteccion de fallas en centrales con turbina de vapor. El principal reto de crear esta infraestructura es la

  12. Analysis and control of erosion by solid particles in the elements of the flow system of steam turbines; Analisis y control de erosion por particulas solidas en los elementos del sistema de flujo de turbinas de vapor

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    Mazur Czerwiec, Zdzislaw; Campos Amezcua, Alfonso; Campos Amezcua, Rafael [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2010-07-01

    The analysis of erosion by solid particles is presented of different elements of the flow channel of the steam turbines that operate in Mexico: nozzles, stop valves, blade bosses, labyrinth seals and rotor disc; using tools of of Computational Fluid Dynamics (CFD). In these main elements of turbines a strong problem of erosion was registered that threatens the reliable operation of the turbines, its availability and its optimal yield. With base on the results of the numerical analyses, the design modifications of the different elements were developed from the flow channel of the steam turbines, in order to reduce the erosion and thus diminishing the energy losses and increasing the steam turbine efficiency. This work presents the main benefits that the Thermoelectric Power Plants obtain with the reduction of the erosion by solid particles that affect the critical components of steam turbines: extension of the period between maintenance, replacement of components, reduction of operation and maintenance costs of the turbines, and extension of the useful life of the main components. [Spanish] Se presenta el analisis de erosion por particulas solidas de diferentes elementos del canal de flujo de las turbinas de vapor que operan en Mexico: toberas, valvula de paro, tetones de los alabes, sellos de laberinto y disco del rotor; utilizando herramientas de Dinamica de Fluidos Computacional (DFC). En estos elementos principales de turbinas se registro un fuerte problema de erosion que amenaza la operacion confiable de las turbinas, su disponibilidad y su rendimiento optimo. Con base en los resultados de los analisis numericos, se desarrollaron las modificaciones de diseno de los diferentes elementos del canal de flujo de las turbinas de vapor, con el proposito de reducir la erosion y asi, disminuir las perdidas de energia e incrementar el rendimiento de las turbinas de vapor. Este trabajo presenta los principales beneficios que obtienen las Centrales Termoelectricas con la

  13. Useful life extension of steam turbine rotors; Alargamiento de la vida en rotores de turbina de vapor

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    Garcia Arelle, Carlos [Turbomaquinas S. A. de C.V., La Piedad, Michoacan (Mexico)

    2007-11-15

    The continuous use of steam turbines, the chemistry of the steam itself and the variations of operation velocities, cause the gradual deterioration by erosion, oxidation and/or corrosion of the rotors and blades. When this happens most of the original manufacturers recommend to rectify the areas, diminishing the surfaces, or to compare with a new rotor. TURBOMAQUINARIAS S.A. de C.V. has developed the most reliable and safe methods to return the rotor to its original dimensions and in case of recurrent problems such as erosion, oxidation and/or wear, it offers the alternative of attaching coatings metallurgically compatible with which these problems are eliminated or diminished that might show up on the rotor surface as well as in the body of the discs or of the blades. These restoring methods are recommended by the international standards such as API 687. [Spanish] El uso continuo de las turbinas de vapor, la quimica del mismo vapor y la variacion de las velocidades de operacion, ocasionan el deterioro gradual por erosion, oxidacion y/o corrosion de los rotores y de los alabes. Al ocurrir esto la mayoria de los fabricantes originales recomiendan rectificar las areas, disminuyendo las superficies, o bien comparar un rotor nuevo. TURBOMAQUINARIAS S.A. de C.V. ha desarrollado los metodos mas confiables y seguros para devolver a su rotor las dimensiones originales y en caso de problemas recurrentes tales como erosion, oxidacion y/o desgaste, ofrece la alternativa de agregar recubrimientos metalurgicamente compatibles con los cuales se eliminan o se disminuyen estos problemas que pueden presentarse tanto en la superficie del rotor como del cuerpo de los discos o bien de los alabes. Estos metodos de restauracion son recomendados por las normas internacionales tales como la API 687.

  14. Reparación por soldadura de rotores de turbinas de vapor y de gas fabricados con aceros al Cr-Mo-V

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    Mazur, Z.

    1999-04-01

    Full Text Available An analysis of typical steam turbine and gas turbine rotor failures is carried out. On the base of the rotors different failure causes and their mode of occurring, an evaluation of the weldability of the Cr-Mo-V steels and the classification of the common turbine rotors repair possibilities is presented. The developing of specific in-situ welding repair process of the damaged 20.65 MW gas turbine rotor is described. After repair, the rotor was put back into service.

    Se presenta un análisis de daños típicos en rotores de turbinas de vapor y de gas fabricados con aceros de baja aleación al Cr-Mo-V. Partiendo de las causas y modos de presentación de los fallos y el deterioro del material de los rotores durante la operación de la turbina, se lleva a cabo un análisis de la soldabilidad de los aceros al Cr-Mo-V y se presenta una clasificación de los posibles tipos de reparaciones de los rotores de turbinas. Con base en los daños presentados en el rotor de la turbina de gas de 20,65 MW, se presenta el desarrollo de la tecnología de reparación por soldadura llevada a cabo in situ. El rotor fue puesto nuevamente en servicio después del proceso de reparación.

  15. Thermodynamic performance of gas turbine; Comportamiento termodinamico de las turbinas de gas

    Energy Technology Data Exchange (ETDEWEB)

    Lugo Leyte, Raul [Universidad Autonoma Metropolitana-Iztapalapa, Mexico D.F. (Mexico); Velazquez Toledo, Miguel; Hernandez Fernandez, Angel [Escuela Superior de Ingenieria Mecananica y Electrica, Academia Mecanica, Instituto Politecnico Nacional, Mexico D.F. (Mexico); Torres Aldaco, Alejandro [Universidad Autonoma Metropolitana-Iztapalapa, Mexico D.F. (Mexico)

    2003-01-15

    This work presents a computer code developed to simulate thermodynamic performance of a gas turbine cycle. The predicted performance is determined by measurements, in terms of various thermodynamics performance parameters which are defined and discussed in this paper. These parameters include the output, efficiency, fuel flow rate and air flow rate in relation to variations in the ambient temperature, pressure ratio, turbine entry temperature, compressor isentropic efficiency and turbine isentropic efficiency. [Spanish] Se presenta el comportamiento termodinamico de las centrales termicas que operan con turbinas de gas al variar los siguientes parametros: condiciones ambientales, relacion de presiones, temperatura de los gases a la entrada de la turbina de gas y las eficiencias isentropicas de compresion y expansion. Los resultados obtenidos son la eficiencia termica, el trabajo motor generado, el exceso de aire y los flujos de combustible en funcion de los parametros citados anteriormente. El analisis parametrico se realizo con el simulador TURBOGAS disenado en el laboratorio de ingenieria termica e hidraulica aplicada de la seccion de estudios de posgrado e investigacion de la escuela superior de Ingenieria Mecanica y Electrica del Instituto Politecnico Nacional.

  16. Evaluation of the useful life of steam turbine rotors; Evaluacion de vida util de rotores de turbinas de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Carnero Parra, Antonio; Garcia Illescas, Rafael; Kubiak Szyszka, Janusz [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    This article presents the methodology applied by the Management of Turbomachinery of the Institute of Investigaciones Electricas (IIE), for the evaluation of the remaining useful life of steam turbine rotors in the phase of initiation of fissures. The evaluation of the remaining useful life of turbines, will reveal the real state of health of the rotor and will serve as a base for the future decision making that guarantees their structural integrity. [Spanish] El presentes articulo presenta la metodologia aplicada por la Gerencia de Turbomaquinaria del Instituto de Investigaciones Electricas (IIE), para la evaluacion de la vida util remanente de rotores de turbinas de vapor en la fase de iniciacion de fisuras. La evaluacion de la vida util de turbinas, revelar el estado real de salud del rotor y servira de base para la toma de decisiones futuras que garanticen su integridad estructural.

  17. Repair by weld of steam and gas turbine rotors made of Cr-Mo-V steel; Reparacion por soldadura de rotores de turbinas de vapor y de gas fabricados con aceros al Cr-Mo-V

    Energy Technology Data Exchange (ETDEWEB)

    Mazur C, Zdzislaw; Hernandez R, Alejando [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Orozco S, Julian; Banuelos P, Jose E. [Comision Federal de Electricidad (Mexico)

    2003-07-01

    In this article an analysis is presented of the typical damages in steam and gas turbine rotors made of Cr-Mo-V low alloy steels. An analysis of the weldability of the Cr-Mo-V steel is carried out and a classification of the possible types of repairs of the turbine rotors is presented, starting off from the causes and ways of presentation of the faults/deterioration of the rotor materials during the operation of the turbine. With base on the damages detected in the rotor of a gas turbine of 20.65 MW, the development of the repairing technology carried out by weld in site is presented. After the repair process, the rotor was put again in operation. [Spanish] En este articulo se presenta un analisis de los danos tipicos en rotores de turbinas de vapor y de gas fabricados con aceros de baja aleacion al Cr-Mo-V. Se lleva a cabo un analisis de la soldabilidad de los aceros al Cr-Mo-V y se presenta una clasificacion de los posibles tipos de reparaciones de los rotores de turbinas, partiendo de las causas y modos de presentacion de las fallas/deterioro del material de los rotores durante la operacion de la turbina. Con base en los danos detectados en el rotor de una turbina de gas de 20.65 MW, se presenta el desarrollo de la tecnologia de reparacion por soldadura llevada a cabo en sitio. Despues del proceso de reparacion, el rotor fue puesto nuevamente en servicio.

  18. Reliability of electric generation units by evaluating the loss of power and efficiency of turbines; Confiabilidad de las unidades de generacion electrica mediante la evaluacion de la perdida de potencia y eficiencia de las turbinas

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Solis, Jose Antonio; Cristalinas Navarro, Victor Manuel [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2012-07-01

    The aim of the specialized technical service to evaluate the loss of power and efficiency of an open steam turbine is to quantify these losses caused by the deterioration of internal seals, deterioration of the steam path geometry components (nozzles and blades) and increased roughness of the blades and nozzle surface due to erosion (steam, humidity and impacts) and, also, due to salts deposition. In the same way, to establish a set of recommendations, in order of importance by the attention of the Power Plant with the purpose of recovering the major quantity of power and efficiency lost by the steam turbine and assurance, by means of technical supervision of the activities set in the recommendations, and in accordance with CFE rules, international standards and the personal experience of the Instituto de Investogaciones Electricas (IIE), staff, an acceptable quality in rehabilitation of mechanical components such as the maintenance of the steam turbine itself. Using an application example, this paper describes, the methodology of execution of this kind of services. Also, the quality of the maintenance and the rehabilitation of the steam turbine components are quantified. [Spanish] El objetivo del servicio tecnico especializado para evaluar la perdida de potencia y eficiencia de una turbina de vapor abierta es cuantificar dichas perdidas a causa del deterioro de los sellos internos, del deterioro la geometria de referencia de los componentes del canal de vapor (alabes fijos y alabes moviles) y del aumento de la rugosidad de la superficie de los alabes a causa de la erosion (marcas de vapor, de humedad y de impactos) y de la deposicion de sales. Asimismo, establecer una serie de recomendaciones en orden prioritario para la atencion de la central, con el fin de recuperar la mayor parte de la potencia y eficiencia perdidas por la turbina y asegurando, mediante la supervision tecnica de las actividades resultantes de las recomendaciones y conforme a la normativa de la

  19. Robust velocity and load control of a steam turbine in a combined cycle thermoelectric power station; Control robusto de velocidad y carga de una turbina de vapor en una central termoelectrica de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Reyes Archundia, Enrique

    1998-12-31

    of the computation, the programming languages and the numerical methods allow to develop mathematical models that simulate in an approximate manner the processes to control, as it is the case of the combined cycle thermoelectric power station and in this way making the evaluation of algorithms of modern control possible. In chapter I a functional description of the steam turbine process is given. Since this belongs to a combined cycle thermoelectric power station, it is begun with the description of this power station, later to emphasize the subsystem of the steam turbine and emphasize each one of the elements that comprise this last one. [Espanol] Este trabajo de investigacion esta orientado a disenar, desarrollar y validar un algoritmo de control moderno, que permita la obtencion de mejores desempenos en el control de velocidad de una turbina de vapor perteneciente a una central termoelectrica de ciclo combinado, en todo el intervalo de operacion, asi como la obtencion de mejores desempenos en el control de la cantidad de megawatts generados por la misma cuando esta acoplada a un generador electrico, comparando el desempeno con el obtenido mediante el controlador convencional existente. Los cambios en la referencia de velocidad o carga, son a solicitud del operador y se dan siempre en forma de rampa, indicando la rapidez con la que se desea efectuar el cambio de valor en la referencia. Esta es la razon por la cual el objetivo principal del control a disenar es realizar un buen seguimiento a referencias del tipo rampa. En el subsistema de la turbina de vapor existente el inconveniente de que las valvulas que regulan el flujo de vapor hacia la turbina, presentan un acoplamiento con la valvula del bypass que permite derivar el flujo de vapor hacia el condensador principal sin tener que pasar por la turbina. Es por esto que se propone un control multivariable que contemple la interaccion que se presenta entre las valvulas antes mencionadas, partiendo de un diseno

  20. Vibration analysis and online thermodynamic assessment of a turbo-blower turbine; Analisis de vibraciones y evaluacion termodinamica en linea de la turbina de un turbosoplador

    Energy Technology Data Exchange (ETDEWEB)

    Munoz Q, Rodolfo; Marino L, Carlos; Ramirez S, Jose A.; Rivera G, Juan J. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-11-15

    In this paper are presented the results of the analysis of dynamic and thermodynamic behavior analysis of a turbo-blower integrated by one 13,080 KW steam turbine and a blower with a flow of 131,520 ft{sup 3}/m, to determine the cause of the excessive wearing of the axial trust bearing of the steam turbine. The main cause of failure is the wearing and severe dirtiness of the turbine stages that contributes with an increment of the turbine axial load. The consequences of the turbine deterioration are: greater axial load due to the additional heating rotor (requires greater steam to generate the same power that in design conditions); turbine motive power reduction and the reduction of isentropic efficiency of the same, for similar average steam consumption between reference and test. Due to the former the turbine power represents a deviation of the 34.74% in Steam Specific Consumption (SSC). [Spanish] Se presenta los resultados del analisis del comportamiento dinamico y termodinamico de un turbosoplador integrado por una turbina de vapor de 13,080 KW y un soplador con un caudal de 131,520 pies{sup 3}/m, para determinar la causa del desgaste excesivo de la chumacera de empuje axial de la turbina de vapor. La causa principal de la falla es el desgaste y ensuciamiento severo de las etapas de la turbina que contribuye con un incremento de la carga axial de la turbina. Las consecuencias del deterioro de la turbina son: mayor carga axial debida al calentamiento adicional del rotor (requiere mayor vapor para generar la misma potencia que en condiciones de diseno); reduccion de la potencia motriz de la turbina y de la eficiencia isoentropica de las mismas, para un consumo de vapor promedio similar entre referencia y prueba. Debido a lo anterior la potencia de la turbina representa una desviacion del 34.74% en el Consumo Especifico de Vapor (CVE).

  1. Design and construction of a height caliper of labyrinths seals of high power steam turbines; Diseno y construccion de un calibrador de alturas para sellos laberintos de turbinas de vapor de alta potencia

    Energy Technology Data Exchange (ETDEWEB)

    Quinonez Osuna, Jose R. [Instituto Tecnologico de Mazatlan, Mazatlan, Sinaloa (Mexico); Mazur Czerwiec, Zdzislaw [instituto de Investigaciones Electicas, Cuernavaca, Morelos (Mexico); Valdez Valdez, Omar [Instituto Tecnologico de Mazatlan, Mazatlan, Sinaloa (Mexico)

    2007-11-15

    This article presents the development of a new instrument that allows calibrating with exactness the labyrinths seals height of the radial type, normally used in steam turbines and many other turbo-machines. The calibration process derived from the application of the designed instrument is distinguished from the existing one in the fact of considering a perpendicularity reference that allows high exactness in the measurement of height differences (0,008 mm), which is performed at the moment of adjusting the steam seals each time that its sheets are substituted for new ones. Such characteristic, allows therefore, higher efficiency conditions, stability and trustworthiness in the unit operation, once maintenance of this kind has been applied to it. The lack of monitoring and periodic maintenance of the gaps between seals and rotor constitutes the main cause of efficiency loss in power plant turbines installed in Mexico, generating wastes of up to 4% of its capacity, which represents 15 MW in high power units. [Spanish] El articulo representa el desarrollo de un nuevo instrumento que permite calibrar con exactitud las alturas de los sellos laberinticos de tipo radial, ordinariamente empleados en turbinas de vapor y en muchas otras turbo-maquinas. El proceso de calibracion derivado de la aplicacion del instrumento disenado se distingue del existente, en el hecho de considerar una referencia de perpendicularidad que permite alta precision en la medicion de diferencias de altura (0.008 mm.), lo cual es realizado en el momento de ajustar los sellos de vapor cada vez que sus laminas son sustituidas por nuevas. Dicha caracteristica, procura por ende condiciones mayores de eficiencia, estabilidad y confiabilidad en la operacion de la unidad, una vez que le ha sido brindado un mantenimiento de esta naturaleza. La falta de monitoreo y mantenimiento periodico de los claros entre sellos y rotor, constituye la principal causa de perdida de eficiencia en las turbinas de las

  2. Rehabilitation and extension of the useful operating life of a high pressure casing of the 75 MW steam turbine of the thermoelectric power plant President Juarez in Rosarito, B.C.; Rehabilitacion y extension de vida util de una carcasa de alta presion de la turbina de vapor de 75 MW de la central termoelectrica Presidente Juarez en Rosarito, B.C.

    Energy Technology Data Exchange (ETDEWEB)

    Mazur C, Zdzislaw; Hernandez R, Alejandro; Luna R, Alberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Fernandez, Rafael; Nieblas, Enrique [Comision Federal de Electricidad, Rosarito, Baja California (Mexico)

    2004-07-01

    The effective operation of the steam turbines is important to the world industries, but as all machinery, it is necessary to constantly examine and give maintenance to this equipment with the purpose of producing better results. Yet, many steam turbines arrive at an operation period of 30 or 40 years, over their original design capacity. A factor like this, only augments the probabilities of future problems with the casings, such as: thermal fatigue fissures, deformation of the horizontal union and erosion problems in the low pressure housings. The deformation of the casing can affect its capacity to maintain aligned the stationary parts of the turbine, as a consequence, damages can appear in the fixed and rotary components by interference or friction. Also, the water induction can deform the casing to such a degree that, the alignment of the stationary parts is altered until it causes contact and friction between stationary and rotary parts. However, depending on the type and degree of the casing deformation, different methods of rehabilitation can be applied. The core goal is to recover the planarity of the union of the flanges, re-machining the plane of the flange of the upper and lower casing or, alternatively, to carry out a scraping by hand. [Spanish] El funcionamiento eficaz de las turbinas de vapor es importante para las industrias del mundo, pero como toda maquinaria, es necesario examinar y dar mantenimiento constantemente a este equipo con la finalidad de producir mejores resultados. Con todo, muchas turbinas de vapor llegan a un periodo de operacion de 30 o 40 anos, por encima de su capacidad de diseno original. Un factor como este, solo eleva las probabilidades de futuros problemas con las carcasas, tales como: fisuras por fatiga termica, deformacion de la union horizontal y problemas de erosion en las carcasas de baja presion. La deformacion de la carcasa puede afectar su capacidad para mantener alineadas las partes estacionarias de la turbina, como

  3. Gas turbine application in power plants of Mexican refineries; Aplicacion de turbinas de gas en plantas de fuerza de refinerias mexicanas

    Energy Technology Data Exchange (ETDEWEB)

    Alcaraz Calderon, A. M.; Rodriguez Martinez, H.; Garcia Paredes, Job; Morales Guillen, Magdalena; Manzanares Papayanapolous, Emilio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: malcaraz@iie.org.mx; jhrm@iie.org.mx; jgarcia@iie.org.mx; mmmg@iie.org.mx; emp@iie.org.mx

    2010-11-15

    This article presents an overview of the application to have the gas turbine power generation systems, electric and steam for Mexican refineries. First there is a general description of the gas turbines and heat recovery (system components CHP) and CHP schemes are based on gas turbines capable of use in Mexican refineries. Subsequently referred to the characteristics of energy consumption (steam and electricity) from Mexican refineries and performs a technical analysis of CHP schemes based on gas turbines from the point of view of rates Q/W, power efficiencies and combined concluded that by their nature are very useful for refinery and gives some recommendations for improved implementation. [Spanish] En este articulo se presenta una vision general de la aplicacion que tienen las turbinas de gas en sistemas de generacion de energia electrica y vapor para refinerias mexicanas. Primeramente se da una descripcion general de las turbinas de gas y recuperadores de calor (componentes principales del sistema de cogeneracion) y se muestran los esquemas de cogeneracion basados en turbinas de gas susceptibles de utilizar en refinerias mexicanas. Posteriormente se mencionan las caracteristicas de consumos energeticos (vapor y energia electrica) de las refinerias mexicanas y se realiza un analisis tecnico de los esquemas de cogeneracion basado en turbinas de gas desde el punto de vista de tasas Q/W, eficiencias electricas y combinadas, concluyendose que por sus caracteristicas son muy utiles para refinerias y se dan algunas recomendaciones para su mejor aplicacion.

  4. Modelling and simulation of the steam line, the high and low pressure turbines and the pressure regulator for the SUN-RAH nucleo electric university simulator; Modelado y simulacion de la linea de vapor, las turbinas de alta y de baja presion y el regulador de presion para el simulador universitario de nucleo electricas SUN RAH

    Energy Technology Data Exchange (ETDEWEB)

    Lopez R, A. [DEPFI, Campus Morelos, en IMTA Jiutepec, Morelos, UNAM (Mexico)]. e-mail: andyskamx@yahoo.com.mx

    2003-07-01

    In the following article the development of a simulator that allows to represent the dynamics of the following systems: steam line, nozzle, vapor separator, reheater, high pressure turbine, low pressure turbine, power generator and the pressure regulator of a nucleo electric power station. We start from the supposition that this plant will be modeled from a nuclear reactor type BWR (Boiling Water Reactor), using models of reduced order that represent the more important dynamic variables of the physical processes that happen along the steam line until the one generator. To be able to carry out the simulation in real time the Mat lab mathematical modeling software is used, as well as the specific simulation tool Simulink. It is necessary to point out that the platform on which the one is executed the simulator is the Windows operating system, to allow the intuitive use that only this operating system offers. The above-mentioned obeys to that the objective of the simulator it is to help the user to understand some of the dynamic phenomena that are present in the systems of a nuclear plant, and to provide a tool of analysis and measurement of variables to predict the desirable behavior of the same ones. The model of a pressure controller for the steam lines, the high pressure turbine and the low pressure turbine is also presented that it will be the one in charge of regulating the demand of the system according to the characteristics and critic restrictions of safety and control, assigned according to those wanted parameters of performance of this system inside the nucleo electric plant. This simulator is totally well defined and it is part of the University student nucleo electric simulator with Boiling Water Reactor (SUN-RAH), an integral project and of greater capacity. (Author)

  5. Investigación y Desarrollo Experimental de una Turbina de Flujo Horizontal para el aprovechamiento de las corrientes de Río y su Conversión en Energía Térmica

    OpenAIRE

    Rivera, Zara Mariela

    2013-01-01

    Las corrientes de río son un recurso que se encuentra disponible a lo largo del territorio del País y cuyo potencial aún no ha sido aprovechado para la generación de energía con pequeñas turbinas. En este proyecto se presenta una turbina de eje horizontal para transformar la energía cinética de las corrientes de río en energía térmica o eléctrica, y suministrarlas a sectores rurales que carecen de este tipo de abastecimiento. Después de realizar el análisis de algunos ríos en función de los p...

  6. Borosonic inspection and remaining useful operational life estimation of steam turbine rotors; Inspeccion borosonica y estimacion de vida remanente de rotores de turbinas de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Carnero P, Jose A; Dorantes G, Oscar; Munoz Q, Rodolfo; Serrano R, Luis E. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2004-07-01

    The turbo-generators used in the electric power generation frequently go through transitory operations (start ups, shut downs or power changes). Such actions cause that certain critical components of the turbines, such as rotors and casings, are put under cycles of repetitive stresses, which consume its useful life. The frequency whereupon these transitory thermal cycles happen result in the presence of high thermo-mechanical stresses that produce fatigue (damage) in the rotor material. With time, at the increase of the material fatigue, fissures form that can inclusively lead to severe, catastrophic faults. The borosonic inspection consists in introducing and positioning an automatic probe in the central drill of the rotor, this allows the non-destructive inspection with longitudinal ultrasonic beam, ultrasonic cross-sectional and ultrasonic superficial. This way, it is possible to detect and locate geometric discontinuities (superficial and volumetric), in at least 100 mm of depth from the drill surface in its entire periphery and throughout the rotor length. [Spanish] Los turbogeneradores empleados en la generacion de energia electrica con frecuencia realizan operaciones transitorias (arranques, paros o cambios de potencia). Acciones tales, provocan que ciertos componentes criticos de las turbinas, como los rotores y carcasas, sean sometidos a ciclos de esfuerzos repetitivos, lo que consume su vida util. La frecuencia con que ocurren estos ciclos termicos transitorios da como resultado la presencia de altos esfuerzos termomecanicos que producen una fatiga (dano) en el material del rotor. Con el tiempo, al incrementarse la fatiga del material, se forman fisuras que pueden conducir a fallas severas, catastroficas inclusive. La inspeccion borosonica consiste en introducir y posicionar una sonda automatica en el barreno central del rotor, ello permite la inspeccion no destructiva con haz ultrasonico longitudinal, haz ultrasonico transversal y haz ultrasonico

  7. Combined cycle simulator with gas turbine and steam turbine with one vaporization stage; Simulador de ciclo combinado con turbina de gas y de vapor con un nivel de vaporizacion

    Energy Technology Data Exchange (ETDEWEB)

    Del Valle Cardenas, B.; Lugo Leyte, R. [Universidad Autonoma Metropolitana, Depto de Ingenieria de Procesos e Hidraulica, Mexico, D. F. (Mexico); Toledo Velazquez, Miguel; Tolentino Eslava, G. [Seccion de Estudios de Posgrado e Investigacion, Laboratorio de Ingenieria Termica e Hidraulica Aplicada, ESIME-IPN-COFFA, Mexico, D. F. (Mexico)

    1998-12-31

    This paper shows the thermal analysis of a combined cycle with gas and steam turbines with one vaporization stage. The analysis is performed through a computer program, which allows the simulation of cycles with different operational conditions, obtaining this way a series of results that permits to know the way these cycles behave in effecting temperature and pressure changes; besides of being an excellent tool in thermodynamics for the user. The simulators were performed in Borland C++ and Builder C++ Versions 4.5 and 2.0 respectively, creating in this way a friendly ambient for the user. This tool offers the opportunity to all its users the ability to simulate combined cycles in a fast and easy way in order to obtain a wider understanding of its thermodynamic behavior. [Espanol] En el presente trabajo se muestra el analisis termico de un ciclo combinado con turbinas de gas y de vapor con un nivel de vaporizacion. El analisis se realiza a traves de un programa de computo, el cual permite simular los ciclos con diferentes condiciones de operacion, obteniendo con esto una serie de resultados que permiten conocer la forma en que trabajan estos ciclos al realizar cambios en temperaturas y presiones; ademas de que es una excelente herramienta para el usuario en termodinamica. Los simuladores fueron realizados en Borland C++ y Builder C++ Versiones 4.5 y 2.0 respectivamente, creandose asi un ambiente amigable para el usuario. Esta herramienta brinda la oportunidad a todos los usuarios de poder simular ciclos combinados de una manera rapida y sencilla con el fin de obtener una comprension mas amplia de su comportamiento termodinamico.

  8. Combined cycle simulator with gas turbine and steam turbine with one vaporization stage; Simulador de ciclo combinado con turbina de gas y de vapor con un nivel de vaporizacion

    Energy Technology Data Exchange (ETDEWEB)

    Del Valle Cardenas, B; Lugo Leyte, R [Universidad Autonoma Metropolitana, Depto de Ingenieria de Procesos e Hidraulica, Mexico, D. F. (Mexico); Toledo Velazquez, Miguel; Tolentino Eslava, G [Seccion de Estudios de Posgrado e Investigacion, Laboratorio de Ingenieria Termica e Hidraulica Aplicada, ESIME-IPN-COFFA, Mexico, D. F. (Mexico)

    1999-12-31

    This paper shows the thermal analysis of a combined cycle with gas and steam turbines with one vaporization stage. The analysis is performed through a computer program, which allows the simulation of cycles with different operational conditions, obtaining this way a series of results that permits to know the way these cycles behave in effecting temperature and pressure changes; besides of being an excellent tool in thermodynamics for the user. The simulators were performed in Borland C++ and Builder C++ Versions 4.5 and 2.0 respectively, creating in this way a friendly ambient for the user. This tool offers the opportunity to all its users the ability to simulate combined cycles in a fast and easy way in order to obtain a wider understanding of its thermodynamic behavior. [Espanol] En el presente trabajo se muestra el analisis termico de un ciclo combinado con turbinas de gas y de vapor con un nivel de vaporizacion. El analisis se realiza a traves de un programa de computo, el cual permite simular los ciclos con diferentes condiciones de operacion, obteniendo con esto una serie de resultados que permiten conocer la forma en que trabajan estos ciclos al realizar cambios en temperaturas y presiones; ademas de que es una excelente herramienta para el usuario en termodinamica. Los simuladores fueron realizados en Borland C++ y Builder C++ Versiones 4.5 y 2.0 respectivamente, creandose asi un ambiente amigable para el usuario. Esta herramienta brinda la oportunidad a todos los usuarios de poder simular ciclos combinados de una manera rapida y sencilla con el fin de obtener una comprension mas amplia de su comportamiento termodinamico.

  9. Diseño y construcción de una turbina Pelton para generación eléctrica, capacidad 2 kW

    OpenAIRE

    Bustamante Cabrera, Edwin José; Arias Reyes, Cristian Paúl

    2008-01-01

    Las turbinas Pelton, se conocen como turbinas de presión por ser ésta constante en la zona del rodete, de chorro libre, de impulsión, o de admisión parcial por ser atacada por el agua sólo una parte de la periferia del rodete. Así mismo entran en la clasificación de turbinas tangenciales y turbinas de acción.

  10. Integration of a thermal stresses supervisory system and useful life of steam turbine rotors; Integracion de un sistema supervisorio de esfuerzos termicos y vida util de rotores de turbinas de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Carnero, Antonio; Serrano, Luis E. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Nebradt, G. Jesus; Leyva, M. Luis [Comision Federal de Electricidad, Mexico, D.F. (Mexico)

    2007-11-15

    lado, la mayor eficiencia de centrales de ciclo combinado con respecto a centrales convencionales se refleja en un mayor costo de produccion de la energia electrica, lo que ha obligado a que unidades convencionales de generacion disenadas para operar con carga base, ahora sean utilizadas como unidades de carga variable para satisfacer la demanda durante las horas de mayor demanda. Lo anterior, repercute en una mayor frecuencia de operaciones de paros y arranques en calientes de turbinas, por lo que el dano por fatiga se incrementara al cambiar su regimen de operacion. En Mexico existen turbinas que llevan 15 o 20 anos en operacion y que no cuenta con un supervisor de esfuerzos termicos, por lo que al cambiar su operacion de carga base a carga variable es imprescindible instalar un supervisor de esfuerzos termicos del rotor, con el fin de limitar o reducir los esfuerzos termicos y con ello reducir el dano por fatiga para extender asi su vida util esencial. El articulo trata sobre la integracion de un sistema supervisor de esfuerzos termicos, que a partir de los parametros de operacion de la turbina, se determina el gradiente de temperaturas en la zona de sellos de laberinto entre el paso de control y el primer paso de la seccion del alta presion del rotor, se calculan los esfuerzos termicos y mecanicos y la fatiga, determinando el consumo de vida util por cada ciclo de operacion (paro y arranque).

  11. Análise termodinâmica de um ciclo de potência com célula a combustível sofc e turbina a vapor - DOI: 10.4025/actascitechnol.v28i1.1287

    Directory of Open Access Journals (Sweden)

    Alexandre Sordi

    2006-03-01

    Full Text Available O objetivo deste artigo foi realizar a análise termodinâmica de um sistema híbrido, SOFC / ST (célula a combustível tipo SOFC e turbina a vapor ST. O combustível considerado para a análise foi o gás metano (biogás produzido por meio da digestão anaeróbica de resíduos orgânicos. A metodologia utilizada foi o balanço de energia do sistema SOFC / ST, considerando a reforma interna do metano na célula a combustível, de forma a obter a sua eficiência elétrica. O resultado foi comparado a um ciclo combinado convencional de turbina a gás e turbina a vapor (GT / ST para potências entre 10 MW e 30 MW. A eficiência do sistema híbrido SOFC / ST variou de 61% a 66% em relação ao poder calorífico do metano; e a eficiência do ciclo combinado GT / ST variou de 41% a 55% para o mesmo intervalo de potência. Para geração distribuída a célula a combustível SOFC é a tecnologia mais eficiente.

  12. Criteria for the provision and assembly of the rotor blades of a 300 MW low pressure steam turbine for electrical generation; Criterios para el suministro y ensambles de la alabes de rotor de turbina de vapor de 300 MW baja presion para generacion electrica

    Energy Technology Data Exchange (ETDEWEB)

    Bertin, Galo; Felix, Jorge A; Quijano, Octavio [Especialistas en Turbopartes, S.A. de C.V., Queretaro, Queretaro (Mexico)

    2007-11-15

    This paper presents some of the main criteria to consider from the inspection, disassembling and assembly of blades with different root types of a turbine rotor of steam turbines for power generation, having as an aim to count on a reliable rotor, fulfilling with the equipment original design and norms and international standards. [Spanish] Este trabajo presenta algunos de los criterios principales a considerar desde la inspeccion, desmontaje y montaje de alabes de diferentes tipos de raiz de un rotor de turbinas de vapor de generacion electrica, teniendo como finalidad contar con un rotor confiable, cumpliendo con el diseno original del equipo y con normas y estandares internacionales.

  13. Performance optimization methodology in a Francis turbine vacuum cleaner based on the modification of the boundary conditions; Metodologia de optimizacion del rendimiento en un aspirador de turbina Francis en base a la modificacion de las condiciones de frontera

    Energy Technology Data Exchange (ETDEWEB)

    Galvan Gonzalez, S.; Rubio Maya, C.; Mendoza Covarrubias, C. [Universidad Michoacana de San Nicolas Hidalgo, Morelia, Michoacan (Mexico)]. E-mail: srgalvan@umich.mx; crmaya@umich.mx; cmendoza@umich.mx; Pacheco Ibarra, J.; Martinez Patino, J. [Universidad de Guanajuato, Salamanca, Guanajuato (Mexico)

    2010-11-15

    This paper focus on establishing an optimization methodology for maximizing the draft tube performance as a function of the inlet velocity profile. The overall work is defined by four steps: the inlet velocity profile parametrization, the numerical optimization set-up, the numerical computational fluid dynamics (CFD) draft tube model and the objective function definition. However as the inlet velocity profile is a new challenge, each step of the parametrization must be properly validated. In the first step, a suitable parametrization with an appropriate number of variables is chosen to approximate an experimental draft tube inlet velocity profile. The second step considers the reduction of the actual numerical model to develop the CFD calculations. In the third step, the optimization algorithm set-up is specified. Finally, the objective function is evaluated. As each step is properly validated, it is considered this proved methodology will help to find an inlet velocity profile shape which will be able to suppress or mitigate the undesirable draft tube flow characteristics. [Spanish] Este documento se enfoca en establecer una metodologia de optimizacion para maximizar el rendimiento del tubo de aspiracion en funcion de las condiciones de frontera del aspirador. El metodo es definido en cuatro etapas: la parametrizacion del perfil de velocidades, la evaluacion del algoritmo de optimizacion, la valoracion de la funcion objetivo y la validacion del modelo numerico. La parametrizacion se realiza con un numero de variables apropiado para aproximar el perfil de velocidades experimental. El segundo paso considera establecer los parametros del algoritmo de optimizacion, la funcion objetivo es obtenida mediante un estudio de sensibilidad y el modelo numerico es validado y reducido en la cantidad de elementos para adecuarlo al proceso de optimizacion. Se considera que esta metodologia ayudara a encontrar un perfil de velocidad de entrada el cual reduzca las perdidas de

  14. Effect on the performance with the washing of the gas turbines Ruston TB5000 with a system of washing out of line in high contamination conditions; Efecto en el rendimiento con el lavado de las turbinas de gas Ruston TB5000 con un sistema de lavado fuera de linea en condiciones de alta contaminacion

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Diaz, Carlos Rodolfo; Aboites Davila, Fernando [CIATEQ, A.C., Queretaro (Mexico); Rocha Orozco, Moises [PEMEX Refinacion, Mexico, D.F. (Mexico)

    2007-11-15

    This paper shows the effects on the gas turbine performance with a washing system out of line, based on liquid detergent and water for the case of 2 Ruston TB5000 gas turbines located in conditions of high contamination in the atmosphere such as ashes, high humidity and temperature. The investigation was realized making periodical measurements of the main parameters of the turbo-pump during 1 year of operation with load conditions without stopping of about 125 mbpd (million of barrels per day) of gas LP. This article suggests how the low performance of the turbines in a hostile atmosphere can be improved and which could be the limitations of the washing systems based on liquid detergents. The data of the washing sessions were collected during a year and studied under statistical methods creating performance curves and comparing them with curves of other machines being washed with other washing systems. [Spanish] Este trabajo muestra los efectos en el rendimiento de la turbina de gas con un sistema de lavado fuera de linea, basado en detergente liquido y agua para el caso de 2 turbinas de gas Ruston TB5000 localizados en condiciones de alta contaminacion en el ambiente como cenizas, alta humedad y temperatura. La investigacion fue realizada haciendo mediciones periodicas de los parametros principales de turbo bomba durante 1 ano de operacion con condiciones de carga sin parar de alrededor de 125 mbpd (millones de barriles por dia) de gas LP. Este articulo sugiere como se puede mejorar el bajo desempeno de las turbinas en un ambiente hostil y cuales podrian ser las limitaciones de los sistemas de lavado basados en detergentes liquidos. Los datos de las sesiones de lavado fueron recolectados durante un ano y estudiados bajo metodos estadisticos creando curvas de rendimiento y comparandolas con curvas de otras maquinas siendo lavadas con otros sistemas de lavado.

  15. Code for the steam tables for pure water in visual basic 6.0.; Un codigo para las tablas de vapor para agua pura en visual basic 6.0

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Mahendra P. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2002-07-01

    The thermodynamic data of the water are of extreme importance in all of the branches of science and technology; the facilitate the understanding of the natural Earth processes. Nevertheless, for the electrical industry the water plays a very important role during the generation of electrical energy process. Different heat sources such as coal, oil, natural gas, nuclear fuel or the geothermal heat boil the water that forms the steam used to move the turbines. Consequently, the steam tables (the thermodynamic water data) are vital to model thermal and mass transference and physical-chemical processes during the generation of electrical energy. [Spanish] Los datos termodinamicos del agua son de suma importancia en todas las ramas de la ciencia y tecnologia, ellos facilitan el entendimiento de los procesos naturales de la Tierra. Sin embargo, para la industria electrica el agua juega un papel muy importante durante el proceso de generacion de energia electrica. Diferentes fuentes de calor tales como carbon, aceite, gas natural, combustible nuclear o el calor geotermico calientan el agua que forma el vapor utilizado para mover las turbinas. Luego entonces, las tablas de vapor (los datos termodinamicos de agua) son vitales para modelar transferencia termica y de masa y procesos fisico-quimico durante la generacion energia electrica.

  16. Análise termodinâmica de um ciclo de potência com célula a combustível sofc e turbina a vapor = Thermodynamic analysis of a power cycle such as SOFC fuel cell and steam turbine

    Directory of Open Access Journals (Sweden)

    Alexandre Sordi

    2006-01-01

    Full Text Available O objetivo deste artigo foi realizar a análise termodinâmica de um sistema híbrido, SOFC / ST (célula a combustível tipo SOFC e turbina a vapor ST. O combustível considerado para a análise foi o gás metano (biogás produzido por meio da digestão anaeróbica de resíduos orgânicos. A metodologia utilizada foi o balanço de energia dosistema SOFC / ST, considerando a reforma interna do metano na célula a combustível, de forma a obter a sua eficiência elétrica. O resultado foi comparado a um ciclo combinado convencional de turbina a gás e turbina a vapor (GT / ST para potências entre 10 MW e 30MW. A eficiência do sistema híbrido SOFC / ST variou de 61% a 66% em relação ao poder calorífico do metano; e a eficiência do ciclo combinado GT / ST variou de 41% a 55% para o mesmo intervalo de potência. Para geração distribuída a célula a combustível SOFC é atecnologia mais eficiente.The objective of this article was to analyze the thermodynamic of ahybrid system, SOFC / ST (SOFC fuel cell and ST steam turbine. The fuel for the analysis was the gas methane (biogas produced through the anaerobic digestion of the organic residues. The utilized methodology was the energy balance of the system SOFC / ST,considering the internal reforming of methane in the fuel cell, in a way to obtain its electric effectiveness. The result was compared to a conventional combined cycle of gas turbine and steam turbine (GT / ST for powers between 10 MW and 30 MW. The efficiency of the hybrid system SOFC / ST varied from 61 to 66% in relation to the lower heating value of methane; and the efficiency of the combined cycle GT / ST varied from 41 to 55% within the same power interval. For distributed generation, the SOFC fuel cell is the most efficienttechnology.

  17. Cooling system at the compressors air inlet of the gas turbines from the Tula`s combined cycle central; Sistema de enfriamiento en la succion del compresor de las turbinas de gas de la central de ciclo combinado de Tula

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez F, Oscar [Comision Federal de Electricidad, Tula (Mexico); Romero Paredes, Hernando; Vargas, Martin; Gomez, Jose Francisco [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

    1996-12-31

    It has been formerly evaluated that it is possible to enhance notably the electric power generation in gas turbine power plants by cooling the air at the compressor inlet. It has been pointed out that provided a source of waste heat is available it can be very attractive the use of absorption refrigeration systems. In this paper the technical and the economical benefits of bringing the air inlet temperature down 8 Celsius degrees of the four gas turbines of the Combined Cycle Central of Tula, in the State of Hidalgo (combined cycle central-Tula) are evaluated. The results show that it is possible to achieve an efficiency enhancement of at least 1%, and that in very warm days up to 48 additional Megawatts can be generated, or about 10% of the installed capacity. The final economic result is very encouraging and an annual economical benefit in the order of 50 million pesos can be obtained and the refrigeration units can be amortized in approximately one year. [Espanol] Se ha evaluado anteriormente que es posible mejorar notablemente la capacidad de generacion electrica en plantas que utilizan turbinas de gas, mediante el enfriamiento del aire de succion del compresor. Se ha senalado que en la medida en que se encuentre disponible una fuente termica de desecho puede ser muy atractivo el uso de sistemas de refrigeracion por absorcion. En el presente trabajo se evaluan los beneficios tecnicos y economicos que puede tener el llevar el aire de succion hasta una temperatura de 8 grados Celsius, de las cuatro unidades de gas de la Central de Ciclo Combinado de Tula, Hidalgo (CCC-Tula). Los resultados muestran que es posible alcanzar un aumento en la eficiencia de al menos 1% y que se pueden generar, en dias muy calurosos, hasta 48 MW extras, equivalente al 10% de la capacidad instalada. El resultado economico final es muy alentador y puede llegar a tenerse un beneficio economico del orden de los 50 millones de pesos anuales y las unidades de refrigeracion podran pagarse en

  18. Cooling system at the compressors air inlet of the gas turbines from the Tula`s combined cycle central; Sistema de enfriamiento en la succion del compresor de las turbinas de gas de la central de ciclo combinado de Tula

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez F, Oscar [Comision Federal de Electricidad, Tula (Mexico); Romero Paredes, Hernando; Vargas, Martin; Gomez, Jose Francisco [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

    1997-12-31

    It has been formerly evaluated that it is possible to enhance notably the electric power generation in gas turbine power plants by cooling the air at the compressor inlet. It has been pointed out that provided a source of waste heat is available it can be very attractive the use of absorption refrigeration systems. In this paper the technical and the economical benefits of bringing the air inlet temperature down 8 Celsius degrees of the four gas turbines of the Combined Cycle Central of Tula, in the State of Hidalgo (combined cycle central-Tula) are evaluated. The results show that it is possible to achieve an efficiency enhancement of at least 1%, and that in very warm days up to 48 additional Megawatts can be generated, or about 10% of the installed capacity. The final economic result is very encouraging and an annual economical benefit in the order of 50 million pesos can be obtained and the refrigeration units can be amortized in approximately one year. [Espanol] Se ha evaluado anteriormente que es posible mejorar notablemente la capacidad de generacion electrica en plantas que utilizan turbinas de gas, mediante el enfriamiento del aire de succion del compresor. Se ha senalado que en la medida en que se encuentre disponible una fuente termica de desecho puede ser muy atractivo el uso de sistemas de refrigeracion por absorcion. En el presente trabajo se evaluan los beneficios tecnicos y economicos que puede tener el llevar el aire de succion hasta una temperatura de 8 grados Celsius, de las cuatro unidades de gas de la Central de Ciclo Combinado de Tula, Hidalgo (CCC-Tula). Los resultados muestran que es posible alcanzar un aumento en la eficiencia de al menos 1% y que se pueden generar, en dias muy calurosos, hasta 48 MW extras, equivalente al 10% de la capacidad instalada. El resultado economico final es muy alentador y puede llegar a tenerse un beneficio economico del orden de los 50 millones de pesos anuales y las unidades de refrigeracion podran pagarse en

  19. Estimation of consumption of the useful life in the nozzles of a gas turbine by the phenomenon of thermal fatigue; Estimacion de consumo de vida util en las toberas de una turbina de gas por el fenomeno de fatiga termica

    Energy Technology Data Exchange (ETDEWEB)

    Perez Hernandez, Efrain [Centro Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico); Mazur C, Zdzislaw; Garcia Illescas, R. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-11-15

    damage. [Spanish] La estimacion de vida util en los componentes calientes de las turbinas de gas como toberas y alabes es importante ya que sufren de cambios criticos de temperatura los cuales producen fatiga termomecanica durante los arranques, paros y cambios de fatiga para estimacion de vida util en las toberas de turbina de gas fabricados de aleacion base cobalto FSX-414 en las cuales se han desarrollado grietas durante la operacion. La inspeccion visual y metalografia de la tobera revelo muchas grietas por fatiga termomecanica en la superficie del alabe ademas de deterioracion de la aleacion. En los limites de grano se encontro una pelicula continua de carburos y tambien aumento de fraccion de carburos dentro de los granos. Esta densa y continua red de carburos reduce la ductilidad y aumenta la fragilidad, junto con la reduccion de energia de impacto (Charpy), facilita la iniciacion y propagacion de grietas. La iniciacion y propagacion de grieta en la aleacion fue debido a un mecanismo de fatiga termica y termofluencia que fue facilitado por fragilidad del material debido al deterioro previamente mencionado y a significativos niveles de esfuerzos termomecanicos. En el presente articulo se presentan los resultados de analisis de esfuerzos termicos a partir de los resultados de temperatura obtenidas de estudios previos de un analisis de transferencia de calor y flujo de fluidos mediante el programa Star-CD basado en volumen finito. Se muestra la metodologia empleada y las distribuciones de esfuerzos, los cuales se emplearon para el analisis de fatiga para la estimacion de vida util. Para eso se utilizo un modelo de elementos finitos en el programa NISA, asi como el programa de analisis de fatiga nCode. Para el conteo de ciclo de utilizo el metodo de Rainflow y se compararon los modelos de vida por fatiga de Manson-Coffin, Basquin, Morrow y Smih-Watson-Topper. La variacion de las propiedades mecanicas con la temperatura de la superaleacion empleada en esos componentes

  20. Classification of the operating conditions of a Kaplan turbine according to its impact in the structural integrity of the runner; Clasificacion de las condiciones de operacion de una turbina Kaplan de acuerdo a su impacto en la integridad estructural del rodete

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, Luis M; Bautista, Eder A; Espitia, J Ernesto [Instituto Tecnologico de Pachuca, Pachuca, Hidalgo (Mexico); Mazur C, Zdzislaw [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-11-15

    Each one of the operating conditions of the turbine according to the impact they have in the structural integrity of the runner is evaluated. By means of CFD (Computational Fluid Dynamics) analysis the pressure that the working fluid exerts on the blade for the turbine operating conditions is obtained. The oscillating disturbances induced by the flow, the angular velocity of the runner and the cavitation effect have been considered. The value of maximum stress for each one of the operating conditions is related to its respective values of cavitation. With this information those operating conditions that induce the greater values of stress and represent greater wears away in the runner are determined. This way, it is possible to avoid the more severe operating conditions and if this is not possible, lineaments of redesign are established to obtain more favorable operating conditions for the runner. [Spanish] Se evaluan y clasifican cada una de las condiciones de operacion de la turbina de acuerdo al impacto que tienen en la integridad estructural del rodete. Mediante analisis de CFD (Computacional Fluid Dynamics) se obtiene la presion que el fluido de trabajo ejerce sobre el alabe para las condiciones de operacion de la turbina. Se han considerado las perturbaciones oscilatorias inducidas por el flujo, la velocidad angular del rodete y el efecto de la cavitacion. Se relacionan los valores de esfuerzo maximo para cada una de las condiciones de operacion con sus respectivos valores de cavitacion. Con esta informacion se determinan aquellas condiciones de operacion que inducen los mayores valores de esfuerzo y representan mayor desgaste en el rodete. De esta manera, es posible evitar las condiciones de operacion mas severas, y si esto no es posible, se establecen lineamientos de rediseno para obtener condiciones de operacion mas favorables para el rodete.

  1. Re-diseño de la línea de ejes de turbinas Francis de salto elevado para la mejora de su competitividad

    OpenAIRE

    GARCÍA MÓNACO, ALEJANDRO

    2015-01-01

    El objetivo de este proyecto es mejorar la línea de ejes de las turbinas Francis de eje horizontal. En especial, se ha trabajado con aquellas máquinas diseñadas para funcionar con saltos de agua elevados. El proyecto surge del conocimiento de importantes ventajas económicas de las turbinas horizontales frente a las verticales y de la voluntad por parte de ALSTOM HYDRO de mejorar los rendimientos de las primeras para hacerlas más competitivas. Los capítulos 3 y 4 son introductorios a la pro...

  2. Vapor recovery system in the gasolines commercialization; Sistema de recuperacion de vapores en la comercializacion de las gasolinas

    Energy Technology Data Exchange (ETDEWEB)

    Casas Barba, R.; Molina Gallegos, J.R. [Instituto Mexicano del Petroleo (IMP), Mexico, D. F. (Mexico)

    1995-12-31

    In the last years the studies performed with respect to the environmental pollution show that the ozone is one of the most problematic contaminants in the Metropolitan Zone of Mexico City (MZMC) and that the hydrocarbons are the main forerunners of it. The main source of hydrocarbon vapor emissions originates from the handling and distribution operations. In this paper a description is made of the involved stages in the commercialization of gasolines in the MZMC and a description is also made of the systems employed to control the emissions in the three stages of the fuels storage and distribution cycle and explains the degree the hydrocarbon emissions to the atmosphere will be reduced, once the recovery systems are installed in all of the involved stages. [Espanol] En los ultimos anos los estudios realizados con respecto a contaminacion ambiental reflejan que el ozono es uno de los contaminantes mas problematicos de la zona metropolitana de la ciudad de Mexico (ZMCM), y los hidrocarburos son los principales precursores de este. La principal fuente de emision de vapores de hidrocarburos proviene de las operaciones de manejo y distribucion de combustibles. En este articulo se hace una descripcion de las etapas involucradas en la comercializacion de las gasolinas en la ZMCM, se describen tambien los sistemas utilizados para controlar las emisiones en las tres etapas del ciclo de almacenamiento y distribucion de combustibles y se explica en que grado se reduciran las emisiones de hidrocarburos a la atmosfera, una vez que se instalen los sistemas de recuperacion en todas las etapas involucradas.

  3. Vapor recovery system in the gasolines commercialization; Sistema de recuperacion de vapores en la comercializacion de las gasolinas

    Energy Technology Data Exchange (ETDEWEB)

    Casas Barba, R; Molina Gallegos, J R [Instituto Mexicano del Petroleo (IMP), Mexico, D. F. (Mexico)

    1996-12-31

    In the last years the studies performed with respect to the environmental pollution show that the ozone is one of the most problematic contaminants in the Metropolitan Zone of Mexico City (MZMC) and that the hydrocarbons are the main forerunners of it. The main source of hydrocarbon vapor emissions originates from the handling and distribution operations. In this paper a description is made of the involved stages in the commercialization of gasolines in the MZMC and a description is also made of the systems employed to control the emissions in the three stages of the fuels storage and distribution cycle and explains the degree the hydrocarbon emissions to the atmosphere will be reduced, once the recovery systems are installed in all of the involved stages. [Espanol] En los ultimos anos los estudios realizados con respecto a contaminacion ambiental reflejan que el ozono es uno de los contaminantes mas problematicos de la zona metropolitana de la ciudad de Mexico (ZMCM), y los hidrocarburos son los principales precursores de este. La principal fuente de emision de vapores de hidrocarburos proviene de las operaciones de manejo y distribucion de combustibles. En este articulo se hace una descripcion de las etapas involucradas en la comercializacion de las gasolinas en la ZMCM, se describen tambien los sistemas utilizados para controlar las emisiones en las tres etapas del ciclo de almacenamiento y distribucion de combustibles y se explica en que grado se reduciran las emisiones de hidrocarburos a la atmosfera, una vez que se instalen los sistemas de recuperacion en todas las etapas involucradas.

  4. Detection of the high vibration origin in the body of an electrical generator driven by steam turbine applying diagnostic techniques; Deteccion del origen de alta vibracion en el cuerpo de un generador electrico accionado por turbinas de vapor aplicando tecnicas de diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Bravo, Fernando (Mexico)

    2007-11-15

    One of the problems that electric generators present is the high vibration due to causes that can go from simple mechanical unbalance, misalignment, mechanical relaxation, resonance or some other interaction that can influence in the system. In this document is presented the vibration analysis of an electric generator with a capacity of 350 MW, driven by a steam turbine composed of three stages (high pressure, intermediate pressure and low pressure) connected to the electric generator through a rigid connection. [Spanish] Uno de los problemas que se presentan en los generadores electricos es la alta vibracion debida a causas que pueden ir desde un simple desbalance mecanico, desalineamiento, aflojamiento mecanico, resonancia o alguna otra interaccion que pueda influir en el sistema. Se presenta en este documento el analisis de vibracion de un generador electrico con una capacidad de 350 MW, impulsado por una turbina de vapor compuesta de tres etapas (alta presion, presion intermedia y baja presion) acopladas al generador electrico a traves de un acoplamiento rigido.

  5. Detección de cavitación en turbina Francis

    OpenAIRE

    Pedro Ayuso, Jorge-Mauro de

    2004-01-01

    En el presente proyecto se pretenden aplicar y validar diversas técnicas de detección de cavitación, prestando especial atención a los fenómenos de cavitación erosiva, pues son estos los que mayor impacto pueden tener –en términos de reducción de la vida útil- sobre las turbinas hidráulicas. Tras una introducción teórica sobre el fenómeno de la cavitación en turbinas hidráulicas, se hace un breve recorrido por el estado del arte. A continuación, se presentan una serie de med...

  6. Estudio termodinámico de una planta de ciclo combinado con turbina de gas y pre-diseño del HRSG

    OpenAIRE

    Martín Díaz, Carlos Daniel

    2015-01-01

    Dentro del gran alcance que se puede dar a los estudios de plantas de ciclos combinados, el presente estudio se centra en analizar un ciclo combinado convencional con turbina de gas, y en condiciones de diseño. En concreto, se trata de realizar un análisis termodinámico de un ciclo combinado en configuración monoeje 1x1 con recalentamiento y tres niveles de presión, con turbina de gas refrigerada por sistema vapor-aire y posteriormente un análisis de transferencia de calor en los intercamb...

  7. Cálculo de la transmisión paralela helicoidal de la caja multiplicadora de una turbina eólica

    Directory of Open Access Journals (Sweden)

    César Alberto Chagoyén-Méndez

    2014-01-01

    Full Text Available La caja multiplicadora de una turbina eólica es el componente de mayor complejidad mecánica y es la responsable de la mayoría de la pérdida de tiempo operacional de la turbina y del incremento de los costos. La misma no alcanza una vida proyectada de 20 años. Todos los estudios hasta el momento indican que estas fallas surgen desde el proceso de diseño. Este trabajo tuvo como objetivo demostrar algunas de las insuficiencias de las normas actuales de diseño de las cajas multiplicadoras de las turbinas eólicas, a través de la realización de una comparación de los resultados del cálculo de la transmisión paralela helicoidal de una turbina eólica de 2,5 MW, realizados por tres vías: con las normas ISO 6336:2006 Método B y AGMA 2101-D04 ( Metric Edition y mediante simulación numérica. De este análisis resulta que no existen problemas de resistencia ni de rigidez en ambas transmisiones, sin embargo la diferencia entre estos tres métodos de cálculo es considerable.

  8. Analysis of the consumption of useful life by thermal fatigue in the gas turbine nozzles during the operation at continuous load and transients; Analisis de consumo de vida por fatiga termica en las toberas de turbina de gas durante operacion con carga continua y transitorios

    Energy Technology Data Exchange (ETDEWEB)

    Perez Hernandez, Efrain Betuel

    2007-08-15

    The gas turbines operate at extremely high temperatures, with high thermal and mechanical stresses, causing that the life of the involved components diminishes. In the present thesis the temperature distribution on the nozzle obtained in other investigation as a result of heat transfer and fluid flow analysis applying CDF code Star-CD was used. Next, the program NISA was used to perform the analysis of thermal stresses by means of finite element method. Finally, the results of stress analysis were introduced to the program nCode to accomplish the nozzle remaining useful life assessment due to thermal fatigue in critical location on the nozzle by means of the CLF module (Critical Location Fatigue). The full methodology used to determine the nozzle operational conditions, load history, material properties and the fatigue model used to determine the number of cycles to failure of the nozzle during constant load and transients operation is presented. [Spanish] Las turbinas de gas operan a temperaturas extremadamente altas, a elevados esfuerzos termicos y mecanicos, ocasionando que la vida de los componentes involucrados se reduzca. En la presente tesis se presentan los resultados realizados por otras investigaciones de temperaturas obtenidas a partir de un analisis de transferencia de calor y flujo de fluidos de la tobera mediante el programa Star-CD basado en volumenes finitos. Posteriormente, se utilizo el programa NISA para realizar el analisis de esfuerzos mediante elementos finitos. Finalmente, se llevaron los resultados al programa nCode para realizar la estimacion de vida util por fatiga termica en un punto critico de la tobera mediante el modulo CLF (Critical Location Fatigue). Se muestra la metodologia empleada para determinar las condiciones de operacion, historial de carga, propiedades del material y el modelo de dano por fatiga para determinar el numero de ciclo para falla de la tobera durante operacion con carga continua y transitorios.

  9. The aggressiveness of the geothermal steam controlled; La agresividad del vapor geotermico controlada

    Energy Technology Data Exchange (ETDEWEB)

    Mercado, Sergio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    The first two units of Cerro Prieto have generated electric energy since 1973; in 1988 completed 15 years of continuous operation, without corrosion problems in the turbines in spite of the utilization of geothermal steam. The experience and the good results obtained during the first years of operation of these two units of 37.5 MW each, were of great help for the Cerro Prieto extension, having as of this date an installed capacity of 620 MW. [Espanol] Las dos primeras unidades de Cerro Prieto han generado energia electrica desde 1973; cumplieron 15 anos de operacion continua en 1988, sin problemas de corrosion en las turbinas a pesar del uso de vapor geotermico. La experiencia y los buenos resultados obtenidos durante los primeros anos de operacion de estas dos unidades de 37.5 MW cada una fueron de gran apoyo para la aplicacion de Cerro Prieto, teniendose a la fecha 620 MW de capacidad instalada.

  10. The aggressiveness of the geothermal steam controlled; La agresividad del vapor geotermico controlada

    Energy Technology Data Exchange (ETDEWEB)

    Mercado, Sergio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1989-12-31

    The first two units of Cerro Prieto have generated electric energy since 1973; in 1988 completed 15 years of continuous operation, without corrosion problems in the turbines in spite of the utilization of geothermal steam. The experience and the good results obtained during the first years of operation of these two units of 37.5 MW each, were of great help for the Cerro Prieto extension, having as of this date an installed capacity of 620 MW. [Espanol] Las dos primeras unidades de Cerro Prieto han generado energia electrica desde 1973; cumplieron 15 anos de operacion continua en 1988, sin problemas de corrosion en las turbinas a pesar del uso de vapor geotermico. La experiencia y los buenos resultados obtenidos durante los primeros anos de operacion de estas dos unidades de 37.5 MW cada una fueron de gran apoyo para la aplicacion de Cerro Prieto, teniendose a la fecha 620 MW de capacidad instalada.

  11. Diseño constructal de álabes de turbina de gas refrigerados mediante conductos elipticos

    OpenAIRE

    Bosc, Cristian

    2017-01-01

    Las turbinas de gas (en adelante TG), son máquinas térmicas utilizadas para transformar la energía liberada en la combustión de un hidrocarburo, en potencia o trabajo. La parte crítica en el diseño de una TG, recae en las secciones expuestas a condiciones extremas. La temperatura de entrada al rotor (RIT, por sus siglas en inglés, “rotor inlet temperature”) es la variable crítica que limita la eficiencia y la durabilidad. La eficiencia está limitada por la máxima temperatura que pueden soport...

  12. Protitlaková parní turbina

    OpenAIRE

    Kubiš, Zdeněk

    2013-01-01

    Tématem diplomové práce je návrh jednotělesové parní turbiny o výkonu 60 MW pro dvoustupňový ohřev topné vody. Turbina je určena pro kogenerační cyklus, má čtyři neregulované odběry a výstup dolů do topného ohříváku. Nejprve je proveden tepelný výpočet turbiny pro provoz se 100 % páry. Dále je vypracován detailní návrh průtočného kanálu spolu s pevnostním výpočtem lopatek a rozváděcích kol. V závěru práce jsou porovnány požadované provozy a uvedena příslušná bilanční schémata. Součástí práce ...

  13. TRAZADO DE CURVAS DE POTENCIA DE UNA TURBINA EÓLICA DE EJE VERTICAL CON GEOMETRÍA VARIABLE

    OpenAIRE

    Mario F. Bergoglio; Carlos G. Medaglia; Javier A. Carletto; Víctor Rodrigo

    2017-01-01

    En este trabajo se describe el diseño y las primeras pruebas de una turbina eólica de eje vertical con geometría va riable, diseñado y construido íntegramente en la Facultad de Ingeniería y Ciencias Agropecuarias de la Universidad Nacional de San Luis - Argentina. Los ensayos de laboratorio, tendientes a conocer el comportamiento integral y determinar los valores de potencia que puede entregar el dispositivo se realizaron en un túnel de viento somet...

  14. Criterios para la determinación del número de cucharas en una turbina Pelton

    OpenAIRE

    Octavio Jaramillo Valencia; José Fernando Baquero Herrera

    2011-01-01

    Los criterios descritos en el presente artículo se aplican en los programas de computador del proyecto de grado "Comportamiento Hidráulico de Cucharas Pelton", calificado con la distinción de meritorio, en el cual a partir de la altura neta, el caudal y la velocidad angular, se determina la geometria de las cucharas. Forma parte del programa de investigación que la Facultad de Ingeniería está llevando a cabo con el propósito de desarrollar turbinas Pelton de baja potencia con la financiación ...

  15. Diseño y fabricación de un prototipo a pequeña escala de una turbina de aire, para el aprovechamiento de la energía marina, a bajo coste mediante técnicas de prototipado rápido

    OpenAIRE

    Salueña Berna, Javier; Ortiz Marzo, José Antonio; Raso Bautista, A.

    2009-01-01

    Existen diferentes procedimientos para aprovechar la energía de las olas [1]. El procedimiento que cuenta con mayor rendimiento y menor coste de mantenimiento es el de Columna Oscilante de Agua (OWC). El sistema consiste en la generación del movimiento de una turbina con el aire generado por el vaivén de la olas, con el problema añadido de que el flujo de aire es bidireccional. Actualmente la única turbina que puede girar en un solo sentido independientemente del sentido del flujo de aire es ...

  16. Analysis of the malfunctioning and failure of a 15 MW hydraulic turbine; Analisis de malfuncionamiento y de falla de una turbina hidraulica de 15 MW

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Illescas, R.; Perez Rodriguez, N. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-11-15

    A case history is presented of the rehabilitation process of three hydraulic turbines with a capacity of 15 MW each one. Such units are used for electric power generation, mainly to supply part of the center zone of the Mexican Republic. The turbo-generator units had been practically destroyed by catastrophic floods and only part of the equipment was recovered and reconditioned for its operation. One of the three turbines presented serious functioning problems preventing its reliable operation that was evidenced by excessive mechanical vibrations and heating in the bearing zone. This paper presents the diagnosis of the possible causes of failure and the corrective measures taken. Serious rotor misalignment problems were observed respect to its bearings and the turbine scroll. Additionally, during the inspection of the turbine runner and of the bearing it was observed that important friction have existed, which incremented the vibrations. It is shown that such rubbings are not the cause of the problem but only a manifestation of the same. Finally some of the conclusions and their solution are presented. [Spanish] Se presenta un caso historico del proceso de rehabilitacion de tres turbinas hidraulicas con capacidad de 15 MW cada una. Dichas unidades son empleadas en la generacion electrica, principalmente para abastecer parte de la zona centro de la republica mexicana. Las unidades turbogeneradores habian sido practicamente destruidas por inundaciones catastroficas y solo parte del equipo fue rescatado y rehabilitado para su operacion. Una de las tres turbinas presento graves problemas de funcionamiento, impidiendo su operacion confiable, lo cual se manifestaba mediante vibraciones mecanicas excesivas y calentamiento en zona de chumaceras. En este articulo se presenta el diagnostico de las posibles causas de falla y las acciones correctivas tomandas. Se observan problemas fuertes de desalineamiento del rotor respecto a sus chumaceras y al caracol de la turbina

  17. Analysis of the fault and malfunctioning of a 15 MW hydraulic turbine; Analisis de la falla y malfuncionamiento de una turbina hidraulica de 15 MW

    Energy Technology Data Exchange (ETDEWEB)

    Garcia I, Rafael; Perez R, Norberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-07-01

    An historical case of the rehabilitation process of three hydraulic turbines with capacity of 15 MW each is presented. These units are used for the electrical generation, mainly to supply part of the central zone of the Mexican Republic. The turbo-generator units had been practically destroyed by catastrophic floods and only part of the equipment was rescued and rehabilitated for its operation. One of the three turbines presented serious operational problems, preventing its reliable operation evidenced by the excessive mechanical vibrations and heating of the bearing zone. This article presents the diagnosis of the possible causes of fault and the remedial actions taken. Strong misalignment problems of the runner with respect to its bearings and to the scroll case of the turbine are observed. In addition, during the inspection of the turbine runner and of the bearings it is observed that important frictions have existed, which increased the vibrations. It is shown that these frictions are not the cause of the problem but only one manifestation of the same. Finally some conclusions of the problem and their solution are presented. [Spanish] Se presenta un caso historico del proceso de rehabilitacion de tres turbinas hidraulicas con capacidad de 15 MW cada una. Dichas unidades son empleadas en la generacion electrica, principalmente para abastecer parte de la zona centro de la Republica Mexicana. Las unidades turbogeneradores habian sido practicamente destruidas por inundaciones catastroficas y solo parte del equipo fue rescatado y rehabilitado para su operacion. Una de las tres turbinas presento graves problemas de funcionamiento, impidiendo su operacion confiable, lo cual se manifestaba mediante vibraciones mecanicas excesivas y calentamiento en zona de chumaceras. En este articulo se presenta el diagnostico de las posibles causas de falla y las acciones correctivas tomadas. Se observan problemas fuertes de desalineamiento del rotor respecto a sus chumaceras y al

  18. Recubrimientos contra la corrosión a alta temperatura para componentes de turbinas de gas

    Directory of Open Access Journals (Sweden)

    Agüero, A.

    2007-10-01

    Full Text Available Hot section gas turbine components are made of superalloys, developed to withstand high temperatures in conditions in which mechanical stresses are high and that require high surface stability. However, during the 50s it became evident that compositions resulting in high mechanical strength for these materials were not compatible with those offering optimal protection from the working environments. The idea of employing protective coatings over materials with high mechanical strength resulted therefore from this situation. Presently, both aeronautic and power generation turbines operate at temperatures within the 900-1400 °C, thanks to these coatings, indispensable for their correct operation. In this work, the principal degradation mechanisms in these operating conditions and the different type of coatings presently employed by the industrial sector are described, beginning by the oldest Ni or Co aluminides, following with the addition of other metals such as Pt, Cr, etc. to the former coatings in order to increase their useful life, continuing with the overlay MCrAlY coatings and finishing with the thermal barrier coating systems. Moreover, the corresponding deposition techniques industrially employed to deposit these coatings are described, and finally, an insight of the latest research lines currently being developed is also included.

    Los componentes de las zonas calientes de las turbinas de gas están hechos de superaleaciones desarrolladas para soportar altas temperaturas, en condiciones en que las tensiones mecánicas son relativamente altas y en las que se requiere una alta estabilidad superficial. Sin embargo, durante la década de 1950-60, se hizo evidente que las composiciones que aumentaban la resistencia mecánica de estos materiales y aquellas que ofrecían una óptima protección contra ambientes agresivos no eran compatibles. Esto, condujo a la idea de emplear recubrimientos protectores sobre materiales con alta

  19. Efecto de las condiciones de secado sobre el endurecimiento de los granos de caraota (Phaseolus vulgaris pretratados con vapor

    Directory of Open Access Journals (Sweden)

    María Virginia Mujica

    2017-12-01

    Full Text Available El endurecimiento de los granos de caraota (Phaseolus vulgaris generado por el almacenamiento en condiciones de alta temperatura y humedad relativa representa una limitante importante para su consumo. El objetivo del presente trabajo fue evaluar el efecto de un tratamiento con vapor y luego secado a los granos de P. vulgaris recién cosechados en la prevención de su endurecimiento. Inicialmente, se construyeron las curvas de secado a 40; 47,5 y 55 ºC. Seguidamente, los granos se trataron con vapor por 8 min 20 s y se sometieron a un proceso de secado, bajo un diseño central compuesto cuyos factores fueron la temperatura del aire (40 y 55 ºC y el tiempo de secado (4 y 8 h. La muestra secada de cada tratamiento se dividió en 3 lotes, el primero se analizó de inmediato y los otros se almacenaron por 5 semanas bajo 2 condiciones distintas 5 ºC/34 % HR y 37 ºC/75 % HR. Las determinaciones realizadas fueron humedad, capacidad de imbibición, tiempo de cocción y actividad de la peroxidasa soluble. El tiempo de secado fue de 6,5; 5 y 2,5 h a 40; 47,5 y 55 ºC, respectivamente, para alcanzar una humedad de 13 % (b.s.. El coeficiente de difusión resultó igual a 3,40x10-9; 3,52x10-9 y 3,87x10-9 m2/s, a 40, 47,5 y 55 ºC, respectivamente. El valor de la energía de activación fue de 7,33 kJ/mol. La aplicación de vapor y posterior secado de los granos no previno su endurecimiento, y este no dependió de la actividad de la peroxidasa soluble. Por lo que se puede inferir que los compuestos fenólicos y la enzima peroxidasa no son los únicos implicados en el mecanismo de endurecimiento de los granos de P. vulgaris.

  20. Enhancement of C/C-LAS joint using aligned carbon nanotubes prepared by injection chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Feng-Ling; Fu, Qian-Gang, E-mail: fuqiangang@nwpu.edu.cn; Feng, Lei; Shen, Qing-Liang

    2016-01-05

    Carbon nanotubes (CNTs) enhanced carbon/carbon-lithium aluminum silicate (C/C-LAS) joint was prepared by a three-step technique of pack cementation, injection chemical vapor deposition (ICVD) and hot-pressing. A layer of aligned CNTs was grown on the surface of SiC coated C/C composites by ICVD method, and the joint was obtained by hot-pressing with magnesium aluminum silicate (MAS) as the interlayer. SEM observation reveals that the introduced CNTs result in the formation of a dense and crack-free CNT/MAS nanocomposite interface between SiC and MAS. Compared with the joints without CNTs, the average shear strength of the joints reinforced by CNTs was improved by 48% accompanied by an obvious change in failure mode from brittle fracture without CNTs to plastic fracture with CNTs. The pulling-out and bridging of CNTs on the fracture surfaces had a positive effect on the strength enhancement of the C/C-LAS joint.

  1. Metalurgia de alabes móviles con banda integrada de turbinas de gas y su influencia sobre el comportamiento de los alabes

    Directory of Open Access Journals (Sweden)

    Mazur, Z.

    1999-02-01

    Full Text Available The influence of the microstructure of the gas turbine blades with integral shroud on the blades performance is presented. The analysis of the solidification process of the gas turbine blades during conventionally casting process (equiaxed grains with all elements which has influence on the mode of its solidification and variation of the microstructure is carried out. Also, the evaluation of the failure of the gas turbine blade is presented. A detailed analysis of the blade tip shroud microstructure (presence of the equiaxed and columnar grains and its influence on the failure initiation and propagation is carried out. Finally, conclusions and some necessary improvements of the blades casting process to prevent blades failures are presented.

    Se presenta la influencia de la microestructura en el comportamiento de los alabes móviles con banda integrada de turbinas de gas bajo condiciones reales de trabajo. Para el proceso de vaciado convencional (granos equiaxiales de los alabes de turbinas de gas se lleva a cabo el análisis del proceso de solidificación presentando todos los elementos que influyen al modo de solidificación de un alabe y en la variación de la microestructura resultante. Se hace la evaluación de la falla de un alabe con la banda integrada de turbina de gas presentando el mecanismo de la falla y la influencia de la microestructura de la banda del alabe al inicio y propagación de la falla. Finalmente, se presentan las conclusiones determinando los elementos principales de la microestructura que influyen en el comportamiento de los alabes y las medidas preventivas para adecuar la microestructura a las condiciones de trabajo de los alabes.

  2. Fundaciones para turbinas eólicas costa afuera Foundations for offshore wind turbines

    Directory of Open Access Journals (Sweden)

    Felipe Alberto Villalobos Jara

    2009-01-01

    Full Text Available Este artículo describe el comienzo y la evolución de la hoy en día creciente mundialmente industria de la energía eólica costa afuera. Como un caso particular, se describe la actual política de energías renovables en el Reino Unido. Se explican las características de las cargas ambientales existentes costa afuera, tipos de suelos del fondo marino y las fundaciones que se utilizan comúnmente. El tipo de estructura y régimen de carga establecen nuevas condiciones desde el punto de vista de la Ingeniería Civil. Se presentan las cámaras a succión como una fundación alternativa para turbinas de viento costa afuera. Las cámaras a succión son actualmente una alternativa aceptada en vez de usar pilotes en aplicaciones para la industria del petróleo y el gas. Sin embargo, este no es el caso todavía en aplicaciones para aerogeneradores costa afuera.This paper describes the beginning and evolution of the now worldwide growing offshore wind energy industry. In particular, the current renewable energy policy in the UK is described. The characteristics of the environmental loads offshore, type of seabed soils and foundations commonly adopted are explained. The type of structure and loading regime establish new conditions from a Civil Engineering point of view. Suction caissons are introduced as an alternative foundation for offshore wind turbines. Suction caissons are currently an accepted alternative to pile foundations in applications for the oil and gas industry. However, this is not yet the case in applications for offshore wind turbines.

  3. Criterios para la determinación del número de cucharas en una turbina Pelton

    Directory of Open Access Journals (Sweden)

    Octavio Jaramillo Valencia

    1985-05-01

    Full Text Available Los criterios descritos en el presente artículo se aplican en los programas de computador del proyecto de grado "Comportamiento Hidráulico de Cucharas Pelton", calificado con la distinción de meritorio, en el cual a partir de la altura neta, el caudal y la velocidad angular, se determina la geometria de las cucharas. Forma parte del programa de investigación que la Facultad de Ingeniería está llevando a cabo con el propósito de desarrollar turbinas Pelton de baja potencia con la financiación de Colciencias y bajo la dirección del Ingeniero Alvaro Rey Romero.

  4. ANÁLISE DOS PARÂMETROS DE FUNCIONAMENTO E SIMULAÇÃO COMPUTACIONAL EM UM PROTÓTIPO DE TURBINA OPERANDO A AR COMPRIMIDO

    Directory of Open Access Journals (Sweden)

    Wesley Saldanha Nogueira Oliveira

    2016-12-01

    Full Text Available RESUMO. Este trabalho apresenta os resultados iniciais da comparação de alguns parâmetros de funcionamento do protótipo de uma turbina de ação simples, operando com ar comprimido como fluido de trabalho, realizados na unidade do SENAI de Barra do Piraí/RJ. O protótipo foi desenvolvido integralmente no Centro Universitário Geraldo Di Biase - UGB - Campus de Barra do Piraí/RJ, que inicialmente teve como o fluido de trabalho o vapor d’água, que nos testes inicias se mostrou ineficiente. A simulação computacional do sistema foi feita através do software SolidWorks na Universidade Federal Fluminense - UFF - Campus de Volta Redonda/RJ, o que permitiu determinar a faixa de trabalho que apresentou maior eficiência nos resultados experimentais do sistema por meio da relação entre pressão de operação, velocidade angular transmitida pelo fluido ao eixo da turbina e a potência da mesma. Os valores nas simulações em velocidade tangencial na região rotacional apresentaram-se convergentes aos valores experimentais medidos no protótipo.

  5. The decrease of the energy performance for the soiling of the air filters in gas turbines; Disminucion de la eficiencia energetica por ensuciamiento de filtros de aire en turbinas de gas

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, H.; Ambriz, J. J.; Vargas, M.; Godinez, M.; Gomez, F.; Valdez, L.; Pantoja, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Mexico D. F. (Mexico)

    1995-12-31

    The object of this paper is to study the effect in the turbine output of a gas turbine of the conditions of the compressor air inlet in going through a series of filters. The algorithm for the calculation of the energy losses due to the variation of the pressure drop caused by the filters according to their cleanliness condition. In the first part the series of variables that affect the gas turbines performance are exemplified, afterwards the characteristics of the air flow into a turbine are presented as well as their effects on the system. Later on, the results obtained of the system simulation are presented and compared with a real case. From the results it can be determined, that depending on the system and on the environment conditions the efficiency drop might be up to 3%, in accordance with the filters cleanliness. The maintenance periods strongly depend on the air quality variations at the filter house inlet in the zone where the power plant is located. [Espanol] El presente trabajo tiene por objetivo estudiar el efecto en la potencia generada en una turbina de gas de las condiciones de entrada del aire al compresor de una turbina de gas al pasar por un conjunto de filtros. Se presenta el algoritmo para la determinacion de las perdidas energeticas debidas a la variacion de la caida de presion generada por los filtros de acuerdo con su estado de limpieza. En la primera parte se ejemplifica el conjunto de variables que influyen en la eficiencia de las turbinas de gas, posteriormente se mencionan las caracteristicas de flujo de aire hacia una turbina y se muestran los efectos sobre el sistema. A continuacion se presentan los resultados obtenidos de la simulacion del sistema y se comparan con un caso real. De los resultados se puede apreciar que, dependiendo del sistema y de las condiciones ambientales el decremento en la eficiencia puede ser hasta del 3% en funcion del nivel de limpieza de los filtros. Los periodos de mantenimiento dependen fuertemente de las

  6. The decrease of the energy performance for the soiling of the air filters in gas turbines; Disminucion de la eficiencia energetica por ensuciamiento de filtros de aire en turbinas de gas

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, H; Ambriz, J J; Vargas, M; Godinez, M; Gomez, F; Valdez, L; Pantoja, G [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Mexico D. F. (Mexico)

    1996-12-31

    The object of this paper is to study the effect in the turbine output of a gas turbine of the conditions of the compressor air inlet in going through a series of filters. The algorithm for the calculation of the energy losses due to the variation of the pressure drop caused by the filters according to their cleanliness condition. In the first part the series of variables that affect the gas turbines performance are exemplified, afterwards the characteristics of the air flow into a turbine are presented as well as their effects on the system. Later on, the results obtained of the system simulation are presented and compared with a real case. From the results it can be determined, that depending on the system and on the environment conditions the efficiency drop might be up to 3%, in accordance with the filters cleanliness. The maintenance periods strongly depend on the air quality variations at the filter house inlet in the zone where the power plant is located. [Espanol] El presente trabajo tiene por objetivo estudiar el efecto en la potencia generada en una turbina de gas de las condiciones de entrada del aire al compresor de una turbina de gas al pasar por un conjunto de filtros. Se presenta el algoritmo para la determinacion de las perdidas energeticas debidas a la variacion de la caida de presion generada por los filtros de acuerdo con su estado de limpieza. En la primera parte se ejemplifica el conjunto de variables que influyen en la eficiencia de las turbinas de gas, posteriormente se mencionan las caracteristicas de flujo de aire hacia una turbina y se muestran los efectos sobre el sistema. A continuacion se presentan los resultados obtenidos de la simulacion del sistema y se comparan con un caso real. De los resultados se puede apreciar que, dependiendo del sistema y de las condiciones ambientales el decremento en la eficiencia puede ser hasta del 3% en funcion del nivel de limpieza de los filtros. Los periodos de mantenimiento dependen fuertemente de las

  7. La tecnología del vapor aplicada en las Minas de Almadén. Desde su origen hasta el Consejo de Administración

    OpenAIRE

    Calderón Herrera, David

    2017-01-01

    La desaparición de un gran número de elementos importantes del patrimonio industrial está siendo compensada en los últimos años con el incremento de la labor investigadora tradicional combinada con el uso de las técnicas de reconstrucción virtual, lo que le ha dado un nuevo impulso a la recuperación y puesta en valor de éste patrimonio acercándolo con ello a la sociedad. En este trabajo de investigación se estudia la etapa de instalación de la tecnología del vapor en las minas de Almadén (Ciu...

  8. Mitigación de la cavitación de extremo de alabe mediante la implementación de inyección de aire en un modelo a escala reducida de turbina Kaplan

    OpenAIRE

    Rivetti, Arturo; Angulo, Mauricio Abel; Lucino, Cecilia Verónica; Liscia, Sergio Oscar

    2015-01-01

    Las Turbinas Kaplan que operan en condiciones de alta carga pueden estar sometidas a vibraciones excesivas, ruido y cavitación. En estos casos puede presentarse erosión por cavitación sobre el anillo de descarga asociada al desarrollo de cavitación de extremo de alabe. Este fenómeno involucra características de diseño tales como sobreapertura de los alabes del distribuidor; perfil de los alabes del rodete; el incremento del huelgo debido a la apertura del alabe; la altura neta de aspiración; ...

  9. Contribución a la caracterización experimental y al modelado de turbinas de geometría variable en grupos de sobrealimentación.

    OpenAIRE

    Cervelló Romero, Carmen

    2008-01-01

    La incorporación generalizada de los sistemas de sobrealimentación a los motores diesel de automoción está haciendo imprescindible desarrollar un nivel de investigación capaz de profundizar en los factores que influyen en el funcionamiento y rendimiento de los turbogrupos acoplados a los motores de combustión interna alternativos.En esta tesis se presentan dos herramientas que van a permitir progresar en el estudio de los turbogrupos y en especial en las turbinas de geometría variable. En pri...

  10. Conditioned food aversion to control outbreaks of intoxication by Ipomoea carnea and Turbina cordata in goats

    Science.gov (United States)

    Conditioned food aversion is used to train livestock to avoid the ingestion of toxic plants. This technique was used to control Turbina cordata poisoning in goats in one farm, and to control Ipomoea carnea subsp. istulosa poisoning in another farm. The goats were penned at night and the next mornin...

  11. Diffuse control of gas turbines in power stations of combined cycle; Contral difuso de turbinas de gas en centrales de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez P, Marino; Garduno R, Raul; De Lara J, Salvadror; Castelo C, Luis [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2001-07-01

    In this article the application of the technology of the fuzzy logic to the control of gas turbines is presented in order to evaluate it in one of the most difficult processes and with stricter control requirements that exist in the electrical generation industry. For being important for the generation electrical sector, given their use in Comision Federal de Electricidad (CFE), the first selected prototype was the gas turbines model W501 of Westinghouse, installed in the of combined cycle power stations of Dos Bocas, Veracruz, Gomez Palacio, Durango and Tula, Hidalgo, Mexico. The second selected prototype was the one of the turbo gas units type 5001 (that applies to the GE 5001 models and Westinghouse of series 191 and 251). Based on the analysis of the performance of the system of conventional control previously made, the controllers of speed and generation of electrical power were selected to be replaced by diffuse controllers. [Spanish] En este articulo se presenta la aplicacion de la tecnologia de la logica difusa al control de turbinas de gas con el proposito de evaluarla en uno de los procesos mas dificiles y con requerimientos mas estrictos de control que existen en la industria de generacion electrica. Por ser importantes para el sector electrico de generacion, dada su utilizacion en Comision Federal de Electricidad (CFE), el primer prototipo seleccionado fueron las turbinas de gas modelo W501 de Westinghouse, instaladas en la central de ciclo combinado de Dos Bocas, Veracruz, Gomez Palacio, Durango y Tula, Hidalgo, Mexico. El segundo prototipo seleccionado fue el de unidades turbogas tipo 5001 (que aplica a los modelos GE 5001 y Westinghouse de la serie 191 y 251). Basados en el analisis del desempeno del sistema de control convencional realizado previamente, los controladores de velocidad y de generacion de potencia electrica fueron seleccionados para ser sustituidos por controladores difusos.

  12. Rotor optimization of a Francis type hydraulic turbine through the computer flow analysis (CFD); Optimizacion del rodete de una turbina hidraulica tipo Francis a traves del analisis computacional del flujo (CFD)

    Energy Technology Data Exchange (ETDEWEB)

    Rosado Tamariz, Erick

    2007-06-15

    basicas para el analisis de flujo y el proceso de optimizacion en las turbinas, los cuales consisten en: modelado de flujo a traves de toda la turbina (conjunto), o bien el modelado de cada componente por separado, obteniendo resultados satisfactorios por ambas metodologias. En la mayoria de los casos implementando el metodo de volumen finito (MVF), con consideraciones de flujo no viscoso, con la implementacion de los modelos de dos ecuaciones para la solucion de las ecuaciones que rigen el flujo turbulento. Asi mismo, se utilizan tecnicas de optimizacion que se basan en la parametrizacion geometrica, el planteamiento de una funcion objetivo y en la disminucion del fenomeno de cavitacion. En el presente trabajo se presenta la optimizacion de un rodete de una turbina hidraulica tipo Francis modelo, considerando tres condiciones de carga (75%, 85% y 100%) a traves de la dinamica de fluidos computacionales (CFD) como parte de un analisis hidraulico para la modernizacion de una unidad de generacion de potencia. Se realiza la optimizacion del rodete de una turbina tipo Francis, mediante un analisis previo de CFD mediante el MVF, considerando los efectos viscosos del fluido y el modelo de turbulencia Sparlat-Allmaras; modelando el distribuidor y el rodete por separado. Posteriormente se realiza la generacion de un modelo parametrico del rodete y se configura la simulacion para la generacion de la base de datos. Finalmente se plantea una funcion objetivo para con ello obtener la geometria optima de los alabes del rodete. Los resultados se presentan en forma grafica donde se muestra la distribucion de presiones del rodete original y el rodete optimizado; de igual forma, se comparan las formas geometricas y los resultados globales de desempeno (potencia y rendimiento) de ambos rodetes.

  13. Estimación del Error en un Medidor de Turbina con Insuficientes Tramos Rectos Estimación del Error en un Medidor de Turbina con Insuficientes Tramos Rectos

    Directory of Open Access Journals (Sweden)

    Francisco Martínez González

    2012-02-01

    Full Text Available In agricultural pumping plants flowmeters are frequently installed with insufficient straight sections of pipe both upstream and downstream from the meter, in order to meet the established installation specifications. It has been found that flowmeter manufacturers do not know the error rate in flow measurements under these no optimal conditions. In 1998, Hanson found that a propeller flowmeter had an error of 3,5 % when it was installed in a position a distance of two pipe diameters downstream from an elbow. This project investigated the performance of a turbine flowmeter under no optimal upstream and downstream conditions (conditions not considered by Hanson. Experiments were carried out in the Hydraulic Laboratory of the University of Guanajuato. Measurements were made in different flowmeter positions considering different flow rates. Results from this project showed that the flowmeter does not have a large error, even if it is installed in an incorrect position. However, lowest error rate is obtained when it was installed in the position recommended by the manufacturer. En pozos agrícolas, frecuentemente se presenta el caso de trenes de descarga con insuficientes tramos rectos para cumplir las especificaciones de instalación de medidores de flujo. Los fabricantes no conocen la variación del error de medición en que se incurre si los medidores se colocan bajo condiciones de insuficientes tramos rectos. Hanson (1998 encontró que un medidor de propela presenta un error de 3,5 % si se coloca con dos diámetros aguas abajo de un codo de 90o. Para conocer el desempeño de un medidor de turbina con poco tramo recto, tanto aguas arriba como aguas abajo (condiciones no consideradas por Hanson se realizaron pruebas en el Laboratorio de Hidráulica de la Universidad de Guanajuato. Se compararon las lecturas del medidor contra las de un tanque volumétrico, colocando el medidor en diferentes posiciones y con varios gastos. Los resultados indican que

  14. Desarrollo de un simulador de turbinas de gas fuera de diseño

    OpenAIRE

    Saiz Boned, Mercedes

    2016-01-01

    Este Trabajo Fin de Grado está englobado dentro de un conjunto de proyectos relacionados con la simulación y el estudio teórico de los ciclos de Turbina de Gas. Estos proyectos están siendo desarrollados dentro de la Unidad Docente de Motores Térmicos, perteneciente al Departamento de Ingeniería Energética de la Escuela Superior de Ingenieros Industriales de Madrid. Manuel Valdés del Fresno, tutor de este proyecto, ha sido la persona que ha guiado y seguido el desarrollo del proyecto desde...

  15. Speed control and generation of electric power of a gas turbine by means of fuzzy-logic; Control de velocidad y de generacion de potencia electrica de una turbina de gas mediante logica difusa

    Energy Technology Data Exchange (ETDEWEB)

    Bahamaca Fernandez, Luis Jonathan

    2000-08-01

    ) en una estrategia de control automatico. Los controladores difusos fueron validados mediante el desarrollo de pruebas funcionales en una estructura de simulacion de un modelo matematico no lineal para turbina de gas, ambos en lenguaje de programacion C. Estas pruebas de simulacion realizadas para la evaluacion de una buena regulacion y seguimiento de la velocidad/carga dieron resultados satisfactorios, es decir, los controladores difusos minimizaron los efectos producidos por las perturbaciones programadas del sistema (originadas por las acciones del control) y presentaron un mejor seguimiento a la referencia. Por ello, el sistema de control difuso propuesto presenta un mejor desempeno en comparacion al sistema de control convencional.

  16. Digital implementation, simulation and tests in MATLAB of the models of Steam line, the turbines, the pressure regulator of a BWR type nucleo electric power plant; Implementacion digital, simulacion y pruebas en MATLAB de los modelos de la linea de vapor, las turbinas y el regulador de presion de una central Nucleoelectrica tipo BWR

    Energy Technology Data Exchange (ETDEWEB)

    Lopez R, A [UNAM, Laboratorio de Analisis de Ingenieria de Reactores Nucleares, DEPFI, Campus Morelos, en IMTA Jiutepec, Morelos (Mexico)

    2004-07-01

    In this phase of the project they were carried out exhaustive tests to the models of the steam lines, turbines and pressure regulator of a BWR type nucleo electric central for to verify that their tendencies and behaviors are it more real possible. For it, it was necessary to also analyze the transfer functions of the different components along the steam line until the power generator. Such models define alone the dominant poles of the system, what is not limitation to reproduce a wide range of anticipated transitoriness of a power station operation. In the same manner, it was integrated and proved the integrated model form with the models of feeding water of the SUN-RAH, simulating the nuclear reactor starting from predetermined entrances of the prospective values of the vessel. Also it was coupled with the graphic interface developed with the libraries DirectX implementing a specific monitoring panel for this system. (Author)

  17. Numerical simulation by CFD of the behavior of the Inter stage 1 flow in stable state of a gas turbine Frame 7; Simulacion numerica por CFD del comportamiento del flujo en la inter etapa 1 en estado estable de una turbina de gas frame 7

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez R, Alejandro; Lopez H, Juan Arturo R; Mazur Czerwiec, Zdizslaw; Cordero G, Jesus [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2006-07-01

    This technical article presents an analysis including the three-dimensional modeling of the flow channel in the nozzle and the movable blade in order to discover the velocity distribution, temperatures and pressures of the main hot gas flow produced in the inter-stage 1. The aim is to establish key evaluation criteria leading to an opportune repair and therefore smaller operation expenses. Thus, the application of a commercial software of CFD is described to model the channel of the first stage in the gas turbine Frame 7, the geometric architecture is shown in the web of the gas turbine, as well as the border conditions used in the results assessment. [Spanish] Este articulo tecnico presenta un analisis que incluye la modelacion tridimensional del canal de flujo en la tobera y el alabe movil para conocer las distribuciones de las velocidades, temperaturas y presiones del flujo principal de gases calientes que se desarrollan en la inter-etapa 1. El fin es establecer criterios clave de evaluacion que conduzcan a una oportuna reparacion y por ende menores gastos de operacion. Asi, se describe la aplicacion de un software comercial de CFD para modelar el canal de flujo de la primera etapa de una turbina de gas Frame 7, se muestra la arquitectura geometrica y el mallado de la turbina de gas, asi como las condiciones de frontera usadas y la validacion de resultados.

  18. Stress analysis in the last stage blade of a geothermal turbine under different excitation conditions; Analisis de esfuerzos en el alabe de la ultima etapa de turbina geotermica bajo diferentes condiciones de excitacion

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Alcazar, Rony Ediberto

    2009-11-15

    The blades of the steam turbines operate below severe conditions of pressure, temperature and steam flow, and at high rotary speeds too. These excitements generate states of stress, which depending on its magnitude and time of application; they can threaten the structural reliability of these mechanical components. In this work a stress analysis is realized in a blade L-0 of a geothermal turbine of low pressure, by means of the finite element method, by the aim to determine the states of static stress caused by the combined action of the centrifugal force and pressure of system flow, and dynamic stresses caused by the harmonic fluctuation in the steam flow. The analysis is realized under two superficial conditions in the blade: without presence of superficial damage and with presence of erosion in the bottom part of the trailing edge. The combined action of these conditions of stress is evaluated by means of an analysis of fatigue. This allows knowing the influence of the stress calculated, on the useful life of the blade. [Spanish] Los alabes de turbinas de vapor operan bajo condiciones severas de presion, temperatura y flujo de vapor, asi como a altas velocidades rotativas. Estas excitaciones generan estados de esfuerzos, que dependiendo de su magnitud y tiempo de aplicacion, pueden amenazar la confiabilidad estructural de estos componentes mecanicos. En este trabajo se realiza un analisis de esfuerzos en un alabe L-0 de una turbina geotermica de baja presion, mediante el metodo de elemento finito, con el objetivo de determinar los estados de esfuerzos estaticos causados por la accion combinada de la carga por fuerza centrifuga y presion de flujo de vapor, y esfuerzos dinamicos causados por la fluctuacion armonica en el flujo de vapor. El analisis se realiza bajo dos condiciones superficiales en el alabe: sin presencia de dano superficial y con presencia de erosion en la parte inferior del borde de salida. La accion combinada de estos estados de esfuerzos se

  19. Calculation of the temperature distribution and thermal stresses in a gas turbine nozzle cooled by air film; Calculo de la distribucion de temperaturas y esfuerzos termicos en una tobera de turbina de gas enfriada por pelicula de aire

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez R, Alejandro; Garcia I, Rafael; Mazur C, Zdislaw [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2004-07-01

    The analysis begins with the generation of a computational geometric model of the gas turbine nozzle using reverse engineering techniques. For the obtaining of the original geometry of the blade, a measurement machine by coordinates and computerized numerical control was used. Next, the computational model is converted into a three-dimensional mesh. In advance, a study of boundary conditions was made of the nozzle material as well as of the turbine operating conditions during non-operating cycles, start-ups and shut-downs. On the other hand, with the boundary conditions imposed to the model, the distributions of the temperature and pressures on the aerofoil profile of the nozzle blade were calculated. These results had to be manipulated to be exported to a finite element software (ANSYS); at this point, another nozzle model was elaborated to be able to import the temperature distribution. With the temperatures correctly imported, the simulations for the calculation of the thermal stresses were made in the nozzle. [Spanish] El analisis inicia con la generacion de un modelo geometrico computacional de la tobera de la turbina de gas utilizando tecnicas de ingenieria inversa. Para la obtencion de la geometria original del alabe, se utilizo una maquina de medicion por coordenadas y control numerico computarizado. A continuacion, el modelo computacional es convertido en una malla tridimensional. Con antelacion, se realizo un estudio de las condiciones de frontera, tanto del material de la tobera como de las condiciones de operacion de la turbina, durante ciclos de paro, arranque y disparo. Por otra parte, con las condiciones de frontera impuestas al modelo, se calcularon las distribuciones de las temperaturas y presiones sobre el perfil aerodinamico de la paleta de la tobera. Estos resultados tuvieron que ser manipulados para ser exportados a un software de elemento finito (ANSYS); en este punto, se elaboro otro modelo de la tobera para poder importar la distribucion de

  20. Changes in steam production due to the reservoir conditions in Cerro Prieto, Baja California; Cambios en la produccion de vapor debido a las condiciones del yacimiento en Cerro Prieto, Baja California

    Energy Technology Data Exchange (ETDEWEB)

    Morales Cardenas, Ramon; Rodriguez Rodriguez, Marco H. [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)]. E-mail: marco.rodriguez01@gfe.gob.mx

    2011-07-15

    In more than 35 years of exploitation, thermodynamic conditions have changed in the Cerro Prieto geothermal reservoir. The effects are analyzed of the changes to the reservoir and their consequences to steam production in different field zones. For steam production, the most important features of reservoir fluids are enthalpies and pressures. The evolution of these features is presented in an enthalpy-pressure diagram. Here it can be seen that some reservoir zones have almost reached abandonment conditions. [Spanish] En mas de 35 anos de explotacion el yacimiento geotermico de Cerro Prieto ha experimentado cambios en sus condiciones termodinamicas. En este trabajo se analiza el efecto de esos cambios del yacimiento y su repercusion en la produccion de vapor para las diferentes zonas en las que se ha dividido el campo. Las propiedades mas importantes del fluido en el yacimiento para la produccion de vapor son su entalpia y su presion, por lo que se presenta la evolucion de esas propiedades en un diagrama de presion-entalpia, en el que se observa que hay zonas del yacimiento que estan proximas a alcanzar condiciones de abandono.

  1. Evaluación exergética de propuestas de disminución de consumo de vapor en usinas azucareras Exergetic evaluation of proposals for steam consumption reduction in sugar factories

    Directory of Open Access Journals (Sweden)

    Dora Paz

    2005-12-01

    Full Text Available Se realizó un modelado exergético, basado en la 2° ley de la Termodinámica, para la evaluación de las operaciones térmicas de Calentamiento-Evaporación-Cristalización (CEC en un ingenio de Tucumán. Una vez resueltos los balances de masa y energía de sistemas CEC, se determinaron los balances de exergía, evaluando las pérdidas de exergía y la eficiencia exergética. Se emplearon ecuaciones y gráficos existentes en la bibliografía para evaluar las propiedades termodinámicas de los flujos intervinientes. Se simularon y compararon con el caso base (zafra 2000, dos propuestas tendientes a disminuir las pérdidas de exergía, considerando: aumento de efectos de evaporación, mayor aprovechamiento de vapores vegetales, aumento en la concentración de melado, empleo de vapor vegetal para la cristalización y reemplazo de turbinas de vapor ineficientes por motores oleohidráulicos y eléctricos. Los resultados mostraron que las menores eficiencias exergéticas se producen en condensadores barométricos de cristalización y evaporación, y en cristalización. La reducción de irreversibilidades en las propuestas analizadas permitiría eliminar el combustible adicional necesario para operar calderas bagaceras antiguas.Exergetic modelling, based on exergetic analysis (2nd law of Thermodynamics, was applied in assessing Heating-Evaporation-Crystallization (H-E-C thermal operations in a cane sugar mill in Tucumán (Argentina. After solving mass and energy balances in H-E-C systems, exergy balance was determined. Exergy losses and exergetic efficiency were calculated. Equations and graphics found in bibliographic sources were used to calculate thermodynamic properties of intervening flows. Two alternatives for reducing exergy losses were simulated and compared with base case (2000 season. These alternatives aimed at the following goals: more evaporation effects, better use of juice vapours, increase in syrup concentration, and replacement of

  2. Control de Matriz de Turbinas Eólicas de Eje Vertical, Mediante Fuzzy Logic.

    OpenAIRE

    Javier Ordóñez Riba

    2014-01-01

    En este TFM se pretende mejorar la extracción de energía eléctrica a partir de energía eólica, utilizando una matriz de 18 turbinas de eje vertical, posicionadas de forma, que afecten lo menos posible a la máxima transformación de energía eólica a energía eléctrica. Se pretende obtener los conocimientos necesarios en los datos eólicos, para poder decidir sobre el movimiento de la matriz, en la búsqueda de una mayor producción energética. La matriz estará dispuesta en nueve grup...

  3. Fatigue lifespan of a mobile blade gas turbine with ceramic coating; Vida util por fatiga de un alabe movil de turbina de gas con recubrimiento ceramico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Illescas, Rafael; Z. Mazur Czerwiec, Zdzislaw; Islas Mungarro, Ricardo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rgi@iie.org.mx; mazur@iie.org.mx; rick_iie@terra.com.mx

    2010-11-15

    Fatigue analysis of a gas turbine moving blade made of IN738LC was carried out in order to evaluate useful life time. The life estimation was done from a previous 3D linear finite element analysis where thermal and mechanical stress calculation at high temperatures was done during steady and transient state i.e. normal start ups and shutdowns. Several load histories with different stresses and strains in the blade were used for different cooling conditions including a thermal barrier coating in comparison with to simple blade without such coating. The important effect of high temperatures on the blade material and stress calculations is shown. The analysis is focused on two different critical zones in the blade: the leading edge at the middle of the height and a cooling channel surface, where high stresses were found in numerical analysis as well as in reality. Finally, the benefit of the presence of a thermal barrier coating in the blade life is shown. [Spanish] Se realizo el analisis de fatiga de un alabe movil de turbina de gas fabricado de IN738LC a fin de evaluar su vida util. La estimacion de vida fue realizada a partir de simulaciones lineales de esfuerzos termomecanicos por elemento finito en 3D a altas temperaturas y durante el arranque y paro normal. Se utilizaron diversos historiales de carga, esfuerzos y deformaciones del alabe para diferentes configuraciones de enfriamiento incluyendo el recubrimiento ceramico tipo barrera termica en comparacion con los resultados sin incluir dicho recubrimiento. Se presenta el efecto importante de las temperaturas elevadas en las propiedades de fatiga del material del alabe y en sus esfuerzos. El analisis se centra en dos puntos de interes identificados como criticos: borde de entrada y un canal de enfriamiento, en donde esfuerzos elevados fueron encontrados tanto numericamente como en la realidad. Finalmente se muestra el beneficio del recubrimiento tipo barrera termica en la vida del alabe.

  4. Flow measurement in a 170-MW hydraulic turbine using the Gibson method; Medicion del flujo de una turbina hidraulica de 170 MW utilizando el metodo Gibson

    Energy Technology Data Exchange (ETDEWEB)

    Urquiza, Gustavo [Universidad Autonoma del Estado de Morelos (Mexico); Adamkowski, Adam [The Szewalski Institute of Fluid-Flow Machinery (Poland); Kubiak, Janusz; Sierra, Fernando [Universidad Autonoma del Estado de Morelos (Mexico); Janicki, Waldemar [The Szewalski Institute of Fluid-Flow Machinery (Poland); Fernandez, J. Manuel [Comision Federal de Electricidad (Mexico)

    2007-07-15

    -tiempo o de Gibson. Este metodo esta basado en el fenomeno del golpe de ariete y es aplicado al caso de una tuberia de presion de tuberia hidraulica. La version del metodo usado en el presente trabajo consiste en la medicion, durante el rechazo total de carga, del historial de tiempo y del cambio de presion en una seccion de la tuberia de presion y relaciona este cambio de presion con el nivel del embalse de la central hidroelectrica. El flujo volumetrico se determina mediante la integracion del incremento de la diferencia de presion medida con respecto al tiempo. La medicion del flujo fue posible gracias a la poca influencia de la entrada del flujo a la tuberia de presion, de 300 m longitud, evitando asi introducir un error considerable en la medicion. Se aplicaron y adoptaron para la medicion los criterios de la norma IEC-41-1991 y experiencias previas. Se utilizo un sistema de adquisicion de datos rapido y eficiente, el cual incluye una tarjeta de 16 bit. El flujo fue calculado usando un programa de computo desarrollado y probado en varios casos anteriores. Los resultados obtenidos con el metodo Gibson fueron utilizados para la calibracion de un sistema de medicion en linea basado en el metodo relativo de Winter-Kennedy. Este ultimo se usa comunmente para el monitoreo continuo del flujo de turbinas hidraulicas, siempre y cuando la calibracion en sitio haya sido realizada usando los resultados de las mediciones de un metodo absoluto. Una vez medido el flujo y la potencia de salida, se calculo la eficiencia para diferentes condiciones de operacion. Se discuten y presentan los resultados obtenidos en una curva, la cual muestra las mejores condiciones de operacion basadas en la mayor eficiencia. Los detalles de la instrumentacion, su instalacion y otros resultados obtenidos se discuten tambien en el presente articulo.

  5. Considerations over the effects caused by a heat recovery system for exhaust gases, adapted to gas turbines originally designed for the operation in a simple cycle; Consideraciones sobre los efectos causados por un sistema de recuperacion de calor de gases de escape, adaptado a turbinas de gas disenadas originalmente para operar bajo un ciclo simple

    Energy Technology Data Exchange (ETDEWEB)

    Cuesta Escobar, Cesar A [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico)

    1994-12-31

    This article sets out the considerations on what a heat recovery system from exhaust gases, to already installed and in operation gas turbines, and that were not originally designed to operate with this system, can cause. The potential effects are set forth on the control systems, on the combustion chambers, and in the gas turbine blades, utilized for natural gas pumping or power generation in land installations or in offshore platforms in trying to adapt to them a regenerative cycle or a heating system. Observed effects, fundamentally in the flame stability loop, flow velocity, thermal intensity coefficient, air/fuel relationships and mass flow. Also are presented the consequences that primary production system would suffer, mainly due to the natural gas pumping reduction, the space availability, the fuel consumption, and the maximum amount of heat susceptible to be recovered, comparing the requirements of this in the system. [Espanol] En este articulo se plantean las consideraciones sobre lo que puede provocar un sistema de recuperacion de calor de gases de escape adaptado a turbinas de gas ya instaladas, operando y que no fueron disenadas originalmente para operar con este sistema. Se plantean los probables efectos en los sistemas de control, en las camaras de combustion y en los empaletados de las turbinas de gas usadas para bombeo de gas natural o generacion electrica en instalaciones de tierra o plataformas marinas, al tratar de adaptarseles un ciclo regenerativo o un sistema para calentamiento. Efectos observados, fundamentalmente, en el LOOP de estabilidad de flama, velocidad del flujo, coeficiente de intensidad termica, relaciones aire-combustible y flujo masico. Tambien se presentan las consecuencias que sufriria el sistema primario de produccion debido, principalmente, a la reduccion del bombeo de gas natural, a la disponibilidad de espacio, al consumo de combustible y a la cantidad maxima de calor susceptible de recuperarse, comparada con los

  6. Estudo de um sistema de concentração integrado numa pequena turbina eólica de eixo vertical

    OpenAIRE

    Santos, António José Alves da Silva

    2014-01-01

    Tese de mestrado integrado em Engenharia da Energia e do Ambiente, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2014 Este trabalho pretende estudar um novo conceito de aproveitamento energético, através de um sistema de concentração eólico adaptado para turbinas de eixo vertical (VAWT). O sistema permite aumentar a velocidade do vento à entrada do rotor da turbina e assim a potência disponível. O aproveitamento energético de fonte eólica ainda não é comum no ...

  7. Optimización del mantenimiento preventivo utilizando las técnicas de diagnóstico integral. Fundamento teóricopráctico; Optimization of the Preventive Maintenance Using the Technique of Integral Diagnosis. Base Theoretical-Practical

    Directory of Open Access Journals (Sweden)

    Pedro L Hernández Domínguez

    2011-02-01

    Full Text Available Se expone un método para la optimización del mantenimiento preventivo planificado (MPP a partir de laintroducción del mantenimiento basado en la condición (MBC en las turbinas y generadores de vapor de unacentral termoeléctrica cubana, utilizando las técnicas de diagnóstico integral. Se presenta el estado del arte deldesarrollo del mantenimiento y se caracteriza este en las centrales termoeléctricas cubanas; además, se realizaun estudio estadístico de las fallas y se presentan varios casos de estudio con la finalidad que el lector puedacomprender la necesidad de implantación de esta técnica, cuyos únicos costos son la organización de los datosde fallas y la colaboración del personal técnico ligado a las mismas. In this present paper the author exposed a method for the optimization of the planned preventive maintenance(PPM starting from the introduction of the condition based maintenance (CBM in the steam turbines and generatorsin a cuban thermoelectric power station, using the techniques of Integral Diagnosis. In the same one thestate of the art of the development of the maintenance is presented and the last one is characterized in the cubanthermoelectric power station, it is also carried out a statistical study of the failures and several cases of study arepresented with the purpose that the reader can understand the necessity of installation of this technique whoseonly costs belong the organization of the data of failures and the collaboration from the bound technical personnelto the same ones.

  8. Temperature control of a steam generator by means of an hybrid system PID-RLC; Control de las temperaturas de un generador de vapor mediante un sistema hibrido PID-RLC

    Energy Technology Data Exchange (ETDEWEB)

    Palomares Gonzalez, Daniel; Garcia Mendoza, Raul [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    A description is made of the design and evaluation of an hybrid control system, formed by a quadratic gaussian linear regulator (QLR) and proportional integral derivative (PID) type regulators. This scheme is used to control the reheater and secondary superheater steam temperatures of a steam generator model with a maximum capacity of 2,150,000 pounds per hour. Once applied to the model of a 300 MW steam power plant, this system showed better results than the traditional schemes and inclusively better than some modern control schemes. This fact characterizes it as a high potential system to be applied to steam power plants. [Espanol] Se describe el diseno y la evaluacion de un sistema de control hibrido, formado por un regulador lineal cuadratico gaussiano (RLC) y reguladores tipo proporcional integral derivativo (PID). Este esquema se utiliza para controlar las temperaturas de vapor del recalentador y sobrecalentador secundario del modelo de un generador de vapor con capacidad maxima de 2,150,000 libras por hora. Una vez aplicado al modelo de una unidad termoelectrica de 300 MW, este sistema produjo mejores resultados que los esquemas tradicionales e incluso mejores que algunos esquemas de control moderno. Esto lo caracteriza como un sistema con un alto potencial para aplicarse a unidades termoelectricas.

  9. Temperature control of a steam generator by means of an hybrid system PID-RLC; Control de las temperaturas de un generador de vapor mediante un sistema hibrido PID-RLC

    Energy Technology Data Exchange (ETDEWEB)

    Palomares Gonzalez, Daniel; Garcia Mendoza, Raul [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1991-12-31

    A description is made of the design and evaluation of an hybrid control system, formed by a quadratic gaussian linear regulator (QLR) and proportional integral derivative (PID) type regulators. This scheme is used to control the reheater and secondary superheater steam temperatures of a steam generator model with a maximum capacity of 2,150,000 pounds per hour. Once applied to the model of a 300 MW steam power plant, this system showed better results than the traditional schemes and inclusively better than some modern control schemes. This fact characterizes it as a high potential system to be applied to steam power plants. [Espanol] Se describe el diseno y la evaluacion de un sistema de control hibrido, formado por un regulador lineal cuadratico gaussiano (RLC) y reguladores tipo proporcional integral derivativo (PID). Este esquema se utiliza para controlar las temperaturas de vapor del recalentador y sobrecalentador secundario del modelo de un generador de vapor con capacidad maxima de 2,150,000 libras por hora. Una vez aplicado al modelo de una unidad termoelectrica de 300 MW, este sistema produjo mejores resultados que los esquemas tradicionales e incluso mejores que algunos esquemas de control moderno. Esto lo caracteriza como un sistema con un alto potencial para aplicarse a unidades termoelectricas.

  10. Analysis of conjugated heat transfer, in transient state of the first stage of a gas turbine; Analisis de transferencia de calor conjugada, en estado transitorio, de la primera etapa de una turbina de gas

    Energy Technology Data Exchange (ETDEWEB)

    Campos Amezcua, Alfonso; Mazur C, Zdzislaw [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Gallegos Munoz, Armando [Facultad de Ingenieria Mecanica, Electrica y Electronica (FIMEE), Universidad de Guanajuato, Guanajuato (Mexico)

    2007-11-15

    This article presents an analysis of conjugated heat transfer in the first stage of movable blades during the starting of a gas turbine, covering a period of 1,012 seconds. The developed computer model is in 3D and uses as initial and border conditions typical starting curves for stack gases, the cooling air and the angular velocity of the blades. As a result of the numerical predictions, the temperature distributions in stack gases, the trowel of the blade and the cooling air are included, doing emphasis in the results obtained in the solid (body of the blade), since these are used for thermo-mechanical stress analysis and later estimation of the blade residual life. [Spanish] Este articulo presenta un analisis de transferencia de calor conjugada en la primera etapa de alabes moviles, durante el arranque de una turbina de gas, cubriendo un periodo de 1.012 segundos. El modelo computacional desarrollado es en tres dimensiones y utiliza como condiciones iniciales y de frontera curvas de arranque tipicas para los gases de combustion, el aire de enfriamiento y la velocidad angular de los alabes. Como resultado de las predicciones numericas, se incluyen las distribuciones de temperatura en los gases de combustion, la paleta del alabe y el aire de enfriamiento, haciendo enfasis en los resultados obtenidos en el solido (cuerpo del alabe), ya que estos se utilizan para analisis de esfuerzos termomecanicos y posterior estimacion de vida residual del alabe.

  11. Supervisory system for real time monitoring of transient thermal stresses in turbines rotors; Sistema supervisorio para el monitoreo en tiempo real de esfuerzos termicos transitorios en rotores de turbinas

    Energy Technology Data Exchange (ETDEWEB)

    Urquiza Beltran, Gustavo; Rios Miranda, Edmundo; Venegas Guzman, Ricardo; Alvarez Garcia, Gabriela [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1991-12-31

    This article presents a supervisory system that, as its main functions, assists the operator on base of the thermal stresses, monitoring in real time the high pressure (HP) and intermediate pressure rotors (IP) of a steam turbine during the start, shut down and/or sudden load changes. The system is based on a thermal model uni-dimensional integrated to the SIMPER (Information System for the Predictive Maintenance of Rotating Equipment), tested in a 300 MW unit of Comision Federal de Electricidad (CFE). [Espanol] En este articulo se presenta un sistema supervisorio que, como funciones principales, asiste al operador con base en el monitoreo de esfuerzos termicos en tiempo real en los rotores de presion alta (PA) y presion intermedia (PI) de una turbina de vapor durante un arranque, paro y/o variaciones bruscas de carga. El sistema esta basado en un modelo termico unidimensional integrado al SIMPER (sistema informatico para el mantenimiento predictivo de equipo rotatorio), experimentado en una unidad de 300 MW de la Comision Federal de Electricidad (CFE).

  12. Supervisory system for real time monitoring of transient thermal stresses in turbines rotors; Sistema supervisorio para el monitoreo en tiempo real de esfuerzos termicos transitorios en rotores de turbinas

    Energy Technology Data Exchange (ETDEWEB)

    Urquiza Beltran, Gustavo; Rios Miranda, Edmundo; Venegas Guzman, Ricardo; Alvarez Garcia, Gabriela [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-12-31

    This article presents a supervisory system that, as its main functions, assists the operator on base of the thermal stresses, monitoring in real time the high pressure (HP) and intermediate pressure rotors (IP) of a steam turbine during the start, shut down and/or sudden load changes. The system is based on a thermal model uni-dimensional integrated to the SIMPER (Information System for the Predictive Maintenance of Rotating Equipment), tested in a 300 MW unit of Comision Federal de Electricidad (CFE). [Espanol] En este articulo se presenta un sistema supervisorio que, como funciones principales, asiste al operador con base en el monitoreo de esfuerzos termicos en tiempo real en los rotores de presion alta (PA) y presion intermedia (PI) de una turbina de vapor durante un arranque, paro y/o variaciones bruscas de carga. El sistema esta basado en un modelo termico unidimensional integrado al SIMPER (sistema informatico para el mantenimiento predictivo de equipo rotatorio), experimentado en una unidad de 300 MW de la Comision Federal de Electricidad (CFE).

  13. State of the art of technologies thermosolar to concentration; Estado del arte de las tecnologias termosolares a concentracion

    Energy Technology Data Exchange (ETDEWEB)

    Ramos Berume, Carlos; Huacuz Villamar, Jorge M; Medrano Vaca, M. Consolacion [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    2000-07-01

    focal (tubo metalico receptor). Por el interior de este tubo circula un fluido de trabajo (aceite termico) a temperaturas de hasta 390 grados Celsius, el cual es enviado a intercambiadores de calor para producir vapor sobrecalentado para operar una turbina y generar la energia electrica y Plato Parabolico (PP), contiene una estructura formada por segmentos de espejos que conforman un paraboloide donde en su punto focal (receptor/maquina termica) incide en la radiacion reflejada y se produce energia electrica. En este documento se presenta el estado del arte de las Tecnologias Termosolares a Concentracion (YYC) que permiten identificar sus desarrollos y problematica actual. Ademas, se incluye una descripcion de las perspectivas de mercado, costos de las TTC y las perspectivas tecnologicas.

  14. Application of monitoring techniques of operational parameters for the implementation of preventive and predictive maintenance programs to gas turbines; Aplicacion de tecnicas de monitoreo de parametros operacionales para la implantacion de programas de mantenimiento predictivo y preventivo en turbinas de gas

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez Villareal, Julio Cesar

    1998-12-31

    components. These techniques are: hardness testing, liquid penetrant inspection, magnetic particle inspections and metallographic examination. Chapter five describes the boroscopy inspection and its applications for a rotor analysis and gas turbine blades. Chapter six shows the results obtained and give recommendations for the vibration analysis that were carried out at a gas turbine facility. [Espanol] Esta tesis se realiza con la finalidad de implantar un programa de mantenimiento preventivo y predictivo, mediante tecnicas de monitoreo de parametros que permita sistematizar, documentar y administrar las actividades del mantenimiento. La metodologia de mantenimiento aqui descrita, se aplica a las turbinas de gas de la Terminal Maritima Dos Bocas Tabasco, Mexico. El mantenimiento preventivo se basa en la revision periodica de los equipos, mediante listas de inspeccion, donde la idea es detectar problemas que provoquen posibles fallas y realizar la reparacion o ajusted necesarios para evitarlo. Sin embargo enfrenta a la posibilidad de que el equipo este en perfecto estado y al estar en revision, tenga retrasos y problemas de arranque posteriores. El mantenimiento predictivo se basa en tecnicas que permiten la deteccion e identificacion de fallas incipientes en los equipos. Las tecnicas recomendadas en esta tesis son: Analisis de vibraciones; Evaluacion no destructivas e Inspeccion boroscopica. La estructura de la tesis consta de los capitulos siguientes: El capitulo uno describe la importancia de los programas y estrategias del mantenimiento, sus ventajas y desventajas al aplicarlas en las plantas de proceso continuo. Se plantean los procedimientos para el diseno de un programa de mantenimiento. El capitulo dos presenta la manera de planear los recursos y materiales de mantenimiento, las tecnicas de inspecciones aplicados a la turbina de gas, y finalmente se disenan listas de verificacion de inspecciones como herramienta del mantenimiento preventivo. Los capitulos siguientes

  15. Diseño y construcción de una turbina de gas para generación de baja potencia (TGBP con ciclo regenerativo a partir de un turbocargador

    Directory of Open Access Journals (Sweden)

    Cesar Eduardo Mondragón Cediel

    2010-01-01

    Full Text Available La ciudad de Cantagallo (Bolívar en Colombia requiere 21kW de energía eléctrica para suplir las necesidades de su población ya que no tiene acceso a la red de interconexión eléctrica como muchas otras ciudades del país. La aplicación de la generación distribuida a partir de turbinas de gas de baja potencia (TGBP para suplir estas necesidades es viable en Colombia, además las TGBP a partir de turbocargadores automotrices suplen completamente los requerimientos de la generación distribuida aislada y de soporte de la red de distribución en plantas, fábricas y edificios; por lo tanto se realiza el dise.o detallado y construcción de una TGBP que genera 30kW, cuyas características específicas y técnicas le permiten ser aplicable como sistema de Generación Distribuida en Colombia a partir de un turbocargador automotriz empleando el ciclo termodinámico regenerativo para disminuir  el consumo espec.fico de combustible (SFC y por lo tanto aumentar la eficiencia del ciclo, con sus respectivos sistemas de inyección de combustible, ignición, lubricación y de adquisición de datos. Se realiza una metodolog.a de dise.o de: TGBP con ciclo regenerativo, de c.maras de combusti.n tubulares y de intercambiadores de calor (recuperadores empleando fuentes bibliográficas especializadas en el desarrollo de motores a reacción a nivel mundial así como software FEA, CFD y tecnologías de fabricación asequibles y encontradas en Colombia.

  16. Mobile vapor recovery and vapor scavenging unit

    International Nuclear Information System (INIS)

    Stokes, C.A.; Steppe, D.E.

    1991-01-01

    This patent describes a mobile anti- pollution apparatus, for the recovery of hydrocarbon emissions. It comprises a mobile platform upon which is mounted a vapor recovery unit for recovering vapors including light hydrocarbons, the vapor recovery unit having an inlet and an outlet end, the inlet end adapted for coupling to an external source of hydrocarbon vapor emissions to recover a portion of the vapors including light hydrocarbons emitted therefrom, and the outlet end adapted for connection to a means for conveying unrecovered vapors to a vapor scavenging unit, the vapor scavenging unit comprising an internal combustion engine adapted for utilizing light hydrocarbon in the unrecovered vapors exiting from the vapor recovery unit as supplemental fuel

  17. Petroleum Vapor Intrusion

    Science.gov (United States)

    One type of vapor intrusion is PVI, in which vapors from petroleum hydrocarbons such as gasoline, diesel, or jet fuel enter a building. Intrusion of contaminant vapors into indoor spaces is of concern.

  18. Curvas de entrada - salida y características de regulación de velocidad de las centrales termoeléctricas de gas - diesel mediante pruebas de campo del sistema eléctrico interconectado de potencia (SEIP) de Petroproducción

    OpenAIRE

    Cabrera Pazmiño, Waldo José; Morales Pazmiño, Mario Iván; Játiva Ibarra, Jesús

    2012-01-01

    En el presente trabajo se presentan las curvas de entrada–salida de las unidades de generación térmica con turbinas a gas del Sistema Eléctrico Interconectado de Petroproducción (SEIP). Dentro de estas curvas se encuentran: curva de costos de generación, curva de energía térmica, curva de costo incremental, curva de consumo específico y curva de eficiencia. Se presentan los resultados de las características de regulación de velocidad, como son: rapidez controlada de subida y...

  19. Gas turbine modular helium reactor in cogeneration; Turbina de gas reactor modular con helio en cogeneracion

    Energy Technology Data Exchange (ETDEWEB)

    Leon de los Santos, G. [UNAM, Facultad de Ingenieria, Division de Ingenieria Electrica, Departamento de Sistemas Energeticos, Ciudad Universitaria, 04510 Mexico, D. F. (Mexico)], e-mail: tesgleon@gmail.com

    2009-10-15

    This work carries out the thermal evaluation from the conversion of nuclear energy to electric power and process heat, through to implement an outline gas turbine modular helium reactor in cogeneration. Modeling and simulating with software Thermo flex of Thermo flow the performance parameters, based on a nuclear power plant constituted by an helium cooled reactor and helium gas turbine with three compression stages, two of inter cooling and one regeneration stage; more four heat recovery process, generating two pressure levels of overheat vapor, a pressure level of saturated vapor and one of hot water, with energetic characteristics to be able to give supply to a very wide gamma of industrial processes. Obtaining a relationship heat electricity of 0.52 and efficiency of net cogeneration of 54.28%, 70.2 MW net electric, 36.6 MW net thermal with 35% of condensed return to 30 C; for a supplied power by reactor of 196.7 MW; and with conditions in advanced gas turbine of 850 C and 7.06 Mpa, assembly in a shaft, inter cooling and heat recovery in cogeneration. (Author)

  20. 3D analysis of Navier-Stokes in steady state of the behavior of the flow in the Inter stage 1 of a gas turbine Frame 7; Analisis de navier-stokes tridimensional en estado estable del comportamiento del flujo en la inter etapa 1 de una turbina de gas frame 7

    Energy Technology Data Exchange (ETDEWEB)

    Henandez Rosete, Alejandro; Mazur C, Zdzislaw [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-11-15

    The results of the simulation by CFD (Computacional Fluid Dynamics) realized to the first stage of a gas turbine GE Frame 7 are presented. The analysis includes the 3D modeling of the flow channel in the nozzle and the movable blade to know the velocities distributions, temperatures and pressures of the main hot gas flow that are developed in the Inter stage. The results are influenced by the imposed border conditions in the properties of the main flow, the rotation of the movable blade, as well as the simulation of cooling air injection in the nozzle. The present study focuses in the validation of the model of the meshes of the ensemble nozzle-blade, for later realize an analysis of conjugated heat transfer in a model with ceramic lining type heat barrier (THB) in the movable blade. The analysis is realized in a CFD commercial code oriented to turbo-machinery using the equations of unstable flows 3D of Navier Stokes. [Spanish] Se presentan los resultados de la simulacion por CFD (Computacional Fluid Dynamics) realizada a la primera etapa de una turbina de gas GE Frame 7. El analisis incluye la modelacion tridimensional del canal de flujo en la tobera y el alabe movil para conocer las distribuciones de las velocidades, temperaturas y presiones del flujo principal de gases calientes que se desarrollan en la inter etapa. Los resultados son influenciados por las condiciones de frontera impuestos en las propiedades del flujo principal, la rotacion del alabe movil, asi como la simulacion de inyeccion de aire de enfriamiento en la tobera. El presente estudio se enfoca en la validacion del modelo de la malla del conjunto tobera-alabe, para posteriormente realizar un analisis de transferencia de calor conjugada en un modelo con recubrimiento ceramico tipo barrera termica (TBC) en el alabe movil. El analisis es realizado en un codigo de CFD comercial orientado a turbomaquinaria utilizando las ecuaciones de flujos inestables 3D de Navier Stokes.

  1. Fault diagnosis in the steam turbo-generator of a Combined Cycle Power Plant; Diagnostico de fallas en el turbogenerador a vapor de una central de generacion de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Flores Abad, Angel

    2006-12-15

    sensores y actuadores. En la actualidad este tipo de centrales tiende a dominar el mercado de generacion electrica por medio de combustibles fosiles, debido a que son las mas eficientes, rentables, de operacion flexible y con menor impacto ambiental. En la CGCC, la turbina de vapor (TV) es una componente fundamental, ya que representa la ganancia del proceso en el sentido de que permite la generacion de energia electrica adicional al aprovechar los gases de escape de la turbina de gas. En caso de que la TV falle, la eficiencia global del proceso se reduce hasta en un 40%. Por lo anterior, en este trabajo se desarrollo un sistema de diagnostico de fallas basado en modelos, de acuerdo a la metodologia FDI (Fault Detection and Isolation) de la teoria de control, con capacidad para detectar y localizar fallas en los sensores y actuadores del turbogenerador a vapor de una CGCC. El enfoque que se utilizo emplea la redundancia analitica con el objetivo de optimizar la redundancia fisica, de manera que sea posible disminuir el costo y espacio extra que implica el utilizar dispositivos repetidos. El diseno del sistema se llevo a cabo usando el analisis estructural AE) que es una herramienta basada en la teoria de grafos y ciencias de la computacion. El AE permitio realizar: analisis de monitoreabilidad, detectabilidad y aislabilidad del proceso; y proporciono la secuencia de computo de las variables no monitoreadas (desconocidas) para obtener las relaciones de redundancia analitica. Para validar el sistema de diagnostico de fallas de la TV, se programaron los algoritmos de deteccion y localizacion de fallas en LabWindows, CVI y se integraron al simulador de la CGCC. Ademas para facilitar al usuario la visualizacion de la presencia de una falla se desarrollo una interfase grafica que indica el elemento con comportamientos anormales, ya sea sensor o actuador.

  2. Intelligent control system for the temperature regulation in a gas turbine of a combined cycle fossil fuel power plant; Sistema de control inteligente para regular la temperatura en la turbina de gas de una central termoelectrica de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Espindola Vasquez, Agustin

    2004-11-15

    logic theory and its performance was evaluated using a non- linear mathematical model that emulates the CTCC behavior. The fuzzy supervision system is integrated by three main modules: Supervision of blades temperature during the starting stage of the UTG; Supervision of blades temperature runback during the power generation stage of the UTG, and Control by Temperature during power generation stage of the UTG. The temperature fuzzy supervisor is implemented in a nonlinear mathematical model that simulates a CTCC. The obtained and analyzed results in the different sceneries of the simulation tests show that the temperature fuzzy supervision system displays a better performance than the obtained with the scheme of conventional supervision. [Spanish] En las Unidades Turbogas (UTG) de una Central Termoelectrica de Ciclo Combinado (CTCC), una de las variables criticas tanto desde el punto de vista operativo como desde el punto de vista de seguridad, es la temperatura de los alabes de la turbina. El mejor desempeno de la unidad turbogas desde el punto de vista de generacion electrica se obtiene cuando es posible lograr la mayor eficiencia termica. Desde el punto de vista de seguridad se busca mantener la temperatura de los alabes en el limite impuesto por el fabricante, garantizando con esto la integridad de las partes internas de la UTG al evitar que esfuerzos termicos considerables decrementen su vida util. Para mantener la temperatura de alabes dentro del limite establecido, el sistema de control de la UTG cuenta con un sistema de supervision de temperatura de alabes, que modifica la referencia de los controladores PI de velocidad o de potencia generada, mismos que regulan la valvula de flujo de combustible a la camara de combustion de la UTG. Este sistema de supervision esta basado en condiciones logicas para generar su salida. En las plantas de proceso cuya operacion es compleja y su comportamiento dinamico es no lineal, las estrategias de control de lazo simple no

  3. Study of PWR reactor efficiency as a function of turbine steam extractions; Estudo da otimizacao da eficiencia de reator PWR em funcao das extracoes de vapor da turbina

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Janine Gandolpho da; Alvim, Antonio Carlos Marques; Martinez, Aquilino Senra [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear

    2002-07-01

    The objective of this work is to optimize the extractions of the low-pressure turbine of a PWR nuclear reactor, in order to obtain the best thermodynamic cycle efficiency. We have analyzed typical data of a 1300 MW PWR reactor, operating at 25%, 50%, 75% and 100% capacities, respectively. The first stage of this study consists of generating a mathematical model capable of describing the reactor behavior and efficiency at any power level. The second stage of this study consists of to combine the generated mathematical model in an optimization computer program that optimize the extractions flow of the low-pressure turbine until it finds the optimal system efficiency. This work does not alter the nuclear facility project in any way. (author)

  4. Co-generation on steam industrial systems with disks turbines; Co-geracao em sistemas industriais de vapor com turbinas de discos

    Energy Technology Data Exchange (ETDEWEB)

    Lezsovits, Ferenc [Universidad de Tecnologia y Economia de Budapest (Hungary)

    2010-03-15

    The disk turbine, also called Tesla turbine, being of simple construction and low cost, can be used as steam pressure reduction on industrial systems, generating simultaneously electric power, becoming the co-generation even at lower levels. Can be used for various operational parameters and mass flux ratios.This paper analyses the advantages and disadvantages of the turbines under various operation conditions.

  5. Custo de bombas centrífugas funcionando como turbinas em microcentrais hidrelétricas Cost of pumps as hydraulic turbines for micro-scale hydropower

    Directory of Open Access Journals (Sweden)

    Carlos R. Balarim

    2004-04-01

    Full Text Available A implantação de microcentrais hidrelétricas é uma das alternativas para suprir com energia comunidades pequenas e isoladas, situadas normalmente na área rural. O aproveitamento de potenciais hidráulicos de pequeno porte é uma alternativa cada vez mais viável devido não só à falta de recursos financeiros para os grandes empreendimentos, mas também pelo imenso potencial de geração em centrais de pequeno porte, que pouco tem sido aproveitado. O objetivo deste trabalho foi de apresentar uma metodologia simples de engenharia para estimar o custo das Bombas Funcionando como Turbinas (BFTs utilizadas em microcentrais hidrelétricas, que possam ser usadas em estudos preliminares de novos aproveitamentos hidrelétricos, sem uma investigação detalhada dos lugares onde se pretende implantar. Os custos foram obtidos consultando-se diretamente os fabricantes de equipamentos e o mercado da praça de Ponta Grossa - PR. Os resultados mostraram que, para as microcentrais hidrelétricas, sempre que os custos constituírem o aspecto dominante, e para potências até 50 kW, a opção por Bombas Funcionando como Turbinas (BFTs deve ser considerada em lugar das turbinas hidráulicas.The implantation of micro hydroelectric power stations is one of the alternatives to supply energy to small and isolated communities, normally located in rural areas. The use of small load hydraulic potential is an alternative more feasible nowadays, not only because it lacks financial resources for big undertakings, but also, due to the small hydro power station hydraulic generation potential, which just a very small part has been taken advantage of. The objective of this study was to show a simple engineering methodology in order to estimate the electro-mechanic (generating set equipment costs used in micro hydroelectric power plants, which can be applied on preliminary studies about new hydroelectric power stations to be built, without detailed investigation about the

  6. Análisis y simulación del comportamiento térmico del vapor de agua en el interior de las tuberías de distribución mediante el sofware especializado ANSYS

    OpenAIRE

    Cajamarca Peñafiel, Diego Alejandro; Cárdenas Padilla, José Daniel

    2018-01-01

    This project consists in the analysis of the thermal behavior of the water vapor inside the distribution pipes, carried out in a specialized Ansys software. The input values are taken from a Pyro tubular boiler of Clayton brand of 125 BHP, with maximum load of 1226 kW, maximum equivalent steam delivery 1957 kg / h and at a pressure of 6 bars. The results obtained are analyzed along the final stretch of the network, by comparing the results varying the speed and thermal insulati...

  7. Flow prediction and heat transfer in a cooling square duch of a gas turbine blade using CFD; Predicciones de flujo y transferencia de calor en un conductor de alabe enfriado de turbina de gas utilizando CFD

    Energy Technology Data Exchange (ETDEWEB)

    Urquiza B, Gustavo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Sierra E, Fernando [Universidad Nacional Autonoma de Mexico, Mexico D.F. (Mexico); Kubiak S, Janusz; Campos A, Rafael [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2003-10-15

    A numerical investigation has been conducted to study the turbulent flow and the heat transfer in a blade turbine coolant passage involving a 180 degrees turn. The study provides a comparison test for two turbulence models. The numerical solution was conducted employing two models for turbulence, the renormalization Group Theory (RNG) and the Reynolds Stress Model (RSM), using a refined grid to model with detail the recirculating flow. Computations are performed with a commercial finite volume code which solves three dimensional, incompressible, Navier-Stokes and Energy equations. At the passage turn, significant secondary flows are present, formed by a pair of symmetrical vortices. Results have been compared against published experimental data for Re = 53 000. Very good agreement is achieved for the prediction of the local static pressure distribution along the passage. A strong effect of rotation has been observed mainly in the flow field as described in detail in the paper. [Spanish] En este trabajo se presenta una investigacion numerica para estudiar el flujo turbulento y la transferencia de calor en un conducto de enfriamiento de un alabes de turbina de gas con giro de 180 grados. El estudio proporciona una comparacion de resultados para dos modelos de turbulencia. La solucion numerica emplea dos modelos de turbulencia: el modelo de esfuerzos de Reynolds (RSM) y el modelo de la teoria del grupo de renormalizacion (RNG), utilizando una malla refinada para modelar con detalle el flujo de recirculacion. Los calculos fueron realizados con un codigo comercial de volumenes finitos el cual resuelve las ecuaciones tridimensionales de Navier-Stoke y de energia para flujo incompresible. En la seccion de giro del conductor, aparecen flujos secundarios significativos, formados por un par de celulas simetricas. Los resultados han sido comparados contra datos experimentales de la literatura para Re = 53 000. se obtuvo un buen acuerdo para la prediccion de la distribucion de

  8. Degradación de materiales cerámicos en atmósferas de combustión. Dos casos prácticos: quemadores y turbinas de gas

    Directory of Open Access Journals (Sweden)

    García, Eugenio

    2008-12-01

    Full Text Available The use of ceramic materials in energy applications with the aim of power saving through the use of high working temperatures is widely extended due to their better behaviour in those working conditions compared to than metallic materials. However, the combustion environments developed in specific applications can lead to the degradation of such materials. In this work, two ceramic materials employed in these applications are studied; a cordierite material, used as gas radiant burner for its possible application in domestic combustion boilers, and an Y2O3 stabilized ZrO2 coating, used as thermal barrier coating on metallic components of a gas turbine for power generation. The microstructure and phase evolution in both materials after ageing under working conditions allows identifying the main degradation mechanism responsible of the degradation.

    El buen comportamiento de los materiales cerámicos en ambientes corrosivos y a altas temperaturas los sitúa, preferentemente, en todos aquellos procesos industriales que buscan el ahorro energético, en particular los procesos de combustión de gases o de derivados del petróleo. Sin embargo, las atmósferas de combustión que se producen en ciertas aplicaciones producen la degradación de estos materiales. En este trabajo se estudian dos ejemplos de materiales cerámicos empleados en este tipo de aplicaciones; un material de cordierita, empleado como quemador de gas radiante para su posible aplicación en calderas de combustión domésticas y un recubrimiento de ZrO2 estabilizado con Y2O3, empleado como barrera térmica en componentes de una turbina de gas para la producción de energía eléctrica. El estudio de la microestructura, la composición química y de fases cristalinas de ambos materiales después de su degradación en uso permite determinar cuales son los mecanismos que han tenido lugar y qué elementos de la atm

  9. Viabilidade de utilização de micro-turbinas eólicas para produção de energia elétrica

    OpenAIRE

    Oliva, João Miguel Ferreira

    2016-01-01

    A utilização de combustíveis fósseis para colmatar as necessidades energéticas tem vindo a aumentar continuamente as emissões de Dióxido de Carbono e outros gases de efeito estufa (GEE) que contribuem, também, para o aquecimento global. Uma das formas de minimizar estes efeitos negativos é com a utilização de energias renováveis, como a energia proveniente do sol, vento, ondas e biomassa. A energia do vento é utilizada para a produção de energia elétrica através de turbinas eólicas, estas pod...

  10. Fuel vapor pressure (FVAPRS)

    International Nuclear Information System (INIS)

    Mason, R.E.

    1979-04-01

    A subcode (FVAPRS) is described which calculates fuel vapor pressure. This subcode was developed as part of the fuel rod behavior modeling task performed at EG and G Idaho, Inc. The fuel vapor pressure subcode (FVAPRS), is presented and a discussion of literature data, steady state and transient fuel vapor pressure equations and estimates of the standard error of estimate to be expected with the FVAPRS subcode are included

  11. Nonlinear analysis of thermal stresses of a of first stage nozzle of a gas turbine at full load from the results of an analysis of conjugated heat transference; Analisis no lineal de esfuerzos termicos de una tobera de primera etapa de turbina de gas a plena carga a partir de resultados de un analisis de transferencia de calor conjugado

    Energy Technology Data Exchange (ETDEWEB)

    Perez Hernandez, Efrain [Centro Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico); Mazur C, Zdzislaw; Garcia Illescas, R; Hernandez Rossette, Alejandro [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-11-15

    The gas turbines operate at extremely high temperatures, at high thermal and mechanical stresses, causing that the useful life of the involved components be reduced. In the present article the results realized by previous investigations of temperatures obtained from analysis of heat transfer and flow of fluids of the nozzle by means of the Star-CD program based on finite volumes is presented. Later, the NISA program of finite elements was used to realize the analysis of thermal stresses considering the material plasticity. The methodology employed to determine the material properties variable with the temperature of the super-alloy FSX-414 and the plasticity model used in the structural analysis in the finite element program. The result will be later used in the fatigue analysis for the useful life assessment. [Spanish] Las turbinas de gas operan a temperatura extremadamente altas, a elevados esfuerzos termicos y mecanicos, ocasionando que la vida de los componentes involucrados se reduzca. En el presente articulo se presentan los resultados realizados por previas investigaciones de temperaturas obtenidas a partir de analisis de transferencia de calor y flujo de fluidos de la tobera mediante el programa Star-CD basado en volumenes finitos. Posteriormente, se utilizo el programa NISA de elementos finitos para realizar el analisis de esfuerzos termicos considerando plasticidad del material. Se muestra la metodologia empleada para determinar las propiedades del material variables con la temperatura de la superaleacion FSX-414 y el modelo de plasticidad utilizado en el analisis estructural en el programa de elemento finito. Los resultados seran empleados posteriormente en el analisis de fatiga para la estimacion de vida util.

  12. Physical model for vaporization

    OpenAIRE

    Garai, Jozsef

    2006-01-01

    Based on two assumptions, the surface layer is flexible, and the internal energy of the latent heat of vaporization is completely utilized by the atoms for overcoming on the surface resistance of the liquid, the enthalpy of vaporization was calculated for 45 elements. The theoretical values were tested against experiments with positive result.

  13. Petroleum Vapor - Field Technical

    Science.gov (United States)

    The screening approach being developed by EPA OUST to evaluate petroleum vapor intrusion (PVI) requires information that has not be routinely collected in the past at vapor intrusion sites. What is the best way to collect this data? What are the relevant data quality issues and ...

  14. Activities for turbine maintenance: planning, implementation and evaluation of inspection results; Actividades para el mantenimiento de la turbina: planificacion, ejecucion y evaluacion de resultados de las inspecciones

    Energy Technology Data Exchange (ETDEWEB)

    Azcue, J.; Sanchez, M. A.; Alvaro, M.

    2014-04-01

    The article will cover the most significant aspects of how Tecnatom carry out the turbine maintenance work, both from the point of view of the inspection itself as the pre-and post tasks associated. Thus, the issues that will be part of the article are the Manual Inspection Service (MISI) and the inspection database, ISI WEB. These tools are essential for planning field work and serve as a guide to run later turbine inspections in different plants. Following this introduction the inspection teams and the techniques used by Tecnatom will be described. finally, the article will contain a small mention about management studies of life and integrity analysis of the turbine that can be performed, as well as involvement in its safe operation that is derived from them. Ultimately, the intention is to provide a comprehensive approach to the issue in question, the turbine maintenance work, so that the reader can get an ideal of the whole process. (Author)

  15. Piezoelectric trace vapor calibrator

    International Nuclear Information System (INIS)

    Verkouteren, R. Michael; Gillen, Greg; Taylor, David W.

    2006-01-01

    The design and performance of a vapor generator for calibration and testing of trace chemical sensors are described. The device utilizes piezoelectric ink-jet nozzles to dispense and vaporize precisely known amounts of analyte solutions as monodisperse droplets onto a hot ceramic surface, where the generated vapors are mixed with air before exiting the device. Injected droplets are monitored by microscope with strobed illumination, and the reproducibility of droplet volumes is optimized by adjustment of piezoelectric wave form parameters. Complete vaporization of the droplets occurs only across a 10 deg. C window within the transition boiling regime of the solvent, and the minimum and maximum rates of trace analyte that may be injected and evaporated are determined by thermodynamic principles and empirical observations of droplet formation and stability. By varying solution concentrations, droplet injection rates, air flow, and the number of active nozzles, the system is designed to deliver--on demand--continuous vapor concentrations across more than six orders of magnitude (nominally 290 fg/l to 1.05 μg/l). Vapor pulses containing femtogram to microgram quantities of analyte may also be generated. Calibrated ranges of three explosive vapors at ng/l levels were generated by the device and directly measured by ion mobility spectrometry (IMS). These data demonstrate expected linear trends within the limited working range of the IMS detector and also exhibit subtle nonlinear behavior from the IMS measurement process

  16. Improvements to vapor generators

    International Nuclear Information System (INIS)

    Keller, Arthur; Monroe, Neil.

    1976-01-01

    A supporting system is proposed for vapor generators of the 'supported' type. Said supporting system is intended to compensate the disparities of thermal expansion due to the differences in the vertical dimensions of the tubes in the walls of the combustion chamber and their collectors compared to that of the balloon tanks and the connecting tube clusters of vaporization, the first one being longer than the second ones. Said system makes it possible to build said combustion chamber higher than the balloon tanks and the tube clusters of vaporization. The capacity of steam production is thus enhanced [fr

  17. Optimización del sistema de control de las pequeñas centrales hidroeléctricas (primera parte: Factores que dificultan la regulación

    Directory of Open Access Journals (Sweden)

    Luis Jerónimo García Faure

    2011-02-01

    Full Text Available En ocasiones se aborda el problema de la regulación de la velocidad de las turbinas mediante el gasto deagua como un hecho especializado de determinada rama de la ingeniería, y se trata de aplicar a las microy minicentrales las mismas soluciones que para la regulación de otros procesos industriales en loscuales el comportamiento dinámico de los sistemas externos ejerce poca influencia sobre el sistema decontrol utilizado.  In some occasions the problem of the regulation of the speed of hydraulic turbines is approached bymeans of the flow of water as a specialized problem of certain branch of the engineering, and it is appliedto micro hydropower and mini hydropower the same solutions that are applied to the regulation of otherindustrial processes in which the dynamic behavior of the external systems exerts little influence on thecontrol system employed.

  18. Gasoline Reid Vapor Pressure

    Science.gov (United States)

    EPA regulates the vapor pressure of gasoline sold at retail stations during the summer ozone season to reduce evaporative emissions from gasoline that contribute to ground-level ozone and diminish the effects of ozone-related health problems.

  19. R-22 vapor explosions

    International Nuclear Information System (INIS)

    Anderson, R.P.; Armstrong, D.R.

    1977-01-01

    Previous experimental and theoretical studies of R-22 vapor explosions are reviewed. Results from two experimental investigations of vapor explosions in a medium scale R-22/water system are reported. Measurements following the drop of an unrestrained mass of R-22 into a water tank demonstrated the existence of two types of interaction behavior. Release of a constrained mass of R-22 beneath the surface of a water tank improved the visual resolution of the system thus allowing identification of two interaction mechansims: at low water temperatures, R-22/water contact would produce immediate violent boiling; at high water temperatures a vapor film formed around its R-22 as it was released, explosions were generated by a surface wave which initiated at a single location and propagated along the vapor film as a shock wave. A new vapor explosion model is proposed, it suggests explosions are the result of a sequence of three independent steps: an initial mixing phase, a trigger and growth phase, and a mature phase where a propagating shock wave accelerates the two liquids into a collapsing vapor layer causing a high velocity impact which finely fragments and intermixes the two liquids

  20. Las Sinapsis

    OpenAIRE

    Jorge Eduardo Duque Parra; Genaro Morales Parra; Carlos Alberto Duque Parra

    1997-01-01

    Introducción

    El estudio del sistema nervioso considera entre múltiples conexiones, aquéllas de carácter bioquímico que se median a través de sustancias elaboradas por las neuronas y que reciben la denominación de neurotransmisores’, dichas sustancias se vierten en las zonas de resquicio neuromuscular, neuroneuronal o neuroglandular, para modificar las condiciones de membrana y permitir la continuidad de los p...

  1. Vapor pressures and enthalpies of vaporization of azides

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.; Emel'yanenko, Vladimir N.; Algarra, Manuel; Manuel Lopez-Romero, J.; Aguiar, Fabio; Enrique Rodriguez-Borges, J.; Esteves da Silva, Joaquim C.G.

    2011-01-01

    Highlights: → We prepared and measured vapor pressures and vaporization enthalpies of 7 azides. → We examined consistency of new and available in the literature data. → Data for geminal azides and azido-alkanes selected for thermochemical calculations. - Abstract: Vapor pressures of some azides have been determined by the transpiration method. The molar enthalpies of vaporization Δ l g H m of these compounds were derived from the temperature dependencies of vapor pressures. The measured data sets were successfully checked for internal consistency by comparison with vaporization enthalpies of similarly structured compounds.

  2. Modelo matemático para el diseño aerodinámico de los álabes de una turbina eólica de eje horizontal (TEEH Mathematical Model for Blades Aerodynami c Design of a Horizontal Axis Wind Turbine (HAWT

    Directory of Open Access Journals (Sweden)

    Julio José–Chirinos García

    2016-02-01

    Full Text Available El objetivo de esta investigación es elaborar un modelo matemát ico para el diseño aerodinámico de las palas de una turbina eólica de eje horizontal en forma rápida y confiable qu e facilite a construcción y comportamiento bajo diferentes condiciones. Este resultado se obtuvo por el método inductivo y deductivo partiendo de las teorías aerodinámicas de Glauert y otros introduciéndole modificaciones. Igualmente el d esarrollo del modelo fue programado en una hoja de cálculo que permitió calcular el radio R del rotor, la distribu ción de la cuerda c(r y la variación del ángulo de torsión Ө(r de forma automática. El desarrollo del modelo está estructura do de acuerdo a las siguientes etapas: identificación y definición, conceptualización, formulación e implementación y finalmente la validación del modelo. La validación del modelo fue hecha comparando la geometría de la pala y la potenc ia generada por el rotor con una familia de palas de fabricantes europeos. The research purpose is elaborate a mathematical model fo r blade aerodynamic designing of horizontal axis wind turbine in fast and reliable way to facilitate the construc tion and performance evaluation under different operational conditions. To reach the theoretical and empirical approa ch it was used induction and deduction method starting from aerodynamic theories of Glauert and other researchers, in which necessary modifications were introduced. Also, the development of the model was programmed in aspreadsheet which allows to calc ula table de radio R, the distribution of chord c (r, and the variation of twist angle or pitch Ө (r in automatic way. The development of the model was structured according to the following stages: identification and definition, conceptualization, formulation andimplementation and finally the validation of the m odel. The model validation was made comparing the blade geometry and generated power by the rotor with a blade family of

  3. Modelo matemático para el diseño aerodinámico de los álabes de una turbina eólica de eje horizontal (TEEH; Mathematical Model for Blades Aerodynamic Design of a Horizontal Axis Wind Turbine (HAWT

    Directory of Open Access Journals (Sweden)

    Julio José Chirinos García

    2015-12-01

    Full Text Available El objetivo de esta investigación es elaborar un modelo matemático para el diseño aerodinámico de las palas de una turbina eólica de eje horizontal en forma rápida y confiable que facilite a construcción y comportamiento bajo diferentes condiciones. Este resultado se obtuvo por el método inductivo y deductivo partiendo de las teorías aerodinámicas de Glauert y otros introduciéndole modificaciones. Igualmente el desarrollo del modelo fue programado en una hoja de cálculo que permitió calcular el radio R del rotor, la distribución de la cuerda c(r y la variación del ángulo de torsiónӨ(r de forma automática. El desarrollo del modelo está estructurado de acuerdo a las siguientes etapas: identificación y definición, conceptualización, formulación e implementación y finalmente la validación del modelo. La validación del modelo fue hecha comparando la geometría de la pala y la potencia generada por el rotor con una familia de palas defabricantes europeos.The research purpose is elaborate a mathematical model for blade aerodynamic designing of horizontal axis wind turbine in fast and reliable way to facilitate the construction and performance evaluation under different operational conditions. To reach the theoretical and empirical approach it was used induction and deduction method starting from aerodynamic theories of Glauert and other researchers, in which necessary modifications were introduced. Also, the development of the model was programmed in aspreadsheet which allows to calcula table de radio R, the distribution of chord c (r, and the variation of twist angle or pitch Ө (r in automatic way. The development of the model was structured according to the following stages: identification and definition, conceptualization, formulationandimplementation and finally the validation of the model. The model validation was made comparing the blade geometry and generated power by the rotor with a blade family of European

  4. Vaporization of irradiated droplets

    International Nuclear Information System (INIS)

    Armstrong, R.L.; O'Rourke, P.J.; Zardecki, A.

    1986-01-01

    The vaporization of a spherically symmetric liquid droplet subject to a high-intensity laser flux is investigated on the basis of a hydrodynamic description of the system composed of the vapor and ambient gas. In the limit of the convective vaporization, the boundary conditions at the fluid--gas interface are formulated by using the notion of a Knudsen layer in which translational equilibrium is established. This leads to approximate jump conditions at the interface. For homogeneous energy deposition, the hydrodynamic equations are solved numerically with the aid of the CON1D computer code (''CON1D: A computer program for calculating spherically symmetric droplet combustion,'' Los Alamos National Laboratory Report No. LA-10269-MS, December, 1984), based on the implict continuous--fluid Eulerian (ICE) [J. Comput. Phys. 8, 197 (1971)] and arbitrary Lagrangian--Eulerian (ALE) [J. Comput. Phys. 14, 1227 (1974)] numerical mehtods. The solutions exhibit the existence of two shock waves propagating in opposite directions with respect to the contact discontinuity surface that separates the ambient gas and vapor

  5. Vapor liquid fraction determination

    International Nuclear Information System (INIS)

    1980-01-01

    This invention describes a method of measuring liquid and vapor fractions in a non-homogeneous fluid flowing through an elongate conduit, such as may be required with boiling water, non-boiling turbulent flows, fluidized bed experiments, water-gas mixing analysis, and nuclear plant cooling. (UK)

  6. Heat of vaporization spectrometer

    International Nuclear Information System (INIS)

    Edwards, D. Jr.

    1978-01-01

    Multilayer desorption measurements of various substances adsorbed on a stainless steel substrate are found to exhibit desorption profiles consistent with a zeroth order desorption model. The singleness of the desorption transients together with their narrow peak widths makes the technique ideally suited for a heat of vaporization spectrometer for either substance analysis or identification

  7. Enthalpy of Vaporization and Vapor Pressures: An Inexpensive Apparatus

    Science.gov (United States)

    Battino, Rubin; Dolson, David A.; Hall, Michael A.; Letcher, Trevor M.

    2007-01-01

    A simple and inexpensive method to determine the enthalpy of vaporization of liquids by measuring vapor pressure as a function of temperature is described. The vapor pressures measured with the stopcock cell were higher than the literature values and those measured with the sidearm rubber septum cell were both higher and lower than literature…

  8. Las Sinapsis

    Directory of Open Access Journals (Sweden)

    Jorge Eduardo Duque Parra

    1997-12-01

    Full Text Available

    Introducción

    El estudio del sistema nervioso considera entre múltiples conexiones, aquéllas de carácter bioquímico que se median a través de sustancias elaboradas por las neuronas y que reciben la denominación de neurotransmisores’, dichas sustancias se vierten en las zonas de resquicio neuromuscular, neuroneuronal o neuroglandular, para modificar las condiciones de membrana y permitir la continuidad de los potenciales de acción (por creación de nuevos potenciales en las células subsiguientes, de la neurona hacia el órgano blanco.

    La integridad de los diversos elementos de la “zona de unión funcional” o sinapsis, asegura la adecuada comunicación entre el sistema nervioso y la mayoría de los elementos restantes del organismo humano.

    Las alteraciones de los elementos de las sinapsis, conllevan a la génesis de estados variables fisiológicos y patológicos somáticos, psicosomáticos o psíquicos, inconsecuentes con el estado de homeostasis.

    Las moléculas que se vierten en las hendiduras sinápticas, sirven, por tanto, de transductoras para efectos elementales (como los reflejos y en las estrategias complejas (como los de la actividad intelectual.

    Antecedentes

    Ya desde los tiempos de Galeno, se sabía que los nervios eran los responsables de la rápida comunicación entre el cuerpo y el cerebro; el estudio de las sinapsis nos remonta de manera indirecta a
    1791, fecha en la que Luigi Galvani, descubrió en sus experimentos con ancas de ranas, que entre los eventos eléctricos y los ocurridos en los nervios, existía una relación evidente (28,37,45’, los experimentos de Galvani se han refinado con el paso del tiempo, en nuestro siglo por ejemplo, el desarrollo del osciloscopio de rayos catódicos combinado con un amplificador potente, ha permitido medir las débiles y variables corrientes bioeléctricas de los

  9. Soldadura por fricción lineal de las aleaciones de titanio: caracterización de una soldadura longitudinal mediante ensayos a tracción

    OpenAIRE

    Grand, Arnaud

    2006-01-01

    Doble titulació La unión entre los álabes y el disco de una turbina de avión está en plena evolución por la aplicación del proceso de soldadura por fricción lineal (LFW) a las aleaciones de titanio. Ello permite conseguir una pieza única llamada blisk (blade + disk). Hasta ahora, la unión álabe / disco se hacía por un ensamblaje mecánico, pero estos sufren un fenómeno de fatiga por fretting en el punto de anclaje. A parte de evitar ese fenómeno, la soldadura por fricción lin...

  10. Vapor pressure and enthalpy of vaporization of linear aliphatic alkanediamines

    International Nuclear Information System (INIS)

    Pozdeev, Vasiliy A.; Verevkin, Sergey P.

    2011-01-01

    Highlights: → We measured vapor pressure of diamines H 2 N-(CH 2 ) n -NH 2 with n = 3 to 12. → Vaporization enthalpies at 298 K were derived. → We examined consistency of new and available in the literature data. → Enthalpies of vaporization show linear dependence on numbers n. → Enthalpies of vaporization correlate linearly with Kovat's indices. - Abstract: Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic alkanediamines H 2 N-(CH 2 ) n -NH 2 with n = (3 to 12) have been determined using the transpiration method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the alkanediamines with the number n and with the Kovat's indices has been found, proving the internal consistency of the measured data.

  11. Constrained Vapor Bubble Experiment

    Science.gov (United States)

    Gokhale, Shripad; Plawsky, Joel; Wayner, Peter C., Jr.; Zheng, Ling; Wang, Ying-Xi

    2002-11-01

    Microgravity experiments on the Constrained Vapor Bubble Heat Exchanger, CVB, are being developed for the International Space Station. In particular, we present results of a precursory experimental and theoretical study of the vertical Constrained Vapor Bubble in the Earth's environment. A novel non-isothermal experimental setup was designed and built to study the transport processes in an ethanol/quartz vertical CVB system. Temperature profiles were measured using an in situ PC (personal computer)-based LabView data acquisition system via thermocouples. Film thickness profiles were measured using interferometry. A theoretical model was developed to predict the curvature profile of the stable film in the evaporator. The concept of the total amount of evaporation, which can be obtained directly by integrating the experimental temperature profile, was introduced. Experimentally measured curvature profiles are in good agreement with modeling results. For microgravity conditions, an analytical expression, which reveals an inherent relation between temperature and curvature profiles, was derived.

  12. Vapor condensation device

    International Nuclear Information System (INIS)

    Sakurai, Manabu; Hirayama, Fumio; Kurosawa, Setsumi; Yoshikawa, Jun; Hosaka, Seiichi.

    1992-01-01

    The present invention enables to separate and remove 14 C as CO 3 - ions without condensation in a vapor condensation can of a nuclear facility. That is, the vapor condensation device of the nuclear facility comprises (1) a spray pipe for spraying an acidic aqueous solution to the evaporation surface of an evaporation section, (2) a spray pump for sending the acidic aqueous solution to the spray pipe, (3) a tank for storing the acidic aqueous solution, (4) a pH sensor for detecting pH of the evaporation section, (5) a pH control section for controlling the spray pump, depending on the result of the detection of the pH sensor. With such a constitution, the pH of liquid wastes on the vaporization surface is controlled to 7 by spraying an aqueous solution of dilute sulfuric acid to the evaporation surface, thereby enabling to increase the transfer rate of 14 C to condensates to 60 to 70%. If 14 C is separated and removed as a CO 2 gas from the evaporation surface, the pH of the liquid wastes returns to the alkaline range of 9 to 10 and the liquid wastes are returned to a heating section. The amount of spraying the aqueous solution of dilute sulfuric acid can be controlled till the pH is reduced to 5. (I.S.)

  13. The vapor pressures of explosives

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, Robert G.; Waltman, Melanie J.; Atkinson, David A.; Grate, Jay W.; Hotchkiss, Peter

    2013-01-05

    The vapor pressures of many explosive compounds are extremely low and thus determining accurate values proves difficult. Many researchers, using a variety of methods, have measured and reported the vapor pressures of explosives compounds at single temperatures, or as a function of temperature using vapor pressure equations. There are large variations in reported vapor pressures for many of these compounds, and some errors exist within individual papers. This article provides a review of explosive vapor pressures and describes the methods used to determine them. We have compiled primary vapor pressure relationships traceable to the original citations and include the temperature ranges for which they have been determined. Corrected values are reported as needed and described in the text. In addition, after critically examining the available data, we calculate and tabulate vapor pressures at 25 °C.

  14. System control model of a turbine for a BWR; Modelo del sistema de control de una turbina para un BWR

    Energy Technology Data Exchange (ETDEWEB)

    Vargas O, Y. [Universidad del Valle de Mexico, Campus Toluca, Av. Las Palmas No. 136, Col. San Jorge Pueblo Nuevo, 52140 Metepec, Estado de Mexico (Mexico); Amador G, R.; Ortiz V, J.; Castillo D, R.; Delfin L, A. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)], e-mail: rodolfo.amador@inin.gob.mx

    2009-10-15

    In this work is presented a design of a control system of a turbine for a nuclear power plant with a BWR like energy source. The model seeks to implement later on at thermal hydraulics code of better estimate RELAP/SCDAPSIM. The model is developed for control and protection of turbine, and the consequent protection to the BWR, considering that the turbine control could be employed for one or several turbines in series. The quality of present designs of control pattern of turbine it is that it considers the parameters more important in the operation of a turbine besides that is has incorporated at control the secondary parameters that will be activated originally as true when the turbine model is substituted by a model more detailed. The development of control model of a turbine will be good in short and medium term to realize analysis about the operation of turbine with different operation conditions, of vapor extraction specific steps of turbine to feed other equipment s, besides analyzing the separate effect and integrated effect. (Author)

  15. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    Energy Technology Data Exchange (ETDEWEB)

    Eric M. Suuberg; Vahur Oja

    1997-07-01

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  16. Las denominaciones de las ocupaciones

    Directory of Open Access Journals (Sweden)

    Jesus Emilio Castañeda

    1990-04-01

    Full Text Available RESUMEN El propósito de este artículo, es mostrar al lector la forma como en nuestro ámbito existen diversos factores que han permitido la proliferación de maneras de llamar las ocupaciones. Aspectos regionales, la tradición, clases de organización, situaciones románticas, adjetivización de los cargos, peyorización  son entre otras razones que han generado  la creación de serie de sinónimos, de las ocupaciones, objeto de estudio de la sociologia del trabajo y de la administración de los recursos humanos.

  17. Las Farmacodependencias

    Directory of Open Access Journals (Sweden)

    José Francisco Socarrás

    1994-09-01

    Full Text Available

    Ahora, cuando la Corte Constitucional ha despenalizado al farmacodependiente por el consumo de drogas, conviene informar sobre las consecuencias perjudiciales de estas. A quienes deseen un conocimiento detallado al respecto, les recomiendo documentarse en “Enciclopedia de Psiquiatría”, publicada por “El Ateneo” en Buenos Aires.

    El Capítulo respectivo es del doctor Daniel L. Murguia. El denominador corriente de su abuso es sencillamente la dependencia, nombre propuesto por la Organización Mundial de la Salud, definido como el “estado psíquico y a veces físico causado por la interacción entre un organismo vivo y un fármaco”. Su carácter esencial es el impulso psicofísico a consumir el producto en forma continua o periódica, con el fin de experimentar los efectos que acarrea y evitar los malestares de su privación. Todas las drogas del respectivo género, consumidas a dosis altas, tienen efectos psicotóxicos que alteran la conducta y en algunos casos conducen a la muerte.

    Los expertos de la Organización Mundial califican las mencionadas sustancias en seis grupos, a saber:

    1. Morfina y opiáceas, los cuales crean dependencia física y psicológica, con tolerancia precoz, necesidad de aumentar las dosis y síndrome de abstinencia bastante peligroso. Entre los derivados se cuentan los siguientes: Hidromorfina (Dilaudid; oximorfina (Nurmophan; heroína,
    éter diacético de la morfina (Diacetilmorfina; codeína (Metilmorfina; hidrocodeína (Hicadan’ oxicodeína (Perdocan. Los efectos de los opiáceo~ son los siguientes: analgesia, depresión respiratoria y espasmo gastrointestinal. Las dosis tóxicas pueden provocar convulsiones.

    2. Barbitúricos, alcohol y sedantes como el fenobarbital, que provocan así mismo dependencia física.

    3. Anfetaminas, en particular la Bencedrina inhalante, que acarrea dependencia psicológica.

    4. Cocaína, cuya dependencia psíquica es tal que muchos

  18. A study on vapor explosions

    International Nuclear Information System (INIS)

    Takagi, N.; Shoji, M.

    1979-01-01

    An experimental study was carried out for vapor explosions of molten tin falling in water. For various initial metal temperatures and subcooling of water, transient pressure of the explosions, relative frequency of the explosions and the position where the explosions occur were measured in detail. The influence of ambient pressure was also investigated. From the results, it was concluded that the vapor explosion is closely related to the collapse of a vapor film around the molten metal. (author)

  19. Nuclear system vaporization

    International Nuclear Information System (INIS)

    Bougault, R.; Brou, R.; Colin, J.; Cussol, D.; Durand, D.; Le Brun, C.; Lecolley, J.F.; Lopez, O.; Louvel, M.; Nakagawa, T.; Peter, J.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.; Vient, E.; Yuasa-Nakagawa, K.; Wieloch, A.

    1998-01-01

    A particular case of the hot nuclei de-excitation is the total nuclear dislocation into light particles (n, p, d, t, 3 He and α). Such events were first observed at bombarding energies lower than 100 MeV/nucleon due to high detection performances of the INDRA multidetector. The light system Ar + Ni was studied at several bombarding energies ranging from 32 to 95 MeV/nucleon. The events associated to a total vaporization of the system occur above the energy threshold of ∼ 50 MeV/nucleon. A study of the form of these events shows that we have essentially two sources. The excitation energy of these sources may be determined by means of the kinematic properties of their de-excitation products. A preliminary study results in excitation energy values of the order 10 - 14 MeV/nucleon. The theoretical calculation based on a statistical model modified to take into account high excitation energies and excited levels in the lightest nuclei predicts that the vaporization of the two partner nuclei in the Ar + Ni system takes place when the excitation energy exceeds 12 MeV/nucleon what is qualitatively in agreement with the values deduced from calorimetric analysis

  20. Aprovechamiento de la energía eólica mediante turbinas savonius para bombeo de agua en el poblado de San Jerónimo, Región Junín (2011 - 2013)

    OpenAIRE

    Tacza Casallo, Óscar Teodoro

    2014-01-01

    La investigación se realizó en el poblado de San Jerónimo, Región Junín, en la cual el diseño propuesto permite el aprovechamiento de la energía eólica para transformarla en energía mecánica mediante turbinas Savonius. El diseño propuesto permite el bombeo del agua de 2 709,6 litros por hora, que es utilizado para solucionar el problema de la escasez del agua y así poder obtener hasta dos cosechas por año. Para el diseño del sistema se determinó la localización de la zona, en la rivera del ri...

  1. Chemical vapor composites (CVC)

    International Nuclear Information System (INIS)

    Reagan, P.

    1993-01-01

    The Chemical Vapor Composite, CVC trademark , process fabricates composite material by simply mixing particles (powders and or fibers) with CVD reactants which are transported and co-deposited on a hot substrate. A key feature of the CVC process is the control provided by varing the density, geometry (aspect ratio) and composition of the entrained particles in the matrix material, during deposition. The process can fabricate composite components to net shape (± 0.013 mm) on a machined substrate in a single step. The microstructure of the deposit is described and several examples of different types of particles in the matrix are illustrated. Mechanical properties of SiC composite material fabricated with SiC powder and fiber will be presented. Several examples of low cost ceramic composite products will be shown. (orig.)

  2. Iron bromide vapor laser

    Science.gov (United States)

    Sukhanov, V. B.; Shiyanov, D. V.; Trigub, M. V.; Dimaki, V. A.; Evtushenko, G. S.

    2016-03-01

    We have studied the characteristics of a pulsed gas-discharge laser on iron bromide vapor generating radiation with a wavelength of 452.9 nm at a pulse repetition frequency (PRF) of 5-30 kHz. The maximum output power amounted to 10 mW at a PRF within 5-15 kHz for a voltage of 20-25 kV applied to electrodes of the discharge tube. Addition of HBr to the medium produced leveling of the radial profile of emission. Initial weak lasing at a wavelength of 868.9 nm was observed for the first time, which ceased with buildup of the main 452.9-nm line.

  3. Vapor-droplet flow equations

    International Nuclear Information System (INIS)

    Crowe, C.T.

    1975-01-01

    General features of a vapor-droplet flow are discussed and the equations expressing the conservation of mass, momentum, and energy for the vapor, liquid, and mixture using the control volume approach are derived. The phenomenological laws describing the exchange of mass, momentum, and energy between phases are also reviewed. The results have application to development of water-dominated geothermal resources

  4. Vapor pressure and enthalpy of vaporization of aliphatic propanediamines

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.; Chernyak, Yury

    2012-01-01

    Highlights: ► We measured vapor pressure of four aliphatic 1,3-diamines. ► Vaporization enthalpies at 298 K were derived. ► We examined consistency of new and available data in the literature. ► A group-contribution method for prediction was developed. - Abstract: Vapor pressures of four aliphatic propanediamines including N-methyl-1,3-propanediamine (MPDA), N,N-dimethyl-1,3-propanediamine (DMPDA), N,N-diethyl-1,3-propanediamine (DEPDA) and N,N,N′,N′-tetramethyl-1,3-propanediamine (4MPDA) were measured using the transpiration method. The vapor pressures developed in this work and reported in the literature were used to derive molar enthalpy of vaporization values at the reference temperature 298.15 K. An internal consistency check of the enthalpy of vaporization was performed for the aliphatic propanediamines studied in this work. A group-contribution method was developed for the validation and prediction vaporization enthalpies of amines and diamines.

  5. A Citizen's Guide to Vapor Intrusion Mitigation

    Science.gov (United States)

    This guide describes how vapor intrusion is the movement of chemical vapors from contaminated soil and groundwater into nearby buildings.Vapors primarily enter through openings in the building foundation or basement walls.

  6. Vapor pressure measured with inflatable plastic bag

    Science.gov (United States)

    1965-01-01

    Deflated plastic bag in a vacuum chamber measures initial low vapor pressures of materials. The bag captures the test sample vapors and visual observation of the vapor-inflated bag under increasing external pressures yields pertinent data.

  7. Passive vapor extraction feasibility study

    International Nuclear Information System (INIS)

    Rohay, V.J.

    1994-01-01

    Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft 3 /min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft 3 /min air flow rates, passive vapor extraction is more cost effective below 100 ppm

  8. The lithium vapor box divertor

    International Nuclear Information System (INIS)

    Goldston, R J; Schwartz, J; Myers, R

    2016-01-01

    It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m −2 , implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et al as well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. At the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma. (paper)

  9. Las obras de acondicionamiento del Salto del Mont-Cenis

    Directory of Open Access Journals (Sweden)

    Vié, Georges

    1969-06-01

    Full Text Available The new dam at Mont Cenis has increased to water volume in the reservoir from 32 to 320 million m3 and provides a potential energy of 650.000 million Mp x m. This article describes the work involved in the construction of this project. Among other features, the water has been led to the reservoir along a network of varying cross-section, and of 28 km total length. The pressure conduit has been designed for a flow rate of 51 m3/s, its diameter varying between 4 and 5 m. The new power stations at Villarodin are fed by a pipe 3.6 km in length and 3 m in diameter. This conduit runs along a trench and is isolated from the ground, because of the gypsum and anhydrites contained in the soil. Its weight is 10.000 Mp, which is a European record. The power station comprises to vertical Pelton turbines of 195 MVA each, and a yearly output of 485 kWh.La capacidad de la nueva presa del Mont-Cenis ha aumentado con estas obras desde 32 hasta 320 millones de m3, permitiendo el abastecimiento de una energía potencial de 650.000 millones de Mp x m. En el artículo se describen las obras y operaciones necesarias para ello; entre otras, que las aguas captadas han sido llevadas al embalse por una red de galerías de sección variable de 28 km de longitud; y que la conducción forzada, de 18 km de longitud, fue dimensionada para un caudal de 51 m3/s, con un diámetro comprendido entre 4 y 5 metros. Las nuevas centrales de Villarodin están alimentadas por una desviación de 3,6 km de longitud y 3 m de diámetro. Este conducto, colocado en un foso inclinado para aislarlo del ter reno, en esa zona de yesos y anhidritas, principalmente, tiene un peso de 10.000 Mp, lo que constituye un récord europeo. La Central comprende dos grupos verticales de turbinas Pelton de 195 MVA cada uno, con una productividad de 485 millones de kWh.

  10. Las redes sociales presentes en las bibliotecas

    Directory of Open Access Journals (Sweden)

    Magda Cecilia Sandí S.

    2012-01-01

    Full Text Available El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

  11. Las redes sociales presentes en las bibliotecas

    Directory of Open Access Journals (Sweden)

    Magda Cecilia Sandí Sandí

    2012-07-01

    Full Text Available El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

  12. Las redes sociales presentes en las bibliotecas

    OpenAIRE

    Magda Cecilia Sandí S.

    2012-01-01

    El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

  13. Dimers in nucleating vapors

    Science.gov (United States)

    Lushnikov, A. A.; Kulmala, M.

    1998-09-01

    The dimer stage of nucleation may affect considerably the rate of the nucleation process at high supersaturation of the nucleating vapor. Assuming that the dimer formation limits the nucleation rate, the kinetics of the particle formation-growth process is studied starting with the definition of dimers as bound states of two associating molecules. The partition function of dimer states is calculated by summing the Boltzmann factor over all classical bound states, and the equilibrium population of dimers is found for two types of intermolecular forces: the Lennard-Jones (LJ) and rectangular well+hard core (RW) potentials. The principle of detailed balance is used for calculating the evaporation rate of dimers. The kinetics of the particle formation-growth process is then investigated under the assumption that the trimers are stable with respect to evaporation and that the condensation rate is a power function of the particle mass. If the power exponent λ=n/(n+1) (n is a non-negative integer), the kinetics of the process is described by a finite set of moments of particle mass distribution. When the characteristic time of the particle formation by nucleation is much shorter than that of the condensational growth, n+2 universal functions of a nondimensional time define the kinetic process. These functions are calculated for λ=2/3 (gas-to-particle conversion in the free molecular regime) and λ=1/2 (formation of islands on surfaces).

  14. Tubing For Sampling Hydrazine Vapor

    Science.gov (United States)

    Travis, Josh; Taffe, Patricia S.; Rose-Pehrsson, Susan L.; Wyatt, Jeffrey R.

    1993-01-01

    Report evaluates flexible tubing used for transporting such hypergolic vapors as those of hydrazines for quantitative analysis. Describes experiments in which variety of tubing materials, chosen for their known compatibility with hydrazine, flexibility, and resistance to heat.

  15. Vapor trap for liquid metal

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T

    1968-05-22

    In a pipe system which transfers liquid metal, inert gas (cover gas) is packed above the surface of the liquid metal to prevent oxidization of the liquid. If the metal vapor is contained in such cover gas, the circulating system of the cover gas is blocked due to condensation of liquid metal inside the system. The present invention relates to an improvement in vapor trap to remove the metal vapor from the cover gas. The trap consists of a cylindrical outer body, an inlet nozzle which is deeply inserted inside the outer body and has a number of holes to inject the cove gas into the body, metal mesh or steel wool which covers the exterior of the nozzle and on which the condensation of the metal gas takes place, and a heater wire hich is wound around the nozzle to prevent condensation of the metal vapor at the inner peripheral side of the mesh.

  16. Conventional and intelligent generalized supervisory control for combined cycle generating power stations.; Control supervisiorio generalizado convencional e inteligente para centrales de generacion de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Martinez M, Miguel A; Sanchez P, Marino [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Gonzalez Rubio S, Jose L [Cento Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico)

    2005-07-01

    Under the expectations of expansion of electric power generation in Mexico, this work exposes the development of a conventional and intelligent generalized supervisory control (CSG) for a combined cycle generation power plant. This one allows to obtain the optimal operation of the power plant through the automatic starting of the generating units and to obtain the maximum possible amount of electrical power in automatic and safe form. For the development of the CSG a control loop by temperature was implemented for the gas turbine system and a control loop by strangled pressure for the gas turbine and a control loop by strangled pressure for the steam turbine. The design of these supervisory systems was made with base in the critical limits on the involved variables of the process: blading average temperature, for the gas turbine (GT) and strangled pressure for the steam turbine (ST) [Spanish] Bajo estas expectativas de expansion de generacion de energia en Mexico, este trabajo expone el desarrollo de un control supervisorio generalizado (CSG) para una central generacion de ciclo combinado. Este permite lograr la operacion optima de la planta a traves del arranque automatico de las unidades generadoras y obtener la maxima cantidad posible de potencia electrica en forma automatica y segura. Para el desarrollo del CSG se implanto un lazo de control por temperatura para el sistema de turbina de gas y un lazo de control por presion estrangulada para la turbina de gas y un lazo de control por presion estrangulada para la turbina de vapor. El diseno de estos sistemas supervisorio se realizo con base en los limites criticos de las variables del proceso involucradas: temperatura promedio de empaletado para la turbina de gas (TG) y presion estrangulada para la turbina de vapor (TV)

  17. Adsorción física de gases y vapores por carbones

    OpenAIRE

    Martín-Martínez, José Miguel

    1990-01-01

    El establecimiento de las características texturales de carbones es esencial para su utilización en procesos industriales. La evaluación de la textura porosa de carbones se suele realizar mediante adsorción de gases y vapores. Por esta razón, en este libro se pretende plantear las principales estrategias más generalmente empleadas para cualificar la superficie y porosidad de carbones.

  18. Las aguas termominerales de Tabio

    Directory of Open Access Journals (Sweden)

    Antonio María Barriga Villalba

    1933-01-01

    Full Text Available La pintoresca población de Tabio, situada en el vallecito que forman dos repliegues de la gran cordillera montañosa que rodea la sabana de Bogotá, es un pueblecito apacible, famoso desde tiempo inmemorial por las aguas termales que brotan en la falda de los cerros situados al occidente, a unos mil metros de la iglesia de la población, en terrenos de propiedad del doctor Pompilio Martínez. Fue fundada Tabio en el año 1761 (*. Se halla a 4°50'50" de latitud norte y 0° 04'00" de longitud del meridiano de Bogotá. Clima seco en la mayor parte del año, temperatura media 14°.5 C. Presión atmosférica 560 mm.; altura sobre el nivel del mar 2.650 metros; temperatura de. ebullición del agua 91°.62 C.; humedad en vapor de agua, por metro cúbico, en los días secos 127,5 gramos por metro cúbico; en los días húmedos, 251,8 gramos por metro cúbico. En el sitio de las fuentes la humedad relativa media es de 38.38 por 100 y la temperatura de la atmósfera varía de 10° C. hasta 23°C.; en los días de sol, hacia las doce del día, la temperatura de la atmósfera cerca de las fuentes es de 20°-22°C.

  19. Melting temperature, vapor density, and vapor pressure of molybdenum pentafluoride

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Jr, R F; Douglas, T B [National Bureau of Standards, Washington, D.C. (USA). Inst. for Materials Research

    1977-12-01

    A sample of MoF/sub 5/ was prepared by reaction of MoF/sub 6/(g) and Mo(c). Melting curves of temperature against time established the melting temperature at zero impurity to be 318.85 K, the enthalpy of fusion to be 6.1 kJ mol/sup -1/ (+ - 5 per cent), and the cryoscopic impurity of the sample to be 0.15 mole per cent. In the presence of MoF/sub 6/(g) which was added to suppress disproportionation, the vapor density of MoF/sub 5/ over the liquid was measured by the transpiration method at 343, 363, and 383 K, the total MoF/sub 5/ that evaporated being determined by permanganate titration. The total vapor pressure of MoF/sub 5/ oligomers over the liquid was measured by a simple static method at 373 and 392 K, while melting temperatures were taken alternately to monitor possible contamination of the sample. Although the vapor pressures were adjusted for disproportionation, solution of MoF/sub 6/ in MoF/sub 5/ (1), and wall adsorption of MoF/sub 6/ their percentage uncertainty is probably several times that of the vapor densities. A combination of the two properties indicates the average extent of association of the saturated vapor to be near 2, which is the value for the dimer species (MoF/sub 5/)/sub 2/.

  20. The use of laser diodes for control of uranium vaporization rates

    International Nuclear Information System (INIS)

    Hagans, K.; Galkowski, J.

    1993-09-01

    Within the Atomic Vapor Laser Isotope Separation (AVLIS) program we have successfully used the laser absorption spectroscopy technique (LAS) to diagnose process physics performance and control vaporization rate. In the LAS technique, a narrow line-width laser is tuned to an absorption line of the species to be measured. The laser light that is propagated through the sample is and, from this data, the density of the species can be calculated. These laser systems have exclusively consisted of expensive, cumbersome, and difficult to maintain argon-ion-pumped ring dye lasers. While the wavelength flexibility of dye lasers is very useful in a laboratory environment, these laser systems are not well suited for the industrial process control system under development for an AVLIS plant. Diode-lasers offer lower system costs, reduced man power requirements, reduced space requirements, higher system availability, and improved operator safety. We report the. successful deployment and test of a prototype laser diode based uranium vapor rate control system. Diode-laser generated LAS data was used to control the uranium vaporization rate in a hands-off mode for greater than 50 hours. With one minor adjustment the system successfully controlled the vaporization rate for greater than 147 hours. We report excellent agreement with ring dye laser diagnostics and uranium weigh-back measurements

  1. Las creencias y las concepciones. Perspectivas complementarias

    Directory of Open Access Journals (Sweden)

    Fuensanta HERNÁNDEZ PINA

    2011-01-01

    Full Text Available Las creencias y las concepciones sobre la enseñanza y el aprendizaje que los profesores sostienen como docentes es una línea de investigación que está suponiendo un avance en el conocimiento sobre factores relevantes para la mejor de la educación. Desde hace más de dos décadas han sido numerosos los investigadores que han venido proporcionando resultados de investigación en torno a las creencias y las concepciones de la enseñanza y el aprendizaje lo que ha supuesto establecer nuevas e interesantes interpretaciones en dicha relación. En el trabajo que presentamos se abordan algunas de las aportaciones sobre dichas creencias y sobre las concepciones de la enseñanza y el aprendizaje.

  2. Alternative analysis to increase the power in combined-cycle power plants; Analisis de alternativas para el incremento de potencia en plantas termoelectricas de Ciclo Combinado

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco Cruz, Hector; Arriola Medellin, Alejandro M. [Gerencia de Procesos Termicos, Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: hpacheco@iie.org.mx; aarriola@iie.org.mx

    2010-11-15

    The electricity industry traditionally had two thermodynamic cycles for power generation: conventional steam turbine (Rankine cycle) used to supply a base load during the day, and gas turbines (Brayton cycle), for its speed response, normally used to cover peak loads. However, to provide variable peak loads, the gas turbine, as a volumetric machine is affected by the change in air density by changing the combustion temperature. This paper shows the scheme of integration of both systems, that it's known as combined cycle and the different options that would have these power plants, to maintain or increase their power in variable ambient conditions. It analyzes different options, such as: 1. Supplementary fire in the stove. 2. Air cooling intake in the gas turbine (evaporation system or mechanical system). 3. Steam injection in the combustion chamber. [Spanish] La industria electrica tradicionalmente a contado con dos ciclos termodinamicos para generacion electrica: las turbinas convencionales de vapor (ciclo de Rankine) se utilizan para suministrar una carga base durante el dia, y las turbinas de gas (ciclo de Brayton), por su rapidez de respuesta, se utilizan normalmente para cubrir las cargas pico. Sin embargo, para suministrar las cargas variables pico, la turbina a gas, por ser una maquina volumetrica, se ve afectada por el cambio de la densidad del aire de combustion al cambiar la temperatura ambiente. En este trabajo se muestra el esquema de integracion de ambos sistemas, en lo que se conoce como ciclo combinado y las diferentes opciones que tendrian estas plantas de generacion electrica para mantener o incrementar su potencia en condiciones ambiente variable. Para ello se analizan diferentes opciones, tales como: 1.- Combustion suplementaria en el recuperador de calor. 2.- Enfriamiento del aire de admision a la turbina de gas (mediante un sistema de evaporacion o mediante un sistema mecanico). 3.- Inyeccion de vapor a la camara de combustion. Palabras

  3. Thermal plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Heberlein, J.; Pfender, E.

    1993-01-01

    Thermal plasmas, with temperatures up to and even exceeding 10 4 K, are capable of producing high density vapor phase precursors for the deposition of relatively thick films. Although this technology is still in its infancy, it will fill the void between the relatively slow deposition processes such as physical vapor deposition and the high rate thermal spray deposition processes. In this chapter, the present state-of-the-art of this field is reviewed with emphasis on the various types of reactors proposed for this emerging technology. Only applications which attracted particular attention, namely diamond and high T c superconducting film deposition, are discussed in greater detail. (orig.)

  4. Waste Tank Vapor Project: Tank vapor database development

    International Nuclear Information System (INIS)

    Seesing, P.R.; Birn, M.B.; Manke, K.L.

    1994-09-01

    The objective of the Tank Vapor Database (TVD) Development task in FY 1994 was to create a database to store, retrieve, and analyze data collected from the vapor phase of Hanford waste tanks. The data needed to be accessible over the Hanford Local Area Network to users at both Westinghouse Hanford Company (WHC) and Pacific Northwest Laboratory (PNL). The data were restricted to results published in cleared reports from the laboratories analyzing vapor samples. Emphasis was placed on ease of access and flexibility of data formatting and reporting mechanisms. Because of time and budget constraints, a Rapid Application Development strategy was adopted by the database development team. An extensive data modeling exercise was conducted to determine the scope of information contained in the database. a A SUN Sparcstation 1000 was procured as the database file server. A multi-user relational database management system, Sybase reg-sign, was chosen to provide the basic data storage and retrieval capabilities. Two packages were chosen for the user interface to the database: DataPrism reg-sign and Business Objects trademark. A prototype database was constructed to provide the Waste Tank Vapor Project's Toxicology task with summarized and detailed information presented at Vapor Conference 4 by WHC, PNL, Oak Ridge National Laboratory, and Oregon Graduate Institute. The prototype was used to develop a list of reported compounds, and the range of values for compounds reported by the analytical laboratories using different sample containers and analysis methodologies. The prototype allowed a panel of toxicology experts to identify carcinogens and compounds whose concentrations were within the reach of regulatory limits. The database and user documentation was made available for general access in September 1994

  5. Estimated vapor pressure for WTP process streams

    Energy Technology Data Exchange (ETDEWEB)

    Pike, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Poirier, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-01-01

    Design assumptions during the vacuum refill phase of the Pulsed Jet Mixers (PJMs) in the Hanford Waste Treatment and Immobilization Plant (WTP) equate the vapor pressure of all process streams to that of water when calculating the temperature at which the vacuum refill is reduced or eliminated. WTP design authority asked the authors to assess this assumption by performing calculations on proposed feed slurries to calculate the vapor pressure as a function of temperature. The vapor pressure was estimated for each WTP waste group. The vapor pressure suppression caused by dissolved solids is much greater than the increase caused by organic components such that the vapor pressure for all of the waste group compositions is less than that of pure water. The vapor pressure for each group at 145°F ranges from 81% to 98% of the vapor pressure of water. If desired, the PJM could be operated at higher temperatures for waste groups with high dissolved solids that suppress vapor pressure. The SO4 group with the highest vapor pressure suppression could be operated up to 153°F before reaching the same vapor pressure of water at 145°F. However, most groups would reach equivalent vapor pressure at 147 to 148°F. If any of these waste streams are diluted, the vapor pressure can exceed the vapor pressure of water at mass dilution ratios greater than 10, but the overall effect is less than 0.5%.

  6. Vapor generation methods for explosives detection research

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Ewing, Robert G.; Atkinson, David A.

    2012-12-01

    The generation of calibrated vapor samples of explosives compounds remains a challenge due to the low vapor pressures of the explosives, adsorption of explosives on container and tubing walls, and the requirement to manage (typically) multiple temperature zones as the vapor is generated, diluted, and delivered. Methods that have been described to generate vapors can be classified as continuous or pulsed flow vapor generators. Vapor sources for continuous flow generators are typically explosives compounds supported on a solid support, or compounds contained in a permeation or diffusion device. Sources are held at elevated isothermal temperatures. Similar sources can be used for pulsed vapor generators; however, pulsed systems may also use injection of solutions onto heated surfaces with generation of both solvent and explosives vapors, transient peaks from a gas chromatograph, or vapors generated by s programmed thermal desorption. This article reviews vapor generator approaches with emphasis on the method of generating the vapors and on practical aspects of vapor dilution and handling. In addition, a gas chromatographic system with two ovens that is configurable with up to four heating ropes is proposed that could serve as a single integrated platform for explosives vapor generation and device testing. Issues related to standards, calibration, and safety are also discussed.

  7. Vapor generating unit blowdown arrangement

    International Nuclear Information System (INIS)

    McDonald, B.N.

    1978-01-01

    A vapor generating unit having a U-shaped tube bundle is provided with an orificed downcomer shroud and a fluid flow distribution plate between the lower hot and cold leg regions to promote fluid entrained sediment deposition in proximity to an apertured blowdown pipe

  8. Hanford soil partitioning and vapor extraction study

    International Nuclear Information System (INIS)

    Yonge, D.; Hossain, A.; Cameron, R.; Ford, H.; Storey, C.

    1996-07-01

    This report describes the testing and results of laboratory experiments conducted to assist the carbon tetrachloride soil vapor extraction project operating in the 200 West Area of the Hanford Site in Richland, Washington. Vapor-phase adsorption and desorption testing was performed using carbon tetrachloride and Hanford Site soils to estimate vapor-soil partitioning and reasonably achievable carbon tetrachloride soil concentrations during active vapor extractions efforts at the 200 West Area. (CCl 4 is used in Pu recovery from aqueous streams.)

  9. Vapor Pressure Data Analysis and Statistics

    Science.gov (United States)

    2016-12-01

    near 8, 2000, and 200, respectively. The A (or a) value is directly related to vapor pressure and will be greater for high vapor pressure materials...1, (10) where n is the number of data points, Yi is the natural logarithm of the i th experimental vapor pressure value, and Xi is the...VAPOR PRESSURE DATA ANALYSIS AND STATISTICS ECBC-TR-1422 Ann Brozena RESEARCH AND TECHNOLOGY DIRECTORATE

  10. Thermo mechanical analysis and optimization in transient state of the first stage of blades in a gas turbine with internal cooling; Analisis y optimizacion termomecanica, en estado transitorio, de la primera etapa de alabes en una turbina de gas con enfriamiento interno

    Energy Technology Data Exchange (ETDEWEB)

    Campos Amezcua, Alfonso

    2007-04-15

    ). This interface allows integrating the computational models virtually, although they have different grids, and that the CFD model registers the data in center cells, whereas the FEA model registers them in the nodes. Pressure, temperature and velocity profiles were obtained for the fluid and, temperature and stress for the solid. The obtained results are compared with experimental data reported in literature obtaining acceptable results. With this work, information for complementary studies is generated, as failure analysis faults and blade life assessment. [Spanish] Este trabajo presenta una metodologia para el analisis termomecanico de un alabe de turbina de gas con enfriamiento interno, la cual permite eliminar simplificaciones tipicas en este tipo de estudios, tales como: analisis ensamblados de perfiles bidimensionales, que desprecia los efectos tridimensionales del flujo que rodea la punta del alabe entre otras zonas; uso de coeficientes de transferencia de calor semi-empiricos obtenidos de predicciones de flujo adiabatico, entre otros. Esta metodologia utiliza dinamica de fluidos computacional ((CFD) por sus siglas en ingles) para el analisis de flujo y transferencia de calor conjugado y, analisis por elementos finitos ((FEA) por sus siglas en ingles) para el analisis termoestructural, estas tecnicas de simulacion han llegado a ser herramientas estandar para cada uno de los analisis, pero su integracion virtual aun esta en proceso de desarrollo. El codigo de CFD utiliza las ecuaciones de conservacion, asi como ecuaciones constitutivas adicionales para los diversos fenomenos que se presentan, permitiendo utilizar funciones definidas por el usuario para utilizar condiciones de frontera dinamicas en el analisis transitorio y propiedades variables de los materiales, lo cual incrementa la presion de las predicciones. Para resolver las ecuaciones y encontrar una solucion aproximada, se utiliza el metodo de volumen finito. Por otro lado, el codigo de FEA utiliza las

  11. Estudio de las Startups

    OpenAIRE

    Rodríguez Reina, Cristina

    2016-01-01

    Este trabajo trata de analizar las pautas a la hora de poner en marcha una startup. Se explica el método que hay que seguir (Lean Startup), se expone una breve biografía de su autor, se muestran las distintas fases por las que atraviesa, las formas de financiación, así como una serie de puntos que servirán de ayuda para adentrarse en este mundo tan novedoso y hasta entonces tan poco conocido, como es el de la startups. Dentro del ámbito de las startups, se explicará el tema ...

  12. Aborto en las adolescentes

    OpenAIRE

    Cedeño Donet, Marisel; García García, María T; Jímenez Mendeliú, Irene M

    2000-01-01

    Se realizó un estudio descriptivo y transversal sobre el comportamiento del aborto en la población adolescente del territorio occidental de la provincia de Camagüey, desde enero de 1997 hasta agosto de 1998. Se encontró que el 26, 2 % de las jóvenes se realizó un aborto, las regulaciones menstruales fueron el 47, 6 %, el 25 % de las sepsis posinterrupción correspondió a las adolescentes. Más de la cuarta parte de los abortos realizados en la Provincia corresponde a las menores de 20 años. Cas...

  13. Las versiones homericas Las versiones homericas

    Directory of Open Access Journals (Sweden)

    Jorge Luis Borges

    2008-04-01

    Full Text Available Ningún problema tan consustancial con las letras con su modesto misterio como el que propone una traducción. Un olvido animal por la vanidad, el tenor de confesar procesos mentales que adivinamos peligrosamente comunes, el conato de mantener intacta y central una reserve incalculable de sombre, velan las tales escrituras directas. La traducciOn, en cambio, parece destinada a ilustrar la discusión estitica. El modelo propuesto a su imitaciOn es un texto visible, no un labirint° inestimable de proyectos preteritos o la acatada tentaciOn momentanea de una facilidad. Bertrand Russell define un objeto extern( como un sistema circular, irradiante, de impresiones posibles; lo mismo puede aseverarse de un texto, dadas las repercusiones incalculables de lo verbal. Un parcial y precioso documento de las vicisitudes que sufre queda en sus traducciones.

  14. Estimating enthalpy of vaporization from vapor pressure using Trouton's rule.

    Science.gov (United States)

    MacLeod, Matthew; Scheringer, Martin; Hungerbühler, Konrad

    2007-04-15

    The enthalpy of vaporization of liquids and subcooled liquids at 298 K (delta H(VAP)) is an important parameter in environmental fate assessments that consider spatial and temporal variability in environmental conditions. It has been shown that delta H(VAP)P for non-hydrogen-bonding substances can be estimated from vapor pressure at 298 K (P(L)) using an empirically derived linear relationship. Here, we demonstrate that the relationship between delta H(VAP)and PL is consistent with Trouton's rule and the ClausiusClapeyron equation under the assumption that delta H(VAP) is linearly dependent on temperature between 298 K and the boiling point temperature. Our interpretation based on Trouton's rule substantiates the empirical relationship between delta H(VAP) degree and P(L) degrees for non-hydrogen-bonding chemicals with subcooled liquid vapor pressures ranging over 15 orders of magnitude. We apply the relationship between delta H(VAP) degrees and P(L) degrees to evaluate data reported in literature reviews for several important classes of semivolatile environmental contaminants, including polycyclic aromatic hydrocarbons, chlorobenzenes, polychlorinated biphenyls and polychlorinated dibenzo-dioxins and -furans and illustrate the temperature dependence of results from a multimedia model presented as a partitioning map. The uncertainty associated with estimating delta H(VAP)degrees from P(L) degrees using this relationship is acceptable for most environmental fate modeling of non-hydrogen-bonding semivolatile organic chemicals.

  15. Las lenguas en las sociedades del conocimiento

    Directory of Open Access Journals (Sweden)

    Álvarez, J. Francisco

    2008-12-01

    Full Text Available Languages become a strategic resource for information and knowledge societies. By expressing and sharing knowledge by means of languages, every culture generates deposits of knowledge, which can be transferred and exchanged among different epistemic communities. The contemporary technologies of information and communication have changed the structure of knowledge flows. Globalization of knowledge poses a great challenge to every language, including the Spanish one. In order to survive in the digital world, they should develop technolanguages. The lemma “Thinking in Spanish” implies a new model of governance for the Ibero-American knowledge communities.En las sociedades de la información y el conocimiento las lenguas se convierten en un recurso estratégico. Al expresar y compartir conocimiento por medio de los idiomas, las culturas generan yacimientos de conocimiento, que pueden ser transferidos e intercambiados entre comunidades epistémicas diferentes. Las actuales tecnologías de la información y la comunicación han cambiado la estructura de los flujos de conocimiento. La globalización del conocimiento plantea un gran desafío a todas las lenguas, incluyendo la española. Para sobrevivir en el mundo digital, los lenguajes han de convertirse en tecnolenguajes. El lema “Pensar en español” aporta un nuevo modelo de gobernanza para las comunidades iberoamericanas del conocimiento.

  16. Vapor deposition of tantalum and tantalum compounds

    International Nuclear Information System (INIS)

    Trkula, M.

    1996-01-01

    Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition

  17. What Good is Raman Water Vapor Lidar?

    Science.gov (United States)

    Whitman, David

    2011-01-01

    Raman lidar has been used to quantify water vapor in the atmosphere for various scientific studies including mesoscale meteorology and satellite validation. Now the international networks of NDACC and GRUAN have interest in using Raman water vapor lidar for detecting trends in atmospheric water vapor concentrations. What are the data needs for addressing these very different measurement challenges. We will review briefly the scientific needs for water vapor accuracy for each of these three applications and attempt to translate that into performance specifications for Raman lidar in an effort to address the question in the title of "What good is Raman water vapor Iidar."

  18. High temperature vapors science and technology

    CERN Document Server

    Hastie, John

    2012-01-01

    High Temperature Vapors: Science and Technology focuses on the relationship of the basic science of high-temperature vapors to some areas of discernible practical importance in modern science and technology. The major high-temperature problem areas selected for discussion include chemical vapor transport and deposition; the vapor phase aspects of corrosion, combustion, and energy systems; and extraterrestrial high-temperature species. This book is comprised of seven chapters and begins with an introduction to the nature of the high-temperature vapor state, the scope and literature of high-temp

  19. Importance Profiles for Water Vapor

    Science.gov (United States)

    Mapes, Brian; Chandra, Arunchandra S.; Kuang, Zhiming; Zuidema, Paquita

    2017-11-01

    Motivated by the scientific desire to align observations with quantities of physical interest, we survey how scalar importance functions depend on vertically resolved water vapor. Definitions of importance begin from familiar examples of water mass I m and TOA clear-sky outgoing longwave flux I OLR, in order to establish notation and illustrate graphically how the sensitivity profile or "kernel" depends on whether specific humidity S, relative humidity R, or ln( R) are used as measures of vapor. Then, new results on the sensitivity of convective activity I con to vapor (with implied knock-on effects such as weather prediction skill) are presented. In radiative-convective equilibrium, organized (line-like) convection is much more sensitive to moisture than scattered isotropic convection, but it exists in a drier mean state. The lesson for natural convection may be that organized convection is less susceptible to dryness and can survive and propagate into regions unfavorable for disorganized convection. This counterintuitive interpretive conclusion, with respect to the narrow numerical result behind it, highlights the importance of clarity about what is held constant at what values in sensitivity or susceptibility kernels. Finally, the sensitivities of observable radiance signals I sig for passive remote sensing are considered. While the accuracy of R in the lower free troposphere is crucial for the physical importance scalars, this layer is unfortunately the most difficult to isolate with passive remote sensing: In high emissivity channels, water vapor signals come from too high in the atmosphere (for satellites) or too low (for surface radiometers), while low emissivity channels have poor altitude discrimination and (in the case of satellites) are contaminated by surface emissions. For these reasons, active ranging (LiDAR) is the preferred observing strategy.

  20. Vapor Pressure of Antimony Triiodide

    Science.gov (United States)

    2017-12-07

    unlimited. iii Contents List of Figures iv 1. Introduction 1 2. Vapor Pressure 1 3. Experiment 3 4. Discussion and Measurements 5 5...SbI3 as a function of temperature ......................... 6 Approved for public release; distribution is unlimited. 1 1. Introduction ...single-crystal thin films of n-type (Bi,Sb)2(Te,Se)3 materials presents new doping challenges because it is a nonequilibrium process. (Bi,Sb)2(Te,Se)3

  1. Sodium vapor charge exchange cell

    International Nuclear Information System (INIS)

    Hiddleston, H.R.; Fasolo, J.A.; Minette, D.C.; Chrien, R.E.; Frederick, J.A.

    1976-01-01

    An operational sequential charge-exchange ion source yielding a 50 MeV H - current of approximately 8 mA is planned for use with the Argonne 500 MeV booster synchrotron. We report on the progress for development of a sodium vapor charge-exchange cell as part of that planned effort. Design, fabrication, and operating results to date are presented and discussed. (author)

  2. Análisis de la redundancia en la generación de vapor con parámetros inferiores en un monobloque de 64 MW // Analysis of redundancy in the steam generation with inferior parameters in an unit of 64 MW.

    Directory of Open Access Journals (Sweden)

    A. Paneque Matos

    2000-10-01

    Full Text Available La necesidad del país de mantener la generación eléctrica a fin de evitar los cortes de servicio planificados e imprevistos,debido a la difícil situación económica actual, obliga a buscar soluciones que al menos sirvan de paliativo temporal a estadesagradable situación. En una central termoeléctrica ubicada en el perímetro de la ciudad, se presentó la situación de queproducto de un accidente, un bloque quedó sin turbogenerador, estando su generador de vapor en magníficas condicionesde explotación; y que otro bloque presentaba muchas salidas forzosas fuera de servicio producto de una insuficientereparación de su generador de vapor. La carencia de fondos para acometer una efectiva reparación, hizo pensar en elanálisis de la posibilidad de utilizar la caldera de una unidad para alimentar el turbogenerador de la otra. En el presentetrabajo se muestran los cálculos correspondientes para determinar aproximadamente el comportamiento de la turbina en lasnuevas condiciones impuestas, se realizó un análisis de fiabilidad del sistema propuesto y se utilizó la simulación comoherramienta para modelar el proceso.Palabras claves: centrales termoeléctricas, fiabilidad, eficiencia, turbina de gas, caldera._______________________________________________________________________Abstract:The necessity of Cuba to maintain the electric generation in order to avoid the interruption of service in planned oraccidental way, due to the difficult current economic situation, forces to solutions that at least serve for temporary palliativeto this unpleasant situation. In a thermoelectric power station located in the perimeter of the city, a situation was presenteddue to an accident, a block with fail in the turbogenerator and the steam generator in good conditions of exploitation; andthat another block, the No.7, presented many mandatory out of service product of an insufficient repair of its generator.This situation lead to analyze the possibility of

  3. Las ondas en las universidades o las universidades en las ondas

    Directory of Open Access Journals (Sweden)

    Verónica Marín Díaz

    2014-01-01

    Full Text Available En las aulas y pasillos de las universidades vuelven a sonar las ondas hercianas que raen una variedad de programas a la anodina vida de la comunidad universitaria, inmersa en la implantación de títulos de Grado, nuevos programas de doctorado, legislación universitaria variable y un largo etcétera que afecta al devenir de la vida en el ámbito de la educación superior.

  4. Las incubadoras de las empresas de Quebec

    Directory of Open Access Journals (Sweden)

    Bernardo Parra Restrepo

    1993-01-01

    Full Text Available Este articulo contiene información de las incubadoras de empresas especialmente aquellas encontradas en Quebec. A través de los 80's, el concepto de incubadoras de empresas fue introducido en América por expertos en el desarrollo económico. Sus metas fueron el estudio de los efectos del desempleo resultante de la quiebra de plantas industriales o del uso del proceso de producción automático por parte de las grandes compañías. Además se esperaba crear empleo para los inmigrantes. El campo más prometedor de estas experiencias se encuentra en el desarrollo de alta tecnología industrial, especialmente en electrónica, microprocesadores y software para sistemas de computación. Esta área también cubre las industrias innovadoras.

  5. Las serpientes en colombia

    OpenAIRE

    Daniel, H.

    2012-01-01

    El estudio de las serpientes en Colombia no deja de tener su particular interés; existe una inmensa variedad de especies que se escalonan desde los valles ardientes hasta alturas relativamente considerables; en estos últimos puntos disminuye notablemente la variedad de formas y de modo especial las especies provistas de veneno. Hacer una distinción entre las especies venenosas y las inofensivas, resulta un tanto difícil; en algunos textos se dan unas cuántas reglas, pero la mayor parte d...

  6. Recubrimientos protectores para componentes de turbinas de aviación y de generación de energía depositados por proyección por plasma

    Directory of Open Access Journals (Sweden)

    Agüero Bruna, A.

    2000-08-01

    Full Text Available Coatings produced by aluminium diffusion, called aluminide are employed to increase the oxidation and corrosion resistance, increasing the life of Ni and Co base superalloys components at temperatures comprised between 900 and 1050ºC. Consequently these coatings are frequently employed in aeronautic and power generation turbines as well as in the chemical industry. Aluminides are industrially produced by pack cementation or CVD and recently it has been demonstrated that its resistance significantly increases when Cr is added (chrome-aluminides. During this work, a feasibility study has been carried out in order to determine if plasma spray can be employed for depositing this type of coatings on turbine blades. Therefore, aluminium and aluminium/chromium layers were deposited on Ni base IN100 superalloy specimens that were subsequently subjected to a diffusion heat treatment under Ar flow. Characterisation and analysis of the coatings were carried out by metallography , SEM and EDS. Cyclic oxidation tests were carried out at 1050º C while molten sulphate hot corrosion was performed at 900º C. The results of this preliminary study are promising and indicate that plasma spray can be developed as an industrial process for production of aluminide and chrome-aluminide coatings.

    Los recubrimientos producidos por difusión de aluminio, llamados aluminuros, se emplean para aumentar la resistencia a la oxidación y a la corrosión, incrementando la vida de componentes fabricados con superaleaciones de níquel y cobalto a temperaturas comprendidas entre 900 y 1050º C. Por ello se emplean muy frecuentemente en turbinas aeronaúticas y de producción de energía y en la industria química. Los aluminuros se obtienen industrialmente mediante cementación o CVD y recientemente se ha demostrado que su resistencia aumenta significativamente cuando se añade cromo (cromoaluminuros. Durante el presente trabajo, se ha realizado un estudio de viabilidad

  7. Mesh sensitivity in the thermal analysis of a gas turbine a blade with internal cooling; Sensibilidad de malla en el analisis termico de un alabe de turbina de gas con enfriamiento interno

    Energy Technology Data Exchange (ETDEWEB)

    Alfaro Ayala, Jorge Arturo; Gallegos Munoz, Armando [Facultad de Ingenieria Mecanica, Electrica y Electronica (FIMEE), Universidad de Guanajuato (Mexico); Campos Amezcua, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-11-15

    This article presents the methodology to generate the mesh model of the computer model of a blade by means of commands in the software of CFD Fluent, mainly in the fluid zone, since a mesh sensitivity analysis becomes too expensive in terms of human and computer resources. When geometry is too irregular, modifications are required in the mesh to avoid problems such as the divergence, instability in the solution and the dependency on the results of temperature, pressure, velocity, etc. Such is the case of a blade with internal cooling of the first stage of a gas turbine. The results are included of the generated mesh as well as of the thermal analysis of the blade. Additionally the results of temperature, pressure and velocity of the combustion gases and of the cooling air are shown. [Spanish] Este articulo presenta la metodologia para generar el mallado del modelo computacional de un alabe por medio de comandos en el software de CFD Fluent, principalmente en la zona del fluido, ya que un analisis de sensibilidad de malla se vuelve demasiado costoso en terminos de recursos humanos y computacionales. Cuando la geometria es demasiado irregular, se requiere de modificaciones en la malla para evitar problemas como son la divergencia, inestabilidad en la solucion y la dependencia de los resultados de temperatura, presion, velocidad, etc. Tal es el caso de un alabe con enfriamiento interno de la primera etapa de una turbina de gas. Se incluyen los resultados tanto de la malla generada como del analisis termico del alabe. Adicionalmente se muestran los resultados de temperatura, presion y velocidad de los gases de la combustion y del aire de enfriamiento.

  8. Pressure fluctuations on the bed of surge tank at the H.P. Zimapan, Hgo., with different arrangements studied on hydraulic model, with the lowest operation conditions; Fluctuaciones de presion en la base del pozo de oscilacion del P.H. Zimapan Hgo., con diferentes arreglos estudiados en modelo hidraulico ante las condiciones minimas de operacion

    Energy Technology Data Exchange (ETDEWEB)

    Marengo Mogollon, H. [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico (Mexico)]. E-mail: humberto.marengo@cfe.gob.mx; Ochoa Alvarez, F.J.; Cortes Cortes, C. [Comision Federal de Electricidad (Mexico)]. E-mail: federico.ochoa@cfe.gob.mx; carlos.cortes01@cfe.gob.mx

    2009-10-15

    In this paper, the pressure fluctuations of the surge tank in the Zimapan Hydroelectric Project are compared in a hydraulic model. The shaft is located lateral, over the conduction tunnel and in the simple form (permitting the tunnel entering the shaft); with and without orifice plates taking into account the demand and supply condition of energy with the minimum level of water of the conduction. It was determined the hydraulic efficiency and it was found that it was the best constructive option. [Spanish] En este articulo se comparan las fluctuaciones de presion en el pozo de oscilacion del P.H. Zimapan, Hgo., Mexico las cuales fueron estudiadas en modelo hidraulico al considerar dicho pozo ubicado en diferentes posiciones; lateralmente y sobre el eje de la conduccion; pozo simple y con tuberia de conexion; con y sin placa de orificio, para maniobras de rechazo y demanda de carga de las turbinas de generacion con el nivel del agua correspondiente al NAMINO. Se determino la eficiencia hidraulica comparandola con las otras opciones encontrandose que la mejor opcion para el funcionamiento hidraulico es el pozo lateral, que ademas permite optimizar el procedimiento constructivo.

  9. Microwave assisted chemical vapor infiltration

    International Nuclear Information System (INIS)

    Devlin, D.J.; Currier, R.P.; Barbero, R.S.; Espinoza, B.F.; Elliott, N.

    1991-01-01

    A microwave assisted process for production of continuous fiber reinforced ceramic matrix composites is described. A simple apparatus combining a chemical vapor infiltration reactor with a conventional 700 W multimode oven is described. Microwave induced inverted thermal gradients are exploited with the ultimate goal of reducing processing times on complex shapes. Thermal gradients in stacks of SiC (Nicalon) cloths have been measured using optical thermometry. Initial results on the ''inside out'' deposition of SiC via decomposition of methyltrichlorosilane in hydrogen are presented. Several key processing issues are identified and discussed. 5 refs

  10. Overview of chemical vapor infiltration

    Energy Technology Data Exchange (ETDEWEB)

    Besmann, T.M.; Stinton, D.P.; Lowden, R.A.

    1993-06-01

    Chemical vapor infiltration (CVI) is developing into a commercially important method for the fabrication of continuous filament ceramic composites. Current efforts are focused on the development of an improved understanding of the various processes in CVI and its modeling. New approaches to CVI are being explored, including pressure pulse infiltration and microwave heating. Material development is also proceeding with emphasis on improving the oxidation resistance of the interfacial layer between the fiber and matrix. This paper briefly reviews these subjects, indicating the current state of the science and technology.

  11. Las ruinas y las sombras de Manderley

    Directory of Open Access Journals (Sweden)

    Donapetry Camacho, María

    2010-02-01

    Full Text Available The ruins and the shadows of Manderley explores possible reciprocal interpretative relations between Daphne du Maurier’s novel Rebecca and Alfred Hitchcock’s cinematic version. Some of the relevant aspects considered here are: the treatment of the Derridean “ruins of memory” within the novel and within Hitchcock himself, the differentiation and the confrontation of the protagonist as outsider vis á vis the world of Manderley’s insiders, the iconic and symbolic values of the literary text and its filmic visualization, and the ethical positions implied by the choice or rejection of certain narrative devices in both works.

    Las ruinas y las sombras de Manderley aborda posibles relaciones interpretativas recíprocas entre la novela de Daphne du Maurier Rebecca y la película homónima de Alfred Hitchcock. Algunos de los aspectos que se consideran relevantes en este estudio son: el tratamiento de las “ruinas de la memoria” derridianas dentro de la novela y del propio Hitchcock, la diferenciación y el enfrentamiento de la protagonista “externa” con el mundo de los “internos” de Manderley, los valores icónicos y simbólicos del texto literario y de la visualización fílmica, y las posiciones éticas que implican la elección o el rechazo de ciertos recursos narrativos en ambas obras.

  12. Evaluation of a process for the removal of gases contained in geothermal steam through condensation and re-evaporation; Evaluacion de un proceso de remocion de gases contenidos en el vapor geotermico, por medio de la condensacion y de revaporacion

    Energy Technology Data Exchange (ETDEWEB)

    Angulo C, Raul; Lam Rea, Luis; Garmino, Hector; Jimenez, Humberto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    The Cerro Prieto I Geothermal Field, developed and operated by the Comision Federal de Electricidad (CFE), has currently an installed electric power generation capacity of 180 MW and is at a very advanced stage in the development of Cerro Prieto II and III, which will allow to raise the generation capacity to 620 MW. During the exploitation of a geothermal field, in producing steam with the purpose of generating electricity, brines and waste gases are obtained. The hydrogen sulfide exhaust to the environment implies pollution problems, for this reason processes have been developed for the oxidation of these gases downstream the turbogenerator either in the flow of separated gases in the steam condensation or in the condensate produced. The Instituto de Investigaciones Electricas (IIE) has collaborated with CFE in the evaluation of the environmental impact of this gas and in the development of the processes for its abatement. [Espanol] El campo geotermico de Cerro Prieto I, desarrollado y operado por la Comision Federal de Electricidad (CFE), actualmente tiene una capacidad instalada de generacion de energia electrica de 180 MW, y se encuentra en etapa muy avanzada, el desarrollo de Cerro Prieto II y III, lo que permitira incrementar la capacidad de generacion a 620 MW. Durante la explotacion de un campo geotermico, al producir vapor con el proposito de generar electricidad, se obtienen salmueras y gases de desecho. La descarga de acido sulfhidrico a la atmosfera implica problemas de contaminacion, por esta razon se han desarrollado procesos para la oxidacion de este gas aguas abajo de la turbina generadora, ya sea en la corriente de gases que se separan en la condensacion del vapor o en el condensado producido. El Instituto de Investigaciones Electricas (IIE) ha colaborado con la CFE en la evaluacion del impacto ambiental de este gas y en el desarrollo de sus procesos de abatimiento.

  13. Evaluation of a process for the removal of gases contained in geothermal steam through condensation and re-evaporation; Evaluacion de un proceso de remocion de gases contenidos en el vapor geotermico, por medio de la condensacion y de revaporacion

    Energy Technology Data Exchange (ETDEWEB)

    Angulo C, Raul; Lam Rea, Luis; Garmino, Hector; Jimenez, Humberto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1985-12-31

    The Cerro Prieto I Geothermal Field, developed and operated by the Comision Federal de Electricidad (CFE), has currently an installed electric power generation capacity of 180 MW and is at a very advanced stage in the development of Cerro Prieto II and III, which will allow to raise the generation capacity to 620 MW. During the exploitation of a geothermal field, in producing steam with the purpose of generating electricity, brines and waste gases are obtained. The hydrogen sulfide exhaust to the environment implies pollution problems, for this reason processes have been developed for the oxidation of these gases downstream the turbogenerator either in the flow of separated gases in the steam condensation or in the condensate produced. The Instituto de Investigaciones Electricas (IIE) has collaborated with CFE in the evaluation of the environmental impact of this gas and in the development of the processes for its abatement. [Espanol] El campo geotermico de Cerro Prieto I, desarrollado y operado por la Comision Federal de Electricidad (CFE), actualmente tiene una capacidad instalada de generacion de energia electrica de 180 MW, y se encuentra en etapa muy avanzada, el desarrollo de Cerro Prieto II y III, lo que permitira incrementar la capacidad de generacion a 620 MW. Durante la explotacion de un campo geotermico, al producir vapor con el proposito de generar electricidad, se obtienen salmueras y gases de desecho. La descarga de acido sulfhidrico a la atmosfera implica problemas de contaminacion, por esta razon se han desarrollado procesos para la oxidacion de este gas aguas abajo de la turbina generadora, ya sea en la corriente de gases que se separan en la condensacion del vapor o en el condensado producido. El Instituto de Investigaciones Electricas (IIE) ha colaborado con la CFE en la evaluacion del impacto ambiental de este gas y en el desarrollo de sus procesos de abatimiento.

  14. A Lithium Vapor Box Divertor Similarity Experiment

    Science.gov (United States)

    Cohen, Robert A.; Emdee, Eric D.; Goldston, Robert J.; Jaworski, Michael A.; Schwartz, Jacob A.

    2017-10-01

    A lithium vapor box divertor offers an alternate means of managing the extreme power density of divertor plasmas by leveraging gaseous lithium to volumetrically extract power. The vapor box divertor is a baffled slot with liquid lithium coated walls held at temperatures which increase toward the divertor floor. The resulting vapor pressure differential drives gaseous lithium from hotter chambers into cooler ones, where the lithium condenses and returns. A similarity experiment was devised to investigate the advantages offered by a vapor box divertor design. We discuss the design, construction, and early findings of the vapor box divertor experiment including vapor can construction, power transfer calculations, joint integrity tests, and thermocouple data logging. Heat redistribution of an incident plasma-based heat flux from a typical linear plasma device is also presented. This work supported by DOE Contract No. DE-AC02-09CH11466 and The Princeton Environmental Institute.

  15. Thermogravimetric measurements of liquid vapor pressure

    International Nuclear Information System (INIS)

    Rong Yunhong; Gregson, Christopher M.; Parker, Alan

    2012-01-01

    Highlights: ► Rapid determination of vapor pressure by TGA. ► Demonstration of limitations of currently available approaches in literature. ► New model for vapor pressure assessment of small size samples in TGA. ► New model accounts for vapor diffusion and sample geometry and measures vapor pressure normally within 10%. - Abstract: A method was developed using thermo-gravimetric analysis (TGA) to determine the vapor pressure of volatile liquids. This is achieved by measuring the rate of evaporation (mass loss) of a pure liquid contained within a cylindrical pan. The influence of factors like sample geometry and vapor diffusion on evaporation rate are discussed. The measurement can be performed across a wide range of temperature yielding reasonable results up to 10 kPa. This approach may be useful as a rapid and automatable method for measuring the volatility of flavor and fragrance raw materials.

  16. Haciendo resonar las voces

    DEFF Research Database (Denmark)

    Tufte, Thomas; Corrigan, Arran; Ekstrøm, Ylva

    2011-01-01

    sexualidad protegida y el VIH/SIDA”. FEMINA persigue sus objetivos por medio de la producción de dos de las revistas de mayor circulación en Tanzania: SiMchezo! y Fema, apuntando a la juventud rural y urbana mediante una estrategia de intervención comunicacional multimedia y participativa. Las dos revistas...

  17. Ion vapor deposition and its application

    International Nuclear Information System (INIS)

    Bollinger, H.; Schulze, D.; Wilberg, R.

    1981-01-01

    Proceeding from the fundamentals of ion vapor deposition the characteristic properties of ion-plated coatings are briefly discussed. Examples are presented of successful applications of ion-plated coatings such as coatings with special electrical and dielectric properties, coatings for corrosion prevention, and coatings for improving the surface properties. It is concluded that ion vapor deposition is an advantageous procedure in addition to vapor deposition. (author)

  18. Monofilament Vaporization Propulsion (MVP) System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Monofilament Vaporization Propulsion (MVP) is a new propulsion technology targeted at secondary payload applications. It does not compromise on performance while...

  19. Experiences of marijuana-vaporizer users.

    Science.gov (United States)

    Malouff, John M; Rooke, Sally E; Copeland, Jan

    2014-01-01

    Using a marijuana vaporizer may have potential harm-reduction advantages on smoking marijuana, in that the user does not inhale smoke. Little research has been published on use of vaporizers. In the first study of individuals using a vaporizer on their own initiative, 96 adults anonymously answered questions about their experiences with a vaporizer and their use of marijuana with tobacco. Users identified 4 advantages to using a vaporizer over smoking marijuana: perceived health benefits, better taste, no smoke smell, and more effect from the same amount of marijuana. Users identified 2 disadvantages: inconvenience of setup and cleaning and the time it takes to get the device operating for each use. Only 2 individuals combined tobacco in the vaporizer mix, whereas 15 combined tobacco with marijuana when they smoked marijuana. Almost all participants intended to continue using a vaporizer. Vaporizers seem to have appeal to marijuana users, who perceive them as having harm-reduction and other benefits. Vaporizers are worthy of experimental research evaluating health-related effects of using them.

  20. Análisis de la influencia del ingreso del proyecto ciclo combinado 318 MW dentro de la matriz eléctrica del Ecuador

    OpenAIRE

    Cárdenas Dávila, Carlos Alexis

    2014-01-01

    Actualmente el sistema eléctrico ecuatoriano para cubrir la demanda nacional ha utilizado principalmente generación hidroeléctrica y termoeléctrica, ésta última con la operación de unidades con turbinas a vapor y a gas, al ser las más económicas por el tipo de combustible que utilizan. Ambas tecnologías son utilizadas para generar por separado energía eléctrica. Existe la posibilidad de ser explotadas de manera más eficiente, utilizando el calor contenido en los gases de escape de las turb...

  1. Vapor pressures and thermophysical properties of selected hexenols and recommended vapor pressure for hexan-1-ol

    Czech Academy of Sciences Publication Activity Database

    Štejfa, V.; Fulem, Michal; Růžička, K.; Matějka, P.

    2015-01-01

    Roč. 402, Sep (2015), 18-29 ISSN 0378-3812 Institutional support: RVO:68378271 Keywords : alcohols * vapor pressure * heat capacity * ideal - gas thermodynamic properties * vaporization enthalpy Subject RIV: BJ - Thermodynamics Impact factor: 1.846, year: 2015

  2. EFECTOS DE LOS GASES PRODUCTO DE LA COMBUSTIÓN EN LOS GENERADORES DE VAPOR

    Directory of Open Access Journals (Sweden)

    Manuel Plá Duporté

    2011-02-01

    Full Text Available En el trabajo se presentan recopilados, los efectos de ensuciamiento y corrosión que provocan en ungenerador de vapor acuotubular los gases productos de la combustión de combustibles líquidos,explicándose los mecanismos mediante los cuales ocurren tanto en las zonas de alta temperaturacomo en las de baja temperatura  This paper presents gathering of the dirty and corrosion effects of flue gas from liquid fuels, also it’sexplained the process by means of which happen in high and low temperature surfaces in steam watergenerator

  3. Logical model for the control of a BWR turbine;Modelo logico para el control de una turbina de un BWR

    Energy Technology Data Exchange (ETDEWEB)

    Vargas O, Y. [Universidad del Valle de Mexico, Campus Toluca, Av. Las Palmas No. 136, Col. San Jorge Pueblo Nuevo, 52140 Metepec, Estado de Mexico (Mexico); Amador G, R.; Ortiz V, J.; Castillo D, R., E-mail: yonaeton@hotmail.co [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2009-07-01

    In this work a design of a logical model is presented for the turbine control of a nuclear power plant with a BWR like energy source. The model is sought to implement later on inside the thermal hydraulics code of better estimate RELAP/SCDAPSIM. The logical model is developed for the control and protection of the turbine, and the consequent protection to the BWR, considering that the turbine control will be been able to use for one or several turbines in series. The quality of the present design of the logical model of the turbine control is that it considers the most important parameters in the operation of a turbine, besides that they have incorporated to the logical model the secondary parameters that will be activated originally as true when the turbine model is substituted by a detailed model. The development of the logical model of a turbine will be of utility in the short and medium term to carry out analysis on the turbine operation with different operation conditions, of vapor extraction, specific steps of the turbine to feed other equipment s, in addition to analyze the separate and the integrated effect. (Author)

  4. en las relaciones entrenadas

    Directory of Open Access Journals (Sweden)

    Camilo Hurtado P.

    2005-01-01

    Full Text Available El presente estudio exploró los efectos en la adquisición y transferencia de discriminaciones condicionales debidos a las diferentes combinaciones de relaciones entrenadas (identidad-diferencia-semejanza en una tarea de igualación a la muestra de segundo orden. De manera complementaria, fueron además dispuestas en la tarea las características que en estudios relacionados habían sido reportadas como facilitadoras de ejecuciones efectivas, a saber: el uso de instrucciones inespecíficas, arreglos de estímulo de tres formas y dos colores y el entrenamiento concurrente de las relaciones. Ocho sujetos fueron distribuidos en cuatro grupos que variaron en la combinación de relaciones a entrenar. Los resultados mostraron que gran parte de los sujetos cumplieron con el criterio de efectividad en entrenamiento y en transferencia extramodal y extrarrelacional, siendo la relación de identidad la relación en la cual se presentaron ejecuciones perfectas, al margen de si ésta había sido entrenada o no. Se discuten los resultados en términos de velocidad de ajuste a las relaciones y de las configuraciones de la tarea que facilitaron mejores desempeños. Se proponen, además, posibles investigaciones que superen las limitaciones metodológicas encontradas en este estudio y que exploren posibles interacciones de las variables manipuladas con otras variables de interés.

  5. Enthalpy of vaporization and vapor pressure of whiskey lactone and menthalactone by correlation gas chromatography

    International Nuclear Information System (INIS)

    Simmons, Daniel; Chickos, James

    2017-01-01

    Highlights: • The vapor pressure and vaporization enthalpies of cis and trans-whiskey lactone have been evaluated. • Enthalpies of vaporization and vapor pressures of (+)-isomintlactone and (−)-mintlactone were also evaluated. • The sublimation enthalpy and corresponding vapor pressure of (+) -isomintlactone at T = 298.15 K is estimated. - Abstract: Enthalpies of vaporization at T = 298.15 K of cis and trans-whiskey lactone have been evaluated by correlation gas chromatography to be (68.4 ± 1.7) kJ·mol −1 and (67.5 ± 1.7) kJ·mol −1 , respectively. The enthalpies of vaporization of isomintlactone and mintlactone also evaluated by correlation gas chromatography have been found to have vaporization enthalpies of (74.2 ± 1.8) kJ·mol −1 and (73.2 ± 1.8) kJ·mol −1 respectively. The vapor pressures for cis and trans-whiskey lactone at T = 298.15 K have been evaluated as (1.5 ± 0.09) Pa and (2.0 ± 0.1) Pa using vapor pressures of a series of lactones as standards. Vapor pressures for isomintlactone and mintlactone were evaluated as (0.26 ± 0.012) Pa and (0.33 ± 0.02) Pa, respectively. Fusion and sublimation enthalpies for (+)-isomintlactone as well as the vapor pressure of the solid have been estimated.

  6. Las neurosis actuales y las psicosis ordinarias

    OpenAIRE

    Aguirre, Javier

    2013-01-01

    El trabajo tiene por finalidad poner en tensión las categorías de psicosis ordinaria y neurosis actuales. En primer lugar, se procede a examinar ambas categorías para luego establecer sus puntos de coincidencia y disidencia. Se concluye que la categoría de neurosis actual propuesta por Freud, es una posible expresión de lo que en la actualidad se llama psicosis ordinaria.

  7. Historia de las series

    OpenAIRE

    Cascajosa Virino, Concepción

    2017-01-01

    Reseña: Historia de las series de Toni de la Torre: la gran impostura Durante mucho tiempo los profesores de cine en España se han quejado (amargamente y en privado) de la recurrencia en la bibliografía de los trabajos de sus estudiantes de los libros de un autor conocido por la escasa calidad de sus textos, cuyos vistosos títulos garantizan que acaben en las estanterías de las bibliotecas universitarias. Es muy propio de la cultura española hacer duras aseveraciones en foros irrelevantes y, ...

  8. Optical Sensor for Diverse Organic Vapors at ppm Concentration Ranges

    Directory of Open Access Journals (Sweden)

    Dora M. Paolucci

    2011-03-01

    Full Text Available A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index and sensor response are discussed.

  9. Atomic vapor laser isotope separation

    International Nuclear Information System (INIS)

    Stern, R.C.; Paisner, J.A.

    1985-01-01

    Atomic vapor laser isotope separation (AVLIS) is a general and powerful technique. A major present application to the enrichment of uranium for light-water power reactor fuel has been under development for over 10 years. In June 1985 the Department of Energy announced the selection of AVLIS as the technology to meet the nation's future need for the internationally competitive production of uranium separative work. The economic basis for this decision is considered, with an indicated of the constraints placed on the process figures of merit and the process laser system. We then trace an atom through a generic AVLIS separator and give examples of the physical steps encountered, the models used to describe the process physics, the fundamental parameters involved, and the role of diagnostic laser measurements

  10. SOIL VAPOR EXTRACTION TECHNOLOGY: REFERENCE HANDBOOK

    Science.gov (United States)

    Soil vapor extraction (SVE) systems are being used in Increasing numbers because of the many advantages these systems hold over other soil treatment technologies. SVE systems appear to be simple in design and operation, yet the fundamentals governing subsurface vapor transport ar...

  11. Mechanics of gas-vapor bubbles

    NARCIS (Netherlands)

    Hao, Yue; Zhang, Yuhang; Prosperetti, Andrea

    2017-01-01

    Most bubbles contain a mixture of vapor and incondensible gases. While the limit cases of pure vapor and pure gas bubbles are well studied, much less is known about the more realistic case of a mixture. The bubble contents continuously change due to the combined effects of evaporation and

  12. Vapor Pressures of Several Commercially Used Alkanolamines

    NARCIS (Netherlands)

    Klepacova, Katarina; Huttenhuis, Patrick J. G.; Derks, Peter W. J.; Versteeg, Geert F.; Klepáčová, Katarína

    For the design of acid gas treating processes, vapor-liquid equilibrium (VLE) data must be available of the solvents to be applied. In this study the vapor pressures of seven frequently industrially used alkanolamines (diethanolamine, N-methylethanolamine, N,N-dimethylethanolamine,

  13. Recommended Vapor Pressure of Solid Naphthalen

    Czech Academy of Sciences Publication Activity Database

    Růžička, K.; Fulem, Michal; Růžička, V.

    2005-01-01

    Roč. 50, - (2005), s. 1956-1970 ISSN 0021-9568 Institutional research plan: CEZ:AV0Z10100521 Keywords : solid naphthalene * vapor pressure * enthalpy of vaporization * enthalpy of fusion Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.610, year: 2005

  14. Effect of granosan vapors on mitosis

    Energy Technology Data Exchange (ETDEWEB)

    Lishenko, N P; Lishenko, I D

    1974-01-01

    Experiments were performed to determine the effects of granosan on the germination of vetch seeds. Vetch seeds were stored from 4-6 days in ethyl mercuric chloride vapors. Results indicated that the vapors caused a sharp decrease in germination and caused chromosomal aberrations during the anaphase.

  15. Condensation of vapor bubble in subcooled pool

    Science.gov (United States)

    Horiuchi, K.; Koiwa, Y.; Kaneko, T.; Ueno, I.

    2017-02-01

    We focus on condensation process of vapor bubble exposed to a pooled liquid of subcooled conditions. Two different geometries are employed in the present research; one is the evaporation on the heated surface, that is, subcooled pool boiling, and the other the injection of vapor into the subcooled pool. The test fluid is water, and all series of the experiments are conducted under the atmospheric pressure condition. The degree of subcooling is ranged from 10 to 40 K. Through the boiling experiment, unique phenomenon known as microbubble emission boiling (MEB) is introduced; this phenomenon realizes heat flux about 10 times higher than the critical heat flux. Condensation of the vapor bubble is the key phenomenon to supply ambient cold liquid to the heated surface. In order to understand the condensing process in the MEB, we prepare vapor in the vapor generator instead of the evaporation on the heated surface, and inject the vapor to expose the vapor bubble to the subcooled liquid. Special attention is paid to the dynamics of the vapor bubble detected by the high-speed video camera, and on the enhancement of the heat transfer due to the variation of interface area driven by the condensation.

  16. 40 CFR 796.1950 - Vapor pressure.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Physical and Chemical Properties § 796.1950 Vapor pressure. (a.... In addition, chemicals that are likely to be gases at ambient temperatures and which have low water... gases until the measured vapor pressure is constant, a process called “degassing.” Impurities more...

  17. Risk assessment of metal vapor arcing

    Science.gov (United States)

    Hill, Monika C. (Inventor); Leidecker, Henning W. (Inventor)

    2009-01-01

    A method for assessing metal vapor arcing risk for a component is provided. The method comprises acquiring a current variable value associated with an operation of the component; comparing the current variable value with a threshold value for the variable; evaluating compared variable data to determine the metal vapor arcing risk in the component; and generating a risk assessment status for the component.

  18. Las Serpientes en Colombia

    Directory of Open Access Journals (Sweden)

    Daniel H.

    1949-12-01

    Full Text Available El estudio de las serpientes en Colombia no deja de tener su particular interés; existe una inmensa variedad de especies que se escalonan desde los valles ardientes hasta alturas relativamente considerables; en estos últimos puntos disminuye notablemente la variedad de formas y de modo especial las especies provistas de veneno. Hacer una distinción entre las especies venenosas y las inofensivas, resulta un tanto difícil; en algunos textos se dan unas cuántas reglas, pero la mayor parte de ellas sólo tienen aplicación con especies exóticas ya que la mayor parte de esas distinciones se han tomado de obras que hacen referencia a la fauna europea.

  19. Building blocks for ionic liquids: Vapor pressures and vaporization enthalpies of 1-(n-alkyl)-imidazoles

    International Nuclear Information System (INIS)

    Emel'yanenko, Vladimir N.; Portnova, Svetlana V.; Verevkin, Sergey P.; Skrzypczak, Andrzej; Schubert, Thomas

    2011-01-01

    Highlights: → We measured vapor pressures of the 1-(n-alkyl)-imidazoles by transpiration method. → Variations on the alkyl chain length n were C 3 , C 5 -C 7 , and C 9 -C 10 . → Enthalpies of vaporization were derived from (p, T) dependencies. → Enthalpies of vaporization at 298.15 K were linear dependent on the chain length. - Abstract: Vapor pressures of the linear 1-(n-alkyl)-imidazoles with the alkyl chain C 3 , C 5 -C 7 , and C 9 -C 10 have been measured by the transpiration method. The molar enthalpies of vaporization Δ l g H m of these compounds were derived from the temperature dependencies of vapor pressures. A linear correlation of enthalpies of vaporization Δ l g H m (298.15 K) of the 1-(n-alkyl)-imidazoles with the chain length has been found.

  20. Methodology for energy diagnosis in distribution steam lines; Metodologia para diagnostico de energia en lineas de distribucion de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Almanza, M; Ambriz, J J; Romero P, H [Universidad Autonoma Metropolitana Iztapalapa, Mexico, D. F. (Mexico)

    1993-12-31

    This paper shows a methodology that results of great advantage in the development of the energy analysis of an industrial facility that utilizes steam as a mean of energy transport and where the steam operated equipment is physically located in a remote place, away from the generation site. Mention is made here of the equipment characteristics that can be used for such purpose, the most important parameters to identify in a rapid and efficient way the faults presented in the steam distribution system in the industrial plants and the formats that contribute to keep the corresponding records for efficiently maintain in operation the steam pipeline net in conjunction with the involved accessories. [Espanol] En el presenta trabajo se muestra una metodologia que resulta de gran utilidad en el desarrollo del analisis energetico de una planta industrial, en la cual se emplee el vapor como medio de transporte de la energia y en donde el equipo que utiliza el vapor se encuentre fisicamente en un lugar apartado de la zona de generacion. Aqui se mencionan las caracteristicas del equipo que se puede utilizar para dicho diagnostico, los parametros de mayor importancia para identificar en forma rapida y eficiente las fallas que se presentan en el sistema de distribucion de vapor en las plantas industriales y los formatos que contribuyen a llevar los registros correspondientes para mantener operando eficientemente la red de vapor, en conjunto con los accesorios que en ella se involucran.

  1. Methodology for energy diagnosis in distribution steam lines; Metodologia para diagnostico de energia en lineas de distribucion de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Almanza, M.; Ambriz, J. J.; Romero P, H. [Universidad Autonoma Metropolitana Iztapalapa, Mexico, D. F. (Mexico)

    1992-12-31

    This paper shows a methodology that results of great advantage in the development of the energy analysis of an industrial facility that utilizes steam as a mean of energy transport and where the steam operated equipment is physically located in a remote place, away from the generation site. Mention is made here of the equipment characteristics that can be used for such purpose, the most important parameters to identify in a rapid and efficient way the faults presented in the steam distribution system in the industrial plants and the formats that contribute to keep the corresponding records for efficiently maintain in operation the steam pipeline net in conjunction with the involved accessories. [Espanol] En el presenta trabajo se muestra una metodologia que resulta de gran utilidad en el desarrollo del analisis energetico de una planta industrial, en la cual se emplee el vapor como medio de transporte de la energia y en donde el equipo que utiliza el vapor se encuentre fisicamente en un lugar apartado de la zona de generacion. Aqui se mencionan las caracteristicas del equipo que se puede utilizar para dicho diagnostico, los parametros de mayor importancia para identificar en forma rapida y eficiente las fallas que se presentan en el sistema de distribucion de vapor en las plantas industriales y los formatos que contribuyen a llevar los registros correspondientes para mantener operando eficientemente la red de vapor, en conjunto con los accesorios que en ella se involucran.

  2. Water vapor retrieval over many surface types

    Energy Technology Data Exchange (ETDEWEB)

    Borel, C.C.; Clodius, W.C.; Johnson, J.

    1996-04-01

    In this paper we present a study of of the water vapor retrieval for many natural surface types which would be valuable for multi-spectral instruments using the existing Continuum Interpolated Band Ratio (CIBR) for the 940 nm water vapor absorption feature. An atmospheric code (6S) and 562 spectra were used to compute the top of the atmosphere radiance near the 940 nm water vapor absorption feature in steps of 2.5 nm as a function of precipitable water (PW). We derive a novel technique called ``Atmospheric Pre-corrected Differential Absorption`` (APDA) and show that APDA performs better than the CIBR over many surface types.

  3. Water Vapor Permeation in Plastics

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Paul E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-01-01

    Polyvinyl toluene (PVT) and polystyrene (PS) (referred to as “plastic scintillator”) are used for gamma ray detectors. A significant decrease in radiation detection performance has been observed in some PVT-based gamma-ray detectors in systems in outdoor environments as they age. Recent studies have revealed that plastic scintillator can undergo an environmentally related material degradation that adversely affects gamma ray detection performance under certain conditions and histories. A significant decrease in sensitivity has been seen in some gamma-ray detectors in some systems as they age. The degradation of sensitivity of plastic scintillator over time is due to a variety of factors, and the term “aging” is used to encompass all factors. Some plastic scintillator samples show no aging effects (no significant change in sensitivity over more than 10 years), while others show severe aging (significant change in sensitivity in less than 5 years). Aging effects arise from weather (variations in heat and humidity), chemical exposure, mechanical stress, light exposure, and loss of volatile components. The damage produced by these various causes can be cumulative, causing observable damage to increase over time. Damage may be reversible up to some point, but becomes permanent under some conditions. The objective of this report is to document the phenomenon of permeability of plastic scintillator to water vapor and to derive the relationship between time, temperature, humidity and degree of water penetration in plastic. Several conclusions are documented about the properties of water permeability of plastic scintillator.

  4. Internet de las cosas

    OpenAIRE

    Salazar Soler, Jorge; Silvestre Bergés, Santiago

    2016-01-01

    Este es un curso de introducción a la IoT (Internet de las cosas). En los capítulos primeros capítulos se introducen los conceptos básicos sobre la IoT. Seguidamente se presentan nociones básicas sobre el protocolo de internet IPv6 que es el más utilizado en el entorno de la IoT y se describen las principales aplicaciones, el estado actual del mercado y las tecnologías que permiten la existencia de la IoT. Finalmente se analizan los retos de futuro que se consideran más importa...

  5. Las sirenas de Sarhua

    Directory of Open Access Journals (Sweden)

    Luis Millones

    2011-05-01

    Full Text Available El presente artículo es producto de una investigación sobre uno de los motivos más llamativos y recurrentes en las Tablas de Sarhua: la sirena.Realizamos una aproximación a este motivo, que originalmente aparece en la literatura clásica occidental, con la finalidad de explicar las razones de su presencia en el arte andino. Para tal efecto transcribimos algunos testimoniosque, desde una cosmovisión netamente andina, dan cuenta de una serie de creencias vinculadas con el ámbito musical, en el que las sirenas juegan un papel central.Palabras claves: Tablas de Sarhua, sirena, arte andino, música andina.

  6. Tratamiento de las ictericias

    Directory of Open Access Journals (Sweden)

    Roberto de Zubiría

    1955-05-01

    Full Text Available En el tratamiento de los síndromes ictéricos no existe sistematización de criterios y en más de una ocasión se cometen serios errores terapéuticos. Tal sucede frecuentemente con las hepatitis a virus, por ejemplo las que tratadas con un régimen alimenticio inadecuado, constituído casi siempre por dietas de hambre, se va a complicar más la situación. Otras veces se utilizan sistemáticamente los antibióticos de amplio espectro, los cuales son inútiles e inclusive desaconsejados por la posibilidad de producir fibrosis hepática. Hemos querido hacer un resumen analizando someramente el pro y el contra de las principales medidas terapéuticas.

  7. Learning from las Cuencas

    DEFF Research Database (Denmark)

    2016-01-01

    Aprendiendo de las Cuencas (Learning from las Cuencas) research project, awarded with the EU Prize for Cultural Heritage / Europa Nostra Awards 2015, provides a new perspective of industrial cultural landscapes. Despite being focused on a local environment, the coal mining area of the Cuencas...... economic and social structures came to host busy urban agglomerations of unexpected density in their very heart. This heretical urban configuration is equally the result of the impact of economic interests in a specific space and in a relatively short lapse of time. Consequently, the co...

  8. Analizar las interacciones virtuales

    Directory of Open Access Journals (Sweden)

    Luis Gómez Encinas

    2003-11-01

    Full Text Available El propósito de este artículo es abordar una serie de cuestiones relacionadas con las interacciones virtuales. En concreto, nos centraremos en el IRC, los comúnmente llamados chats, para a partir de una crítica a ciertos posicionamientos analíticos, expresar la necesidad de indagar en esa faceta del ciberespacio desde el punto de vista de las relaciones sociales. Nuevas relaciones sociales, que acontecen en un espacio nuevo, y que por tanto se desarrollan bajo reglas y motivaciones que desbordan los viejos esquemas de observación.

  9. Las causas del desempleo

    OpenAIRE

    García Balbás, Salomé

    2014-01-01

    En este documento vamos a tratar de dar respuesta a la siguiente pregunta: ¿cuáles son las causas del desempleo? Para ello realizaremos un repaso de las principales teorías económicas del desempleo llegando a la conclusión de que existe una causa fundamental que lo genera: la rigidez de los salarios a la baja. Consideramos el desempleo como la existencia de un exceso de oferta en el mercado de trabajo y haremos alusión, únicamente, a la existencia de desempleo involuntario. La exposición de l...

  10. Aprendiendo de las Cuencas

    DEFF Research Database (Denmark)

    2016-01-01

    Aprendiendo de las Cuencas (Learning from las Cuencas) research project, awarded with the EU Prize for Cultural Heritage / Europa Nostra Awards 2015, provides a new perspective of industrial cultural landscapes. Despite being focused on a local environment, the coal mining area of the Cuencas....... This has given rise to incredibly heterodox building patterns that contain the conflict on which they are erected embedded in their genetic code. These are hybrid architectures, mutating artefacts which, despite the invisibility of their inevitable marginality, can offer really interesting lessons...

  11. Point of net vapor generation and vapor void fraction in subcooled boiling

    International Nuclear Information System (INIS)

    Saha, P.; Zuber, N.

    1974-01-01

    An analysis is presented directed at predicting the point of net vapor generation and vapor void fraction in subcooled boiling. It is shown that the point of net vapor generation depends upon local conditions--thermal and fluid dynamic. Thus, at low mass flow rates the net vapor generation is determined by thermal conditions, whereas at high mass flow rates the phenomenon is hydrodynamically controlled. Simple criteria are derived which can be used to predict these local conditions for net vapor generation. These criteria are used to determine the vapor void fraction is subcooled boiling. Comparison between the results predicted by this analysis and experimental data presently available shows good agreement for wide range of operating conditions, fluids and geometries. (U.S.)

  12. GOES WATER VAPOR TRANSPORT V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GOES Water Vapor Transport CD contains nineteen months of geostationary satellite-derived products from the GOES-8 satellite spanning the 1987-1988 El Nino...

  13. Vaporization of Samarium trichloride studied by thermogravimetry

    International Nuclear Information System (INIS)

    Esquivel, Marcelo R.; Pasquevich, Daniel M.

    2003-01-01

    In the present work, the vaporization reaction of SmCl 3 (l) obtained from the 'in situ' reaction of Sm 2 O 3 (s) and Cl 2 (g)-C(s) was studied by thermogravimetry under controlled atmosphere. The effects of both the temperature between 825 C degrees and 950 C degrees and the total flow gas on the vaporization rate of the following reaction: SmCl 3 (l) = SmCl 3 (g) were analyzed. The vaporization rate of the process was found to be independent of then total gas flow rate and highly dependent on the temperature. E ap calculation led to a value of 240 ± 10 kJ.mol -1 . A comparison between this value and that of the molar enthalpy of vaporization allow to the conclusion that the reaction occur in conditions near to equilibrium. The SmCl 3 identity was determined by X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). (author)

  14. Perspective: Highly stable vapor-deposited glasses

    Science.gov (United States)

    Ediger, M. D.

    2017-12-01

    This article describes recent progress in understanding highly stable glasses prepared by physical vapor deposition and provides perspective on further research directions for the field. For a given molecule, vapor-deposited glasses can have higher density and lower enthalpy than any glass that can be prepared by the more traditional route of cooling a liquid, and such glasses also exhibit greatly enhanced kinetic stability. Because vapor-deposited glasses can approach the bottom of the amorphous part of the potential energy landscape, they provide insights into the properties expected for the "ideal glass." Connections between vapor-deposited glasses, liquid-cooled glasses, and deeply supercooled liquids are explored. The generality of stable glass formation for organic molecules is discussed along with the prospects for stable glasses of other types of materials.

  15. Fundamentals of Friction and Vapor Phase Lubrication

    National Research Council Canada - National Science Library

    Gellman, Andrew

    2004-01-01

    This is the final report for the three year research program on "Fundamentals of Friction and Vapor Phase Lubrication" conducted at Carnegie Mellon with support from AFOSR grant number F49630-01-1-0069...

  16. GOES WATER VAPOR TRANSPORT V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GOES Water Vapor Transport CD contains nineteen months of geostationary satellite-derived products spanning the 1987/1988 El Nino Southern Oscillation (ENSO)...

  17. Drag Reduction by Leidenfrost Vapor Layers

    KAUST Repository

    Vakarelski, Ivan Uriev; Marston, Jeremy O.; Chan, Derek Y. C.; Thoroddsen, Sigurdur T

    2011-01-01

    , we show that such vapor layers can reduce the hydrodynamic drag by over 85%. These results appear to approach the ultimate limit of drag reduction possible by different methods based on gas-layer lubrication and can stimulate the development

  18. DMSP SSMT/2 - Atmospheric Water Vapor Profiler

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SSM/T-2 sensor is a five channel, total power microwave radiometer with three channels situated symmetrically about the 183.31 GHz water vapor resonance line and...

  19. 78 FR 42595 - Marine Vapor Control Systems

    Science.gov (United States)

    2013-07-16

    ... revise the substance As noted in the NPRM, the changes in this section were of this section. intended... the vapor-moving device, as recommended by CTAC in 1997 to maintain a minimum size of non-flammable...

  20. A technique to depress desflurane vapor pressure.

    Science.gov (United States)

    Brosnan, Robert J; Pypendop, Bruno H

    2006-09-01

    To determine whether the vapor pressure of desflurane could be decreased by using a solvent to reduce the anesthetic molar fraction in a solution (Raoult's Law). We hypothesized that such an anesthetic mixture could produce anesthesia using a nonprecision vaporizer instead of an agent-specific, electronically controlled, temperature and pressure compensated vaporizer currently required for desflurane administration. One healthy adult female dog. Propylene glycol was used as a solvent for desflurane, and the physical characteristics of this mixture were evaluated at various molar concentrations and temperatures. Using a circle system with a breathing bag attached at the patient end and a mechanical ventilator to simulate respiration, an in-circuit, nonprecision vaporizer containing 40% desflurane and 60% propylene glycol achieved an 11.5% +/- 1.0% circuit desflurane concentration with a 5.2 +/- 0.4 (0 = off, 10 = maximum) vaporizer setting. This experiment was repeated with a dog attached to the breathing circuit under spontaneous ventilation with a fresh gas flow of 0.5 L minute(-1). Anesthesia was maintained for over 2 hours at a mean vaporizer setting of 6.2 +/- 0.4, yielding mean inspired and end-tidal desflurane concentrations of 8.7% +/- 0.5% and 7.9% +/- 0.7%, respectively. Rather than alter physical properties of vaporizers to suit a particular anesthetic agent, this study demonstrates that it is also possible to alter physical properties of anesthetic agents to suit a particular vaporizer. However, propylene glycol may not prove an ideal solvent for desflurane because of its instability in solution and substantial-positive deviation from Raoult's Law.

  1. Metal Vapor Arcing Risk Assessment Tool

    Science.gov (United States)

    Hill, Monika C.; Leidecker, Henning W.

    2010-01-01

    The Tin Whisker Metal Vapor Arcing Risk Assessment Tool has been designed to evaluate the risk of metal vapor arcing and to help facilitate a decision toward a researched risk disposition. Users can evaluate a system without having to open up the hardware. This process allows for investigating components at risk rather than spending time and money analyzing every component. The tool points to a risk level and provides direction for appropriate action and documentation.

  2. A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium.

    Science.gov (United States)

    McCarron, Daniel J; Hughes, Ifan G; Tierney, Patrick; Cornish, Simon L

    2007-09-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D(2) transitions in atomic rubidium is described. A 5 cm long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field and cell temperature. For the weaker transitions both the amplitude and gradient of the signal are increased by an order of magnitude.

  3. A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium

    International Nuclear Information System (INIS)

    McCarron, Daniel J.; Hughes, Ifan G.; Tierney, Patrick; Cornish, Simon L.

    2007-01-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D 2 transitions in atomic rubidium is described. A 5 cm long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field and cell temperature. For the weaker transitions both the amplitude and gradient of the signal are increased by an order of magnitude

  4. Vapor Explosions with Subcooled Freon

    International Nuclear Information System (INIS)

    Henry, R.E.; Fauske, Hans K.; McUmber, L.M.

    1976-01-01

    Explosive vapor formation accompanied by destructive shock waves, can be produced when two liquids, at much different temperatures, are brought into intimate contact. A proposed analytical model states that the interface temperature upon contact between the two liquid systems, gust be greater than or equal to the spontaneous nucleation temperature of that liquid-liquid system and that the thermal boundary layer must be sufficiently developed to support a critical size cavity. For time scales greater than 10-12 sec, the interface temperature upon contact of two semi-infinite masses, with constant thermal properties, can be related to the initial liquid temperatures. The spontaneous nucleation behavior at the interface can either be heterogeneous or homogeneous in nature. In either case, the critical size cavities, which initiate the vaporization process, are produced by local density fluctuations within the cold liquid. For homogeneous conditions, the two liquids present a well-wetted system and the vapor embryos are produced entirely within the cold liquid. For heterogeneous conditions, which result from poor, or imperfect wetting, at the liquid-liquid interface, the critical sized cavities are created at the interface at somewhat lower temperatures. A sequence of experiments, using Freon-22 and water, Freon-22 and mineral oil, and Freon-12 and mineral oil have been performed to test this spontaneous nucleation premise. For Freon-22 at its normal boiling point, the interface temperature of the water must be at least 77 deg. C before the interface temperature equals or exceeds the minimum homogeneous nucleation value of 54 deg. C and 84 deg. C before the interface temperature equals 60 deg. C where the homogeneous nucleation rate becomes truly explosive. The Freon-water test demonstrated explosive interactions for water temperatures considerably lower than this value and this was attributed to the heterogeneous nucleation characteristics of that particular system

  5. Effect of impact angle on vaporization

    Science.gov (United States)

    Schultz, Peter H.

    1996-09-01

    Impacts into easily vaporized targets such as dry ice and carbonates generate a rapidly expanding vapor cloud. Laboratory experiments performed in a tenuous atmosphere allow deriving the internal energy of this cloud through well-established and tested theoretical descriptions. A second set of experiments under near-vacuum conditions provides a second measure of energy as the internal energy converts to kinetic energy of expansion. The resulting data allow deriving the vaporized mass as a function of impact angle and velocity. Although peak shock pressures decrease with decreasing impact angle (referenced to horizontal), the amount of impact-generated vapor is found to increase and is derived from the upper surface. Moreover, the temperature of the vapor cloud appears to decrease with decreasing angle. These unexpected results are proposed to reflect the increasing roles of shear heating and downrange hypervelocity ricochet impacts created during oblique impacts. The shallow provenance, low temperature, and trajectory of such vapor have implications for larger-scale events, including enhancement of atmospheric and biospheric stress by oblique terrestrial impacts and impact recycling of the early atmosphere of Mars.

  6. Solución Matricial de Modelos para Cálculo de Equilibrio Líquido-Vapor Matrix Solution of Models to Calculate Liquid-Vapor Equilibrium

    OpenAIRE

    José F Orejel-Pajarito; Raúl González-García

    2008-01-01

    El objetivo de este artículo es demostrar la viabilidad de utilizar modelos termodinámicos de coeficientes de actividad (Wilson, NRTL, UNIQUAC) programados con matrices, en lugar de estar programados con ciclos. Se determina la relación de equilibrio líquido-vapor de las mezclas Metanol-Etanol-Benceno y Acetona-Cloroformo-Metanol representados en mapas de curvas de residuo y en mapas de líneas de destilación. Para obtener resultados más confiables y conclusiones objetivas, el estudio fue apoy...

  7. de las mujeres

    Directory of Open Access Journals (Sweden)

    Elena Margarita Cacheux Pulido

    2003-01-01

    Full Text Available El feminismo chicano tiene múltiples venas que nutrieron el pensamiento ideológico, político y estratégico durante todo el siglo pasado. Una de ellas se forma por los encuentros locales, nacionales e internacionales que sirvieron de plataforma para comunicar, entre mujeres, las propias necesidades para el desarrollo y la liberación de la injusticia, intolerancia y desdén. Las mujeres han luchado por medio de sindicatos y movimientos sociales para plantear justas demandas, entre otras, educación, igual salario por igual trabajo, bienestar, permiso de maternidad, cuidado infantil, autodeterminación, información sexual, igualdad en la participación política y liderazgo. Con el avance teórico en las cuestiones de raza, clase, minorías étnicas y feminismo lésbico, se desarrolló la identidad de la nueva chicana a la luz de la emancipación de las mujeres.

  8. Las marcas no tradicionales

    Directory of Open Access Journals (Sweden)

    Juan David Castro

    2012-11-01

    Full Text Available Las transformaciones en el comercio tanto nacional como internacionalmente han hecho necesario el aparecimiento de nuevas formas de manifestación de los signos destinados a diferenciar los productos y servicios en el mercado. El artículo reseña algunos de ellos.

  9. Comparison of molecular models of carbon monoxide for calculation of vapor-liquid equilibrium

    Directory of Open Access Journals (Sweden)

    Bibian Alonso Hoyos-Madrigal

    2015-01-01

    Full Text Available Existen varios modelos moleculares para el monóxido de carbono desarrollados a partir de diferentes mediciones experimentales. El objetivo de este trabajo es comparar los resultados que varios de estos modelos producen en el cálculo del equilibrio líquido-vapor en busca de recomendar qué modelo debe ser usado de acuerdo la propiedad y la fase que se desea calcular. Los modelos seleccionados corresponden a cuatro modelos no polares, con uno o dos sitios Lennard-Jones, y cuatro modelos polares, con dipolos o cargas parciales para representar la polaridad del monóxido de carbono. Simulaciones Monte Carlo en la versión Gibbs canónica (NVT-GEMC se emplearon para determinar las densidades de las fases en equilibrio, la presión de vapor y la entalpia de vaporización entre 80 y 130 K con cada uno de los modelos seleccionados. Se encontró que los modelos más complejos SVH, ANC y PGB, son los que mejor describen la densidad del líquido saturado (alrededor de 7% de desviación promedio, pero estos modelos generan desviaciones mayores al 40% para las propiedades del vapor y al 20% para la entalpia de vaporización. Por otro lado, el modelo no- polar BLF generó las menores desviaciones para la presión de saturación y la densidad del vapor (6.8 y 21.5%, respectivamente. Este modelo, al igual que el modelo HCB, produce desviaciones aceptables para la densidad del líquido y la entalpia de vaporización (entre 10 y 12%. Los modelos no polares BLF y HCB, que no requieren el cálculo de las interacciones de largo alcance, se pueden considerar como los modelos moleculares que presentan un balance satisfactorio entre desviaciones en los resultados y complejidad de cálculo.

  10. Aceros sinterizados tratados al vapor para la fabricación de componentes de amortiguadores bitubo

    Directory of Open Access Journals (Sweden)

    Cambronero, L. E. G.

    2000-06-01

    Full Text Available In this work, properties of three sintered and steam treated alloyed irons were analysed. These materials were Fe+2Cu, Fe+0.6C+0.5Cu, and Fe+0.45P+2.5Cu, which were obtained by powder mixing. Once pressed and sintered, samples were steam treated (surface treatment which is characteristic of sintered irons. Density, hardness and tensile strength were obtained on sintered and steam treated samples, within their microstructure analysis. Also, a tribological study was carried out since some parts of shock absorbers are working under friction.

    En este trabajo se analizan las propiedades de tres hierros aleados sintetizados y tratados al vapor. Los materiales seleccionados son el Fe+2Cu, Fe+0.6C+0.5Cu, y Fe+0.45P+2.5Cu, obtenidos por mezcla elemental de polvos. Una vez compactados y sintetizados, se sometieron a un tratamiento de recubrimiento característico de los hierros, como es el tratamiento al vapor. En los materiales sintetizados y tratados al vapor, se determinaron su densidad, dureza y resistencia a tracción, junto con su análisis microestructural. Así mismo dado que algunos de los componentes de los amortiguadores bitubo están sometidos a esfuerzos de fricción, se analizaron el comportamiento tribologíco de los materiales obtenidos tanto en estado sintetizado como tratados al vapor.

  11. 10 conference and Latin American turbomachinery exhibition; 10 congreso y exposicion latinoamericana de turbomaquinaria

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-11-15

    This conference was done to promote the exchange of experiences among specialists, users, manufactures and research institutions in the field of the turbomachinery. To spread the last researches and developments focus to the design and maintenance of steam, gas and hydraulic turbines, axial compressors and centrifugal pumps, fans, electric motors, auxiliary equipment and cogeneration. [Spanish] Este congreso se realizo con el fin de promover el intercambio de experiencias entre especialistas, usuarios, fabricantes e institutos de investigacion en el campo de la turbomaquinaria. Divulgar las ultimas investigaciones y desarrollos enfocados al diseno y mantenimiento de turbinas de vapor, de gas e hidraulicas, compresores axiales y centrifugos, bombas, ventiladores, motores electricos, equipos auxiliares y cogeneracion.

  12. Historia de las Universidades.

    Directory of Open Access Journals (Sweden)

    Jaime Escobar Triana

    1999-04-01

    ínicos”

    La civilización medieval produjo los arquetipos y el impulso dinámico para las fuerzas principales del mundo moderno. Representa el período de gestación de la cultura moderna. La ciencia occidental se desarrolló en las redes de la erudición medieval que en el siglo XII eran las escuelas catedralicias. La catedral de Chartres, simboliza, históricamente los comienzos de nuestra era científica y tecnológica.

    En la escuela de Chartres se establecieron las bases filosóficas para el surgimiento de la ciencia medieval y la moderna. El estudio de la naturaleza se constituyó en disciplina por derecho propio. En Chartres, durante el siglo XII, el estudio de la ciencia obtuvo por primera vez una prioridad definitiva sobre la enseñanza de las artes liberales y los maestros lucharon por la instauración de osadas reformas en la educación superior general centrando el programa de estudios de ciencias naturales en el cuadrivio: aritmética, música (como matemáticas geometría y astronomía y no en las humanidades tradicionales del trivio: gramática, retórica y lógica.

    La escuela de Chartres desafiaba así a los 7 siglos de enseñanzas cristianas a cerca del lugar de la naturaleza en el esquema divino, contra todas las resistencias de las grandes escuelas catedralicias de Orleans, Saint Victor en París y Laon. El ser humano y el mundo eran una unidad en el pensamiento de Chartres; trivio y cuadrivio eran parte de un universo único. Pedro Abelardo En sus escritos (siglo XII se hallan las raíces históricas de la técnica, del método con el que las grandes escuelas universitarias del S XIII construyeron, organizaron y expresaron sus doctrinas, las síntesis teológicas más complejas y más completas de la edad media. Abelardo en la Escuela de Santa Genoveva en París y Cátedra de Notre-Dame, Busca huir de los condicionamientos de las estructuras culturales cerradas e inmóviles y de las rígidas concepciones tradicionales para abrirse a una vía de investigaci

  13. Validation of the thermal balance of Laguna Verde turbine under conditions of extended power increase; Validacion del balance termico de turbina de Laguna Verde en condiciones de aumento de potencia extendido

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda G, M. A.; Cruz B, H. J.; Mercado V, J. J.; Cardenas J, J. B.; Garcia de la C, F. M., E-mail: miguel.castaneda01@cfe.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

    2012-10-15

    The present work is a continuation of the task: Modeling of the vapor cycle of Laguna Verde with the PEPSE code to conditions of thermal power licensed at present (2027 MWt) in which the modeling of the vapor cycle of the nuclear power plant of Laguna Verde was realized with PEPSE code (Performance Evaluation of Power System Efficiencies). Once reached the conditions of nominal operation of extended power increase, operating both units to 2371 MWt; after the tests phase of starting-up and operation is necessary to carry out a verification of the proposed design of the vapor cycle for the new operation conditions. All this, having in consideration that the vapor cycle designer only knows the detail of the prospective performance of the main turbine, for all the other components (for example pumps, heat inter changers, valves, reactor, humidity separators and re-heaters, condensers, etc.) makes generic suppositions based on engineering judgment. This way carries out the calculations of thermal balance to determine the guaranteed gross power. The purpose of the present work is to comment the detail of the validation carried out of the specific thermal balance (thermal kit) of the nuclear power plant, making use of the design characteristics of the different components that conform the vapor cycle. (Author)

  14. A Simple Experiment for Determining Vapor Pressure and Enthalpy of Vaporization of Water.

    Science.gov (United States)

    Levinson, Gerald S.

    1982-01-01

    Laboratory procedures, calculations, and sample results are described for a freshman chemistry experiment in which the Clausius-Clapeyron equation is introduced as a means of describing the variation of vapor pressure with temperature and for determining enthalpy of vaporization. (Author/SK)

  15. Vapor pressure and enthalpy of vaporization of oil of catnip by correlation gas chromatography

    International Nuclear Information System (INIS)

    Simmons, Daniel; Gobble, Chase; Chickos, James

    2016-01-01

    Highlights: • Vaporization enthalpies of the nepetalactones from oil of catnip have been evaluated. • Vapor pressures from T = (298.15 to 350) K have been evaluated. • Oil of catnip has a vapor pressure similar to DEET at T = 298.15 K. - Abstract: The vaporization enthalpy and vapor pressure of the two nepetalactones found in Nepeta cataria have been evaluated by correlation gas chromatography. Vaporization enthalpies at T = 298.15 K of {(68.0 ± 1.9) and (69.4 ± 1.9)} kJ ⋅ mol"−"1 have been derived for the minor diastereomer, (4aS,7S,7aS)-nepetalactone, and major one, (4aS,7S,7aR)-nepetalactone, respectively. Vapor pressures also at T = 298.15 K of p = (1.2 ± 0.04) Pa and (0.91 ± 0.03) Pa have been evaluated for the minor and the major stereoisomer. In addition to being of interest because of the remarkable effect it has on various felids, oil of catnip is also quite effective in repelling mosquitoes, comparable to diethyl-m-toluamide (DEET). The vapor pressures evaluated in this work suggest that the two stereoisomers have similar volatility to DEET at ambient temperatures.

  16. Vapor pressures and enthalpies of vaporization of a series of the linear aliphatic aldehydes

    Czech Academy of Sciences Publication Activity Database

    Verevkin, S. P.; Krasnykh, E. L.; Vasiltsova, T. V.; Koutek, Bohumír; Doubský, Jan; Heintz, A.

    2003-01-01

    Roč. 206, - (2003), s. 331-339 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z4055905 Keywords : aldehydes * vapor pressure * enthalpy of vaporization Subject RIV: CC - Organic Chemistry Impact factor: 1.165, year: 2003

  17. Vapor pressures and vaporization enthalpy of codlemone by correlation gas chromatography

    International Nuclear Information System (INIS)

    Schultz, Shannon M.; Harris, Harold H.; Chickos, James S.

    2015-01-01

    Highlights: • The vaporization enthalpy of codlemone has been evaluated. • The vapor pressure of codlemone has been evaluated from T = (298.15 to T b ) K. • Vapor pressures for the 1-alkanols standards are available from T = (298.15 to 500) K. - Abstract: The vapor pressure and vaporization enthalpy of codlemone (trans, trans 8,10-dodecadien-1-ol), the female sex hormone of the codling moth is evaluated by correlation gas chromatography using a series of saturated primary alcohols as standards. A vaporization enthalpy of (92.3 ± 2.6) kJ · mol −1 and a vapor pressure, p/Pa = (0.083 ± 0.012) were evaluated at T = 298.15 K. An equation for the evaluation of vapor pressure from ambient temperature to boiling has been derived by correlation for codlemone. The calculated boiling temperature of T B = 389 K at p = 267 Pa is within the temperature range reported in the literature. A normal boiling temperature of T B = (549.1 ± 0.1) K is also estimated by extrapolation

  18. Evidence of a sewer vapor transport pathway at the USEPA vapor intrusion research duplex

    Science.gov (United States)

    The role of sewer lines as preferential pathways for vapor intrusion is poorly understood. Although the importance of sewer lines for volatile organic compound (VOC) transport has been documented at a small number of sites with vapor intrusion, sewer lines are not routinely sampl...

  19. Historia de las Hormonas

    Directory of Open Access Journals (Sweden)

    Alfredo Jácome-Roca

    2009-01-01

    Full Text Available

    El historiador Garrison afirma en su libro Introducción a la Historia de la Medicina que… “la nueva ciencia de la endocrinología, aunque arraigada en el pasado prehistórico, es virtualmente una creación del siglo XX…”

    Eso es precisamente lo que se quiere mostrar en este libro: las raíces hundidas en el pasado y los sorprendentes hallazgos de la modernidad de la centuria precedente, con algunos hechos importantes acaecidos en el siglo XIX.

    Los primeros datos conocidos comenzaron por las observaciones sobre animales y humanos castrados, sobre gigantes y enanos, diabéticos, cotudos y cretinos, y luego sobre las descripciones incipientes de los órganos endocrinos más grandes como el cuerpo tiroides, las cápsulas suprarrenales, testículos, ovarios y la glándula pituitaria. Personajes que podrían perfectamente provenir del país de Lilliput o de un circo del vecindario, tal era su extraña apariencia.

    Una eventual relación entre los casos clínicos mencionados y las glándulas se ignoraba casi totalmente, casi porque sí se sabía lo que ocurría a un animal o a un hombre castrado, antes y después de la pubertad. Por eso nos detendremos en algunas anécdotas (imposible la historia completa de los eunucos (y por espacio de dos siglos, particularmente en Italia, de los hombres-soprano denominados los castrati.

    Persistía la incógnita sobre la función de ciertos órganos o tejidos –llamados por siglos glándulas sin conducto (incluídos órganos hematopoyéticos como el timo, el bazo o los ganglios linfáticos: una pituitaria productora de moco, que drenaba en las fosas nasales el moco excesivo que se producía en los catarros; o una tiroides que lubricaba la laringe, unas cápsulas suprarrenales que sostenían los riñones, unos ovarios que eran testículos femeninos, o unos testículos que –esos sí- regaban semilla en el útero de las mujeres. Y tambi

  20. Las organizaciones complejas

    Directory of Open Access Journals (Sweden)

    Julio Mario Rodríguez Devis

    2002-05-01

    Full Text Available El aproximarse a las organizaciones con la visión de la complejidad permite observar sus múltiples interrelaciones, la relación orden-desorden-relaciones-retroacciones que se desarrollan en su interior, la íntima influencia bi-direccional entre el entorno y la organización, la emergencia y la autoorganizacion, la importancia de la información-ruido; en fin, observar a la organización como un sistema dinámico, no lineal, abierto y complejo. En este artículo se presentan los fundamentos de la complejidad en las organizaciones, y se describen los principales elementos que la constituyen.

  1. Humanismo en las universidades

    Directory of Open Access Journals (Sweden)

    Carlos Arturo Caparroso

    1963-08-01

    Full Text Available Algunas universidades del país, con encomiable acierto, han establecido, en los programas de sus ciclos de enseñanza profesional, el estudio de asignaturas de cultura general. Y para prestigiarlas, las han rotulado con una denominación ciertamente esclarecida y grata, término de rancia prosapia, de insigne lastre histórico: humanidades.

  2. Derrida en las pampas

    Directory of Open Access Journals (Sweden)

    Analía Gerbaudo

    2011-07-01

    Full Text Available http://dx.doi.org/10.5007/1984-784X.2011v11n16p16 En el año 2003 Mariano Ben Plotkin publica Freud en las pampas. Orígenes y desarrollo de una cultura psicoanalítica en la Argentina (1910-1983: un estudio minucioso de la recepción y difusión del psicoanálisis que recupero tanto en sus aspectos metodológicos como en sus conjeturas sobre la relación que los intelectuales argentinos suelen entablar con el pensamiento europeo (tesis que se refuerzan si se las lee en conjunción con las desarrolladas respecto de lo que ha acontecido en el campo de los estudios literarios en nuestro país entre la segunda mitad del siglo XX hasta la fecha –cf. Gerbaudo, 2006a, 2007a, 2007b-. Plotkin pone la descripción de la masiva difusión del psicoanálisis en Argentina en el corte temporal seleccionado al servicio del estudio de los factores culturales, sociales y políticos que hicieron lugar a esa acogida.

  3. Las juventudes falangistas

    Directory of Open Access Journals (Sweden)

    Ricardo L. CHUECA RODRÍGUEZ

    2010-03-01

    Full Text Available RESUMEN: Una de las servidumbres de cualquier intervención como la que me propongo realizar aquí es la de los prolegómenos, siempre inevitables. Cuando inicié la preparación de estas líneas pronto caí en la cuenta de que poco se podía entender sin clarificar una serie de cuestiones que yo creía previas. Al final no resultaron ser previas sino más bien contextúales. En todo caso necesarias. Por eso en primer lugar nos detendremos en intentar desentrañar las relaciones entre juventud y fascismo. Veremos después algunos datos contextúales de Falange como partido único en el régimen de Franco, y terminaremos analizando las causas del fracaso de la organización juvenil falangista como aparato del Partido, dirigido a obtener tanto una reprodución política interna como su implantación en la sociedad civil.

  4. Water vapor profiling using microwave radiometry

    Science.gov (United States)

    Wang, J. R.; Wilheit, T. T.

    1988-01-01

    Water vapor is one of the most important constituents in the Earth's atmosphere. Its spatial and temporal variations affect a wide spectrum of meteorological phenomena ranging from the formation of clouds to the development of severe storms. The passive microwave technique offers an excellent means for water vapor measurements. It can provide both day and night coverage under most cloud conditions. Two water vapor absorption features, at 22 and 183 GHz, were explored in the past years. The line strengths of these features differ by nearly two orders of magnitude. As a consequence, the techniques and the final products of water vapor measurements are also quite different. The research effort in the past few years was to improve and extend the retrieval algorithm to the measurements of water vapor profiles under cloudy conditions. In addition, the retrieval of total precipitable water using 183 GHz measurements, but in a manner analogous to the use of 22 GHz measurements, to increase measurement sensitivity for atmospheres of very low moisture content was also explored.

  5. Control of sodium vapor transport in annuli

    International Nuclear Information System (INIS)

    Meadows, G.E.; Bohringer, A.P.

    1983-11-01

    The method used to control sodium vapor transport in the annuli of various components at the Fast Flux Test Facility (FFTF) is a downward purge of the annuli with high purity argon. The purge rates for the FFTF were selected by calculating the gas velocity required to overcome thermal convection transport in the annuli. To evaluate the effectiveness of the gas purge, laboratory apparatus was fabricated which simulated selected annuli in the FFTF In-Vessel Handling Machine (IVHM) and the Instrument Tree (IT) annuli. Tests were conducted at temperatures similar to FFTF conditions. Gas purge rates ranged from zero to 130% of FFTF flow rates. Test results show the effectiveness of a high purity gas purge in decreasing the accumulation of sodium vapor deposits in an annulus. The presence of water vapor and oxygen in the purge gas increased the sodium deposition rate by a factor of three over other tests usig high purity argon. The presence of a vapor control collar used in the IT annulus was shown to be beneficial for controlling vapor transport into the upper region of the annulus

  6. Vapor pressure and thermodynamics of beryllium carbide

    International Nuclear Information System (INIS)

    Rinehart, G.H.; Behrens, R.G.

    1980-01-01

    The vapor pressure of beryllium carbide has been measured over the temperature range 1388 to 1763 K using Knudsen-effusion mass spectrometry. Vaporization occurs incongruently according to the reaction Be 2 C(s) = 2Be(g) + C(s). The equilibrium vapor pressure above the mixture of Be 2 C and C over the experimental temperature range is (R/J K -1 mol -1 )ln(p/Pa) = -(3.610 +- 0.009) x 10 5 (K/T) + (221.43 +- 1.06). The third-law enthalpy change for the above reaction obtained from the present vapor pressures is ΔH 0 (298.15 K) = (740.5 +- 0.1) kJ mol -1 . The corresponding second-law result is ΔH 0 (298.15 K) = (732.0 +- 1.8) kJ mol -1 . The enthalpy of formation for Be 2 C(s) calculated from the present third-law vaporization enthalpy and the enthalpy of formation of Be(g) is ΔH 0 sub(f)(298.15 K) = -(92.5 +- 15.7) kJ mol -1 . (author)

  7. Vapor pumps and gas-driven machines

    International Nuclear Information System (INIS)

    Guillet, R.

    1991-01-01

    The vapor pump, patented in 1979 by Gaz de France, is an additional mass and heat exchanger which uses the combustion air of fuel-burning machines as an additional cold source. This cold source is preheated and, above all, humidified before reaching the burner, by means of the residual sensible and latent heat in the combustion products of the fuel-burning process. This final exchanger thus makes it possible, in many cases, to recover all the gross calorific value of natural gas, even when the combustion products leave the process at a wet temperature greater than 60 0 C, the maximum dew point of the products of normal combustion. Another significant advantage of the vapor pump being worth highlighting is the selective recycling of water vapor by the vapor pump which reduces the adiabatic combustion temperature and the oxygen concentration in the combustion air, two factors which lead to considerable reductions in nitrogen oxides formation, hence limiting atmospheric pollution. Alongside a wide range of configurations which make advantageous use of the vapor pump in association with gas-driven machines and processes, including gas turbines, a number of boiler plant installations are also presented [fr

  8. Distribution of tropical tropospheric water vapor

    Science.gov (United States)

    Sun, De-Zheng; Lindzen, Richard S.

    1993-01-01

    Utilizing a conceptual model for tropical convection and observational data for water vapor, the maintenance of the vertical distribution of the tropical tropospheric water vapor is discussed. While deep convection induces large-scale subsidence that constrains the turbulent downgradient mixing to within the convective boundary layer and effectively dries the troposphere through downward advection, it also pumps hydrometeors into the upper troposphere, whose subsequent evaporation appears to be the major source of moisture for the large-scale subsiding motion. The development of upper-level clouds and precipitation from these clouds may also act to dry the outflow, thus explaining the low relative humidity near the tropopause. A one-dimensional model is developed to simulate the mean vertical structure of water vapor in the tropical troposphere. It is also shown that the horizontal variation of water vapor in the tropical troposphere above the trade-wind boundary layer can be explained by the variation of a moisture source that is proportional to the amount of upper-level clouds. Implications for the nature of water vapor feedback in global warming are discussed.

  9. Thermodynamics and Kinetics of Silicate Vaporization

    Science.gov (United States)

    Jacobson, Nathan S.; Costa, Gustavo C. C.

    2015-01-01

    Silicates are a common class of materials that are often exposed to high temperatures. The behavior of these materials needs to be understood for applications as high temperature coatings in material science as well as the constituents of lava for geological considerations. The vaporization behavior of these materials is an important aspect of their high temperature behavior and it also provides fundamental thermodynamic data. The application of Knudsen effusion mass spectrometry (KEMS) to silicates is discussed. There are several special considerations for silicates. The first is selection of an appropriate cell material, which is either nearly inert or has well-understood interactions with the silicate. The second consideration is proper measurement of the low vapor pressures. This can be circumvented by using a reducing agent to boost the vapor pressure without changing the solid composition or by working at very high temperatures. The third consideration deals with kinetic barriers to vaporization. The measurement of these barriers, as encompassed in a vaporization coefficient, is discussed. Current measured data of rare earth silicates for high temperature coating applications are discussed. In addition, data on magnesium-iron-silicates (olivine) are presented and discussed.

  10. A Numerical Investigation of Vapor Intrusion — the Dynamic Response of Contaminant Vapors to Rainfall Events

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

    2013-01-01

    The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1 m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in

  11. Oxidación en vapor de agua del acero inoxidable aisi 317 a 700 y 750ºc

    OpenAIRE

    MARULANDA AREVALO, JOSE LUDDEY; REMOLINA MILLAN, ADULJAY; BARON, JAIRO ALBERO

    2013-01-01

    Se realizó la oxidación del acero inoxidable austenítico AISI SAE 317, a temperaturas de 700 y 750ºC, en un ambiente con 100% vapor de agua, para evaluar su comportamiento a la corrosión. Se realizaron curvas de ganancia de masa y las películas de óxidos se analizaron por medio de Microscopia Electrónica de Barrido (SEM) y difracción de rayos X (DRX), para observar cómo se forman las capas de óxidos y discutir el posible mecanismo de oxidación en vapor de agua. Se encontró que el mecanismo de...

  12. OXIDACIÓN EN VAPOR DE AGUA DEL ACERO INOXIDABLE AISI 317 A 700 Y 750ºC

    OpenAIRE

    José Luddey Marulanda Arevalo; Aduljay Remolina Millan; Jairo Alberto Barón

    2013-01-01

    Se realizó la oxidación del acero inoxidable austenítico AISI SAE 317, a temperaturas de 700 y 750ºC, en un ambiente con 100% vapor de agua, para evaluar su comportamiento a la corrosión. Se realizaron curvas de ganancia de masa y las películas de óxidos se analizaron por medio de Microscopia Electrónica de Barrido (SEM) y difracción de rayos X (DRX), para observar cómo se forman las capas de óxidos y discutir el posible mecanismo de oxidación en vapor de agua. Se encontró que el mecanismo de...

  13. Las telenovelas juveniles mexicanas y las adolescentas obesas

    Directory of Open Access Journals (Sweden)

    Tania Meza

    2006-01-01

    Full Text Available Esta investigación analiza la opresión por cuerpo (obesidad a la que las mujeres son sometidas dentro del sistema patriarcal durante la adolescencia, específicamente a través de la representación televisiva que de las jóvenes gordas se hace en la telenovela juvenil mexicana. Los enormes niveles de audiencia que poseen las telenovelas en nuestro país hace indispensable, para los estudios de género desde las ciencias dela comunicación, estudiar el papel de las mujeres en dichas teleseries. En este análisis se pretende mostrar la triple marginación a la que son sometidas las adolescentes obesas en las telenovelas juveniles mexicanas: por ser mujeres, por ser jóvenes y por ser gordas.

  14. Carbón activado de semillas de tomate para adsorción de vapores de amoniaco, benceno y gasolina//Activated coal of tomato seeds for adsorption of vapors of ammonia, benzene and gasoline

    Directory of Open Access Journals (Sweden)

    Francisco Márquez-Montesino

    2013-05-01

    Full Text Available El objetivo fue comprobar las posibilidades de adsorción de amoniaco, benceno y gasolina en carbones activados, de semillas de tomate. Se realizó un análisis inmediato a la biomasa. Se concluyó que la adsorción de vapores de amoniaco, está relacionada con la adsorción física y con la presencia de gruposfuncionales de carácter ácido en la superficie activa de los carbones, que forman enlaces débiles con las moléculas de amoniaco. Se realizaron experimentos de adsorción de benceno y gasolina, que no tienen grupos funcionales como el amoniaco, siendo menos adsorbidos, confirmándose una adsorción preferentemente química. La temperatura de activación, la relación de impregnación (RI y laconcentración de la disolución ácida, no tuvieron una influencia significativa en la capacidad de adsorción de benceno, pero sí en la adsorción de amoniaco y vapores de gasolina, de gran aplicación para la eliminación de los vapores de escape en los motores de vehículos.Palabras claves: carbón, activación, adsorción, vapores, amoníaco._______________________________________________________________________________AbstractThe objective was to prove the adsorption possibilities of ammonia, benzene and vapors of gasoline in activated coals with phosphoric acid, of tomato seed. An immediate analysis to the biomass was carried out. It was concluded that the vapors adsorption of ammonia, is related with the physical adsorption andthe presence of functional groups of acid character in the active surface of the coal that form weak connections with the molecules of ammonia. Experiments of adsorption of benzene and gasoline were carried out, these substances haven't functional groups as the ammonia, so they were less adsorbed, and it was confirmed a chemical adsorption preferably. The activation temperature, the relationship of impregnation (RI and the concentration of the acid dissolution haven't a significant influence in the capacity of

  15. Auxiliary Electrodes for Chromium Vapor Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Fergus, Jeffrey; Shahzad, Moaiz; Britt, Tommy

    2018-05-15

    Measurement of chromia-containing vapors in solid oxide fuel cell systems is useful for monitoring and addressing cell degradation caused by oxidation of the chomia scale formed on alloys for interconnects and balance-of-plant components. One approach to measuring chromium is to use a solid electrolyte with an auxiliary electrode that relates the partial pressure of the chromium containing species to the mobile species in the electrolyte. One example is YCrO3 which can equilibrate with the chromium containing vapor and yttrium in yttria stabilized zirconia to establish an oxygen activity. Another is Na2CrO4 which can equilibrate with the chromium-containing vapor to establish a sodium activity.

  16. Monolithic microwave integrated circuit water vapor radiometer

    Science.gov (United States)

    Sukamto, L. M.; Cooley, T. W.; Janssen, M. A.; Parks, G. S.

    1991-01-01

    A proof of concept Monolithic Microwave Integrated Circuit (MMIC) Water Vapor Radiometer (WVR) is under development at the Jet Propulsion Laboratory (JPL). WVR's are used to remotely sense water vapor and cloud liquid water in the atmosphere and are valuable for meteorological applications as well as for determination of signal path delays due to water vapor in the atmosphere. The high cost and large size of existing WVR instruments motivate the development of miniature MMIC WVR's, which have great potential for low cost mass production. The miniaturization of WVR components allows large scale deployment of WVR's for Earth environment and meteorological applications. Small WVR's can also result in improved thermal stability, resulting in improved calibration stability. Described here is the design and fabrication of a 31.4 GHz MMIC radiometer as one channel of a thermally stable WVR as a means of assessing MMIC technology feasibility.

  17. Numerical modeling of a vaporizing multicomponent droplet

    Science.gov (United States)

    Megaridis, C. M.; Sirignano, W. A.

    The fundamental processes governing the energy, mass, and momentum exchange between the liquid and gas phases of vaporizing, multicomponent liquid droplets have been investigated. The axisymmetric configuration under consideration consists of an isolated multicomponent droplet vaporizing in a convective environment. The model considers different volatilities of the liquid components, variable liquid properties due to variation of the species concentrations, and non-Fickian multicomponent gaseous diffusion. The bicomponent droplet model was employed to examine the commonly used assumptions of unity Lewis number in the liquid phase and Fickian gaseous diffusion. It is found that the droplet drag coefficients, the vaporization rates, and the related transfer numbers are not influenced by the above assumptions in a significant way.

  18. Secondhand Exposure to Vapors From Electronic Cigarettes

    Science.gov (United States)

    Czogala, Jan; Fidelus, Bartlomiej; Zielinska-Danch, Wioleta; Travers, Mark J.; Sobczak, Andrzej

    2014-01-01

    Introduction: Electronic cigarettes (e-cigarettes) are designed to generate inhalable nicotine aerosol (vapor). When an e-cigarette user takes a puff, the nicotine solution is heated and the vapor is taken into lungs. Although no sidestream vapor is generated between puffs, some of the mainstream vapor is exhaled by e-cigarette user. The aim of this study was to evaluate the secondhand exposure to nicotine and other tobacco-related toxicants from e-cigarettes. Materials and Methods: We measured selected airborne markers of secondhand exposure: nicotine, aerosol particles (PM2.5), carbon monoxide, and volatile organic compounds (VOCs) in an exposure chamber. We generated e-cigarette vapor from 3 various brands of e-cigarette using a smoking machine and controlled exposure conditions. We also compared secondhand exposure with e-cigarette vapor and tobacco smoke generated by 5 dual users. Results: The study showed that e-cigarettes are a source of secondhand exposure to nicotine but not to combustion toxicants. The air concentrations of nicotine emitted by various brands of e-cigarettes ranged from 0.82 to 6.23 µg/m3. The average concentration of nicotine resulting from smoking tobacco cigarettes was 10 times higher than from e-cigarettes (31.60±6.91 vs. 3.32±2.49 µg/m3, respectively; p = .0081). Conclusions: Using an e-cigarette in indoor environments may involuntarily expose nonusers to nicotine but not to toxic tobacco-specific combustion products. More research is needed to evaluate health consequences of secondhand exposure to nicotine, especially among vulnerable populations, including children, pregnant women, and people with cardiovascular conditions. PMID:24336346

  19. Vapor characterization of Tank 241-C-103

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Story, M.S.

    1994-06-01

    The Westinghouse Hanford Company Tank Vapor Issue Resolution Program has developed, in cooperation with Northwest Instrument Systems, Inc., Oak Ridge National Laboratory, Oregon Graduate Institute of Science and Technology, Pacific Northwest Laboratory, and Sandia National Laboratory, the equipment and expertise to characterize gases and vapors in the high-level radioactive waste storage tanks at the Hanford Site in south central Washington State. This capability has been demonstrated by the characterization of the tank 241-C-103 headspace. This tank headspace is the first, and for many reasons is expected to be the most problematic, that will be characterized (Osborne 1992). Results from the most recent and comprehensive sampling event, sample job 7B, are presented for the purpose of providing scientific bases for resolution of vapor issues associated with tank 241-C-103. This report is based on the work of Clauss et al. 1994, Jenkins et al. 1994, Ligotke et al. 1994, Mahon et al. 1994, and Rasmussen and Einfeld 1994. No attempt has been made in this report to evaluate the implications of the data presented, such as the potential impact of headspace gases and vapors to tank farm workers health. That and other issues will be addressed elsewhere. Key to the resolution of worker health issues is the quantitation of compounds of toxicological concern. The Toxicology Review Panel, a panel of Pacific Northwest Laboratory experts in various areas, of toxicology, has chosen 19 previously identified compounds as being of potential toxicological concern. During sample job 7B, the sampling and analytical methodology was validated for this preliminary list of compounds of toxicological concern. Validation was performed according to guidance provided by the Tank Vapor Conference Committee, a group of analytical chemists from academic institutions and national laboratories assembled and commissioned by the Tank Vapor Issue Resolution Program

  20. Vapor characterization of Tank 241-C-103

    Energy Technology Data Exchange (ETDEWEB)

    Huckaby, J.L. [Westinghouse Hanford Co., Richland, WA (United States); Story, M.S. [Northwest Instrument Systems, Inc. Richland, WA (United States)

    1994-06-01

    The Westinghouse Hanford Company Tank Vapor Issue Resolution Program has developed, in cooperation with Northwest Instrument Systems, Inc., Oak Ridge National Laboratory, Oregon Graduate Institute of Science and Technology, Pacific Northwest Laboratory, and Sandia National Laboratory, the equipment and expertise to characterize gases and vapors in the high-level radioactive waste storage tanks at the Hanford Site in south central Washington State. This capability has been demonstrated by the characterization of the tank 241-C-103 headspace. This tank headspace is the first, and for many reasons is expected to be the most problematic, that will be characterized (Osborne 1992). Results from the most recent and comprehensive sampling event, sample job 7B, are presented for the purpose of providing scientific bases for resolution of vapor issues associated with tank 241-C-103. This report is based on the work of Clauss et al. 1994, Jenkins et al. 1994, Ligotke et al. 1994, Mahon et al. 1994, and Rasmussen and Einfeld 1994. No attempt has been made in this report to evaluate the implications of the data presented, such as the potential impact of headspace gases and vapors to tank farm workers health. That and other issues will be addressed elsewhere. Key to the resolution of worker health issues is the quantitation of compounds of toxicological concern. The Toxicology Review Panel, a panel of Pacific Northwest Laboratory experts in various areas, of toxicology, has chosen 19 previously identified compounds as being of potential toxicological concern. During sample job 7B, the sampling and analytical methodology was validated for this preliminary list of compounds of toxicological concern. Validation was performed according to guidance provided by the Tank Vapor Conference Committee, a group of analytical chemists from academic institutions and national laboratories assembled and commissioned by the Tank Vapor Issue Resolution Program.

  1. Vacuum distillation/vapor filtration water recovery

    Science.gov (United States)

    Honegger, R. J.; Neveril, R. B.; Remus, G. A.

    1974-01-01

    The development and evaluation of a vacuum distillation/vapor filtration (VD/VF) water recovery system are considered. As a functional model, the system converts urine and condensates waste water from six men to potable water on a steady-state basis. The system is designed for 180-day operating durations and for function on the ground, on zero-g aircraft, and in orbit. Preparatory tasks are summarized for conducting low gravity tests of a vacuum distillation/vapor filtration system for recovering water from urine.

  2. Detection of water vapor on Jupiter

    Science.gov (United States)

    Larson, H. P.; Fink, U.; Treffers, R.; Gautier, T. N., III

    1975-01-01

    High-altitude (12.4 km) spectroscopic observations of Jupiter at 5 microns from the NASA 91.5 cm airborne infrared telescope have revealed 14 absorptions assigned to the rotation-vibration spectrum of water vapor. Preliminary analysis indicates a mixing ratio about 1 millionth for the vapor phase of water. Estimates of temperature (greater than about 300 K) and pressure (less than 20 atm) suggest observation of water deep in Jupiter's hot spots responsible for its 5 micron flux. Model-atmosphere calculations based on radiative-transfer theory may change these initial estimates and provide a better physical picture of Jupiter's atmosphere below the visible cloud tops.

  3. Vapor deposition in basaltic stalactites, Kilauea, Hawaii

    Science.gov (United States)

    Baird, A. K.; Mohrig, D. C.; Welday, E. E.

    Basaltic stalacties suspended from the ceiling of a large lava tube at Kilauea, Hawaii, have totally enclosed vesicles whose walls are covered with euhedral FeTi oxide and silicate crystals. The walls of the vesicles and the exterior surfaces of stalactites are Fe and Ti enriched and Si depleted compared to common basalt. Minerals in vesicles have surface ornamentations on crystal faces which include alkali-enriched, aluminosilicate glass(?) hemispheres. No sulfide-, chloride-, fluoride-, phosphate- or carbonate-bearing minerals are present. Minerals in the stalactites must have formed by deposition from an iron oxide-rich vapor phase produced by the partial melting and vaporization of wall rocks in the tube.

  4. Flammability characteristics of combustible gases and vapors

    Energy Technology Data Exchange (ETDEWEB)

    Zabetakis, M. G. [Bureau of Mines, Pittsburgh, PA (United States)

    1964-05-01

    This is a summary of the available limit of flammability, autoignition and burning-rate data for more than 200 combustible gases and vapors in air and other oxidants, as well as of empirical rules and graphs that can be used to predict similar data for thousands of other combustibles under a variety of environmental conditions. Spec$c data are presented on the paraffinic, unsaturated, aromatic, and alicyclic hydrocarbons, alcohols, ethers, aldehydes, ketones, and sulfur compounds, and an assortment of fuels, fuel blends, hydraulic fluids, engine oils, and miscellaneous combustible gases and vapors.

  5. Laser vapor phase deposition of semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Karlov, N.V.; Luk' ianchuk, B.S.; Sisakian, E.V.; Shafeev, G.A.

    1987-06-01

    The pyrolytic effect of IR laser radiation is investigated with reference to the initiation and control of the vapor phase deposition of semiconductor films. By selecting the gas mixture composition and laser emission parameters, it is possible to control the deposition and crystal formation processes on the surface of semiconductors, with the main control action achieved due to the nonadiabatic kinetics of reactions in the gas phase and high temperatures in the laser heating zone. This control mechanism is demonstrated experimentally during the laser vapor deposition of germanium and silicon films from tetrachlorides on single-crystal Si and Ge substrates. 5 references.

  6. The vertical distribution of Mars water vapor

    Science.gov (United States)

    Davies, D. W.

    1979-01-01

    Analysis of observations made from the Viking 1 Orbiter indicates that the water vapor over the Viking 1 landing site is uniformly mixed with the atmosphere and not concentrated near the surface. The analysis incorporates the effects of atmospheric scattering and explains why previous earth-based observations showed a strong diurnal variation in water content. It also explains the lack of an early morning fog and removes the necessity of daily exchange of large amounts of water between the surface and the atmosphere. A water vapor volume mixing ratio of 1.5 x 10 to the -4th is inferred for the Viking 1 site in late summer.

  7. Drag Reduction by Leidenfrost Vapor Layers

    KAUST Repository

    Vakarelski, Ivan Uriev

    2011-05-23

    We demonstrate and quantify a highly effective drag reduction technique that exploits the Leidenfrost effect to create a continuous and robust lubricating vapor layer on the surface of a heated solid sphere moving in a liquid. Using high-speed video, we show that such vapor layers can reduce the hydrodynamic drag by over 85%. These results appear to approach the ultimate limit of drag reduction possible by different methods based on gas-layer lubrication and can stimulate the development of related energy saving technologies.

  8. Low temperature vapor phase digestion of graphite

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, Robert A.

    2017-04-18

    A method for digestion and gasification of graphite for removal from an underlying surface is described. The method can be utilized to remove graphite remnants of a formation process from the formed metal piece in a cleaning process. The method can be particularly beneficial in cleaning castings formed with graphite molding materials. The method can utilize vaporous nitric acid (HNO.sub.3) or vaporous HNO.sub.3 with air/oxygen to digest the graphite at conditions that can avoid damage to the underlying surface.

  9. Las marcas propias en Colombia

    Directory of Open Access Journals (Sweden)

    Carlos Felipe Payán Rodríguez

    2013-11-01

    Full Text Available El artículo analiza la situación actual de las marcas propias en Colombia, teniendo en cuenta su creciente auge al interior de las grandes superficies. Mediante este tipo de marcas el mismo distribuidor vende productos y servicios con su nombre o recurriendo a una marca de su propiedad, compitiendo con las marcas ya posicionadas en el mercado de los fabricantes. El texto se articula, primero, en una contextualización con base en doctrina comparada respecto de las marcas propias. Luego, se aplican las reglas de dichos conceptos doctrinales a la situación actual colombiana. Por último, se plantean dos problemas jurídicos respecto de las marcas propias, uno, analizado desde la propiedad industrial, y el otro, desde las reglas del Estatuto del Consumidor.

  10. Las mujeres lacandonas: cambios recientes

    Directory of Open Access Journals (Sweden)

    Lucie Nečasová

    2010-08-01

    Full Text Available El artículo se enfoca en los cambios en la vida de las mujeres lacandonas contemporáneas. Analiza cómo se han modificado el modo de la vida, las costumbres y las relaciones de la mujer dentro de las propias familias pero también dentro de la sociedad y la comunidad. El objetivo es mostrar los cambios reflejados en la vida de las mujeres de tres generaciones. El estudio está basado en las etnografías disponibles combinadas con el propio trabajo de campo realizado en las comunidades Lacanjá y Nahá en los años 2008 y 2009.

  11. Separation of aromatics by vapor permeation through solvent swollen membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ito, A.; Adachi, K.; Feng, Y. [Niigata University, Niigata (Japan)

    1995-12-20

    A vapor permeation process for aromatics separation from a hydrocarbon mixture was studied by means of the simultaneous permeation of dimethylsulfoxide vapor as an agent for membrane swelling and preferential permeation of aromatics. The separation performance of the process was demonstrated by a polyvinylalcohol membrane for mixed vapors of benzene/cyclohexane, xylene/octane and a model gasoline. The aromatic vapors preferentially permeated from these mixed vapor feeds. The separation factor was over 10. The separation mechanism of the process mainly depends on the relative salability of the vapors between aromatics and other hydrocarbons in dimethylsulfoxide. 14 refs., 9 figs., 1 tab.

  12. Las narcodemocracias andinas

    Directory of Open Access Journals (Sweden)

    Olivier DABÈNE

    2009-11-01

    Full Text Available RESUMEN: Los países de América Latina están afectados en diferentes aspectos por el tráfico de drogas. En especial, en los países andinos, esta actividad ha condicionado de manera decisiva el tipo de régimen democrático iniciado en algún caso en la década de 1980, como Perú o Bolivia, o el régimen colombiano. El autor califica a estos regímenes como narcodemocracias por los efectos del tráfico de drogas no sólo en el orden social y económico, que analiza de forma profunda, sino por la politización del narcotráfico. Las respuestas de las democracias han sido bien distintas en los tres casos analizados, afectando, sin embargo, en todos ellos, a la gobernabilidad de las mismas y a su legitimidad.ABSTRACT: Latin American countries are affected by narcotrafico in different aspects. Particularly, in Andean countries, this activity has deeply conditioned the type of democratic regime installed in some cases in the eighties, as Perou and Bolivia, or the colombian regimen. The author characterizes these regimes as narcodemocracias by effects of narcotrafico in them, not only in social and economic arenas, but also by the politization of narcotrafico. Responses of democracies have been very different in these cases analyzed in the article. Nevertheless, in all of them, governability and legitmity of democracy are affected.

  13. A Local Propagation for Vapor Explosions

    International Nuclear Information System (INIS)

    Ochiai, M.; Bankoff, S.G.

    1976-01-01

    Explosive boiling, defined as energy transfer leading to formation of vapor rapidly enough to produce large shock waves, has been widely studied in a number of contexts. Depending upon the nature and temperatures of the liquids and mode of contacting, large-scale mixing and explosive vaporization may occur, or alternatively, only relatively non-energetic, film-type boiling may exist. The key difference is whether a mechanism is operative for increasing the liquid-liquid interfacial area in a time scale consistent with the formation of a detonation wave. Small drops of a cold volatile liquid were dropped onto a free surface of a hot, non-volatile liquid. The critical Weber number for coalescence is obtained from the envelope of the film boiling region. Markedly different behavior for the two hot liquids is observed. A 'splash' theory for local propagation of vapor explosions in spontaneously nucleating liquid-liquid systems is now formulated. After a random contact is made, explosive growth and coalescence of the vapor bubbles occurs as soon as the surrounding pressure is relieved, resulting in a high-pressure vapor layer at the liquid-liquid contact area. This amounts to an impact pressure applied to the free surface, with a resulting velocity distribution obtained from potential flow theory. The peak pressure predictions are. consistent with data for Freon-oil mixing, but further evaluation will await additional experimental data. Nevertheless, the current inference is that a UO 2 -Na vapor explosion in a reactor environment cannot be visualized. In conclusion: The propagation model presented here differs in some details from that of Henry and Fauske, although both are consistent with some peak pressure data obtained by Henry, et al. Clearly, additional experimental information is needed for further evaluation of these theories. Nevertheless, it should be emphasized that even at this time a number of important observations concerning the requirements for a vapor

  14. Las actividades de lucha

    OpenAIRE

    Villamón Herrera, Miguel; Gutiérrez García, Carlos; Espartero Casado, Julián

    2003-01-01

    La lucha, como práctica lúdica y agonística está vinculada a la historia de todos los pueblos y civilizaciones. Su origen se remonta a los albores de la humanidad, por la necesidad de defender la propia vida y la integridad física frente a situaciones de peligro para la supervivencia. Así, para someter violentamente al adversario, a lo largo de la historia y en las diversas civilizaciones, se desarrollaron en cada región del mundo distintas técnicas de combate que, en unos casos, utilizaba...

  15. Knudsen cell vaporization of rare earth nitrides: enthalpy of vaporization of HoN098

    International Nuclear Information System (INIS)

    Brown, R.C.; Clark, N.J.

    1975-01-01

    The enthalpy of vaporization of HoN 0 . 98 was measured by the weight-loss Knudsen cell technique using Motzfeldt-Whitman extrapolations to zero orifice area. A third-law enthalpy of vaporization of HoN 0 . 98 of 155.9 +- 5 kcal mole -1 was obtained compared to a second-law value of 162.0 +- 5 kcal mole -1 . Similar measurements on the nitrides of samarium, erbium, and ytterbium gave third-law enthalpies of vaporization of 126.8 +-- 5 kcal mole -1 ; 159.6 +- 5 kcal mole -1 , and 121.0 +- 5 kcal mole -1 , respectively. 7 tables

  16. Collapsing criteria for vapor film around solid spheres as a fundamental stage leading to vapor explosion

    International Nuclear Information System (INIS)

    Freud, Roy; Harari, Ronen; Sher, Eran

    2009-01-01

    Following a partial fuel-melting accident, a Fuel-Coolant Interaction (FCI) can result with the fragmentation of the melt into tiny droplets. A vapor film is then formed between the melt fragments and the coolant, while preventing a contact between them. Triggering, propagation and expansion typically follow the premixing stage. In the triggering stage, vapor film collapse around one or several of the fragments occurs. This collapse can be the result of fragments cooling, a sort of mechanical force, or by any other means. When the vapor film collapses and the coolant re-establishes contact with the dry surface of the hot melt, it may lead to a very rapid and rather violent boiling. In the propagation stage the shock wave front leads to stripping of the films surrounding adjacent droplets which enhance the fragmentation and the process escalates. During this process a large quantity of liquid vaporizes and its expansion can result in destructive mechanical damage to the surrounding structures. This multiphase thermal detonation in which high pressure shock wave is formed is regarded as 'vapor explosion'. The film boiling and its possible collapse is a fundamental stage leading to vapor explosion. If the interaction of the melt and the coolant does not result in a film boiling, no explosion occurs. Many studies have been devoted to determine the minimum temperature and heat flux that is required to maintain a film boiling. The present experimental study examines the minimum temperature that is required to maintain a film boiling around metal spheres immersed into a liquid (subcooled distilled water) reservoir. In order to simulate fuel fragments that are small in dimension and has mirror-like surface, small spheres coated with anti-oxidation layer were used. The heat flux from the spheres was calculated from the sphere's temperature profiles and the sphere's properties. The vapor film collapse was associated with a sharp rise of the heat flux during the cooling

  17. las distintas organizaciones

    Directory of Open Access Journals (Sweden)

    A. Maldonado Ibáñez

    2006-01-01

    Full Text Available El presente artículo trata sobre la definición de un repositorio-catálogo de estilos aplicables a la representación cartográfica de los distintos fenómenos geográficos, basándose en la simbología normalizada de las distintas Organizaciones Cartográficas, tales como el Instituto Geográfico Nacional, el Ministerio de Medio Ambiente, el Instituto Nacional de Estadística, etc. El catálogo permitirá una elección rápida y sencilla de los diversos estilos utilizados por dichos organismos oficiales. Se trata de definir un repositorio en el que almacenar los estilos individualizados aplicables a los fenómenos geográficos, en el que se disponga de la capacidad de insertar, borrar y actualizar nuevos estilos. El repositorio debe responder como catálogo sobre el que buscar y descargar estilos. Una de las aplicaciones del repositorio-catálogo es la generación de estilos en el formato Style Layer Descriptor (SLD para ser visualizados mediante Servidores de Mapas en Red conformes con OGC.

  18. Las carreras del futuro

    Directory of Open Access Journals (Sweden)

    Luis Piscoya Hermoza

    2011-07-01

    Full Text Available La primera década del siglo XXI ha estado signada por un énfasis en los estudiosde prospectiva, los mismos que, a partir de procesos de complejizacióny articulación de la sociedad planetaria como son la digitalización, el progresivodeterioro del medio ambiente, la necesidad del cambio de la matriz energéticay la globalización del mercado, han ensayado hipótesis para identificar lastendencias que se fortalecerán y profundizarán durante las próximas décadas.Desde el punto de vista metodológico, existen muchas maneras de clasificarlaspara conceptualizarlas y entenderlas mejor. Sin embargo, considerando lanaturaleza de esta edición nos proponemos enfocar directamente aquellas queestán estrechamente ligadas a la formación universitaria.Naturalmente, no pensamos que estamos ante tendencias inevitables en lamedida que epistemológicamente la creencia en leyes históricas deterministases insostenible y la práctica social nos muestra que la construcción del futuroes nuestra responsabilidad y siempre rebasa las mejores previsiones.

  19. Las crisis familiares

    Directory of Open Access Journals (Sweden)

    Idarmis González Benítez

    2000-06-01

    Full Text Available Con este trabajo nos propusimos actualizar el tema de las crisis familiares. Se pone de manifiesto que tanto los eventos propios del desarrollo, como los accidentales, dan lugar a la aparición de crisis en la familia. Queda esclarecido, que no necesariamente han de tener implicaciones negativas para la familia. Se hace énfasis en la valoración del evento por la familia y su significación. Se destaca el papel de los recursos familiares como protectores y moduladores de las crisis. Por último se señalan algunos pasos a seguir en la intervención familiarWith this paper we intend to update the topic of the family crises. It is shown that the own events of development as well as the accidental ones bring about the appearance of crises in the family. It is made clear that they not always have negative implications for the family. Emphasis is made on the assessment of the event for the family and its significance. The role played by the family resources as protective and modulators of the crisis is stressed. Finally, some of the steps to be taken in family intervention are mentioned

  20. Solvent-vapor-assisted imprint lithography

    NARCIS (Netherlands)

    Voicu, Nicoleta E.; Ludwigs, Sabine; Crossland, Edward J. W.; Andrew, Piers; Steiner, Ullrich

    2007-01-01

    Sub-micrometer features are replicated into high-molecular-weight polymer resists by using solvent-assisted nanoimprint lithography (see figure). By swelling the polymer in a controlled solvent-vapor atmosphere, millibar pressures and ambient temperatures are sufficient to achieve high-fidelity

  1. General well function for soil vapor extraction

    Science.gov (United States)

    Perina, Tomas

    2014-04-01

    This paper develops a well function applicable to extraction of groundwater or soil vapor from a well under the most common field test conditions. The general well function (Perina and Lee, 2006) [12] is adapted to soil vapor extraction and constant head boundary at the top. For groundwater flow, the general well function now applies to an extraction well of finite diameter with uniform drawdown along the screen, finite-thickness skin, and partially penetrating an unconfined, confined, and leaky aquifer, or an aquifer underneath a reservoir. With a change of arguments, the model applies to soil vapor extraction from a vadose zone with no cover or with leaky cover at the ground surface. The extraction well can operate in specified drawdown (pressure for soil vapor) or specified flowrate mode. Frictional well loss is computed as flow-only dependent component of the drawdown inside the extraction well. In general case, the calculated flow distribution is not proportional to screen length for a multiscreen well.

  2. Atomic lithium vapor laser isotope separation

    CERN Document Server

    Olivares, I E

    2002-01-01

    An atomic vapor laser isotope separation in lithium was performed using tunable diode lasers. The method permits also the separation of the isotopes between the sup 6 LiD sub 2 and the sup 7 LiD sub 1 lines using a self-made mass separator which includes a magnetic sector and an ion beam designed for lithium. (Author)

  3. Atomic lithium vapor laser isotope separation

    International Nuclear Information System (INIS)

    Olivares, I.E.; Rojas, C.

    2002-01-01

    An atomic vapor laser isotope separation in lithium was performed using tunable diode lasers. The method permits also the separation of the isotopes between the 6 LiD 2 and the 7 LiD 1 lines using a self-made mass separator which includes a magnetic sector and an ion beam designed for lithium. (Author)

  4. Resonant second harmonic generation in potassium vapor

    International Nuclear Information System (INIS)

    Kim, D.; Mullin, C.S.; Shen, Y.R.; Lawrence Berkeley Lab., CA

    1995-06-01

    Picosecond pulses are used to study resonant second harmonic generation in potassium vapor. Although the process is both microscopically and macroscopically forbidden, it can readily be observed. The results can be quantitatively understood by a multiphoton-ionization-initiated, dc-field-induced, coherent transient model

  5. Vapor Bubbles in Flow and Acoustic Fields

    NARCIS (Netherlands)

    Prosperetti, Andrea; Hao, Yue; Sadhal, S.S

    2002-01-01

    A review of several aspects of the interaction of bubbles with acoustic and flow fields is presented. The focus of the paper is on bubbles in hot liquids, in which the bubble contains mostly vapor, with little or no permanent gas. The topics covered include the effect of translation on condensation

  6. A FGGE water vapor wind data set

    Science.gov (United States)

    Stewart, Tod R.; Hayden, Christopher M.

    1985-01-01

    It has been recognized for some time that water vapor structure visible in infrared imagery offers a potential for obtaining motion vectors when several images are considered in sequence (Fischer et al., 1981). A study evaluating water vapor winds obtained from the VISSR atmospheric sounder (Stewart et al., 1985) has confirmed the viability of the approach. More recently, 20 data sets have been produced from METEOSAT water vapor imagery for the FGGE period of 10-25 November 1979. Where possible, two data sets were prepared for each day at 0000 and 1200 GMT and compared with rawinsondes over Europe, Africa, and aircraft observations over the oceans. Procedures for obtaining winds were, in general, similar to the earlier study. Motions were detected both by a single pixel tracking and a cross correlation method by using three images individually separated by one hour. A height assignment was determined by matching the measured brightness temperature to the temperature structure represented by the FGGE-IIIB analyses. Results show that the METEOSAT water vapor winds provide uniform horizontal coverage of mid-level flow over the globe with good accuracy.

  7. External fuel vaporization study, phase 2

    Science.gov (United States)

    Szetela, E. J.; Chiappetta, L.

    1981-01-01

    An analytical study was conducted to evaluate the effect of variations in fuel properties on the design of an external fuel vaporizaton system. The fuel properties that were considered included thermal stability, critical temperature, enthalpy a critical conditions, volatility, and viscosity. The design parameters that were evaluated included vaporizer weight and the impact on engine requirement such as maintenance, transient response, performance, and altitude relight. The baseline fuel properties were those of Jet A. The variation in thermal stability was taken as the thermal stability variation for Experimental Referee Broad Specification (ERBS) fuel. The results of the analysis indicate that a change in thermal stability equivalent to that of ERBS would increase the vaporization system weight by 20 percent, decrease oprating time between cleaning by 40 percent and make altitude relight more difficult. An increase in fuel critical temperature of 39 K would require a 40 percent increase in vaporization system weight. The assumed increase in enthalpy and volatility would also increase vaporizer weight by 40 percent and make altitude relight extremely difficult. The variation in fuel viscosity would have a negligible effect on the design parameters.

  8. Atomic-vapor-laser isotope separation

    International Nuclear Information System (INIS)

    Davis, J.I.

    1982-10-01

    This paper gives a brief history of the scientific considerations leading to the development of laser isotope separation (LIS) processes. The close relationship of LIS to the broader field of laser-induced chemical processes is evaluated in terms of physical criteria to achieve an efficient production process. Atomic-vapor LIS processes under development at Livermore are reviwed. 8 figures

  9. Fractional condensation of biomass pyrolysis vapors

    NARCIS (Netherlands)

    Westerhof, Roel Johannes Maria; Brilman, Derk Willem Frederik; Garcia Perez, M.; Wang, Zhouhong; Oudenhoven, Stijn; van Swaaij, Willibrordus Petrus Maria; Kersten, Sascha R.A.

    2011-01-01

    In this paper, we have investigated the possibilities to steer the composition and, thus, the quality of pyrolysis liquids by the reactor temperature and the pyrolysis vapor condenser temperature. Pine wood was pyrolyzed in a 1 kg/h fluidized-bed pyrolysis reactor operated at 330 or 480 °C. The

  10. 75 FR 65151 - Marine Vapor Control Systems

    Science.gov (United States)

    2010-10-21

    ... Classification UFL Upper flammable limit USCG U.S. Coast Guard VCS Vapor control system VOC Volatile organic... transfer substance to new Subpart P, beginning with 33 CFR 154.2000, to facilitate the substantive changes... that guidance. Limit requirements for flame arresters or flame screens to the flammable, combustible...

  11. Covering sources of toxic vapors with foam

    International Nuclear Information System (INIS)

    Aue, W. P.; Guidetti, F.

    2009-01-01

    In a case of chemical terrorism, first responders might well be confronted with a liquid source of toxic vapor which keeps spreading out its hazardous contents. With foam as an efficient and simple means, such a source could be covered up in seconds and the spread of vapors mitigated drastically. Once covered, the source could then wait for a longer time to be removed carefully and professionally by a decontamination team. In order to find foams useful for covering up toxic vapor sources, a large set of measurements has been performed in order to answer the following questions: - Which foams could be used for this purpose? - How thick should the foam cover be? - For how long would such a foam cover be effective? - Could the practical application of foam cause a spread of the toxic chemical? The toxic vapors sources included GB, GD and HD. Among the foams were 10 fire fighter foams (e.g. AFFF, protein) and the aqueous decontamination foam CASCAD. Small scale experiments showed that CASCAD is best suited for covering a toxic source; a 10 cm layer of it covers and decontaminates GB. The large scale experiments confirmed that any fire fighter foam is a suitable cover for a longer or shorter period.(author)

  12. Similarities and differences in vapor explosion criteria

    International Nuclear Information System (INIS)

    Cronenberg, A.W.

    1978-01-01

    An overview of recent ideas pertaining to vapor explosion criteria indicates that in general sense, a consensus of opinion is emerging on the conditions applicable to explosive vaporization. Experimental and theoretical work has lead a number of investigators to the formulation of such conditions which are quite similar in many respects, although the quantitative details of the model formulation of such conditions are somewhat different. All model concepts are consistent in that an initial period of stable film boiling, separating molten fuel from coolant, is considered necessary (at least for large-scale interactions and efficient intermixing), with subsequent breakdown of film boiling due to pressure and/or thermal effects, followed by intimate fuel-coolant contact and a rapid vaporization process which is sufficient to cause shock pressurization. Although differences arise as to the conditions for and the energetics associated with film boiling destabilization and the mode and energetics of fragmentation and intermixing. However, the principal area of difference seems to be the question of what constitutes the requisite condition(s) for rapid vapor production to cause shock pressurization

  13. HYDROCARBON VAPOR DIFFUSION IN INTACT CORE SLEEVES

    Science.gov (United States)

    The diffusion of 2,2,4-trimethylpentane (TMP) and 2,2,5-trimethylhexane (TMH) vapors put of residually contaminated sandy soil from the U.S. Environmental Protection Agency (EPA) field research site at Traverse City, Michigan, was measured and modeled. The headspace of an intact ...

  14. Multicomponent droplet vaporization in a convecting environment

    International Nuclear Information System (INIS)

    Megaridis, C.M.; Sirignano, W.A.

    1990-01-01

    In this paper a parametric study of the fundamental exchange processes for energy, mass and momentum between the liquid and gas phases of multicomponent liquid vaporizing droplets is presented. The model, which examines an isolated, vaporizing, multicomponent droplet in an axisymmetric, convecting environment, considers the different volatilities of the liquid components, the alteration of the liquid-phase properties due to the spatial/temporal variations of the species concentrations and also the effects of multicomponent diffusion. In addition, the model accounts for variable thermophysical properties, surface blowing and droplet surface regression due to vaporization, transient droplet heating with internal liquid circulation, and finally droplet deceleration with respect to the free flow due to drag. The numerical calculation employs finite-difference techniques and an iterative solution procedure that provides time-varying spatially-resolved data for both phases. The effects of initial droplet composition, ambient temperature, initial Reynolds number (based on droplet diameter), and volatility differential between the two liquid components are investigated for a liquid droplet consisting of two components with very different volatilities. It is found that mixtures with higher concentration of the less volatile substance actually vaporize faster on account of intrinsically higher liquid heating rates

  15. Terahertz radiation in alkali vapor plasmas

    International Nuclear Information System (INIS)

    Sun, Xuan; Zhang, X.-C.

    2014-01-01

    By taking advantage of low ionization potentials of alkali atoms, we demonstrate terahertz wave generation from cesium and rubidium vapor plasmas with an amplitude nearly one order of magnitude larger than that from nitrogen gas at low pressure (0.02–0.5 Torr). The observed phenomena are explained by the numerical modeling based upon electron tunneling ionization

  16. Vapor pressure of selected organic iodides

    Czech Academy of Sciences Publication Activity Database

    Fulem, M.; Růžička, K.; Morávek, P.; Pangrác, Jiří; Hulicius, Eduard; Kozyrkin, B.; Shatunov, V.

    2010-01-01

    Roč. 55, č. 11 (2010), 4780-4784 ISSN 0021-9568 R&D Projects: GA ČR GA203/08/0217 Institutional research plan: CEZ:AV0Z10100521 Keywords : vapor pressure * static method * organic iodides Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.089, year : 2010

  17. Las cruces del olvido

    Directory of Open Access Journals (Sweden)

    Carla Fernandes

    2012-08-01

    Full Text Available Les tragiques événements du « mars paraguayen » ont signifié la disparition de l’espoir en la transition démocratique dans laquelle le pays s’était engagé depuis presque une dizaine d’années. Renée Ferrer, poète, dramaturge, auteur de plusieurs recueils de contes et de deux romans, consigne alors le témoignage poétique de ce drame national dans le recueil Las cruces del olvido (2001. Elle a auparavant publié d’autres textes qui peuvent rentrer dans la catégorie de la poésie sociale : c’est le cas en particulier de Viaje a destiempo (1989 dédié aux victimes de la dictature. Las cruces del olvido, dès son paratexte, insiste sur la fonction de témoignage que l’auteur souhaite assigner à ses vers et sur le rôle que ceux-ci peuvent jouer dans la transmission d’une mémoire collective. La voix d’un jeune disparu de ce « mars paraguayen », le dédoublement qu’il subit et travers lequel il évoque son entrée dans la mort et son absence du monde des vivants, rendent possible l’écriture de cette expérience de l’indicible qu’est la disparition.Los trágicos acontecimientos del «marzo paraguayo» significaron la desaparición de la esperanza en la transición democrática que el país está viviendo desde unos diez años. Renée Ferrer, poeta, dramaturga, autora de varios libros de cuentos y de dos novelas, escribe entonces el testimonio poético de ese drama nacional en su poemario Las cruces del olvido (2001. Ya había publicado antes textos que se pueden considerar como poesía social: es el caso de Viaje a destiempo (1989 dedicado a las víctimas de la dictadura. Desde el texto apertural, Las cruces del olvido potencia la función de testimonio que la autora desea conceder a sus versos y el papel que éstos pueden desempeñar en la transmisión de una memoria colectiva. La voz de un joven desaparecido del «marzo paraguayo», el desdoblamiento que sufre y a través del cual evoca su entrada en la

  18. Las histiocitosis Histiocytosis

    Directory of Open Access Journals (Sweden)

    Eva Svarch

    2001-12-01

    Full Text Available El término histiocitosis identifica un grupo de alteraciones que tienen en común la proliferación de células dendríticas (CD y los macrófagos, y se diagnostican más frecuentemente en niños. Dentro de las relacionadas con las CD las fundamentales son las histiocitosis a células de Langerhans (HCL. Las HCL tienen un comportamiento clínico muy variable, que puede ir desde una lesión que involucra un solo sitio o sistema hasta una enfermedad multisistémica. El tratamiento depende de la extensión del proceso. Una lesión única tiende a desaparecer espontáneamente. También la biopsia diagnóstica con o sin inyección de un esteroide puede iniciar la curación. Los pacientes con enfermedad multisistémica pueden beneficiarse con el tratamiento esteroideo y citostático o inclusive con el trasplante de células progenitoras hematopoyéticas. La histiocitosis sinusal con linfoadenopatías masivas o enfermedad de Rosai Dorfman se debe a la proliferación de los macrófagos, es de naturaleza benigna y usualmente autolimitada. Afecta sobre todo a niños y adultos jóvenes. La linfohistiocitosis hemofagocítica también se produce por la proliferación de los macrófagos y es una enfermedad rara con una alta mortalidad. Puede ser familiar (autosómica recesiva o secundaria a infecciones virales. Esta última forma se presenta más frecuentemente en el lactante pequeño. En la actualidad, sobre todo en la variedad familiar, el trasplante alogénico de células progenitoras hematopoyéticas puede ser la única medida curativaThe term histiocytosis identifies a group of disorders that have in common the proliferation of dentritic cells (DC and macrophages and is frequently diagnosed in children. Among the fundamental variants of histiocytosis related with DC, we find Langerhans cell histiocytosis (LCH. Langerhans cell histiocytosis has very variable clinical behavior that ranges from a lesion involving only one site or system to a multisystem

  19. Vaporization of fault water during seismic slip

    Science.gov (United States)

    Chen, Jianye; Niemeijer, André R.; Fokker, Peter A.

    2017-06-01

    Laboratory and numerical studies, as well as field observations, indicate that phase transitions of pore water might be an important process in large earthquakes. We present a model of the thermo-hydro-chemo-mechanical processes, including a two-phase mixture model to incorporate the phase transitions of pore water, occurring during fast slip (i.e., a natural earthquake) in order to investigate the effects of vaporization on the coseismic slip. Using parameters from typical natural faults, our modeling shows that vaporization can indeed occur at the shallow depths of an earthquake, irrespective of the wide variability of the parameters involved (sliding velocity, friction coefficient, gouge permeability and porosity, and shear-induced dilatancy). Due to the fast kinetics, water vaporization can cause a rapid slip weakening even when the hydrological conditions of the fault zone are not favorable for thermal pressurization, e.g., when permeability is high. At the same time, the latent heat associated with the phase transition causes the temperature rise in the slip zone to be buffered. Our parametric analyses reveal that the amount of frictional work is the principal factor controlling the onset and activity of vaporization and that it can easily be achieved in earthquakes. Our study shows that coseismic pore fluid vaporization might have played important roles at shallow depths of large earthquakes by enhancing slip weakening and buffering the temperature rise. The combined effects may provide an alternative explanation for the fact that low-temperature anomalies were measured in the slip zones at shallow depths of large earthquakes.

  20. The vapor pressure and enthalpy of vaporization of M-xylene

    Energy Technology Data Exchange (ETDEWEB)

    Rothenberg, S J; Seiler, F A; Bechtold, W E; Eidson, A F

    1988-12-01

    We measured the vapor pressure of m-xylene over the temperature range 273 to 293 deg K with a single-sided capacitance manometer. The enthalpy of vaporization was 42.2 {+-} 0.1 (SE) kj/ g{center_dot}mol. Combining our own data with previously published data, we recommend using the values 42.0, 40.6, and 39.1 ({+-} 0.1) (SE) kjg{center_dot}mol for the enthalpy of vaporization of m-xylene at 300, 340, and 380 deg. K, respectively, and a value for the change in heat capacity on vaporization ({delta}Cpdeg.) of 35 {+-} 3 (SE) J/g{center_dot}mol{center_dot}K over the temperature range studied. (author)

  1. The vapor pressure and enthalpy of vaporization of M-xylene

    International Nuclear Information System (INIS)

    Rothenberg, S.J.; Seiler, F.A.; Bechtold, W.E.; Eidson, A.F.

    1988-01-01

    We measured the vapor pressure of m-xylene over the temperature range 273 to 293 deg K with a single-sided capacitance manometer. The enthalpy of vaporization was 42.2 ± 0.1 (SE) kj/ g·mol. Combining our own data with previously published data, we recommend using the values 42.0, 40.6, and 39.1 (± 0.1) (SE) kjg·mol for the enthalpy of vaporization of m-xylene at 300, 340, and 380 deg. K, respectively, and a value for the change in heat capacity on vaporization (ΔCpdeg.) of 35 ± 3 (SE) J/g·mol·K over the temperature range studied. (author)

  2. 46 CFR 182.480 - Flammable vapor detection systems.

    Science.gov (United States)

    2010-10-01

    ... 100 GROSS TONS) MACHINERY INSTALLATION Specific Machinery Requirements § 182.480 Flammable vapor... permit calibration in a vapor free atmosphere. (g) Electrical connections, wiring, and components for a...

  3. Ammonia IR Absorbance Measurements with an Equilibrium Vapor Cell

    National Research Council Canada - National Science Library

    Field, Paul

    2004-01-01

    Infrared (IR) absorbance spectra were acquired for 18 ammonia vapor pressures. The vapor pressures were generated with 15 gravimetrically prepared aqueous solutions and three commercial aqueous solutions using a dynamic method I.E...

  4. Water vapor movement in freezing aggregate base materials.

    Science.gov (United States)

    2014-06-01

    The objectives of this research were to 1) measure the extent to which water vapor movement results in : water accumulation in freezing base materials; 2) evaluate the effect of soil stabilization on water vapor movement : in freezing base materials;...

  5. Idicadores intrínsicamente seguros para las explosiones en la industria de procesos

    Directory of Open Access Journals (Sweden)

    Ernesto Salzano

    2013-04-01

    Full Text Available Los parámetros de seguridad de las sustancias inflamables, medidos por procedimientos estandarizados que, generalmente, se han adoptado para la definición de los índices de seguridad inherente, incluso si las explosiones de gas industrial, de vapor o de polvo, son motivo de preocupación. Sin embargo, es bien conocido que la naturaleza de los accidentes con explosiones son más complejos en la vida real, que los observados en el laboratorio, bajo un ambiente controlado. Por otro lado, puede haber consecuencias mucho más severas, cuando se tienen equipos de diseño o dinámica de fluidos especiales. Este trabajo propone nuevos indicadores de seguridad inherentes a las explosiones basadas en los avances recientes en la seguridad de la combustión y en las metodologías para el análisis de consecuencias.

  6. Bionanomaterials and Bioinspired Nanostructures for Selective Vapor Sensing

    Science.gov (United States)

    2013-04-03

    agricultural crops. To meet the requirements for these and other demanding applications, new sensing approaches with improved sensor selectivity are required...of these vapors with key side- chain amino acids. DNT-binding peptide receptors were further conjugated to an oligo(ethylene glycol) hydrogel for vapor...coefficient for DNT over TNT vapor. Vapor-phase binding performance was attributed to the ability of the oligo(ethylene glycol) hydrogel to maintain the

  7. DSMC simulations of vapor transport toward development of the lithium vapor box divertor concept

    Science.gov (United States)

    Jagoe, Christopher; Schwartz, Jacob; Goldston, Robert

    2016-10-01

    The lithium vapor divertor box concept attempts to achieve volumetric dissipation of the high heat efflux from a fusion power system. The vapor extracts the heat of the incoming plasma by ionization and radiation, while remaining localized in the vapor box due to differential pumping based on rapid condensation. Preliminary calculations with lithium vapor at densities appropriate for an NSTX-U-scale machine give Knudsen numbers between 0.01 and 1, outside both the range of continuum fluid dynamics and of collisionless Monte Carlo. The direct-simulation Monte Carlo (DSMC) method, however, can simulate rarefied gas flows in this regime. Using the solver contained in the OpenFOAM package, pressure-driven flows of water vapor will be analyzed. The use of water vapor in the relevant range of Knudsen number allows for a flexible similarity experiment to verify the reliability of the code before moving to tests with lithium. The simulation geometry consists of chains of boxes on a temperature gradient, connected by slots with widths that are a representative fraction of the dimensions of the box. We expect choked flow, sonic shocks, and order-of-magnitude pressure and density drops from box to box, but this expectation will be tested in the simulation and then experiment. This work is supported by the Princeton Environmental Institute.

  8. Ambiente psicologico en las organizaciones

    Directory of Open Access Journals (Sweden)

    Damarcy Cortés Baracaldo

    2002-01-01

    Full Text Available El talento humano en las organizaciones se ha convertido en las ultimas decadas en un recurso que se administra de acuerdo al estilo de liderazgo del jefe, lo que implica una marcada relación hacia la tarea, hacia las relaciones con el personal o una combinación de estas dos, que desencadenan en un ambiente psicológico exclusive en cada organización.

  9. Las industrias en hueso

    Directory of Open Access Journals (Sweden)

    Jorge Martinez-Moreno

    2005-01-01

    Full Text Available La elaboración de instrumentos en hueso con anterioridad a la aparición de Homo sapiens moderno ha sido descrita en numerosos yacimientos del Paleolítico Medio, entre ellos en Lezetxiki y Axlor. En este artículo se pretende evaluar si estos artefactos pueden considerarse el resultado de comportamientios tecnicos dirigidos a elaborar y/o utilizar esos soportes. Estas observaciones son extensibles a otros conjuntos en los que se mensionan estos óseos con atributos similares. Es esta revisión se describen los procesos y contextos que explican la presencia de esas modificaciones y a las que se les ha atribuido un significado tecnológico

  10. Las culturas no existen

    Directory of Open Access Journals (Sweden)

    Joel Feliu i Samuel-Lajeunesse

    2004-05-01

    Full Text Available Tras un somero recordatorio del hecho, a menudo olvidado, de que la cultura no es una realidad social sino tan solo un concepto, el artículo pretende argumentar en pro de la inexistencia de tal entidad (a pesar de las apariencias. La pregunta principal a la que se intenta responder es cual es el papel ideológico que tiene la idea de cultura, es decir ¿qué efectos de construcción de realidad genera? Para ello se realiza una crítica del concepto y de sus usos argumentando que tanto el concepto como su uso cotidiano entrañan prácticas de clasificación y segregación. Finalmente se aboga por la caída en desuso del concepto y por nuevas formas de pensar la diversidad humana más acordes con la posibilidad de una ética situada.

  11. OMC y las telecomunicaciones

    OpenAIRE

    Orbe Astudillo, Marcos

    2010-01-01

    El mercado mundial de las telecomunicaciones crece rápidamente convirtiéndose en un sector de mayor crecimiento en la economía mundial y en uno de los componentes más importantes de la actividad social, cultural y política del mundo, por ello, la tendencia mundial es la liberalización de los mercados de bienes y servicios de telecomunicaciones y tecnologías de la información y comunicación (TIC´s), volviéndose muy importante para éste propósito el actuar de la Organización Mundial del Comerci...

  12. 40 CFR 52.255 - Gasoline transfer vapor control.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Gasoline transfer vapor control. 52.255... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.255 Gasoline transfer vapor control. (a) “Gasoline” means any petroleum distillate having a Reid vapor pressure of 4 pounds or greater...

  13. 40 CFR 52.787 - Gasoline transfer vapor control.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Gasoline transfer vapor control. 52.787... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.787 Gasoline transfer vapor control. (a) Gasoline means any petroleum distillate having a Reid vapor pressure of 4 pounds or greater...

  14. 21 CFR 888.4220 - Cement monomer vapor evacuator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement monomer vapor evacuator. 888.4220 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a device intended for use during surgery to contain or remove...

  15. Review of literature on the asymmetric collapse of vapor bubbles

    International Nuclear Information System (INIS)

    Fremd, R.; Froehlich, G.

    1977-06-01

    This report contains a review of literature on the asymmetric collape of vapor bubbles by cavitation with special consideration to vapor explosions. Two numerical models, which describe the collapse of cavities in the neighbourhood of a solid surface, are presented. Moreover experimental results for this case are provided. Propositions to apply the numerical models to vapor explosions are made. (orig.) [de

  16. The separation of hydrocarbons from waste vapor streams

    International Nuclear Information System (INIS)

    Behling, R.D.; Ohlrogge, K.; Peinemann, K.V.; Kyburz, E.

    1989-01-01

    Hydrocarbon vapors generated from industrial processes dispersed into air are contributing factors for the creation of photochemical smog. The separation of hydrocarbon vapor by means of membranes is in case of some applications a technically simple and economic process. A membrane vapor separation process with a following treatment of the retentate by catalytic incineration is introduced in this paper

  17. Recommended vapor pressures for thiophene, sulfolane, and dimethyl sulfoxide

    Czech Academy of Sciences Publication Activity Database

    Fulem, Michal; Růžička, K.; Růžička, M.

    2011-01-01

    Roč. 303, č. 2 (2011), s. 205-216 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z10100521 Keywords : thiophene sulfolane * dimethyl sulfoxide * vapor pressure * heat capacity * vaporization enthalpy * recommended vapor pressure equation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.139, year: 2011

  18. 33 CFR 154.826 - Vapor compressors and blowers.

    Science.gov (United States)

    2010-07-01

    ...) Excessive shaft bearing temperature. (d) If a centrifugal compressor, fan, or lobe blower handles vapor in... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vapor compressors and blowers....826 Vapor compressors and blowers. (a) Each inlet and outlet to a compressor or blower which handles...

  19. The vaporization enthalpy and vapor pressure of S (+)-methamphetamine at T = 298.15 K by correlation gas chromatography

    International Nuclear Information System (INIS)

    Thornton, Melissa; Gobble, Chase; Chickos, James

    2014-01-01

    Highlights: • The vaporization enthalpy of (d)-methamphetamine was measured. • The vapor pressure of (d)-methamphetamine as a function of temperature was evaluated. • The vapor pressure of 4-benzylpiperidine as a function of temperature was evaluated. - Abstract: The vaporization enthalpy and vapor pressure of S (+)-methamphetamine is evaluated by correlation-gas chromatography. A vaporization enthalpy of (58.7 ± 4.3) kJ · mol −1 and a vapor pressure, p = (38 ± 9) Pa has been obtained using a variety of secondary aliphatic amines as standards. In addition, equations describing the vapor pressure temperature dependence are provided for standards and S (+)-methamphetamine covering the temperature range from T = 298.15 K to the boiling temperature. Boiling temperatures are reproduced within an interval of 8 K or less

  20. Dejar las lagrimas e ir hacia las acciones

    DEFF Research Database (Denmark)

    Jeppesen, Anne Marie Ejdesgaard

    2015-01-01

    Este artículo enfoca en la frontera entre México y los Estados Unidos, las condiciones especiales de la sociedad fronteriza, las economías interconectadas y la violencia, en especial la violencia ejercida contra mujeres y los feminicidios. El artículo discute diferentes perspectivas y maneras de...

  1. Violencia contra las mujeres: las dimensiones de la desigualdad

    OpenAIRE

    Ana Isabel Blanco García

    2008-01-01

    En este número entraremos directamente en el debate acerca de la "Violencia contra las mujeres: las dimensiones de a desigualdad", que desde hace unos años recorre todo el sustrato del pensamiento feminista y del que en buena medida es deudor el propio título de nuestra revista.

  2. Violencia contra las mujeres: las dimensiones de la desigualdad

    Directory of Open Access Journals (Sweden)

    Ana Isabel Blanco García

    2008-12-01

    Full Text Available En este número entraremos directamente en el debate acerca de la "Violencia contra las mujeres: las dimensiones de a desigualdad", que desde hace unos años recorre todo el sustrato del pensamiento feminista y del que en buena medida es deudor el propio título de nuestra revista.

  3. Las TIC como fuente de ventaja competitiva en las PYMES

    Directory of Open Access Journals (Sweden)

    Álvaro Fernando Moncada Niño

    2013-06-01

    Full Text Available Desde su aparición, las Tecnologías de la Información y las Comunicaciones (TIC se han convertido en un recurso fundamental de las empresas para competir en la mayoría de las industrias, generalizando el planteamiento de que son fuente de ventaja competitiva. Pero realmente, ¿cuándo las TIC son fuente potencial de ventaja competitiva para las pymes? ¿Bajo qué condiciones se logra que contribuyan a generar valor y mejorar su posición competitiva? ¿Qué características deben cumplir para alcanzar y sustentar la Ventaja Competitiva? Este documento basado en la Teoría de los Recursos y Capacidades (TRC responde estas preguntas y presenta al análisis de recurso Valioso, Raro, Inimitable y Organización (VRIO como herramienta para la determinación del potencial y valor que las TIC pueden alcanzar en las pymes y cómo pueden contribuir a que la empresa alcance ventajas competitivas sostenibles, en complemento de sus recursos y capacidades organizacionales.

  4. Las TIC como fuente de ventaja competitiva en las PYMES

    Directory of Open Access Journals (Sweden)

    Álvaro Fernando Moncada Niño

    2013-07-01

    Full Text Available Desde su aparición, las Tecnologías de la Información y las Comunicaciones (TIC se han convertido en un recurso fundamental de las empresas para competir en la mayoría de las industrias, generalizando el planteamiento de que son fuente de ventaja competitiva. Pero realmente, ¿cuándo las TIC son fuente potencial de ventaja competitiva para las pymes? ¿Bajo qué condiciones se logra que contribuyan a generar valor y mejorar su posición competitiva? ¿Qué características deben cumplir para alcanzar y sustentar la Ventaja Competitiva? Este documento basado en la Teoría de los Recursos y Capacidades (TRC responde estas preguntas y presenta al análisis de recurso Valioso, Raro, Inimitable y Organización (VRIO como herramienta para la determinación del potencial y valor que las TIC pueden alcanzar en las pymes y cómo pueden contribuir a que la empresa alcance ventajas competitivas sostenibles, en complemento de sus recursos y capacidades organizacionales.

  5. Temperature dependences of saturated vapor pressure and the enthalpy of vaporization of n-pentyl esters of dicarboxylic acids

    Science.gov (United States)

    Portnova, S. V.; Krasnykh, E. L.; Levanova, S. V.

    2016-05-01

    The saturated vapor pressures and enthalpies of vaporization of n-pentyl esters of linear C2-C6 dicarboxylic acids are determined by the transpiration method in the temperature range of 309.2-361.2 K. The dependences of enthalpies of vaporization on the number of carbon atoms in the molecule and on the retention indices have been determined. The predictive capabilities of the existing calculation schemes for estimation of enthalpy of vaporization of the studied compounds have been analyzed.

  6. A numerical investigation of vapor intrusion--the dynamic response of contaminant vapors to rainfall events.

    Science.gov (United States)

    Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

    2012-10-15

    The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in determining

  7. Analysis of the force exercised in pipes by accumulation of water in the head stock of turbine bypass; Analisis de la fuerza ejercida en tuberias por acumulamiento de agua en el cabezal de baipas de turbina

    Energy Technology Data Exchange (ETDEWEB)

    Cecenas F, M.; Ovando C, R.; Campos G, R. M., E-mail: mcf@iie.org.mx [Instituto de Investigaciones Electricas, Reforma 113, Col. Palmira, 62490 Cuernavaca, Morelos (Mexico)

    2011-11-15

    The head stock and valves of turbine bypass allow canalize the main vapor coming from the reactor toward the condenser, without carrying out work in the turbo-generator. In this work is assumed that is accumulates condensed in the head stock during a time period in which the bypass system does not operate. For operation maneuvers, the opening of the bypass is demanded, for what the accumulated water is suddenly dragged by the vapor to high pressure coming from the reactor toward the condenser, which operates to inferior pressures to the atmospheric. The generated flow produces a mechanical effort in the lines and its supports. By means of the RELAP5 code the bypass system is modeled, the discharge transitory to the condenser is simulated and the speeds of the mixture water/vapor are calculated. Processing the exit of RELAP5 the mechanical effort that is subjected the pipe is calculated, and the study is complemented with a sensibility analysis to the quantity of stored water in the volume of the bypass head stock. (Author)

  8. Mass spectrometric study of Nd2S3 vaporization

    International Nuclear Information System (INIS)

    Fenochka, B.V.

    1987-01-01

    The authors conduct a mass-spectrometric study of neodymium(III) sulfide vaporization. The chemical composition of the samples was stoichiometric and the samples were vaporized from tantalum effusion cells. When the vapor over Nd 2 S 3 is ionized by electrons the mass spectra shows monovalent cations of Nd, S, NdS, and NdO. The enthalpy of vaporization if Nd atoms from Nd 2 S 3 at average experimental temperatures and the standard enthalpy of reaction is shown. Also presented is the enthalpy of vaporization of NdS molecules from Nd 2 S 3 at average experimental temperatures and the standard enthalpy of reaction

  9. Cumulus convection and the terrestrial water-vapor distribution

    Science.gov (United States)

    Donner, Leo J.

    1988-01-01

    Cumulus convection plays a significant role in determining the structure of the terrestrial water vapor field. Cumulus convection acts directly on the moisture field by condensing and precipitating water vapor and by redistributing water vapor through cumulus induced eddy circulations. The mechanisms by which cumulus convection influences the terrestrial water vapor distribution is outlined. Calculations using a theory due to Kuo is used to illustrate the mechanisms by which cumulus convection works. Understanding of these processes greatly aids the ability of researchers to interpret the seasonal and spatial distribution of atmospheric water vapor by providing information on the nature of sources and sinks and the global circulation.

  10. Liquid-liquid contact in vapor explosion

    International Nuclear Information System (INIS)

    Segev, A.

    1978-08-01

    The contact of two liquid materials, one of which is at a temperature substantially above the boiling point of the other, can lead to fast energy conversion and a subsequent shock wave. This phenomenon is called a vapor explosion. One method of producing intimate, liquid-liquid contact (which is known to be a necessary condition for vapor explosion) is a shock tube configuration. Such experiments in which water was impacted upon molten aluminum showed that very high pressures, even larger than the thermodynamic critical pressure, could occur. The mechanism by which such sharp pressure pulses are generated is not yet clear. The report describes experiments in which cold liquids (Freon-11, Freon-22, water, or butanol) were impacted upon various hot materials

  11. Thermodynamics of the vaporization of uranium tetrabromide

    International Nuclear Information System (INIS)

    Singh, Z.; Prasad, R.; Venugopal, P.V.; Roy, K.N.; Sood, D.D.

    1981-01-01

    Vapour pressures of solid and liquid uranium tetrabromide have been measured in the temperature range of 696 to 805 K and 805 to 1003 K respectively by transpiration and evaporation-temperature techniques. The vapour pressures obtained by the two techniques are in good agreement and have been combined to give the reported vapour-pressure equations for solid and liquid uranium tetrabromide. The melting temperature, the normal boiling temperature, the standard enthalpy of vaporization ΔH 0 (vap, 298.15 K), and the standard entropy of vaporization ΔS 0 (vap, 298.15 K) are reported. The enthalpy of fusion ΔH 0 (fus, 802 K) is also reported. The thermodynamic quantities from the present study are compared with those in the literature and critically analysed. (author)

  12. Vaporization of structural materials in severe accidents

    International Nuclear Information System (INIS)

    Lorenz, R.A.

    1982-01-01

    Vaporized structural materials form the bulk of aerosol particles that can transport fission products in severe LWR accidents. As part of the Severe Accident Sequence Analysis (SASA) program at Oak Ridge National Laboratory, a model has been developed based on a mass transport coefficient to describe the transport of materials from the surface of a molten pool. In many accident scenarios, the coefficient can be calculated from existing correlations for mass transfer by natural convection. Data from SASCHA fuel melting tests (Karlsruhe, Germany) show that the partial pressures of many of the melt components (Fe, Cr, Co, Mn, Sn) required for the model can be calculated from the vapor pressures of the pure species and Raoult's law. These calculations indicate much lower aerosol concentrations than reported in previous studies

  13. Seguridad de las aplicaciones web

    OpenAIRE

    Luján Mora, Sergio

    2016-01-01

    Conferencia "Seguridad de las aplicaciones web" impartida en las III Jornadas Informáticas - UTE 2016 en la Facultad de Ciencias de la Ingeniería e Industrias de la Universidad Tecnológica Equinoccial (Quito, Ecuador) el 5 de julio de 2016.

  14. Las aventuras con el autoscopio

    Directory of Open Access Journals (Sweden)

    Víctor Florencio Ramírez Hernández

    2006-01-01

    Full Text Available El trabajo se inspira en el famoso personaje Harry Potter para hacer un análisis entre la filosofía y las neurociencias, específicamente sobre las condiciones funcionales que hacen posible filosofar.

  15. La convergencia de las telecomunicaciones

    OpenAIRE

    Galarza, D.

    2000-01-01

    Presenta la evolución de la electrónica y como esta ha influenciado en el desarrollo de las telecomunicaciones, en la creación de redes fijas y móviles. Además visualiza el futuro convergente de las telecomunicaciones.

  16. Improved cell for water-vapor electrolysis

    Science.gov (United States)

    Aylward, J. R.

    1981-01-01

    Continuous-flow electrolytic cells decompose water vapor in steam and room air into hydrogen and oxygen. Sintered iridium oxide catalytic anode coating yields dissociation rates hundredfold greater than those obtained using platinum black. Cell consists of two mirror-image cells, with dual cathode sandwiched between two anodes. Gas traverses serpentine channels within cell and is dissociated at anode. Oxygen mingles with gas stream, while hydrogen migrates through porous matrix and is liberated as gas at cathode.

  17. Ceramic composites by chemical vapor infiltration

    International Nuclear Information System (INIS)

    Stinton, D.P.

    1987-01-01

    Composites consisting of silicon carbide matrices reinforced with continuous ceramic fibers are being developed for high-temperature structural applications. Chemical vapor deposition (CVD) techniques are very effective in fabricating composites with high strengths and exceptional fracture toughness. Mechanical properties of infiltrated composites are controlled by the strength of the interfacial bond between the fibers and matrix. This paper describes two CVD techniques and reviews the models being developed to better understand and control the infiltration process

  18. DuPont Chemical Vapor Technical Report

    International Nuclear Information System (INIS)

    MOORE, T.L.

    2003-01-01

    DuPont Safety Resources was tasked with reviewing the current chemical vapor control practices and providing preventive recommendations on best commercial techniques to control worker exposures. The increased focus of the tank closure project to meet the 2024 Tri-Party Agreement (TPA) milestones has surfaced concerns among some CH2MHill employees and other interested parties. CH2MHill is committed to providing a safe working environment for employees and desires to safely manage the tank farm operations using appropriate control measures. To address worker concerns, CH2MHill has chartered a ''Chemical Vapors Project'' to integrate the activities of multiple CH2MHill project teams, and solicit the expertise of external resources, including an independent Industrial Hygiene expert panel, a communications consultant, and DuPont Safety Resources. Over a three-month time period, DuPont worked with CH2MHill ESH and Q, Industrial Hygiene, Engineering, and the independent expert panel to perform the assessment. The process included overview presentations, formal interviews, informal discussions, documentation review, and literature review. DuPont Safety Resources concluded that it is highly unlikely that workers in the tank farms are exposed to chemicals above established standards. Additionally, the conventional and radiological chemistry is understood, the inherent chemical hazards are known, and the risk associated with chemical vapor exposure is properly managed. The assessment highlighted management's commitment to addressing chemical vapor hazards and controlling the associated risks. Additionally, we found the Industrial Hygiene staff to be technically competent and well motivated. The tank characterization data resides in a comprehensive database containing the tank chemical compositions and relevant airborne concentrations

  19. Discharge characteristics of copper vapor laser

    International Nuclear Information System (INIS)

    Nemoto, Koshichi; Fujii, Takashi

    1988-01-01

    This report describes about the copper vapor laser and experimental results of it's discharge characteristics. We measured time varing of plasma regist, and analyzed electron density. (1) The plasma regist is larger than 100Ω at the beginning of discharge, and is rapidly reduced to about 10Ω. (2) The electron density is estimated about 1∼2 x 10 12 /cc at the begining of discharge. (author)

  20. Transport properties of fission product vapors

    International Nuclear Information System (INIS)

    Im, K.H.; Ahluwalia, R.K.

    1983-07-01

    Kinetic theory of gases is used to calculate the transport properties of fission product vapors in a steam and hydrogen environment. Provided in tabular form is diffusivity of steam and hydrogen, viscosity and thermal conductivity of the gaseous mixture, and diffusivity of cesium iodide, cesium hydroxide, diatomic tellurium and tellurium dioxide. These transport properties are required in determining the thermal-hydraulics of and fission product transport in light water reactors

  1. Quality and Control of Water Vapor Winds

    Science.gov (United States)

    Jedlovec, Gary J.; Atkinson, Robert J.

    1996-01-01

    Water vapor imagery from the geostationary satellites such as GOES, Meteosat, and GMS provides synoptic views of dynamical events on a continual basis. Because the imagery represents a non-linear combination of mid- and upper-tropospheric thermodynamic parameters (three-dimensional variations in temperature and humidity), video loops of these image products provide enlightening views of regional flow fields, the movement of tropical and extratropical storm systems, the transfer of moisture between hemispheres and from the tropics to the mid- latitudes, and the dominance of high pressure systems over particular regions of the Earth. Despite the obvious larger scale features, the water vapor imagery contains significant image variability down to the single 8 km GOES pixel. These features can be quantitatively identified and tracked from one time to the next using various image processing techniques. Merrill et al. (1991), Hayden and Schmidt (1992), and Laurent (1993) have documented the operational procedures and capabilities of NOAA and ESOC to produce cloud and water vapor winds. These techniques employ standard correlation and template matching approaches to wind tracking and use qualitative and quantitative procedures to eliminate bad wind vectors from the wind data set. Techniques have also been developed to improve the quality of the operational winds though robust editing procedures (Hayden and Veldon 1991). These quality and control approaches have limitations, are often subjective, and constrain wind variability to be consistent with model derived wind fields. This paper describes research focused on the refinement of objective quality and control parameters for water vapor wind vector data sets. New quality and control measures are developed and employed to provide a more robust wind data set for climate analysis, data assimilation studies, as well as operational weather forecasting. The parameters are applicable to cloud-tracked winds as well with minor

  2. Estimating evaporative vapor generation from automobiles based on parking activities

    International Nuclear Information System (INIS)

    Dong, Xinyi; Tschantz, Michael; Fu, Joshua S.

    2015-01-01

    A new approach is proposed to quantify the evaporative vapor generation based on real parking activity data. As compared to the existing methods, two improvements are applied in this new approach to reduce the uncertainties: First, evaporative vapor generation from diurnal parking events is usually calculated based on estimated average parking duration for the whole fleet, while in this study, vapor generation rate is calculated based on parking activities distribution. Second, rather than using the daily temperature gradient, this study uses hourly temperature observations to derive the hourly incremental vapor generation rates. The parking distribution and hourly incremental vapor generation rates are then adopted with Wade–Reddy's equation to estimate the weighted average evaporative generation. We find that hourly incremental rates can better describe the temporal variations of vapor generation, and the weighted vapor generation rate is 5–8% less than calculation without considering parking activity. - Highlights: • We applied real parking distribution data to estimate evaporative vapor generation. • We applied real hourly temperature data to estimate hourly incremental vapor generation rate. • Evaporative emission for Florence is estimated based on parking distribution and hourly rate. - A new approach is proposed to quantify the weighted evaporative vapor generation based on parking distribution with an hourly incremental vapor generation rate

  3. Marketing practices of vapor store owners.

    Science.gov (United States)

    Cheney, Marshall; Gowin, Mary; Wann, Taylor Franklin

    2015-06-01

    We examined the marketing strategies for local vapor stores in a large metropolitan area in Oklahoma. Vapor store owners or managers (n = 33) participated in individual interviews regarding marketing practices in 2014. We asked owners about their marketing strategies and the groups they targeted. We transcribed the interviews and analyzed them for themes. Store owners used a variety of marketing strategies to bring new customers to their stores and keep current customers coming back. These marketing strategies showed many parallels to tobacco industry strategies. Most owners engaged in some form of traditional marketing practices (e.g., print media), but only a few used radio or television advertising because of budget constraints. Owners used social media and other forms of electronic communication, pricing discounts and specials, and loyalty programs. Owners also had booths at local events, sponsored community events, and hosted them in their stores. Owners attempted to target different groups of users, such as college students and long-term smokers. Local vapor store marketing practices closely resemble current and former tobacco industry marketing strategies. Surveillance of marketing practices should include local and Web-based strategies.

  4. Released air during vapor and air cavitation

    Energy Technology Data Exchange (ETDEWEB)

    Jablonská, Jana, E-mail: jana.jablonska@vsb.cz; Kozubková, Milada, E-mail: milada.kozubkova@vsb.cz [VŠB-Technical University of Ostrava, Faculty of Mechanical Engineering, Department of Hydromechanics and Hydraulic Equipment, 17. listopadu 15, 708 33 Ostrava-Poruba (Czech Republic)

    2016-06-30

    Cavitation today is a very important problem that is solved by means of experimental and mathematical methods. The article deals with the generation of cavitation in convergent divergent nozzle of rectangular cross section. Measurement of pressure, flow rate, temperature, amount of dissolved air in the liquid and visualization of cavitation area using high-speed camera was performed for different flow rates. The measurement results were generalized by dimensionless analysis, which allows easy detection of cavitation in the nozzle. For numerical simulation the multiphase mathematical model of cavitation consisting of water and vapor was created. During verification the disagreement with the measurements for higher flow rates was proved, therefore the model was extended to multiphase mathematical model (water, vapor and air), due to release of dissolved air. For the mathematical modeling the multiphase turbulence RNG k-ε model for low Reynolds number flow with vapor and air cavitation was used. Subsequently the sizes of the cavitation area were verified. In article the inlet pressure and loss coefficient depending on the amount of air added to the mathematical model are evaluated. On the basis of the approach it may be create a methodology to estimate the amount of released air added at the inlet to the modeled area.

  5. Combined rankine and vapor compression cycles

    Science.gov (United States)

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2005-04-19

    An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

  6. Liquid--liquid contact in vapor explosion

    International Nuclear Information System (INIS)

    Segev, A.

    1978-08-01

    The contact of two liquid materials, one of which is at a temperature substantially above the boiling point of the other, can lead to fast energy conversion and a subsequent shock wave. This well-known phenomenon is called a ''vapor explosion.'' One method of producing intimate, liquid--liquid contact (which is known to be a necessary condition for vapor explosion) is a shock tube configuration. Such experiments in which water was impacted upon molten aluminum showed that very high pressures, even larger than the thermodynamic critical pressure, could occur. The mechanism by which such sharp pressure pulses are generated is not yet clear. In this experiment cold liquids (Freon-11, Freon-22, water, or butanol) were impacted upon various hot materials (mineral oil, silicone oil, water, mercury, molten Wood's metal or molten salt mixture). The main conclusion from the experimental study is that hydrodynamic effects may be very significant in any shock tube analyses, especially when multiple interactions are observed. A theoretical study was performed to check the possibility of vapor film squeezing (between a drop in film boiling and a surface) as a controlling mechanism for making liquid--liquid contact. Using experimental data, the film thickness was calculated and it was found to be too thick for any conceivable film rupture mechanism. It was suggested that the coalescence is a two-stage process, in which the controlling stage depends mainly on temperature and surface properties and can be described as the ability of cold liquid to spread on a hot surface

  7. Vapor-Driven Propulsion of Catalytic Micromotors

    Science.gov (United States)

    Dong, Renfeng; Li, Jinxing; Rozen, Isaac; Ezhilan, Barath; Xu, Tailin; Christianson, Caleb; Gao, Wei; Saintillan, David; Ren, Biye; Wang, Joseph

    2015-08-01

    Chemically-powered micromotors offer exciting opportunities in diverse fields, including therapeutic delivery, environmental remediation, and nanoscale manufacturing. However, these nanovehicles require direct addition of high concentration of chemical fuel to the motor solution for their propulsion. We report the efficient vapor-powered propulsion of catalytic micromotors without direct addition of fuel to the micromotor solution. Diffusion of hydrazine vapor from the surrounding atmosphere into the sample solution is instead used to trigger rapid movement of iridium-gold Janus microsphere motors. Such operation creates a new type of remotely-triggered and powered catalytic micro/nanomotors that are responsive to their surrounding environment. This new propulsion mechanism is accompanied by unique phenomena, such as the distinct off-on response to the presence of fuel in the surrounding atmosphere, and spatio-temporal dependence of the motor speed borne out of the concentration gradient evolution within the motor solution. The relationship between the motor speed and the variables affecting the fuel concentration distribution is examined using a theoretical model for hydrazine transport, which is in turn used to explain the observed phenomena. The vapor-powered catalytic micro/nanomotors offer new opportunities in gas sensing, threat detection, and environmental monitoring, and open the door for a new class of environmentally-triggered micromotors.

  8. Physical Vapor Deposition of Thin Films

    Science.gov (United States)

    Mahan, John E.

    2000-01-01

    A unified treatment of the theories, data, and technologies underlying physical vapor deposition methods With electronic, optical, and magnetic coating technologies increasingly dominating manufacturing in the high-tech industries, there is a growing need for expertise in physical vapor deposition of thin films. This important new work provides researchers and engineers in this field with the information they need to tackle thin film processes in the real world. Presenting a cohesive, thoroughly developed treatment of both fundamental and applied topics, Physical Vapor Deposition of Thin Films incorporates many critical results from across the literature as it imparts a working knowledge of a variety of present-day techniques. Numerous worked examples, extensive references, and more than 100 illustrations and photographs accompany coverage of: * Thermal evaporation, sputtering, and pulsed laser deposition techniques * Key theories and phenomena, including the kinetic theory of gases, adsorption and condensation, high-vacuum pumping dynamics, and sputtering discharges * Trends in sputter yield data and a new simplified collisional model of sputter yield for pure element targets * Quantitative models for film deposition rate, thickness profiles, and thermalization of the sputtered beam

  9. Characterization of a Compact Water Vapor Radiometer

    Science.gov (United States)

    Gill, Ajay; Selina, Rob

    2018-01-01

    We report on laboratory test results of the Compact Water Vapor Radiometer (CWVR) prototype for the Karl G. Jansky Very Large Array (VLA), a five-channel design centered around the 22 GHz water vapor line. Fluctuations in perceptible water vapor cause fluctuations in atmospheric brightness emission, which are assumed to be proportional to phase fluctuations of the astronomical signal seen by an antenna. The design is intended to support empirical radiometric phase corrections for each baseline in the array.The dynamic range, channel isolation, and gain stability of the device were characterized. The device has a useful dynamic range of order 18 dB after calibration, and the CWVR channel isolation requirement of test, the diode detectors were operated in the square-law region, and a K-band noise diode was used as the broadband input power source to the CWVR over a period of 64 hours. Results indicate that the fluctuations in output counts are negatively correlated to the CWVR enclosure ambient temperature, with a change of ~ 405 counts per 1° C change in temperature.A correction for the CWVR ambient temperature makes a considerable improvement in stability for τ > 102.6 sec. With temperature corrections, the single channel and channel difference gain stability per channel is test results indicate that the CWVR meets required specifications for dynamic range, channel isolation, and gain stability in order to proceed with testing on a pair of VLA antennas.

  10. Marketing Practices of Vapor Store Owners

    Science.gov (United States)

    Gowin, Mary; Wann, Taylor Franklin

    2015-01-01

    Objectives. We examined the marketing strategies for local vapor stores in a large metropolitan area in Oklahoma. Methods. Vapor store owners or managers (n = 33) participated in individual interviews regarding marketing practices in 2014. We asked owners about their marketing strategies and the groups they targeted. We transcribed the interviews and analyzed them for themes. Results. Store owners used a variety of marketing strategies to bring new customers to their stores and keep current customers coming back. These marketing strategies showed many parallels to tobacco industry strategies. Most owners engaged in some form of traditional marketing practices (e.g., print media), but only a few used radio or television advertising because of budget constraints. Owners used social media and other forms of electronic communication, pricing discounts and specials, and loyalty programs. Owners also had booths at local events, sponsored community events, and hosted them in their stores. Owners attempted to target different groups of users, such as college students and long-term smokers. Conclusions. Local vapor store marketing practices closely resemble current and former tobacco industry marketing strategies. Surveillance of marketing practices should include local and Web-based strategies. PMID:25880960

  11. A multistratum approach to soil vapor extraction

    International Nuclear Information System (INIS)

    Fuhr, J.M.; Giesler, R.S.

    1993-01-01

    An innovative soil remediation design was implemented to address petroleum hydrocarbon contamination in a gradationally stratified subsurface environment containing alternating layers of clay, sand and clayey sand, and perched water tables in north Florida. The soil vapor extraction (SVE) design enables remediation to focus on distinct subsurface intervals depending on changing site conditions such as constituent concentration levels and periodic water-table fluctuations. Contaminated soils were assessed from the land surface to the top of a two foot thick perched water table located at 13 feet below land surface (bls), and also were encountered below the perched water table downward to another perched water table at 45 feet bls. Use of an organic vapor analyzer equipped with a flame ionization detector revealed hydrocarbon vapor concentrations in soil samples ranging to greater than 1,000 parts per million (ppm). Nonaqueous phase liquids were encountered on both perched water tables. Based on the site assessment, a multistratum soil and ground-water remediation system was designed and constructed. A pilot test was conducted to aid in the design of an effective SVE system

  12. Experimental study of vapor bubble dynamics

    International Nuclear Information System (INIS)

    Pasquini, Maria-Elena

    2015-01-01

    The object of this thesis is an experimental study of vapor bubble dynamics in sub-cooled nucleate boiling. The test section is locally heated by focusing a laser beam: heat fluxes from 1 e4 to 1.5 e6 W/m 2 and water temperature between 100 and 88 C have been considered. Three boiling regimes have been observed. Under saturated conditions and with low heat fluxes a developed nucleate boiling regime has been observed. Under higher sub-cooling and still with low heat fluxes an equilibrium regime has been observed in which the liquid flowrate evaporating at the bubble base is compensated by the vapor condensing flowrate at bubble top. A third regime have been observed at high heat fluxes for all water conditions: it is characterized by the formation of a large dry spot on the heated surface that keeps the nucleation site dry after bubble detachment. The condensation phase starts after bubble detachment. Bubble equivalent radius at detachment varies between 1 and 2.5 mm. Bubble properties have been measured and non-dimensional groups have been used to characterize bubble dynamics. Capillary waves have been observed on the bubble surface thanks to high-speed images acquisition. Two main phenomena have been proposed to explain capillary waves effects on bubble condensation: increasing of the phases interface area and decreasing of vapor bubble translation velocity, because of the increased drag force on the deformed bubble. (author) [fr

  13. Nuclear vapor thermal reactor propulsion technology

    International Nuclear Information System (INIS)

    Maya, I.; Diaz, N.J.; Dugan, E.T.; Watanabe, Y.; McClanahan, J.A.; Wen-Hsiung Tu; Carman, R.L.

    1993-01-01

    The conceptual design of a nuclear rocket based on the vapor core reactor is presented. The Nuclear Vapor Thermal Rocket (NVTR) offers the potential for a specific impulse of 1000 to 1200 s at thrust-to-weight ratios of 1 to 2. The design is based on NERVA geometry and systems with the solid fuel replaced by uranium tetrafluoride (UF 4 ) vapor. The closed-loop core does not rely on hydrodynamic confinement of the fuel. The hydrogen propellant is separated from the UF 4 fuel gas by graphite structure. The hydrogen is maintained at high pressure (∼100 atm), and exits the core at 3,100 K to 3,500 K. Zirconium carbide and hafnium carbide coatings are used to protect the hot graphite from the hydrogen. The core is surrounded by beryllium oxide reflector. The nuclear reactor core has been integrated into a 75 klb engine design using an expander cycle and dual turbopumps. The NVTR offers the potential for an incremental technology development pathway to high performance gas core reactors. Since the fuel is readily available, it also offers advantages in the initial cost of development, as it will not require major expenditures for fuel development

  14. Revestimientos corrosibles de las obras

    Directory of Open Access Journals (Sweden)

    Jiménez Montoya, P.

    1958-02-01

    Full Text Available Not availableEstudio y descripción de los distintos tipos de revestimiento que requieren las obras industriales para protegerlas contra las acciones químicas desarrolladas por las substancias puestas en contacto con ellas. El amplio estado evolutivo actual de los procedimientos industriales exige, como es natural, que las construcciones modernas se proyecten con un conocimiento claro, no ya de su estabilidad estructural, sino de la de sus propios materiales, que, por fenómenos corrosivos, pueden causar la ruina de la construcción. En este trabajo se dan los procedimientos de revestir, las características más importantes de estas protecciones y materiales empleados y, finalmente, su comportamiento en contacto con los agentes agresivos normalmente manipulados en la industria.

  15. Calculating the enthalpy of vaporization for ionic liquid clusters.

    Science.gov (United States)

    Kelkar, Manish S; Maginn, Edward J

    2007-08-16

    Classical atomistic simulations are used to compute the enthalpy of vaporization of a series of ionic liquids composed of 1-alkyl-3-methylimidazolium cations paired with the bis(trifluoromethylsulfonyl)imide anion. The calculations show that the enthalpy of vaporization is lowest for neutral ion pairs. The enthalpy of vaporization increases by about 40 kJ/mol with the addition of each ion pair to the vaporizing cluster. Non-neutral clusters have much higher vaporization enthalpies than their neutral counterparts and thus are not expected to make up a significant fraction of volatile species. The enthalpy of vaporization increases slightly as the cation alkyl chain length increases and as temperature decreases. The calculated vaporization enthalpies are consistent with two sets of recent experimental measurements as well as with previous atomistic simulations.

  16. Vapor pressures and vapor compositions in equilibrium with hypostoichiometric plutonium dioxide at high temperatures

    International Nuclear Information System (INIS)

    Green, D.W.; Fink, J.K.; Leibowitz, L.

    1982-01-01

    Vapor pressures and vapor compositions have been calculated for 1500 less than or equal to T less than or equal to 4000 0 K. Thermodynamic functions for the condensed phase and for each of the gaseous species were combined with an oxygen-potential model extended into the liquid region to obtain the partial pressures of O 2 , O, Pu, PuO and PuO 2 . The calculated oxygen pressures increase very rapidly as stoichiometry is approached. At least part of this increase is a consequence of the exclusion of Pu 6 + from the oxygen-potential model. No reliable method was found to estimate the importance of this ion. As a result of large oxygen potentials at high temperatures, extremely high total pressures that produced unreasonably high vapor densities were calculated. The highest temperature was therefore limited to 400 K, and the range of oxygen-to-metal ratios was limited to 1.994 to 1.70. These calculations show that vapor in equilibrium with hypostoichiometric plutonium dioxide is poorly approximated as PuO 2 for most of the temperture and composition range of interest. The vapor is much more oxygen-rich than the condensed phase. Implications for the (U,Pu)O/sub 2-x/ system are discussed

  17. Una escuela de todas (las personas) para todas (las personas)

    OpenAIRE

    Montolio Pastor, Rosa; Cervellera Martínez, Luiso

    2008-01-01

    Escuela 2 representa una particular manera de entender la educación. Un proyecto educativo nacido de la cooperación entre las personas, concebido para albergar todo un universo de realidades y gestionado de manera colaborativa bajo los principios de la economía social y el movimiento cooperativo. Una escuela de todas, las personas, para todas, las personas. Una escuela decidida a hacer realidad los principios de la inclusión educativa desde el día a día, esforzada por resituar a cada paso su ...

  18. Copper-vapor-catalyzed chemical vapor deposition of graphene on dielectric substrates

    Science.gov (United States)

    Yang, Chao; Wu, Tianru; Wang, Haomin; Zhang, Xuefu; Shi, Zhiyuan; Xie, Xiaoming

    2017-07-01

    Direct synthesis of high-quality graphene on dielectric substrates is important for its application in electronics. In this work, we report the process of copper-vapor-catalyzed chemical vapor deposition of high-quality and large graphene domains on various dielectric substrates. The copper vapor plays a vital role on the growth of transfer-free graphene. Both single-crystal domains that are much larger than previous reports and high-coverage graphene films can be obtained by adjusting the growth duration. The quality of the obtained graphene was verified to be comparable with that of graphene grown on Cu foil. The progress reported in this work will aid the development of the application of transfer-free graphene in the future.

  19. Collapsing criteria for vapor film around solid spheres as a fundamental stage leading to vapor explosion

    Energy Technology Data Exchange (ETDEWEB)

    Freud, Roy [Nuclear Research Center - Negev, Beer-Sheva (Israel)], E-mail: freud@bgu.ac.il; Harari, Ronen [Nuclear Research Center - Negev, Beer-Sheva (Israel); Sher, Eran [Pearlstone Center for Aeronautical Studies, Department of Mechanical Engineering, Ben-Gurion University, Beer-Sheva (Israel)

    2009-04-15

    Following a partial fuel-melting accident, a Fuel-Coolant Interaction (FCI) can result with the fragmentation of the melt into tiny droplets. A vapor film is then formed between the melt fragments and the coolant, while preventing a contact between them. Triggering, propagation and expansion typically follow the premixing stage. In the triggering stage, vapor film collapse around one or several of the fragments occurs. This collapse can be the result of fragments cooling, a sort of mechanical force, or by any other means. When the vapor film collapses and the coolant re-establishes contact with the dry surface of the hot melt, it may lead to a very rapid and rather violent boiling. In the propagation stage the shock wave front leads to stripping of the films surrounding adjacent droplets which enhance the fragmentation and the process escalates. During this process a large quantity of liquid vaporizes and its expansion can result in destructive mechanical damage to the surrounding structures. This multiphase thermal detonation in which high pressure shock wave is formed is regarded as 'vapor explosion'. The film boiling and its possible collapse is a fundamental stage leading to vapor explosion. If the interaction of the melt and the coolant does not result in a film boiling, no explosion occurs. Many studies have been devoted to determine the minimum temperature and heat flux that is required to maintain a film boiling. The present experimental study examines the minimum temperature that is required to maintain a film boiling around metal spheres immersed into a liquid (subcooled distilled water) reservoir. In order to simulate fuel fragments that are small in dimension and has mirror-like surface, small spheres coated with anti-oxidation layer were used. The heat flux from the spheres was calculated from the sphere's temperature profiles and the sphere's properties. The vapor film collapse was associated with a sharp rise of the heat flux

  20. Las aristas del racismo

    Directory of Open Access Journals (Sweden)

    Fredy Rivera Vélez

    2000-01-01

    Full Text Available En el presente trabajo se estudia un ámbito que normalmente se esquiva y se enmascara: Las prácticas racistas. Esta evasión del tema se da en diferentes planos discursivos, y es una práctica, cada vez más frecuente en América Latina, pues aquí se hace de la integración étnica uno de los ejes centrales de la construcción de sus relaciones identitarias y políticas. Se propone, entonces, este trabajo develar la naturaleza y el movimiento de prácticas racistas presentes no sólo discursivamente, en la práctica política, en la práctica laboral, sino que también están presente en nuestra vida cotidiana, bajo nuevas formas y contenidos que se distancian del racismo tradicional e incorpora una nueva gramática racista, una suerte de racismo moderno, no basado en el fenotipo o características físicas como elemento central, sino en un racismo basado en la diferencia cultural, lo cual plantea un plano más excluyente, pues en este planteamiento el “objeto de racismo” no es un objeto de racismo limitado, como en el racismo tradicional, en el cual siempre es utilizado por quien practica el racismo; en el racismo contemporáneo se pretende una ruptura completa y una exclusión total del otro.

  1. Las momias de las pirámides

    Directory of Open Access Journals (Sweden)

    José Miguel Parra

    2011-01-01

    Full Text Available El público general cree, como si fuera un dogma religioso, que las pirámides egipcias no fueron las tumbas de los faraones de los Reino Antiguo y Medio porque en ninguna de las cámaras funerarias se ha encontrado nunca una momia. Este estudio compila todos los datos relevantes al respecto y describe brevemente todos los restos humanos encontrados dentro de las pirámides, demostrando la falta de base de esa extendida creencia.As a religious dogma the general public believe that the Egyptian pyramids were not the tombs for the Old and Middle Kingdom pharaohs, because never was a mummy found inside the burial chamber of any of them. This study just compile all the relevant data on the subject and describe briefly all the human remains found in the pyramids, showing the nonsense of the general belief.

  2. Las multitudes y las revoluciones de nuestro tiempo

    Directory of Open Access Journals (Sweden)

    John Harold Biervliet

    2015-08-01

    Full Text Available Este artículo examina el motivo de las multitudes y las revoluciones de nuestro tiempo. Primeramente, se discuten las diferencias entre los conceptos de multitud y masa. Así, podemos considerar las revoluciones como acontecimientos de cambios sociales, económicos y políticos, provenientes de las clases baja y media de la sociedad. El meollo de este artículo refiere a la dignidad humana articulada a la contracción de los Estados de bienestar. Los ciudadanos están reflejando un desencanto hacia la clase política y una frustración con respecto al empeoramiento de las condiciones económicas y sociales. Podemos observar los casos de indignados en Grecia, España y Portugal pero también en los países árabes. De esta misma manera, las revoluciones de las multitudes siguen avanzando por medio de las demostraciones públicas y protestas sobre los espacios geográficos. Finalmente, las dinámicas de cambio a través de las revoluciones árabes son una cuestión compleja debido al círculo vicioso entre la tendencia autoritaria y la islámica. This article examines the reason of multitudes and revolutions in our time. First of all, it discusses the difference between the concept of multitude and mass. Consequently, revolutions can be considered as social, economic, and political events of changes, which come from the low and middle classes of the society. This article refers to the human dignity articulated with the contraction of Welfare states. Citizens are reflecting disenchantment towards the political class and frustration regarding the deterioration of social and economic conditions. We can observe angry people in Greece, Spain, and Portugal but also in Arabian countries. In this same way, revolutions of multitudes continue by means of public demonstrations and protests on geographical spaces. Finally, the dynamics of change through Arabian Revolutions are a complex matter due to the vicious circle between the authoritarian or Islamic

  3. Las "auctoritates" escolásticas en las Siete Partidas

    OpenAIRE

    Vázquez Janeiro, Isaac

    1992-01-01

    Examen de las fuentes utilizadas en los pasajes de las Siete Partidas relativos a la doctrina general de los sacramentos y en particular de los sacramentos del bautismo y del matrimonio. A base de los resultados obtenidos se sacan conclusiones sobre el carácter de la obra alfonsina. Examination of the sources used in the passages of the Siete Partidas relating to the general doctrine of the Sacraments and specially of the sacraments of Baptism and Marriage.

  4. Las desterradas hijas de Eva

    OpenAIRE

    Quiñonero Hernández, Llum

    2015-01-01

    Ocurrió en España, durante década, en tiempos de Franco y después de Franco. El estado franquista creo una tupida red de instituciones para el control social de las mujeres: para las rebeldes y descarriadas, el encierro; para las madres solteras también el estigma. Carentes de derechos, de garantías, miles, decenas de miles de mujeres, aún sin cuantificar, vieron desaparecer a sus recién nacidos en instituciones privadas y públicas de muy diversa índole: cárceles, reformatorios, maternidades ...

  5. Patagonia: tocando las fibras internas

    OpenAIRE

    Velasco Tafur, Ximena; Borrero Caldas, Silvio

    2013-01-01

    El presente caso, está enfocado en Patagonia, una compañía que desde sus inicios ha desarrollado una forma poco convencional en su estilo de hacer negocios. La gerencia de Patagonia considera que muchos errores administrativos obedecen a que las empresas formulan las mismas soluciones para todos los problemas que enfrentan. Además, desde la revolución industrial, tales soluciones han privilegiado las ganancias económicas sobre la sostenibilidad ambiental, y el planeta está pasando factura por...

  6. Unificar las ciencias del deporte

    Directory of Open Access Journals (Sweden)

    Natàlia Balagué Serre

    2013-12-01

    Full Text Available El deporte no es solo un fenómeno social de nuestro mundo, sino que también es un campo privilegiado para el estudio del comportamiento social y humano. Durante las últimas décadas, se ha producido un enorme crecimiento y especialización de las ciencias del deporte y el lema del 18º Congreso del European College of Sport Sciences (ECSS “Unificar las ciencias del deporte” representa desafiar este proceso de fragmentación. El lema conlleva un cambio de la especialización a la integración, de una concepción de los sistemas vivos basada en la teoría de la información y la ingeniería a una de base biológica, de la investigación multidisciplinaria a la transdisciplinaria. Pero aparece una pregunta: ¿es posible integrar las áreas fragmentadas y facilitar la transferencia de los principios explicativos teóricos, técnicas y perspectivas metodológicas entre disciplinas? En el marco de las contribuciones hechas en el congreso, este artículo tiene como objetivo introducir enfoques científicos ya extendidos en los ámbitos de la física, la química, la biología (incluyendo las ómicas y las ciencias sociales, y que centradas en las interacciones dinámicas complejas de los componentes sistémicos (proteínas, células, organismos, grupos, sociedades, revelan principios explicativos generales que contribuyen a la unificación del conocimiento. Intentamos animar a las personas interesadas en las ciencias del deporte a percibir nuevas formas de investigación y a complementar, sin sustituirlos, los enfoques dominantes, con la esperanza de que ir de las partes al todo y del todo a las partes ayudará a los científicos a reconocer los caminos más adecuados.

  7. Las nuevas formas de racismo

    OpenAIRE

    Gutiérrez López-Dóriga, Cristina

    2012-01-01

    El racismo tal y como lo conocíamos ha disminuido considerablemente ya que ha debido adaptarse a las nuevas exigencias sociales. Esta adaptación ha creado una nueva forma de expresión de este fenómeno, más larvada pero igual de dañina que las anteriores formas manifiestas. Y aunque las bases que sustentan esta nueva forma de racismo dependen de la historia cultural del lugar, siendo así diferentes en Europa y Estados Unidos, ambas aluden a los mismos procesos que crean y mantienen la desigual...

  8. Las escalas de la luz

    OpenAIRE

    Beckers, Benoit

    2009-01-01

    Variando con el paso del día y del año, la luz del Sol y del cielo modula, visual y energéticamente, los territorios, las ciudades y los edificios. ¿Cómo sintetizar y manejar en el proyecto estas informaciones donde se mezcla el azar de las nubes pasajeras con la regularidad astronómica de los trayectos solares? En cuanto a las herramientas de simulación, el mayor avance de estos últimos años se ha producido en los programas de renderización, con los cuales nos vemos forzados a construi...

  9. Efectividad en las redes empresariales

    OpenAIRE

    Álvarez Rey, Natalia; Correal López, Ana María; García Algarra, Laura Ximena

    2014-01-01

    Este estudio tiene como objetivo identificar cuáles son las variables que repercuten en la efectividad de las redes empresariales. Esto, con base en la búsqueda de literatura existente de la efectividad en equipos, en organizaciones y en las redes interorganizacionales, así como el análisis de modelos y estudios empíricos que permitieron el análisis. De acuerdo con la búsqueda, se encontró que variables como la estructura de la red, la estabilidad del sistema, el compromiso de los empleados e...

  10. Molecular dynamics study of the vaporization of an ionic drop.

    Science.gov (United States)

    Galamba, N

    2010-09-28

    The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (Na(n)Cl(n))(n=2-4). The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

  11. Molecular dynamics study of the vaporization of an ionic drop

    Science.gov (United States)

    Galamba, N.

    2010-09-01

    The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (NanCln)n=2-4. The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

  12. Effect of vapor-phase oxygen on chemical vapor deposition growth of graphene

    Science.gov (United States)

    Terasawa, Tomo-o.; Saiki, Koichiro

    2015-03-01

    To obtain a large-area single-crystal graphene, chemical vapor deposition (CVD) growth on Cu is considered the most promising. Recently, the surface oxygen on Cu has been found to suppress the nucleation of graphene. However, the effect of oxygen in the vapor phase was not elucidated sufficiently. Here, we investigate the effect of O2 partial pressure (PO2) on the CVD growth of graphene using radiation-mode optical microscopy. The nucleation density of graphene decreases monotonically with PO2, while its growth rate reaches a maximum at a certain pressure. Our results indicate that PO2 is an important parameter to optimize in the CVD growth of graphene.

  13. La intangibilidad de las acciones privadas de las personas

    Directory of Open Access Journals (Sweden)

    Mauricio Maldonado Muñoz

    2014-03-01

    Full Text Available En este artículo pretendemos acercarnos a una garantía que —siguiendo cierta doctrina— hemos llamado: intangibilidad de las acciones privadas de las personas. Desde una visión que busca ser omnicomprensiva, se analizan las fuentes de las que mana la privacidad y, posteriormente, su contenido y alcances. Sobre todo, se analiza el problema de los límites de la injerencia y regulación estatal, partiendo de una posición que niega las visiones comunitaristas. En general, se trata de conceptualizar a la garantía planteada desde el punto de vista de la libertad, el derecho y las virtudes humanas, los derechos de terceros y la moral pública; concretando su vinculación con otros derechos relacionados con la privacidad. La idea central del presente trabajo consiste en demostrar la transversalidad de la garantía señalada, implicando —en ese proceso— cuestiones trascendentes para la filosofía del derecho, la teoría del derecho y, por supuesto, para el estudio del derecho de los derechos humanos.  

  14. Las cinco grandes dimensiones de la personalidad

    Directory of Open Access Journals (Sweden)

    Jan ter Laak

    1996-12-01

    Full Text Available Este artículo revisa las distintas posiciones teóricas sobre las cinco grandes dimensiones de la personalidad, mostrando las semejanzas y diferencias entre las posturas teóricas. Esta contribución presenta lo siguiente: (a la génesis del contenido y la estructura de las cinco dimensiones; (b la fortaleza de las cinco dimensiones; (e la relación de las cinco grandes dimensiones con otros constructos de personalidad; (d discute el valor predictivo de las puntuaciones del perfil de las cinco dimensiones para criterios pertinentes; (e analiza el estatus teórico de las cinco dimensiones; (f discute críticas históricas sobre las cinco grandes dimensiones y se formulan respuestas a estas críticas; (g hace conjeturas para el futuro de las cinco grandes dimensiones; y (h concluye con algunas conclusiones y comentarios.

  15. Boundary vapor contentsin an annular channel

    International Nuclear Information System (INIS)

    Remizov, O.V.; Shurkin, N.G.; Podgornyj, K.K.; Gal'chenko, Eh.F.; Bukhteev, I.S.

    1978-01-01

    The work is aimed at the experimental investigation of the worsening of the heat transfer in an annular channel. The experiments have been carried out on the annular channel 32x28x3000 mm with the even distribution of the heat flux along the length at pressures of 6.9-19.6 MPa, flow rate of 350-1000 kg/m 2 s, and specific heat fluxes from 0.18 up to 0.6 MW/m 2 . Heating is external, oneside. Water monodistillate of the following composition has been used as a coolant: pH 9; dry residue - 0.8-1.2 mg/kg, oxygen -10-15 mg/kg. It is found out that the change character of the temperature field of the heating surface of the annular channel at the regime with the worsen of heat emission depends on the ratio of regime parameters. At pressures of 6.9-13.7 MPa and flow rate of 350-500 kg/m 2 s the channel wall temperature rises monotoneously, never reaching its maximum. With pressure rise > 13.7 MPa and mass velocity > 500 kg/m 2 s the temperature of the heat emitting surface reaches its maximum, and then slowly falls. At pressures of 6.9-11.8 MPa the boundary vapor content value within the whole range of mass velocities does not depend on the specific heat flux q. At pressures higher than 13.7 MPa and mass velocities of 350-1000 kg/m 2 s the boundary vapor content depends on q. The heating of the external or internal surface of the annular channel affects the value of the boundary vapor content within the whole range of regime parameters' change under investigation

  16. El estado actual de las vacunas contra las drogas

    Directory of Open Access Journals (Sweden)

    Maura Epifanía Matus Ortega

    2017-12-01

    Full Text Available Introducción: por lo común, la adicción a las drogas se trata con psicoterapia y farmacología que evita la unión de las sustancias psicoactivas a receptores específicos en el cerebro. El resultado de estos tratamientos no ha sido del todo satisfactorio, por lo que el desarrollo de terapias más eficaces representa un reto constante para tratar las adicciones. Una alternativa a la farmacología antiadictiva es la vacunación activa dirigida contra las sustancias de abuso. Objetivo: esta revisión reúne la información disponible sobre los fundamentos y avances científicos en la generación de una terapia inmunológica, que coadyuve al tratamiento de la adicción a sustancias como la heroína-morfina, la cocaína, la nicotina y la anfetamina. Método: se consideraron los reportes científicos disponibles en PubMed –de 2005 a abril de 2017–, sobre los fundamentos, la metodología empleada, los estudios preclínicos y clínicos, y los resultados obtenidos en dichas investigaciones para generar vacunas contra las drogas. Resultados: las vacunas lograron mitigar los efectos producidos por las sustancias en los estudios preclínicos en modelos de estudio en animales; sin embargo, con pacientes humanos los resultados no han sido del todo satisfactorios. Discusión y conclusiones: a pesar de los esfuerzos realizados por diferentes grupos de investigación y compañías farmacéuticas para generar vacunas terapéuticas contra el uso de diferentes drogas, ninguna ha alcanzado la fase III de estudios clínicos. En la actualidad, se continúa con los esfuerzos para lograr que las vacunas contra las adicciones alcancen su máxima eficiencia y eficacia, y contribuyan al tratamiento de la adicción a las drogas.

  17. Los que van a morir te saludan: las huellas, las cargas, las historias del cuerpo

    OpenAIRE

    Toro, Marisel; Serna, Yamid; Suárez, Rútber; Patiño, Ana; Moreno, Andrés

    2017-01-01

    Tesis (Maestría en Educación y Desarrollo Humano). Universidad de Manizales. Facultad de Ciencias Sociales y Humanas. CINDE, 2017 Las inquietudes desplegadas en el Programa de Investigación de la Línea en torno a las formas contemporáneas del Juvenicidio y la Necropolítica en Colombia, nos fueron arrojando al enunciado que soporta el título de esta serie: Los que van a morir te saludan. Amparados en el fondo doloroso que emana de esta antigua expresión latina, nosotros encontramos las v...

  18. Analysis of the transient compressible vapor flow in heat pipes

    Science.gov (United States)

    Jang, J. H.; Faghri, A.; Chang, W. S.

    1989-01-01

    The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual vapor flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures.

  19. Analysis of the transient compressible vapor flow in heat pipe

    International Nuclear Information System (INIS)

    Jang, J.H.; Faghri, A.; Chang, W.S.

    1989-07-01

    The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual vapor flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures

  20. Nuevos discursos sobre las ciudades, los municipios y las mujeres

    Directory of Open Access Journals (Sweden)

    Ana María Goetschel

    2009-01-01

    Full Text Available Escritora y activista feminista. Estudió Literatura y Periodismo en la Pontificia Universidad Católica del Perú y se gradúo de Magíster en Política Social por la Universidad Nacional Mayor de San Marcos. Por espacio de más de dos décadas se desempeña como profesora en el Diploma de Estudios de Género de la Pontificia Universidad Católica del Perú y como consultora de proyectos de desarrollo en las áreas de planificación, evaluación institucional y enfoque de género para diversas agencias internacionales de cooperación en Perú y otros países de América Latina. Es Investigadora asociada y miembro del Consejo Directivo del Centro Peruano de Estudios Sociales (CEPES. Maruja Barrig acredita un vasto trabajo de investigación sobre empleo femenino, desarrollo local y organizaciones de mujeres. En una reciente conferencia “Nuevos discursos sobre las ciudades, los municipios y las mujeres” , esta investigadora peruana hizo un balance sobre las formas en que el género ha sido incorporado en las prácticas de desarrollo y las consecuencias que conlleva este tipo de intervención para el avance de la agenda del feminismo crítico. Sobre este y otros temas relacionados con su trayectoria intelectual y la acción del movimiento de mujeres en el contexto político actual de las sociedades latinoamericanas, dialogamos con Maruja Barrig.

  1. Vaporization of a mixed precursors in chemical vapor deposition for YBCO films

    Science.gov (United States)

    Zhou, Gang; Meng, Guangyao; Schneider, Roger L.; Sarma, Bimal K.; Levy, Moises

    1995-01-01

    Single phase YBa2Cu3O7-delta thin films with T(c) values around 90 K are readily obtained by using a single source chemical vapor deposition technique with a normal precursor mass transport. The quality of the films is controlled by adjusting the carrier gas flow rate and the precursor feed rate.

  2. Design and physical features of inductive coaxial copper vapor lasers

    Energy Technology Data Exchange (ETDEWEB)

    Batenin, V. M. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Kazaryan, M. A. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Karpukhin, V. T. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Lyabin, N. A. [Istok Research and Production Corporation (Russian Federation); Malikov, M. M., E-mail: mmalikov@oivtran.ru [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2016-11-15

    A physical model of a copper vapor laser pumped by a pulse-periodic inductive (electrodeless) discharge is considered. The feasibility of efficient laser pumping by an inductive discharge and reaching high output parameters comparable to those of conventional copper vapor lasers pumped by a longitudinal electrode discharge is demonstrated. The design and physical features of an inductive copper vapor laser with an annular working volume are discussed.

  3. Review of enhanced vapor diffusion in porous media

    International Nuclear Information System (INIS)

    Webb, S.W.; Ho, C.K.

    1998-01-01

    Vapor diffusion in porous media in the presence of its own liquid has often been treated similar to gas diffusion. The gas diffusion rate in porous media is much lower than in free space due to the presence of the porous medium and any liquid present. However, enhanced vapor diffusion has also been postulated such that the diffusion rate may approach free-space values. Existing data and models for enhanced vapor diffusion, including those in TOUGH2, are reviewed in this paper

  4. Excessively High Vapor Pressure of Al-based Amorphous Alloys

    Directory of Open Access Journals (Sweden)

    Jae Im Jeong

    2015-10-01

    Full Text Available Aluminum-based amorphous alloys exhibited an abnormally high vapor pressure at their approximate glass transition temperatures. The vapor pressure was confirmed by the formation of Al nanocrystallites from condensation, which was attributed to weight loss of the amorphous alloys. The amount of weight loss varied with the amorphous alloy compositions and was inversely proportional to their glass-forming ability. The vapor pressure of the amorphous alloys around 573 K was close to the vapor pressure of crystalline Al near its melting temperature, 873 K. Our results strongly suggest the possibility of fabricating nanocrystallites or thin films by evaporation at low temperatures.

  5. Comparative study of the vapor analytes of trinitrotoluene (TNT)

    Science.gov (United States)

    Edge, Cindy C.; Gibb, Julie; Dugan, Regina E.

    1998-12-01

    Trinitrotoluene (TNT) is a high explosive used in most antipersonnel and antitank landmines. The Institute for Biological Detection Systems (IBDS) has developed a quantitative vapor delivery system, termed olfactometer, for conducting canine olfactory research. The research is conducted utilizing dynamic conditions, therefore, it is imperative to evaluate the headspace of TNT to ensure consistency with the dynamic generation of vapor. This study quantified the vapor headspace of military- grade TNT utilizing two different vapor generated methodologies, static and dynamic, reflecting differences between field and laboratory environments. Static vapor collection, which closely mimics conditions found during field detection, is defined as vapor collected in an open-air environment at ambient temperature. Dynamic vapor collection incorporates trapping of gases from a high flow vapor generation cell used during olfactometer operation. Analysis of samples collected by the two methodologies was performed by gas chromatography/mass spectrometry and the results provided information with regard to the constituents detected. However, constituent concentration did vary between the sampling methods. This study provides essential information regarding the vapor constituents associated with the TNT sampled using different sampling methods. These differences may be important in determining the detection signature dogs use to recognize TNT.

  6. The liquid to vapor phase transition in excited nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, J.B.; Moretto, L.G.; Phair, L.; Wozniak, G.J.; Beaulieu, L.; Breuer, H.; Korteling, R.G.; Kwiatkowski, K.; Lefort, T.; Pienkowski, L.; Ruangma, A.; Viola, V.E.; Yennello, S.J.

    2001-05-08

    For many years it has been speculated that excited nuclei would undergo a liquid to vapor phase transition. For even longer, it has been known that clusterization in a vapor carries direct information on the liquid-vapor equilibrium according to Fisher's droplet model. Now the thermal component of the 8 GeV/c pion + 197 Au multifragmentation data of the ISiS Collaboration is shown to follow the scaling predicted by Fisher's model, thus providing the strongest evidence yet of the liquid to vapor phase transition.

  7. Fuel conditioning facility electrorefiner cadmium vapor trap operation

    International Nuclear Information System (INIS)

    Vaden, D. E.

    1998-01-01

    Processing sodium-bonded spent nuclear fuel at the Fuel Conditioning Facility at Argonne National Laboratory-West involves an electrometallurgical process employing a molten LiCl-KCl salt covering a pool of molten cadmium. Previous research has shown that the cadmium dissolves in the salt as a gas, diffuses through the salt layer and vaporizes at the salt surface. This cadmium vapor condenses on cool surfaces, causing equipment operation and handling problems. Using a cadmium vapor trap to condense the cadmium vapors and reflux them back to the electrorefiner has mitigated equipment problems and improved electrorefiner operations

  8. Water Vapor Remote Sensing Techniques: Radiometry and Solar Spectrometry

    Science.gov (United States)

    Somieski, A.; Buerki, B.; Cocard, M.; Geiger, A.; Kahle, H.-G.

    The high variability of atmospheric water vapor content plays an important role in space geodesy, climatology and meteorology. Water vapor has a strong influence on transatmospheric satellite signals, the Earth's climate and thus the weather forecasting. Several remote sensing techniques have been developed for the determination of inte- grated precipitable water vapor (IPWV). The Geodesy and Geodynamics Lab (GGL) utilizes the methods of Water Vapor Radiometry and Solar Spectrometry to quantify the amount of tropospheric water vapor and its temporal variations. The Water Vapor Radiometer (WVR) measures the radiation intensity of the atmosphere in a frequency band ranging from 20 to 32 GHz. The Solar Atmospheric MOnitoring Spectrome- ter (SAMOS) of GGL is designed for high-resolution measurements of water vapor absorption lines using solar radiation. In the framework of the ESCOMPTE (ExpÊrience sur Site pour COntraindre les Mod- Éles de Pollution atmosphÊrique et de Transport d'Emissions) field campaign these instruments have been operated near Marseille in 2001. They have aquired a long time series of integrated precipitable water vapor content (IPWV). The accuracy of IPWV measured by WVR and SAMOS is 1 kg/m2. Furthermore meteorological data from radiosondes were used to calculate the IPWV in order to provide comparisons with the results of WVR and SAMOS. The methods of Water Vapor Radiometry and So- lar Spectrometry will be discussed and first preliminary results retrieved from WVR, SAMOS and radiosondes during the ESCOMPTE field campaign will be presented.

  9. A heated vapor cell unit for DAVLL in atomic rubidium

    OpenAIRE

    McCarron, Daniel J.; Hughes, Ifan G.; Tierney, Patrick; Cornish, Simon L.

    2007-01-01

    The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D2 transitions in atomic rubidium is described. A 5 cm-long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field...

  10. Water vapor permeabilities through polymers: diffusivities from experiments and simulations

    International Nuclear Information System (INIS)

    Seethamraju, Sindhu; Ramamurthy, Praveen Chandrashekarapura; Madras, Giridhar

    2014-01-01

    This study experimentally determines water vapor permeabilities, which are subsequently correlated with the diffusivities obtained from simulations. Molecular dynamics (MD) simulations were used for determining the diffusion of water vapor in various polymeric systems such as polyethylene, polypropylene, poly (vinyl alcohol), poly (vinyl acetate), poly (vinyl butyral), poly (vinylidene chloride), poly (vinyl chloride) and poly (methyl methacrylate). Cavity ring down spectroscopy (CRDS) based methodology has been used to determine the water vapor transmission rates. These values were then used to calculate the diffusion coefficients for water vapor through these polymers. A comparative analysis is provided for diffusivities calculated from CRDS and MD based results by correlating the free volumes. (paper)

  11. Ultrasound-assisted vapor generation of mercury

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Anderson S.; Vieira, Mariana A. [Universidade Federal de Santa Catarina, Departamento de Quimica, Florianopolis, SC (Brazil); Willie, Scott; Sturgeon, Ralph E. [National Research Council Canada, Institute for National Measurement Standards, Ottawa, ON (Canada)

    2007-06-15

    Cold vapor generation arising from reduction of both Hg{sup 2+} and CH{sub 3}Hg{sup +} occurs using ultrasonic (US) fields of sufficient density to achieve both localized heating as well as radical-based attack in solutions of formic and acetic acids and tetramethylammonium hydroxide (TMAH). A batch sonoreactor utilizing an ultrasonic probe as an energy source and a flow through system based on a US bath were optimized for this purpose. Reduction of CH{sub 3}Hg{sup +} to Hg{sup 0} occurs only at relatively high US field density (>10 W cm{sup -3} of sample solution) and is thus not observed when a conventional US bath is used for cold vapor generation. Speciation of mercury is thus possible by altering the power density during the measurement process. Thermal reduction of Hg{sup 2+} is efficient in formic acid and TMAH at 70 C and occurs in the absence of the US field. Room temperature studies with the batch sonoreactor reveal a slow reduction process, producing temporally broad signals having an efficiency of approximately 68% of that arising from use of a conventional SnCl{sub 2} reduction system. Molecular species of mercury are generated at high concentrations of formic and acetic acid. Factors affecting the generation of Hg{sup 0} were optimized and the batch sonoreactor used for the determination of total mercury in SLRS-4 river water reference material. (orig.)

  12. Reactions of atmospheric vapors with lunar soil

    International Nuclear Information System (INIS)

    Fuller, E.L. Jr.; Agron, P.A.

    1976-03-01

    Detailed experimental data have been acquired for the hydration of the surfaces of lunar fines. Inert vapor adsorption has been employed to measure the surface properties (surface energy, surface area, porosity, etc.) and changes wrought in the hydration-dehydration processes. Plausible mechanisms have been considered and the predominant process involves hydration of the metamict metallosilicate surfaces to form a hydrated laminar structure akin to terrestrial clays. Additional credence for this interpretation is obtained by comparison to existing geochemical literature concerning terrestrial weathering of primary metallosilicates. The surface properties of the hydrated lunar fines are compared favorably to those of terrestrial clay minerals. In addition, experimental results are given to show that fresh disordered surfaces of volcanic sand react with water vapor in a manner virtually identical to the majority of the lunar fines. The results show that ion track etching and/or grain boundary attack are minor contributions in the weathering of lunar fines in the realm of our microgravimetric experimental conditions. 14 references

  13. Potassium permanganate for mercury vapor environmental control

    Science.gov (United States)

    Kuivinen, D. E.

    1972-01-01

    Potassium permanganate (KMnO4) was evaluated for application in removing mercury vapor from exhaust air systems. The KMnO4 may be used in water solution with a liquid spray scrubber system or as a solid adsorber bed material when impregnated onto a zeolite. Air samples contaminated with as much as 112 mg/cu m of mercury were scrubbed to 0.06mg/cum with the KMnO4-impregnated zeolite (molecular sieve material). The water spray solution of permanganate was also found to be as effective as the impregnated zeolite. The KMnO4-impregnated zeolite was applied as a solid adsorber material to (1) a hardware decontamination system, (2) a model incinerator, and (3) a high vacuum chamber for ion engine testing with mercury as the propellant. A liquid scrubber system was also applied in an incinerator system. Based on the results of these experiments, it is concluded that the use of KMnO4 can be an effective method for controlling noxious mercury vapor.

  14. Ultrasound-assisted vapor generation of mercury.

    Science.gov (United States)

    Ribeiro, Anderson S; Vieira, Mariana A; Willie, Scott; Sturgeon, Ralph E

    2007-06-01

    Cold vapor generation arising from reduction of both Hg(2+) and CH(3)Hg(+) occurs using ultrasonic (US) fields of sufficient density to achieve both localized heating as well as radical-based attack in solutions of formic and acetic acids and tetramethylammonium hydroxide (TMAH). A batch sonoreactor utilizing an ultrasonic probe as an energy source and a flow through system based on a US bath were optimized for this purpose. Reduction of CH(3)Hg(+) to Hg(0) occurs only at relatively high US field density (>10 W cm(-3) of sample solution) and is thus not observed when a conventional US bath is used for cold vapor generation. Speciation of mercury is thus possible by altering the power density during the measurement process. Thermal reduction of Hg(2+) is efficient in formic acid and TMAH at 70 degrees C and occurs in the absence of the US field. Room temperature studies with the batch sonoreactor reveal a slow reduction process, producing temporally broad signals having an efficiency of approximately 68% of that arising from use of a conventional SnCl(2) reduction system. Molecular species of mercury are generated at high concentrations of formic and acetic acid. Factors affecting the generation of Hg(0) were optimized and the batch sonoreactor used for the determination of total mercury in SLRS-4 river water reference material.

  15. Plantas indicadoras de clomazone na fase vapor

    Directory of Open Access Journals (Sweden)

    Fábio Schreiber

    2013-10-01

    Full Text Available A volatilização representa um processo importante no deslocamento de agrotóxicos para o ambiente. As características físico-químicas da molécula do clomazone indicam que este possui potencial de volatilização. Em vista do exposto, para a realização deste estudo, foram conduzidos dois experimentos com o objetivo de avaliar a suscetibilidade das espécies: pepino, melão, milho, sorgo e arroz a diferentes formulações do herbicida clomazone na fase vapor. Para isso, foram utilizadas caixas de vidro hermeticamente fechadas, com a presença de diferentes formulações de clomazone e as espécies vegetais. As formulações utilizadas foram Gamit 360 CS®, Gamit 500 EC® e Gamit Star®. Com os resultados obtidos, foi possível concluir que, dentre as espécies avaliadas, independente da formulação utilizada, a de menor tolerância ao herbicida clomazone na fase vapor foi o sorgo, seguido do milho e do arroz.

  16. Cesium vapor cycle for an advanced LMFBR

    International Nuclear Information System (INIS)

    Fraas, A.P.

    1975-01-01

    A review indicates that a cesium vapor topping cycle appears attractive for use in the intermediate fluid circuit of an advanced LMFBR designed for a reactor outlet temperature of 1250 0 F or more and would have the following advantages: (1) it would increase the thermal efficiency by about 5 to 10 points (from approximately 40 percent to approximately 45 to 50 percent) thus reducing the amount of waste heat rejected to the environment by 15 to 30 percent. (2) the higher thermal efficiency should reduce the overall capital cost of the reactor plant in dollars per kilowatt. (3) the cesium can be distilled out of the intermediate fluid circuit to leave it bone-dry, thus greatly reducing the time and cost of maintenance work (particularly for the steam generator). (4) the large volume and low pressure of the cesium vapor region in the cesium condenser-steam generator greatly reduces the magnitude of pressure fluctuations that might occur in the event of a leak in a steam generator tube, and the characteristics inherent in a condenser make it easy to design for rapid concentration of any noncondensibles that may form as a consequence of a steam leak into the cesium region so that a steam leak can be detected easily in the very early stages of its development

  17. Las artes de leer e interpretar las hojas de coca

    Directory of Open Access Journals (Sweden)

    Eugenia Flores

    2017-03-01

    Full Text Available En este artículo quisiera hablar sobre un oficio secreto, subterráneo, clandestino, que es el arte de leer e interpretar las hojas de coca en espacios marginales del valle de Salta. Muestro en estas páginas las diferentes formas y modos en que la coca es utilizada por la población local, diversa y heterogénea, donde tradiciones indígenas ancestrales se manifiestan en prácticas concretas que rozan los límites entre la magia y la terapia. Presto especial interés, a partir del trabajo de campo realizado, a aquellas personas que manejan estas artes de leer las hojas de coca, las cuales en los casos analizados fueron adquiridas a partir de un ritual de paso, que fue el haber sido “tocado por el rayo”. Me interesa particularmente trabajar con estos hombres y mujeres, cuyo arte de hacer con coca es equiparable a las “maneras de hacer”. Estas maneras de hacer con la coca ritual no están visibilizadas y son subterráneas, marginales y silenciosas, en este artículo se pretende dar cuenta de estas prácticas con coca y sus dinámicas relaciones inter e intra comunales. Palabras-claves: Artes; maneras de hacer; coca; ritual.

  18. Las relaciones de Podemos con las organizaciones sociales

    Directory of Open Access Journals (Sweden)

    Ignacio Mariñas

    2015-09-01

    Full Text Available El 15M fue el principio del proceso de cambio en España y tiene una trascendencia en el mundo porque, por primera vez desde 1989, un movimiento contestatario al sistema alcanza una repercusión mundial. En consecuencia, todos partidos políticos en España atienden las demandas de este movimiento, bien para impulsar cambios en sus programas que atiendan a sus demandas o para intentar asumir su representación política como hace Podemos. En esta exposición se considera la tradición política de este país y el surgir del 15M, para comentar, después, las críticas a Podemos como heredero del 15M, y terminar con el análisis de su relación con las organizaciones sociales. La exposición se organiza en cinco tiempos que en su conjunto dan una visión poliédrica del problema. El objetivo es tratar de contradecir el escepticismo del Quijote sobre la posibilidad de comprender las razones y las dinámicas de los cambios sociales.

  19. Vapor pressures and vaporization enthalpy of (−) α-bisabolol and (dl) menthol by correlation gas chromatography

    International Nuclear Information System (INIS)

    Keating, Leasa; Harris, Harold H.; Chickos, James S.

    2017-01-01

    Highlights: • The vaporization enthalpy and vapor pressure of (−) α-bisabolol and (dl)-menthol have been measured as a function of temperature. • Vapor pressures, vaporization enthalpies and boiling temperatures have been compared to available literature data. • Vapor pressures of (l)-menthol are compared to (dl)-menthol. - Abstract: The vapor pressures and vaporization enthalpies of (−) α-bisabolol and (dl)-menthol, two GRAS chemicals (generally recognized as safe) are evaluated by correlation gas chromatography using a series of saturated primary alcohols as standards. Vaporization enthalpies of (96.6 ± 2.4) and (74.2 ± 2.8) kJ mol −1 and vapor pressures of p/Pa = (0.020 ± 0.003) and (4.5 ± 0.44) were evaluated at T = 298.15 K for (−) α-bisabolol and (dl)-menthol, respectively, and compared to literature values. The vapor pressures of both compounds from T = (298.15 to 500) K have been derived from correlations using vapor pressures of a series of 1-alkanols and corresponding gas chromatographic retention times at 10 K intervals. The results were fit to a second order polynomial. Calculated normal boiling temperatures of T B = (574.8 and 492.7) K are calculated for (−) α-bisabolol and (dl)-menthol, respectively. A normal boiling temperature of T B = (485.2, and 489.7) K has previously been reported for (dl)-menthol. Vapor pressures for both (l)-menthol and (dl)-menthol from a previous study and (dl)-menthol from this study are compared with literature values.

  20. Vapor and gas sampling of single-shell tank 241-S-106 using the in situ vapor sampling system

    International Nuclear Information System (INIS)

    Lockrem, L.L.

    1997-01-01

    The Vapor Issue Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-S-106. This document presents In Situ vapor Sampling System (ISVS) data resulting from the June 13, 1996 sampling of SST 241-S-106. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which'supplied and analyzed the sample media

  1. Vapor and gas sampling of single-shell tank 241-U-104 using the in situ vapor sampling system

    International Nuclear Information System (INIS)

    Lockrem, L.L.

    1997-01-01

    The Vapor Issue.Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-U-104. This document presents In Situ Vapor Sampling System (ISVS) data resulting from the July 16, 1996 sampling of SST 241-U-104. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which supplied and analyzed the sample media

  2. Vapor and gas sampling of single-shell tank 241-S-103 using the in situ vapor sampling system

    International Nuclear Information System (INIS)

    Lockrem, L.L.

    1997-01-01

    The Vapor Issue Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-S-103. This document presents In Situ Vapor Sampling System (ISVS) data resulting from the June 12, 1996 sampling of SST 241-S-103. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which supplied and analyzed the sample media

  3. Relaciones amorosas de pareja en las trayectorias vitales de las mujeres encarceladas

    OpenAIRE

    De Miguel Calvo, Estibaliz

    2012-01-01

    [ES]La tesis doctoral analiza las experiencias amorosas de pareja de mujeres encarceladas, con el doble objetivo de visibilizar a las mujeres presas en el ámbito de las ciencias sociales y de introducir las especificidades de las mujeres encarceladas en los debates sociológicos y feministas acerca del amor. Las escasas aproximaciones al amor entre las mujeres presas han tendido a explicar sus relaciones de pareja desde el concepto de “depende...

  4. Observation and particle simulation of vaporized W, Mo, and Be in PISCES-B plasma for vapor-shielding studies

    Directory of Open Access Journals (Sweden)

    K. Ibano

    2017-08-01

    Full Text Available Interactions of Tungsten (W, Molybdenum (Mo, and Beryllium (Be vapors with a steady-state plasma were studied by the PISCES-B liner plasma experiments as well as Particle-In-Cell (PIC simulations for the understanding of vapor-shielding phenomena. Effective cooling of the plasma by laser-generated Be vapor was observed in PISCES-B. On the other hand, no apparent cooling was observed for W and Mo vapors. The PIC simulation explains these experimental observations of the difference between low-Z and high-Z vapors. Decrease of electron temperature due to the vapor ejection was observed in case of a simulation of the Be vapor. As for the W vapor, it was found that the plasma cooling is localized only near the wall at a higher electron density plasma (∼1019m−3. On the other hand, the appreciable plasma cooling can be observed in a lower density plasma (∼1018m−3 for the W vapor.

  5. Vapor pressures and enthalpies of vaporization of a series of γ and δ-lactones by correlation gas chromatography

    International Nuclear Information System (INIS)

    Kozlovskiy, Mikhail; Gobble, Chase; Chickos, James

    2014-01-01

    Highlights: • The vaporization enthalpies of γ-octanolactone, γ- and δ-undecanolactone and γ and δ-dodecanolactone are reported. • Equations for predicting the vapor pressures over the temperature range T = (298.15 to 350) K are provided. • Vaporization enthalpies are compared to predicted values. - Abstract: The vaporization enthalpies of γ-octanolactone, γ- and δ-undecanolactone and γ and δ-dodecanolactone used commercially as flavor ingredients are reported as are their vapor pressures over the temperature range T = (298.15 to 350) K. Vaporization enthalpies at T = 298.15 K of: (66.0 ± 3.9), (79.4 ± 4.4), (80.1 ± 4.5), (83.9 ± 4.6), and (84.61 ± 4.7) kJ · mol −1 and vapor pressures also at T = 298.15 K of: (2.8 ± 0.9), (0.12 ± 0.05), (0.09 ± 0.04), (0.04 ± 0.02), and (0.03 ± 0.02) Pa, respectively, have been evaluated by correlation gas chromatography experiments. The vaporization enthalpies of the lactones studied are reproduced within ±0.5 kJ · mol −1 using a group additivity scheme reported previously for γ- and δ-lactones. The vaporization enthalpies of the γ- and δ-lactones are compared to a similar series of ω-lactones

  6. Vapor and gas sampling of single-shell tank 241-B-102 using the in situ vapor sampling system

    International Nuclear Information System (INIS)

    Lockrem, L.L.

    1997-01-01

    The Vapor Issue Resolution Program tasked the Vapor Team (the team) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-B-102. This document presents sampling data resulting from the April 18, 1996 sampling of SST 241-B-102. Analytical results will be presented in a separate report issued by Pacific Northwest National Laboratory (PNNL), which supplied and analyzed the sampling media. The team, consisting of Sampling and Mobile Laboratories (SML) and Special Analytical Studies (SAS) personnel, used the vapor sampling system (VSS) to collect representative samples of the air, gases, and vapors from the headspace of SST 241-B-102 with sorbent traps and SUMMA canisters

  7. ¿Las mujeres prefieren las cesáreas?

    Directory of Open Access Journals (Sweden)

    A. Vallejos Parás

    2016-07-01

    Full Text Available Las tasas de cesárea han aumentado de manera constante en la mayoría de los países de medianos y altos ingresos en los últimos decenios sin justificación médica. La solicitud materna es uno de los factores no médicos citados con frecuencia que contribuyen a esta tendencia. El objetivo de este documento es realizar una revisión de la bibliografía actual sobre las preferencias maternas por la cesárea.

  8. Las TIC, el proceso del conocimiento y las competencias docentes

    Directory of Open Access Journals (Sweden)

    Augusto Perez Lindo

    2014-11-01

    Full Text Available En el marco del Seminario Internacional "Formación y conocimiento" organizado por la Universidad de Sorocaba presentamos un análisis de los efectos de las TICs en los procesos del conocimiento. Tratamos de demostrar que esos efectos se producen en varias direcciones: cambios en la visión de la realidad, de la subjetividad, del lenguaje, de los paradigmas, de las relaciones sociales. Propone fortalecer competencias adecuadas al cambio de paradigma, como la capacidad para seleccionar e interpretar informaciones, la capacidad para pensar científicamente, la capacidad para comunicar, la capacidad para convivir, la capacidad para dominar varios lenguajes.

  9. Ecologia de las lombrices de tierra

    Science.gov (United States)

    Grizelle Gonzalez

    2014-01-01

    De los organismos de suelo, las lombrices de tierra son las mas conocidas y a menudo son consideradas las mas importantes por su influencia en el funcionamiento de ecosistemas de suelo (Hendriz y Bohlen, 2002). Tienen un efecto significativo en la estructura del suelo, el ciclo de nutrimentos y ls productividad de las cosechas. En terminos de biomasa, generalmente...

  10. LAS MIGRACIONES INTERNACIONALES EN COLOMBIA

    Directory of Open Access Journals (Sweden)

    Maguemati Wabgou

    2012-01-01

    Full Text Available El artículo expone los resultados de una investigación sobre los flujos migratorios internacionales que han estado llegando a Colombia desde el siglo XVI hasta la actualidad. La metodología investigativa se fundamenta en la recolección y el análisis de datos derivados de investigaciones anteriores. Los resultados son significativos en lamedida que presentan el estado de las migraciones en Colombia entre los siglos XVI y XIX y desde la primera mitad del siglo XX hasta la actualidad. Por un lado, engloban a la inmigración británica, jamaiquina y africana en las islas de San Andrés y Providencia; junto con la inmigración árabe, judía, alemana, francesa, italiana y gitana en Colombia continental. Por otro, aluden a las migraciones japonesas, suramericanas, junto con los crecientes asentamientos de migrantes norteamericanos, europeos y las nuevas oleadas de migraciones asiáticas y africanas en Colombia. Todo ello lleva a aprehender la envergadura del papel jugado por Colombia como un país de destino de las migraciones internacionales, lo que contrasta con la imagen más conocida de Colombia como un país expulsor de emigrantes.

  11. Las canciones mueven tus inteligencias

    Directory of Open Access Journals (Sweden)

    Dayane Mónica Cordeiro

    2014-09-01

    Full Text Available La canción es uno de los recursos más estimulantes y provechosos para enseñar lengua española, pues responde a los objetivos lingüísticos y comunicativos que ideamos fomentar en al aula de E/LE. Llevar las aportaciones de la teoría de las inteligencias múltiples al campo de la didáctica de la enseñanza de lenguas extranjeras ha sido el objetivo de esta experiencia práctica. La unidad didáctica Primavera Trompetera parte de la premisa de que fomentar la diversidad cognitiva propuesta en laTeoría de las Inteligencias Múltiples del psicólogo Howard Gardner, utilizando comorecurso didáctico la canción Primavera Trompetera del grupo «Los Delinquentes», puede facilitar el proceso de enseñanza/aprendizaje de lengua española, trabajando las destrezas integradas a las inteligencias múltiples.

  12. 46 CFR 39.40-1 - General requirements for vapor balancing-TB/ALL.

    Science.gov (United States)

    2010-10-01

    ... Section 39.40-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS VAPOR CONTROL SYSTEMS... to control vapor emissions during a lightering or topping-off operation which does not use vapor... compressor or blower to assist vapor transfer without approval from the Commandant (CG-522). (d) Vapor...

  13. Droplet Vaporization In A Levitating Acoustic Field

    Science.gov (United States)

    Ruff, G. A.; Liu, S.; Ciobanescu, I.

    2003-01-01

    Combustion experiments using arrays of droplets seek to provide a link between single droplet combustion phenomena and the behavior of complex spray combustion systems. Both single droplet and droplet array studies have been conducted in microgravity to better isolate the droplet interaction phenomena and eliminate or reduce the effects of buoyancy-induced convection. In most experiments involving droplet arrays, the droplets are supported on fibers to keep them stationary and close together before the combustion event. The presence of the fiber, however, disturbs the combustion process by introducing a source of heat transfer and asymmetry into the configuration. As the number of drops in a droplet array increases, supporting the drops on fibers becomes less practical because of the cumulative effect of the fibers on the combustion process. To eliminate the effect of the fiber, several researchers have conducted microgravity experiments using unsupported droplets. Jackson and Avedisian investigated single, unsupported drops while Nomura et al. studied droplet clouds formed by a condensation technique. The overall objective of this research is to extend the study of unsupported drops by investigating the combustion of well-characterized drop clusters in a microgravity environment. Direct experimental observations and measurements of the combustion of droplet clusters would provide unique experimental data for the verification and improvement of spray combustion models. In this work, the formation of drop clusters is precisely controlled using an acoustic levitation system so that dilute, as well as dense clusters can be created and stabilized before combustion in microgravity is begun. While the low-gravity test facility is being completed, tests have been conducted in 1-g to characterize the effect of the acoustic field on the vaporization of single and multiple droplets. This is important because in the combustion experiment, the droplets will be formed and

  14. Technical and environmental aspects of combined cycle power stations with integrated gasification (CCGI); Aspectos tecnicos y medioambientales de las centrales de ciclo combinado con gasificacion integrada (CCGI)

    Energy Technology Data Exchange (ETDEWEB)

    Beltran Mora, Hector Alejandro; Urias Romero, Francisco [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2004-06-15

    liquido a estado gaseoso mediante una oxidacion parcial y el gas obtenido de este proceso se llama gas de sintesis (syngas, por sus siglas en ingles) que es utilizado en Centrales de Ciclo Combinado como sustituto del gas natural. Se muestran tambien los demas componentes de este tipo de centrales como la unidad separadora de aire y se detallan algunas de las modificaciones que se deben de hacer para adaptar una turbina de gas para que utilice syngas y las consideraciones de su integracion con la unidad separadora de aire para optimizar la operacion de la planta. Se muestra una comparacion de valores de eficiencia de las centrales CCGI con las carboeletricas convencionales y con las centrales de ciclo combinado que utilizan gas natural. Finalmente se analizan las emisiones de contaminates de SO{sub 2}, NO{sub x} y CO{sub 2}. Se estudia la posibilidad de utilizar combustibles como coque de petroleo y residuos de vacio que se producen en la refineria de Cadereyta para la posible construccion de una central CCGI en Mexico.

  15. Las mujeres en el espejo

    Directory of Open Access Journals (Sweden)

    Graciela Estrada

    2007-12-01

    Full Text Available Las mujeres establecen con el espejo una relación particular en la constitución de su imagen dada la semejanza de un mismo cuerpo con la madre y la trasladan al espejo de otras mujeres en la búsqueda de respuestas al enigma de su sexualidad. En la construcción del cuerpo y sexualidad femeninos tienen un lugar privilegiado el primer vínculo materno y un tercero como instancia simbólica de cuya mirada de aceptación dependerá la relación futura con su cuerpo y con el deseo. Esta estructura se pone a prueba en la pubertad: junto con las transformaciones reales del cuerpo femenino, cobra un primer plano la imagen, irrumpen las pulsiones y aparece la mirada deseante del otro sexo.

  16. Imparting passivity to vapor deposited magnesium alloys

    Science.gov (United States)

    Wolfe, Ryan C.

    Magnesium has the lowest density of all structural metals. Utilization of low density materials is advantageous from a design standpoint, because lower weight translates into improved performance of engineered products (i.e., notebook computers are more portable, vehicles achieve better gas mileage, and aircraft can carry more payload). Despite their low density and high strength to weight ratio, however, the widespread implementation of magnesium alloys is currently hindered by their relatively poor corrosion resistance. The objective of this research dissertation is to develop a scientific basis for the creation of a corrosion resistant magnesium alloy. The corrosion resistance of magnesium alloys is affected by several interrelated factors. Among these are alloying, microstructure, impurities, galvanic corrosion effects, and service conditions, among others. Alloying and modification of the microstructure are primary approaches to controlling corrosion. Furthermore, nonequilibrium alloying of magnesium via physical vapor deposition allows for the formation of single-phase magnesium alloys with supersaturated concentrations of passivity-enhancing elements. The microstructure and surface morphology is also modifiable during physical vapor deposition through the variation of evaporation power, pressure, temperature, ion bombardment, and the source-to-substrate distance. Aluminum, titanium, yttrium, and zirconium were initially chosen as candidates likely to impart passivity on vapor deposited magnesium alloys. Prior to this research, alloys of this type have never before been produced, much less studied. All of these metals were observed to afford some degree of corrosion resistance to magnesium. Due to the especially promising results from nonequilibrium alloying of magnesium with yttrium and titanium, the ternary magnesium-yttrium-titanium system was investigated in depth. While all of the alloys are lustrous, surface morphology is observed under the scanning

  17. Detection system of sodium oxide vapors

    International Nuclear Information System (INIS)

    Hundal, Rolv.

    1976-01-01

    The description is given of a sodium oxide vapor detection system which comprises a containment, a light source located to send a light beam into and through this containment and a photodetector located to intercept the light from the source after it has covered a given path through the containment. In response to the intensity of the incident light, the photodetector produces an output signal representative of it. The feature of this device is a first polarizer located near the light source, along the path of the light coming from it and designed to polarize the light projected through the containment in a given plane, and a second polarizer located near the photodetector, along the path of the polarized light and designed virtually to prevent all the light rays whose orientation differs from the given polarization plane from reaching the photodetector [fr

  18. Installation for low temperature vapor explosion experiment

    International Nuclear Information System (INIS)

    Nilsuwankosit, Sunchai; Archakositt, Urith

    2000-01-01

    A preparation for the experiment on the low temperature vapor explosion was planned at the department of Nuclear Technology, Chulalongkorn University, Thailand. The objective of the experiment was to simulate the interaction between the molten fuel and the volatile cooling liquid without resorting to the high temperature. The experiment was expected to involve the injection of the liquid material at a moderate temperature into the liquid material with the very low boiling temperature in order to observe the level of the pressurization as a function of the temperatures and masses of the applied materials. For this purpose, the liquid nitrogen and the water were chosen as the coolant and the injected material for this experiment. Due to the size of the installation and the scale of the interaction, only lumped effect of various parameters on the explosion was expected from the experiment at this initial stage. (author)

  19. Gas and vapor bubble growth and collapse

    International Nuclear Information System (INIS)

    Bonnin, J.; Reali, M.; Sardella, L.

    1976-01-01

    The rate of growth or collapse of a spherical bubble of gas or vapor under the effect of a nonequilibrium with the ambient liquid can be expressed in terms of generalized parameters taking into account either mass or heat diffusion. Diffusion equations have been solved either by numerical computation or under the form of a asymptotical solution, for a growing bubble only and with a constant nonequilibrium. Solutions are compared between them and with already published ones. Experimental results obtained match with a unique nonequilibrium parameter, analogous to a Jacob number. Discrepancies with asymptotical solutions can require in some cases complete numerical computation. But taking into account convection due to bubble lift will require a more sophisticated numerical computation [fr

  20. Uranium vapor generator: pulsed hollow cathode lamp

    International Nuclear Information System (INIS)

    Carleer, M.; Gagne, J.; Leblanc, B.; Demers, Y.; Mongeau, B.

    1979-01-01

    The production of uranium vapors has been studied in the 5 L 0 6 ground state using a pulsed hollow cathode lamp. The evolution of the 238 U ( 5 L 0 6 ) concentration with time has been studied with Xe and Ar as buffer gases. A density of 2.7 x 10 13 atoms cm -3 was obtained with Xe as a buffer gas. In addition, those measurements, obtained from the absorption of a laser beam tuned to the 5758.143 A ( 5 L 0 6 -17,361 7 L 6 ) transition, allowed the determination of the transition probability A=2.1 x 10 5 sec -1 and of the branching ratio BR=0.08 for this transition

  1. Investigating the effects of water vaporization on the production of ...

    African Journals Online (AJOL)

    The simulations show that water vaporization increases productivity of well by increasing gas saturation and relative permeability near the well walls and improving the mobility of gas; and this effect is stronger in rich gas condensate reservoir than the lean ones. Keywords: Well, Gas, Pressure Drop, Vapor pressure of water ...

  2. Volatilization of multicomponent mixtures in soil vapor extraction applications

    International Nuclear Information System (INIS)

    Bass, D.H.

    1995-01-01

    In soil vapor extraction (SVE) applications involving multicomponent mixtures, prediction of mass removal by volatilization as a function remediation extent is required to estimate remediation time and to size offgas treatment equipment. SVE is a commonly used remediation technology which volatilizes and enhances aerobic biodegradation of contamination adsorbed to vadose zone soils. SVE is often applied at sites contaminated with petroleum products, which are usually mixtures of many different compounds with vapor pressures spanning several orders of magnitude. The most volatile components are removed first, so the vapor pressure of the remaining contaminant continually decreases over the course of the remediation. A method for assessing how vapor pressure, and hence the rate of volatilization, of a multicomponent mixture changes over the course of a vapor extraction remedy has been developed. Each component is listed, alone, with its mass fraction in the mixture, in decreasing order of pure component vapor pressure (where component analyses are unavailable, model compounds can be used), For most petroleum distillates, the vapor pressure for each component plotted against the cumulative mass fraction of the component in the mixture on semilog coordinates will produce a straight line with a high correlation coefficient. This regression can be integrated to produce an expression for vapor pressure of the overall mixture as a function of extent or remediation

  3. Water vapor and Gas Transport through Polymeric Membranes

    NARCIS (Netherlands)

    Metz, S.J.

    2003-01-01

    Water vapor transport through polymeric materials plays an important role in a large number of applications such as: food packaging, breathable clothing, roofing membranes, diapers, and the removal of water vapor from gas streams (e.g. dehydration of natural gas or the drying of compressed air).

  4. Vapor pressures of dimethylcadmium, trimethylbismuth, and tris(dimethylamino)antimony

    Czech Academy of Sciences Publication Activity Database

    Morávek, Pavel; Fulem, Michal; Pangrác, Jiří; Hulicius, Eduard; Růžička, K.

    2013-01-01

    Roč. 360, Dec (2013), s. 106-110 ISSN 0378-3812 R&D Projects: GA ČR GA13-15286S; GA MŠk(CZ) LM2011026 Institutional support: RVO:68378271 Keywords : vapor pressure * dimethylcadmium * trimethylbismuth * tris(dimethylamino)antimony * sublimation and vaporization enthalpy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.241, year: 2013

  5. PWFA plasma source - interferometric diagnostics for Li vapor density measurements

    International Nuclear Information System (INIS)

    Sivakumaran, V.; Mohandas, K.K.; Singh, Sneha; Ravi Kumar, A.V.

    2015-01-01

    A prototype (40 cm long) plasma source based on Li heat pipe oven has been developed for the Plasma Wakefield Acceleration (PWFA) experiments at IPR (IPR), Gujarat as a part of the ongoing Accelerator Programme. Li vapor in the oven is produced by heating solid Li in helium buffer gas. A uniform column of Li plasma is generated by UV photo ionization (193 nm) of the Li vapor in the heat pipe oven. In these experiments, an accurate measurement of Li vapor density is important as it has got a direct consequence on the plasma electron density. In the present experiment, the vapor density is measured optically by using Hook method (spectrally resolved white light interferometry). The hook like structure formed near the vicinity of the Li 670.8 nm resonance line was recorded with a white light Mach Zehnder interferometer crossed with an imaging spectrograph to estimate the Li vapor density. The vapor density measurements have been carried out as a function of external oven temperature and the He buffer gas pressure. This technique has the advantage of being insensitive to line broadening and line shape, and its high dynamic range even with optically thick absorption line. Here, we present the line integrated Lithium vapor density measurement using Hook method and also compare the same with other optical diagnostic techniques (White light absorption and UV absorption) for Li vapor density measurements. (author)

  6. A demonstration experiment for studying the properties of saturated vapor

    Science.gov (United States)

    Grebenev, Igor V.; Lebedeva, Olga V.; Polushkina, Svetlana V.

    2017-11-01

    The paper proposes an important demonstration experiment that can be used at secondary schools in physics. The described experiment helps students learn the main concepts of the topic ‘saturated vapor’, namely, evaporation, condensation, dynamic equilibrium, saturation vapor, partial pressure, and the dependence of saturated vapor pressure on temperature.

  7. Vapor pressures and thermophysical properties of selected monoterpenoids

    Czech Academy of Sciences Publication Activity Database

    Štejfa, V.; Dergal, F.; Mokbel, I.; Fulem, Michal; Jose, J.; Růžička, K.

    2015-01-01

    Roč. 406, Nov (2015), 124-133 ISSN 0378-3812 Institutional support: RVO:68378271 Keywords : monoterpenoids * vapor pressure * heat capacity * ideal - gas thermodynamic properties * vaporization and sublimation enthalpy Subject RIV: BJ - Thermodynamics Impact factor: 1.846, year: 2015

  8. Recommended vapor pressure and thermophysical data for ferrocene

    Czech Academy of Sciences Publication Activity Database

    Fulem, Michal; Růžička, K.; Červinka, C.; Rocha, M.A.A.; Santos, L.M.N.B.F.; Berg, R.F.

    2013-01-01

    Roč. 57, FEB (2013), 530-540 ISSN 0021-9614 Institutional support: RVO:68378271 Keywords : ferrocene * vapor pressure * heat capacity * ideal gas thermodynamic properties * sublimation enthalpy * recommended vapor pressure equation Subject RIV: BJ - Thermodynamics Impact factor: 2.423, year: 2013

  9. Calculation of vapor pressure of fission product fluorides and oxyfluorides

    International Nuclear Information System (INIS)

    Roux, J.P.

    1976-03-01

    The equilibrium diagrams of the condensed phases - solid and liquid - and vapor phase are collected for the principal fluorides and oxyfluorides of fission product elements (atomic number from 30 to 66). These diagrams are used more particularly in fuel reprocessing by fluoride volatility process. Calculations and curves (vapor pressure in function of temperature) are processed using a computer program given in this report [fr

  10. Natural convection and vapor loss during underground waste storage

    International Nuclear Information System (INIS)

    Plys, M.G.; Epstein, M.; Turner, D.

    1996-01-01

    Natural convection and vapor loss from underground waste storage tanks is examined here. Stability criteria are provided for the onset of natural convection flow within the headspace of a tank, and between tanks and the environment. The flowrate is quantified and used to predict vapor losses during storage

  11. Electrospun Polymer Fiber Lasers for Applications in Vapor Sensing

    DEFF Research Database (Denmark)

    Krämmer, Sarah; Laye, Fabrice; Friedrich, Felix

    2017-01-01

    of the narrow lasing modes upon uptake of alcohol vapors (model vapors are methanol and ethanol) serves as sensor signal. Thus, the high sensitivity related to the spectral line shifts of cavity-based transducers can be combined with the fiber's large surface to volume ratio. The resulting optical sensors...

  12. Post-Decontamination Vapor Sampling and Analytical Test Methods

    Science.gov (United States)

    2015-08-12

    is decontaminated that could pose an exposure hazard to unprotected personnel. The chemical contaminants may include chemical warfare agents (CWAs... decontamination process. Chemical contaminants can include chemical warfare agents (CWAs) or their simulants, nontraditional agents (NTAs), toxic industrial...a range of test articles from coupons, panels, and small fielded equipment items. 15. SUBJECT TERMS Vapor hazard; vapor sampling; chemical warfare

  13. El (desorden de las ciudades

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Maldonado

    2014-01-01

    Full Text Available Las ciudades son sistemas físicos, y estos tienen un orden. En la física clásica –esto es, en la mecánica clásica–, el orden era estable, rígido, jerárquico o regular y periódico. Los principios que explican dicho orden son, en verdad, elementales. Sin embargo, con la nueva física, dicho orden se revela como de mayor complejidad. Asimismo, las ciudades son sistemas vivos exactamente en la medida en que metabolizan información, materia y energía. Ahora bien, la complejidad del mundo actual está relacionada profundamente con la digitalización del mismo. Ello implica nuevos modos de escritura, nuevos modos de lectura, nuevos modos de comunicación y, manifiestamente, nuevos lenguajes. De allí que se advierta la emergencia de una nueva clase social: la de los migrantes y los nativos en las tecnologías convergentes. Son ellos los que están redefiniendo el (desorden de las ciudades. Pues no sin ambages, la ciudad es ahora y cada vez más, el lugar de la comunicación y el lenguaje, de las vivencias y el convivio. Y para escándalo de las mentalidades tradicionales, el convivio y el habitar, la comunicación y el lenguaje son cada vez más digitales. Una auténtica revolución, en toda la línea de la palabra.

  14. El (desorden de las ciudades

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Maldonado

    2014-07-01

    Full Text Available Las ciudades son sistemas físicos, y estos tienen un orden. En la física clásica –esto es, en la mecánica clásica–, el orden era estable, rígido, jerárquico o regular y periódico. Los principios que explican dicho orden son, en verdad, elementales. Sin embargo, con la nueva física, dicho orden se revela como de mayor complejidad. Asimismo, las ciudades son sistemas vivos exactamente en la medida en que metabolizan información, materia y energía. Ahora bien, la complejidad del mundo actual está relacionada profundamente con la digitalización del mismo. Ello implica nuevos modos de escritura, nuevos modos de lectura, nuevos modos de comunicación y, manifiestamente, nuevos lenguajes. De allí que se advierta la emergencia de una nueva clase social: la de los migrantes y los nativos en las tecnologías convergentes. Son ellos los que están redefiniendo el (desorden de las ciudades. Pues no sin ambages, la ciudad es ahora y cada vez más, el lugar de la comunicación y el lenguaje, de las vivencias y el convivio. Y para escándalo de las mentalidades tradicionales, el convivio y el habitar, la comunicación y el lenguaje son cada vez más digitales. Una auténtica revolución, en toda la línea de la palabra.

  15. Las cosas por su nombre

    OpenAIRE

    Storani, Emilia

    2017-01-01

    El artículo propone indagar sobre los modos y diferentes formatos que se utilizan tanto en la escritura como en la lectura, para articular con las luchas por la identidad de género. La Ley de Identidad de Género ha sido un puntapié clave para pensarnos a nosotros mismos culturalmente y para pensar a los demás. Pero, ¿cómo mencionamos, escribimos y leemos las diferentes identidades? La escritura, también es un mundo transformador para quienes bregan por una sociedad más libre y sin prejuicios....

  16. Las normas internacionales de contabilidad

    OpenAIRE

    Monge, Pedro

    2006-01-01

    SUMARIO Editorial Peña, Aura Elena Artículos La calidad en la microempresa merideña y su impacto en el ambiente. Bustos F, Carlos E. Mecanismos de transmisión de la política monetaria. Chuecos, Alicia Contabilidad de Costos: una evaluación a la cátedra. Molina, Olga Rosa Las normas internacionales de contabilidad. Monge, Pedro Análisis de la cadena de valor industrial y de la cadena de valor agregado para las pequeñas y medianas indust...

  17. Gobierno corporativo en las pymes

    OpenAIRE

    Vásquez Vélez, Stefany; Dorado Paz, María Isabel

    2016-01-01

    Las pequeñas y medianas empresas - PYMES representan el más alto porcentaje de compañías existentes a nivel mundial 1 y en consecuencia, son el motor que mueve la economía. Pese a ello, experimentan varios inconvenientes que en muchos casos les impide crecer. El gobierno corporativo hoy en día se impone como un tema inquietante en el ámbito empresarial, porque es visto como un mecanismo que les ayuda a las compañías a alcanzar sus objetivos y los de sus grupos de inter...

  18. Las manifestaciones sociales en Brasil

    OpenAIRE

    Gonçalves Chaves, Mariluci

    2013-01-01

    El país del fútbol se ha convertido en el país de las protestas y manifestaciones. Manifestaciones que han sido pacíficas algunas veces y violenta otras, surgió inicialmente como respuesta a los aumentos en las tarifas de transporte público, con convocatorias a través de redes sociales, obtuvo un fuerte apoyo popular después de la violenta y desproporcionada represión de la policía , convirtiéndose en uno de los mayores movimientos sociales en la historia de Brasil, comparable sólo con los mo...

  19. Vapor pressures and enthalpies of vaporization of a series of 1- and 2-halogenated naphthalenes

    International Nuclear Information System (INIS)

    Verevkin, Sergey P.

    2003-01-01

    Molar enthalpies of vaporization, Δ l g H m 0 , of 1-methyl-naphthalene, 1-chloro-napthalene, 2-chloro-naphthalene, 1-bromo-naphthalene, 2-bromo-naphthalene, and 1-iodo-naphthalene, as well as molar enthalpies of sublimation, Δ s g H m 0 , of 2-chloro-naphthalene and 2-bromo-naphthalene have been obtained from the temperature dependence of the vapor pressure determined with the transpiration method. These values and the correlation gas-chromatography method, based on the Kovat's index, have been used to determine Δ l g H m 0 and Δ s g H m 0 of 2-iodo-naphthalene. Results obtained in this work have been compared with those from the literature and found consistent

  20. Gas Separation Using Organic-Vapor-Resistent Membranes In Conjunctin With Organic-Vapor-Selective Membranes

    Science.gov (United States)

    Baker, Richard W.; Pinnau, Ingo; He, Zhenjie; Da Costa, Andre R.; Daniels, Ramin; Amo, Karl D.; Wijmans, Johannes G.

    2003-06-03

    A process for treating a gas mixture containing at least an organic compound gas or vapor and a second gas, such as natural gas, refinery off-gas or air. The process uses two sequential membrane separation steps, one using membrane selective for the organic compound over the second gas, the other selective for the second gas over the organic vapor. The second-gas-selective membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons. The membrane steps can be combined in either order.

  1. Vapor pressures and vapor compositions in equilibrium with hypostoichiometric uranium-plutonium dioxide at high temperatures

    International Nuclear Information System (INIS)

    Green, D.W.; Fink, J.K.; Leibowitz, L.

    1982-01-01

    Vapor pressures and vapor compositions in equilibrium with a hypostoichiometric uranium-plutonium dioxide condensed phase (U/sub 1-y/Pu/sub y/)O/sub 2-x/, as functions of T, x, and y, have been calculated for 0.0 less than or equal to x less than or equal to 0.1, 0.0 less than or equal to y less than or equal to 0.3, and for the temperature range 2500 less than or equal to T less than or equal to 6000 K. The range of compositions and temperatures was limited to the region of interest to reactor safety analysis. Thermodynamic functions for the condensed phase and for each of the gaseous species were combined with an oxygen potential model to obtain partial pressures of O, O 2 , Pu, PuO, PuO 2 , U, UO, UO 2 , and UO 3 as functions of T, x, and y

  2. ¿Quién habla de las mujeres en las noticias donde ellas son las protagonistas?

    Directory of Open Access Journals (Sweden)

    Ana Tamarit

    2011-01-01

    Full Text Available Este artículo presenta un análisis de las fuentes que los periodistas utilizan en las informaciones donde las mujeres son protagonistas de las noticias. La investigación -cuantitativa y cualitativa- se ha realizado en los periódicos de ámbito nacional y local de Castilla y León. Con los resultados obtenidos observamos cómo en los periódicos las noticias que hablan de las mujeres en la mayoría de las ocasiones no se firman. Comprobamos cuáles son las fuentes más utilizadas para la elaboración de esas noticias y las diferentes formas de citar a la fuente cuando se trata de un hombre o de una mujer.

  3. Analysis of organic vapors with laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Nozari, Hadi; Tavassoli, Seyed Hassan; Rezaei, Fatemeh

    2015-01-01

    In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor

  4. Measurement and analysis of transient vaporization in oxide fuel materials

    International Nuclear Information System (INIS)

    Benson, D.A.; Bergeron, E.G.

    1979-01-01

    This paper describes a series of experiments in which samples are heated to produce high vapor pressure states in times of 10 -6 to 10 -3 seconds. Experimental measurements of vapor pressures over fresh UO 2 from the pulsed electron beam and pulsed reactor heating tests are presented and compared with other high temperature data. The interpretation of the vapor pressure measured in the tests is discussed in detail. Effects of original sample stoichiometry, chemical interactions with the container and non-equilibrium evaporation due to induced temperature gradients are discussed. Special attention is given to dynamic behavior in rapid heating and vaporization of the oxide due to chemical non-equilibrium. Finally, similar projected reactor experiments on irradiated fuel are described and vapor pressure predictions made using available equilibrium models. A discussion of information accessible from such future tests and its importance is presented. (orig.) [de

  5. Performance of horizontal versus vertical vapor extraction wells

    International Nuclear Information System (INIS)

    Birdsell, K.H.; Roseberg, N.D.; Edlund, K.M.

    1994-06-01

    Vapor extraction wells used for site remediation of volatile organic chemicals in the vadose zone are typically vertical wells. Over the past few years, there has been an increased interest in horizontal wells for environmental remediation. Despite the interest and potential benefits of horizontal wells, there has been little study of the relative performance of horizontal and vertical vapor extraction wells. This study uses numerical simulations to investigate the relative performance of horizontal versus vertical vapor extraction wells under a variety of conditions. The most significant conclusion that can be drawn from this study is that in a homogeneous medium, a single, horizontal vapor extraction well outperforms a single, vertical vapor extraction well (with surface capping) only for long, linear plumes. Guidelines are presented regarding the use of horizontal wells

  6. Pretreated Butterfly Wings for Tuning the Selective Vapor Sensing

    Directory of Open Access Journals (Sweden)

    Gábor Piszter

    2016-09-01

    Full Text Available Photonic nanoarchitectures occurring in the scales of Blue butterflies are responsible for their vivid blue wing coloration. These nanoarchitectures are quasi-ordered nanocomposites which are constituted from a chitin matrix with embedded air holes. Therefore, they can act as chemically selective sensors due to their color changes when mixing volatile vapors in the surrounding atmosphere which condensate into the nanoarchitecture through capillary condensation. Using a home-built vapor-mixing setup, the spectral changes caused by the different air + vapor mixtures were efficiently characterized. It was found that the spectral shift is vapor-specific and proportional with the vapor concentration. We showed that the conformal modification of the scale surface by atomic layer deposition and by ethanol pretreatment can significantly alter the optical response and chemical selectivity, which points the way to the efficient production of sensor arrays based on the knowledge obtained through the investigation of modified butterfly wings.

  7. Pretreated Butterfly Wings for Tuning the Selective Vapor Sensing.

    Science.gov (United States)

    Piszter, Gábor; Kertész, Krisztián; Bálint, Zsolt; Biró, László Péter

    2016-09-07

    Photonic nanoarchitectures occurring in the scales of Blue butterflies are responsible for their vivid blue wing coloration. These nanoarchitectures are quasi-ordered nanocomposites which are constituted from a chitin matrix with embedded air holes. Therefore, they can act as chemically selective sensors due to their color changes when mixing volatile vapors in the surrounding atmosphere which condensate into the nanoarchitecture through capillary condensation. Using a home-built vapor-mixing setup, the spectral changes caused by the different air + vapor mixtures were efficiently characterized. It was found that the spectral shift is vapor-specific and proportional with the vapor concentration. We showed that the conformal modification of the scale surface by atomic layer deposition and by ethanol pretreatment can significantly alter the optical response and chemical selectivity, which points the way to the efficient production of sensor arrays based on the knowledge obtained through the investigation of modified butterfly wings.

  8. Dynamics of trivalent rare earth molecular vapor lasers

    International Nuclear Information System (INIS)

    Krupke, W.F.

    1976-01-01

    Radiative transition probabilities in neodymium bearing vapors are reviewed and calculations are extended to visible laser transitions in terbium bearing vapor. Nonradiative relaxation processes in the pure and complexed halides are treated in greater detail. While precise, quantitative relaxation probabilities cannot be calculated on the basis of information presently available, plausibility arguments can be established which indicate the order of magnitude of relevant nonradiative decay probabilities. Reference to solid and liquid state nonradiative relaxation data for rare earth ions is reviewed to support the plausibility arguments for the vapor state. Having established the likelihood of high fluorescence yields in the vapor phase, various methods of laser pumping are discussed: optical pumping via parity allowed 4f-5d transitions; optical pumping via charge transfer bands of the vapor complex; and direct electron beam pumping

  9. Analysis of organic vapors with laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nozari, Hadi; Tavassoli, Seyed Hassan [Laser and Plasma Research Institute, Shahid Beheshti University, G. C, 1983963113 Evin, Tehran (Iran, Islamic Republic of); Rezaei, Fatemeh, E-mail: fatemehrezaei@kntu.ac.ir [Department of Physics, K. N. Toosi University of Technology, 15875-4416 Shariati, Tehran (Iran, Islamic Republic of)

    2015-09-15

    In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor.

  10. Numerical simulation of superheated vapor bubble rising in stagnant liquid

    Science.gov (United States)

    Samkhaniani, N.; Ansari, M. R.

    2017-09-01

    In present study, the rising of superheated vapor bubble in saturated liquid is simulated using volume of fluid method in OpenFOAM cfd package. The surface tension between vapor-liquid phases is considered using continuous surface force method. In order to reduce spurious current near interface, Lafaurie smoothing filter is applied to improve curvature calculation. Phase change is considered using Tanasawa mass transfer model. The variation of saturation temperature in vapor bubble with local pressure is considered with simplified Clausius-Clapeyron relation. The couple velocity-pressure equation is solved using PISO algorithm. The numerical model is validated with: (1) isothermal bubble rising and (2) one-dimensional horizontal film condensation. Then, the shape and life time history of single superheated vapor bubble are investigated. The present numerical study shows vapor bubble in saturated liquid undergoes boiling and condensation. It indicates bubble life time is nearly linear proportional with bubble size and superheat temperature.

  11. Measurement and analysis of transient vaporization in oxide fuel materials

    International Nuclear Information System (INIS)

    Gorham-Bergeron, E.; Benson, D.A.

    1978-01-01

    A series of experiments is described in which samples are heated to produce high vapor pressure states in times of 10 -6 to 10 -3 seconds. Experimental measurements of vapor pressures over fresh UO 2 from the pulsed electron beam and pulsed reactor heating tests are presented and compared with other high temperature data. The interpretation of the vapor pressures measured in the tests is discussed in detail. Effects of original sample stoichiometry, chemical interactions with the container and non-equilibrium evaporation due to induced temperature gradients are discussed. Special attention is given to dynamic behavior in rapid heating and vaporization of the oxide due to chemical nonequilibrium. Finally, similar projected reactor experiments on irradiated fuel are described and vapor pressure predictions made using available equilibrium models. A discussion of information accessible from such future tests and its importance is presented

  12. Analysis of the transient compressible vapor flow in heat pipe

    Science.gov (United States)

    Jang, Jong Hoon; Faghri, Amir; Chang, Won Soon

    1989-01-01

    The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures.

  13. Usos de las herramientas digitales entre las personas mayores

    Directory of Open Access Journals (Sweden)

    Javier Fombona Cadavieco

    2012-10-01

    Full Text Available Una sociedad «multiedades» supone diseñar y crear nuevos espacios de aprendizaje y comunicación, capaces de gestionar la demanda existente por parte de las personas mayores. En este artículo, se aborda la relación de las personas mayores con las tecnologías de la información y la comunicación (TIC y para ello se plantean dos objetivos: el primero va dirigido a conocer los recursos tecnológicos que utilizan y el segundo, a describir objetivamente los tipos de uso que estas personas hacen de las TIC. Para ello, se utiliza la técnica de encuesta, cuyos resultados son contrastados mediante grupos de discusión. En el estudio participaron 215 personas mayores usuarias de las TIC y siete grupos de discusión de cinco personas cada uno. Los resultados encontrados indican que los recursos que más utilizan los mayores son, los ordenadores e Internet y el uso que hacen de los mismos se ha agrupado en cuatro grandes categorías: formación, información, comunicación y entretenimiento, no encontrándose diferencias significativas en función del género o de la edad y sí se encontraron diferencias en cuanto a la disponibilidad de dichos recursos para uso particular en función del nivel de estudios.

  14. Headspace gas and vapor characterization summary for the 43 vapor program suspect tanks

    International Nuclear Information System (INIS)

    Huckaby, J.L.; Bratzel, D.R.

    1995-01-01

    During the time period between February 1994 and September 1995, Westinghouse Hanford Company (WHC) sampled the waste tank headspace of 43 single-shell tanks for a variety of gaseous and/or volatile and semi-volatile compounds. This report summarizes the results of analyses of those sampling activities with respect to both the Priority 1 Safety Issues and relative to the detection in the headspace of significant concentrations of target analytes relating to worker breathing space consideration as recommended by the Pacific Northwest Laboratory (PNL) Toxicology Review Panel. The information contained in the data tables was abstracted from the vapor sampling and analysis tank characterization reports. Selected results are tabulated and summarized. Sampling equipment and methods, as well as sample analyses, are briefly described. Vapor sampling of passively ventilated single-shell tanks (tanks C-105, C-106, and SX-106 were sampled and are actively ventilated) has served to highlight or confirm tank headspace conditions associated with both priority 1 safety issues and supports source term analysis associated with protecting worker health and safety from noxious vapors

  15. HANFORD CHEMICAL VAPORS WORKER CONCERNS and EXPOSURE EVALUATION

    International Nuclear Information System (INIS)

    ANDERSON, T.J.

    2006-01-01

    Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site in eastern Washington State are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. Tank farm contractors are in the process of retrieving all remaining waste from aging single-shell tanks, some of which date to World War II, and transferring it to newer double-shell tanks. During the waste retrieval process, tank farm workers are potentially exposed to fugitive chemical vapors that can escape from tank headspaces and other emission points. The tanks are known to hold more than 1,500 different species of chemicals, in addition to radionuclides. Exposure assessments have fully characterized the hazards from chemical vapors in half of the tank farms. Extensive sampling and analysis has been done to characterize the chemical properties of hazardous waste and to evaluate potential health hazards of vapors at the ground surface, where workers perform maintenance and waste transfer activities. Worker concerns. risk communication, and exposure assessment are discussed, including evaluation of the potential hazards of complex mixtures of chemical vapors. Concentrations of vapors above occupational exposure limits-(OEL) were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors have been measured above 50% of their OELs more than five feet from the source. Vapor controls are focused on limited hazard zones around sources. Further evaluations of vapors include analysis of routes of exposure and thorough analysis of nuisance odors

  16. Dynamic friction characterization in a turbine rotor and metallographic analysis of the friction element; Caracterizacion dinamica del rozamiento en rotor de turbina y analisis metalografico del elemento de rozamiento

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Solis, Jose Antonio; Cristalinas Navarro, Victor Manuel; Mojica Calderon, Cecilio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2007-11-15

    As a part of the diagnosis of the root cause of the blades fault of the of the L-1 wheel of a of low pressure rotor of 300 MW, in one of the Power stations of Electrical Generation, a design was made and an experimental rubbing test of friction in the same rotor was performed but in the adjacent wheel of movable blades L-2. The objectives of the experimental rubbing test were to determine the dynamic characteristics of the rubbing to corroborate what was observed in the diagrams of spectra registered by the power station during the operation of the Unit, to determine the maximum bending stress of the used element to provide rubbing to the wheel of blades L-2 and to infer in a qualitative way the magnitude of the necessary friction force to generate the dynamic characteristics of the rubbing and finally to determine the micro-structural changes that underwent the element employed to apply rubbing. [Spanish] Como parte del diagnostico de la causa raiz de la falla de los alabes de la rueda L-1 de un rotor de baja presion de 300 MW, en una de las Centrales de Generacion Electrica, se diseno y efectuo una prueba experimental de rozamiento en el mismo rotor pero en la rueda adyacente de alabes moviles L-2. Los objetivos de la prueba experimental de rozamiento fueron determinar las caracteristicas dinamicas del rozamiento para corroborar lo observado en los diagramas de espectros registrados por la Central durante la operacion de la Unidad, determinar el esfuerzo maximo a la flexion del elemento utilizado para suministrar rozamiento a la rueda de alabes L-2 e inferir de manera cualitativa la magnitud de la fuerza de rozamiento necesaria para generar las caracteristicas dinamicas del razonamiento y por ultimo determinar los cambios microestructurales que experimento el elemento utilizado para aplicar rozamiento.

  17. Dynamic characterization of the friction in turbine rotor and metallographic analysis of the friction element; Caracterizacion dinamica del rozamiento en rotor de turbina y analisis metalografico del elemento de rozamiento

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Solis, Jose Antonio; Cristalinas Navarro, Victor Manuel; Mojica Calderon, Cecilio [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2010-07-01

    As a part of the diagnosis of the root cause of the fault of the blades of the L-1 wheel of a of low pressure rotor of 200 MW, in one of the power stations of electrical generation, an experimental test of friction in the same rotor was designed and carried out, but in the adjacent wheel of movable blades L-2. The objectives of the friction experimental test were to determine the dynamic characteristics of the friction, to corroborate what it was observed in the spectra diagrams registered by the power station during the operation of the unit, to determine the maximum bending stress of the used element to provide friction to the wheel of L-2 blades and to infer, in a qualitative way, the magnitude of the force of friction necessary to generate the dynamic characteristics of the friction and finally to determine the micro-structural changes that underwent the used element to apply friction. [Spanish] Como parte del diagnostico de la causa raiz de la falla de los alabes de la rueda L-1 de un rotor de baja presion de 200 MW, en una de las centrales de generacion electrica, se diseno y efectuo una prueba experimental de rozamiento en el mismo rotor, pero en la rueda adyacente de alabes moviles L-2. Los objetivos de la prueba experimental de rozamiento fueron determinar las caracteristicas dinamicas del razonamiento, para corroborar lo observado en los diagramas de espectros registrados por la central durante la operacion de la unidad, determinar el esfuerzo maximo a la flexion del elemento utilizado para suministrar rozamiento a la rueda de alabes L-2 e inferir, de manera cualitativa, la magnitud de la fuerza de rozamiento necesaria para generar las caracteristicas dinamicas del rozamiento y por ultimo determinar los cambios microestructurales que experimento el elemento utilizado para aplicar rozamiento.

  18. Las rondas de las mujeres por las ventanillas del Estado: Etnografia de un trabajo invisible

    Directory of Open Access Journals (Sweden)

    Emilia Schijman

    2011-06-01

    Full Text Available A partir de una investigación de campo en un barrio de vivienda social de la periferia parisina, el artículo explora los circuitos diarios de las mujeres por las oficinas del Estado. El análisis muestra el trabajo en la ventanilla como una movilización cotidiana, individual y colectiva, que liga sin cesar la esfera doméstica y la esfera pública, la práctica burocrática y la micro-política. Familiarizarse con las categorías administrativas y jurídicas, manipular diferentes regímenes de solicitación, juntar testigos y acumular pruebas escritas, todas estas actividades forman un trabajo invisible pero imprescindible para reclamar derechos y activar la economía de la familia.

  19. Prediction of vapor pressure and heats of vaporization of edible oil/fat compounds by group contribution

    DEFF Research Database (Denmark)

    Ceriani, Roberta; Gani, Rafiqul; Liu, Y.A.

    2013-01-01

    In the present work, a group contribution method is proposed for the estimation of vapor pressures and heats of vaporization of organic liquids found in edible fat/oil and biofuel industries as a function of temperature. The regression of group contribution parameters was based on an extensive...

  20. Demand management in steam generation?; Administracion de la demanda en la generacion de vapor?

    Energy Technology Data Exchange (ETDEWEB)

    Plauchu L., A.; Plauchu A., J. A. [Ingenieros consultores (Mexico)

    1997-12-31

    Energy management has acquired capital importance in all the branches of the industrial activity and services either private o public and it has been, from years behind, more familiar the technology for the demand control in the electric power distribution systems, with excellent results in the energy conservation and economy. The rate of consumption for the different forms of energy shows the prevalence of the thermal energy in a variety of end uses. Not much or almost nothing has been said of the term Demand Management or Control in Steam Generation although 12% of the total energy supply is used for this purpose. Steam demand management and control can avoid unnecessary investments that bring along the increment of operational and maintenance problems and it is for sure that it will always give raise to a more rational and economical utilization of the real capacity of steam generation. A real case is commented. [Espanol] La administracion de la energia ha cobrado importancia capital en todos los giros de actividad industrial y de servicios, privados y publicos y es de varios anos atras cada vez mas familiar la tecnologia en el control de demanda en los sistemas de distribucion de energia electrica, con magnificos resultados en el ahorro, energetico y economico. La relacion de consumos para las diferentes formas de energia muestra el predominio de la energia termica en una variedad de usos finales. Poco o nada oimos del termino Administracion o Control de Demanda en la Generacion de Vapor aun cuando el 12% de la oferta total de energia tiene como destino esta aplicacion. La administracion y control de la demanda de vapor puede evitar inversiones innecesarias e incremento de problemas de operacion y mantenimiento y con seguridad reportaran siempre una utilizacion mas racional y economica de la capacidad real de generacion de vapor, se comenta un caso real.

  1. Demand management in steam generation?; Administracion de la demanda en la generacion de vapor?

    Energy Technology Data Exchange (ETDEWEB)

    Plauchu L, A; Plauchu A, J A [Ingenieros consultores (Mexico)

    1998-12-31

    Energy management has acquired capital importance in all the branches of the industrial activity and services either private o public and it has been, from years behind, more familiar the technology for the demand control in the electric power distribution systems, with excellent results in the energy conservation and economy. The rate of consumption for the different forms of energy shows the prevalence of the thermal energy in a variety of end uses. Not much or almost nothing has been said of the term Demand Management or Control in Steam Generation although 12% of the total energy supply is used for this purpose. Steam demand management and control can avoid unnecessary investments that bring along the increment of operational and maintenance problems and it is for sure that it will always give raise to a more rational and economical utilization of the real capacity of steam generation. A real case is commented. [Espanol] La administracion de la energia ha cobrado importancia capital en todos los giros de actividad industrial y de servicios, privados y publicos y es de varios anos atras cada vez mas familiar la tecnologia en el control de demanda en los sistemas de distribucion de energia electrica, con magnificos resultados en el ahorro, energetico y economico. La relacion de consumos para las diferentes formas de energia muestra el predominio de la energia termica en una variedad de usos finales. Poco o nada oimos del termino Administracion o Control de Demanda en la Generacion de Vapor aun cuando el 12% de la oferta total de energia tiene como destino esta aplicacion. La administracion y control de la demanda de vapor puede evitar inversiones innecesarias e incremento de problemas de operacion y mantenimiento y con seguridad reportaran siempre una utilizacion mas racional y economica de la capacidad real de generacion de vapor, se comenta un caso real.

  2. Experimental Validation of Hybrid Distillation-Vapor Permeation Process for Energy Efficient Ethanol-Water Separation

    Science.gov (United States)

    The energy demand of distillation-based systems for ethanol recovery and dehydration can be significant, particularly for dilute solutions. An alternative separation process integrating vapor stripping with a vapor compression step and a vapor permeation membrane separation step,...

  3. Las herramientas del marketing y las tics: su uso en las Pymes para el desarrollo empresarial

    Directory of Open Access Journals (Sweden)

    Dianexy Carreño Villavicencio

    2015-12-01

    Full Text Available El mundo del marketing ha cambiado significativamente en los últimos años debido, en gran parte, al surgimiento del Internet como herramienta de investigación y búsqueda. Este se ha constituido en uno de los elementos  tecnológicos  más significantes  dentro  del ambiente empresarial. La facilidad que el Internet ofrece a las empresas para acceder a información y proveer datos relacionados  a las transacciones  de negocio,  habilita a dichas empresas  a lograr mayores resultados en su estrategia de marketing. Independientemente del tamaño de la empresa, el Internet ha permitido que estas hayan cambiado la forma de acceder y proveer información.  Este, además,  ha sentado nuevas pautas en la manera de comprar, buscar, recopilar  y aprender.  En este  estudio,  realizado  en  la  ciudad  de  Manta  -  Ecuador,  los resultados demuestran que todas las pymes están conectadas al Internet y solo 3 de cada 10 tienen departamento de marketing  y no emplean adecuadamente  las herramientas que el marketing y las TIC les proporcionan   para alcanzar un mejor desarrollo empresarial. La investigación   realizada   fue cualitativa,   usándose   la   técnica   de   la   encuesta    para  el levantamiento de la información. Por tanto, puede afirmarse que no existe una cultura de marketing en las pymes de la ciudad de Manta - Ecuador. Palabras clave: Generalidades, marketing, publicidad, otros.

  4. Virtual test bench as a complement to study thermal area: application in vapor compression systems

    Directory of Open Access Journals (Sweden)

    Juan Manuel Belman-Flores

    2015-01-01

    Full Text Available Este artículo describe un simulador educativo desarrollado en el software Engineering Equation Solver para representar el comportamiento de un sistema de compresión de vapor. La aplicación está enfocada con propósitos educativos, particularmente para que estudiantes de ingeniería adquieran habilidades en el manejo de instalaciones de refrigeración. Mediante el uso de este simulador, los estudiantes tendrán la capacidad de analizar fácilmente la infl uencia que tienen parámetros medidos experimentalmente (como la velocidad de rotación del compresor, el fl ujo volumétrico y la temperatura de fl uidos secundarios sobre la efi ciencia energética del sistema y sus componentes principales. El banco virtual consta de una pantalla principal que muestra un esquema general del sistema de compresión de vapor con parámetros de entrada y de salida. Desde la pantalla principal, el desempeño de los componentes principales puede ser analizado. Finalmente, este banco de pruebas virtual ha sido probado por estudiantes de ingeniería, concluyendo que el simulador es una herramienta de apoyo que permite mejorar el aprendizaje de las diferentes áreas del conocimiento.

  5. Las fotocomposiciones de Enric Miralles

    Directory of Open Access Journals (Sweden)

    Dra. Arq. Laura Lopes Cezar

    2013-04-01

    Full Text Available Las fotocomposiciones del arquitecto catalán Enric Miralles fueron investigadas en mi tesis doctoral realizada en la Universidad Politécnica da Cataluña como integrantes de su proceso de diseño. Este trabajo inicia con una breve introducción al tema de la fotocomposición a respecto de sus orígenes y evolución en el arte dadaísta y surrealista, presentando una continuidad con el cubismo de Picasso y posteriormente las fotocomposiciones de David Hockney que fueron sin duda una referencia al trabajo de Enric Miralles. Las fotocomposiciones de Enric Miralles se confguran como un medio investigativo y representativo dentro del universo de la arquitectura y de su proceso de diseño. El análisis de sus fotocomposiciones es de fundamental relevancia para el acercamiento de las asignaturas de representación gráfca y de proyectación con la puesta en valor en los procesos creativos

  6. Los Problemas de las Gimnasias

    Directory of Open Access Journals (Sweden)

    Viviana Bulus Rossini

    2011-11-01

    Full Text Available Este artículo se propone sintetizar las principales ideas de las ponencias presentadas en la Mesa de Trabajo "Los problemas de las Gimnasias" que se desarrolló en el marco del 9º Congreso Argentino y 4º Latinoamericano de Educación Física y Ciencias realizado en la Universidad Nacional de La Plata en junio de 2011. Todas ellas coinciden en pensar a la Gimnasia como parte fundamental de una Educación Corporal que se proponga transmitir aquellos saberes corporales culturalmente significativos que sirvan de herramientas para el conocimiento, el cuidado y la autogestión del propio cuerpo. A partir de estos puntos de coincidencia cada ponencia se explaya en su especificidad: ya sea desde la investigación y el análisis de los textos de divulgación y académicos, de los discursos de profesores, alumnos y practicantes; desde el análisis crítico del campo gímnico actual; desde propuestas bien concretas de trabajo de las gimnasias, en este caso la gimnasia aeróbica, la gimnasia funcional, el Método Pilates, o la gimnasia en el Profesorado en Educación Física con proyección en la gimnasia escolar

  7. Del aislacionismo a las alianzas

    Directory of Open Access Journals (Sweden)

    Michavila, Francisco

    2011-12-01

    Full Text Available The universities have passed to look within to seek opportunities for collaboration, either between universities or with public and private entities in other areas. The construction of the European Higher Education Area and the internationalization of universities have made cooperation and partnerships an emerging value for the future. In a scenario of competition between universities, partnerships are essential for the multiplication of opportunities in attracting top students, teachers and university researchers, and to improve the results of university activity.

    Las universidades han pasado de mirar al interior a la búsqueda de oportunidades para la colaboración, sea entre universidades o con entidades públicas y privadas de otros ámbitos. La construcción del Espacio Europeo de Educación Superior y la internacionalización de las universidades han convertido a la cooperación y las alianzas en un valor emergente para el futuro. En un escenario de competencia entre universidades, las alianzas son indispensables para la multiplicación de oportunidades en la captación de los mejores estudiantes, profesores e investigadores universitarios, así como para favorecer los resultados de la actividad universitarias.

  8. Violencia intrafamiliar contra las mujeres

    Directory of Open Access Journals (Sweden)

    Omar Huertas Díaz

    2012-07-01

    Full Text Available El presente texto pretende abordar el tema de violencia en contra de las mujeres desde la perspectiva familiar, es decir la violencia intrafamiliar o también llamada doméstica, entendida y afirmada desde la Corte Constitucional, como aquella violencia que causa daño o maltrato físico, psíquico o sexual, trato cruel, intimidatorio o degradante, amenaza, agravio, ofensa o cualquier otra forma de agresión, producida entre miembros de una familia, llámese cónyuge o compañero permanente, padre o madre, aunque no convivan bajo el mismo techo, ascendientes o descendientes de estos incluyendo hijos adoptivos, y en general todas las personas que de manera permanente se hallaren integrados a la unidad doméstica. Junto a ello el documento explicará de qué forma afecta esta particular clase de violencia a las mujeres, los abusos y malos tratos que la materializan, y las medidas adoptadas por el Estado Colombiano para enfrentar sus consecuencias, y por último la presentación de los conceptos que maneja la Corte Constitucional en la interpretación de dicho fenómeno.

  9. Impacto ambiental de las incineradoras

    OpenAIRE

    Saiz de Omeñaca, José Antonio; Saiz de Omeñaca, Jesús

    1996-01-01

    The pollution caused by incineration plants may be considered quite substantial. It is important to know the risks in order to be able to reduce the impacts.

    La contaminación causada por las incineradoras es, potencialmente, muy importante. Conocer los riesgos ayuda a tomar decisiones para minimizar los impactos.

  10. Aluminum coating by fluidized bed chemical vapor deposition on austenitic stainless steels AISI 304 and AISI 316

    Directory of Open Access Journals (Sweden)

    Jose Luddey Marulanda-Arevalo

    2015-01-01

    Full Text Available Los revestimientos de aluminio f ueron depositados sobre aceros inoxidables AISI 304 y AISI 316 en el rango de temperatura de 5 60 a 600 °C por deposición química de vapor en lecho fluidizado(CVD – FBR. Se utilizó un lecho que consistía en 10 % de aluminio en polvo y 90 % de lecho inerte (alúmina, el cual fue fluidizado con Ar y como ga ses activadores se utilizó una mezcla de ácido clorhídrico con hidrógeno (HCl/H 2 . En el recubrimiento si n tratamiento térmico están las siguiente s especies: Al 13 Fe 4 , Fe 2 Al 5 , FeAl 2 y Al 5 FeNi, las cuales están presentes para ambos aceros. Además, el tratamiento térmico provoca la difusa de alu minio hacia el sustrato y la difusa de hierro del sustrato haci a la superficie del recubrimiento, haciendo la trans formación de los compuestos ant eriores a FeAl, Fe 2 Al 5 , FeAl 2 , Al 0.99 Fe 0.99 Ni 0.02 , AlNi y el Fe 2 AlCr. Se realizó la simulación termodinámica con el s oftware Thermo Calc para obt ener información de la posible composición y la cantidad de mat erial depositado, para condiciones seleccionadas. Las muestras recubi ertas y sin recubrir, se expus ieron a 750 ºC en una atmósfera d onde el vapor agua se transporta a las muestras usando un flujo de N 2 de 40 ml/min, más 100 % vapor de agua (H 2 O. Los dos sustratos sin revestir se comportaron de manera diferente, ya que el acero AISI 304 soportó bien el a taque y ganó poco peso (0.49 mg/cm 2 , en comparación con el acero AISI 316 que perdió mucho peso (25.4 mg/cm 2 . Los aceros recubiertos ganaron poco de peso durante las mil horas de exposición (0.26 mg/cm 2 y soportaron muy bien el ataque corrosivo en c omparación con sustratos sin r ecubrimiento.

  11. Colombia: Escenario de las desigualdades

    Directory of Open Access Journals (Sweden)

    Amylkar Acosta Medina

    2013-01-01

    Full Text Available La distribución del ingreso de la sociedad colombiana dista de ser equitativa. La desigualdad se manifiesta en todos los órdenes de la vida nacional, como consecuencia de un enfoque histórico de las políticas públicas, hacia la regionalización del desarrollo. Las costas Caribe y Pacífica colombianas, presentan las cifras más críticas en materia de desempeño económico y social, situación que se opone al contexto internacional, en donde las zonas costeras son justamente las regiones más prósperas. Los bajo niveles de integración y crecimiento económico regionales, inherentes al atraso en infraestructura de transporte, permiten identificar la recurrente centralización del poder público, que privilegia el desarrollo de unas regiones, mientras otras permanecen rezagadas. Esta estrategia refuerza el desequilibrio económico, social y político, y redunda en la ineficiencia económica nacional. En consecuencia, si bien los índices de producción van en aumento, las tasas de desempleo y la informalidad laboral también muestran una tendencia creciente, teniendo en cuenta que los sectores productivos de mayor crecimiento son aquellos intensivos en capital y no tan intensivos en recurso humano. Lo anterior, sumado al creciente desplazamiento forzado de la población rural que tienen origen en la desigualdad, el desempleo y la pobreza. Así pues, el país enfrenta un gran reto en el sentido de reorientar las políticas de desarrollo, que corrijan los desequilibrios interregionales e intraregionales. Esto, acompañado de la transparencia en el ejercicio de la Política y la integridad en la administración pública, elementos indispensables en la estrategia de desarrollo que requiere el país.

  12. Nota de las editoras invitadas

    Directory of Open Access Journals (Sweden)

    María Eugenia Ibarra Melo

    2016-01-01

    Full Text Available Los estudios de género cada vez adquieren mayor importancia en las Ciencias Sociales, en general y en la sociología, en particular, sobre todo porque en ellos se tratan problemas contemporáneos ligados a la sexualidad, la diversidad, la estructuración de las relaciones de poder, los cuales han sido expresados en público a través de las resistencias que despliegan sus principales afectados. Como demuestran los artículos publicados en revistas dedicadas a estas reflexiones[1], estos estudios se ocupan de las desigualdades sociales entre hombres y mujeres, de la producción de exclusiones y de las identidades diversas que no se ajustan al modelo de género. [1] Entre otras revistas consultadas están: la Revista Interdisciplinaria de Estudios de Género, de El Colegio de México; la Revista de Estudios de Género. La Ventana, de la Universidad de Guadalajara; la Revista Punto G(énero del Núcleo género y sociedad Julieta Kirkwood, de la Universidad de Chile; Nomadías. Revista del Centro de Estudios de Género y Cultura de América Latina, de la Universidad de Chile; Íconos. Revista de Ciencias Sociales, de la Facultad Latinoamericana de Ciencias Sociales. Ecuador, que dedicó tres números a temas relacionados: n.° 45: Nuevas voces feministas en América Latina: ¿continuidades, rupturas, resistencias?, n.° 39: ¿Cómo se piensa lo Queer en América Latina, n.° 35: Ciudadanías y sexualidades en América Latina; La Aljaba Segunda época: Revista de Estudios de la Mujer, de las universidades del Comahue, de Luján y de La Pampa (Argentina, y Cadernos Pagu, Nucleo de estudos de gênero Pagu, de la Universidad de Campinas, de Brasil. Además de las revistas colombianas La Manzana de la Discordia, Sociedad y Economía, CS y otras que recientemente dedicaron monográficos a estos estudios.

  13. Analyses on Water Vapor Resource in Chengdu City

    Science.gov (United States)

    Liu, B.; Xiao, T.; Wang, C.; Chen, D.

    2017-12-01

    Chengdu is located in the Sichuan basin, and it is the most famous inland city in China. With suitable temperatures and rainfall, Chengdu is the most livable cities in China. With the development of urban economy and society, the population has now risen to 16 million, and it will up to 22 million in 2030. This will cause the city water resources demand, and the carrying capacity of water resources become more and more serious. In order to improve the contradiction between urban waterlogging and water shortage, sponge city planning was proposed by Chengdu government, and this is of great practical significance for promoting the healthy development of the city. Base on the reanalysis data from NCEP during 2007-2016, the characters of Water Vapor Resources was analyzed, and the main contents of this research are summarized as follows: The water vapor resource in Chengdu plain is more than that in Southeast China and less in Northwest China. The annual average water vapor resource is approximately 160 mm -320 mm, and the water vapor resource in summer can reach 3 times in winter. But the annual average precipitation in Chengdu is about 800 mm -1200 mm and it is far greater than the water vapor resource, this is because of the transport of water vapor. Using the formula of water vapor flux, the water vapor in Chengdu is comes from the west and the south, and the value is around 50kg/(ms). Base on the calculation of boundary vapor budget, the water vapor transport under 500hPa accounted for 97% of the total. Consider the water vapor transport, transformation and urban humidification effect, the Water Vapor Resource in Chengdu is 2500mm, and it can be used by artificial precipitation enhancement. Therefore, coordinated development of weather modification and sponge city construction, the shortage of water resources in Chengdu plain can be solved. Key words: Chengdu; Sponge city; Water vapor resource; Precipitation; Artificial precipitation enhancement Acknowledgements

  14. Hybrid Vapor Stripping-Vapor Permeation Process for Recovery and Dehydration of 1-Butanol and Acetone/Butanol/Ethanol from Dilute Aqueous Solutions. Part 2. Experimental Validation with Simple Mixtures and Actual Fermentation Broth

    Science.gov (United States)

    BACKGROUND: In Part1 of this work, a process integrating vapor stripping, vapor compression, and a vapor permeation membrane separation step, Membrane Assisted Vapor Stripping (MAVS), was predicted to produce energy savings compared to traditional distillation systems for separat...

  15. El lavado y cuidado de las manos

    OpenAIRE

    Troconis Ganimez, J.E.

    2003-01-01

    Resumen En el presente trabajo hacemos notar la importancia del lavado y cuidado de las manos en el personal del equipo de salud odontológico, aquí incluimos las técnicas correctas del lavado de las manos, la importancia del jabón y los antisépticos que han sido incluidos en los mismos, la técnica como deben ser secadas las manos una vez lavadas, por último hacemos algunas consideraciones en el cuidado general de las manos, mantenimiento de las uñas y el uso de cremas hidratantes.

  16. Non-equilibrium phenomena near vapor-liquid interfaces

    CERN Document Server

    Kryukov, Alexei; Puzina, Yulia

    2013-01-01

    This book presents information on the development of a non-equilibrium approach to the study of heat and mass transfer problems using vapor-liquid interfaces, and demonstrates its application to a broad range of problems. In the process, the following peculiarities become apparent: 1. At vapor condensation on the interface from gas-vapor mixture, non-condensable components can lock up the interface surface and condensation stops completely. 2. At the evolution of vapor film on the heater in superfluid helium (He-II), the boiling mass flux density from the vapor-liquid interface is effectively zero at the macroscopic scale. 3. In problems concerning the motion of He-II bridges inside capillaries filled by vapor, in the presence of axial heat flux the He-II bridge cannot move from the heater as would a traditional liquid, but in the opposite direction instead. Thus the heater attracts the superfluid helium bridge. 4. The shape of liquid-vapor interface at film boiling on the axis-symmetric heaters immersed in l...

  17. Toxicity of vapor phase petroleum contaminants to microbial degrader communities

    International Nuclear Information System (INIS)

    Long, S.C.; Davey, C.A.

    1994-01-01

    Petroleum products constitute the largest quantity of synthetic organic chemical products produced in the US. They are comprised of mostly hydrocarbon constituents from many different chemical classes including alkenes, cycloalkanes, aromatic compounds, and polyaromatic hydrocarbons. Many petroleum constituents are classified as volatile organic compounds or VOCs. Petroleum products also constitute a major portion of environmental pollution. One emerging technology, with promise for applications to VOCs in subsurface soil environments, is bioventing coupled with soil vapor extraction. These technologies involve volatilization of contaminants into the soil gas phase by injection and withdrawal of air. This air movement causes enhancement of the aerobic microbial degradation of the mobilized vapors by the indigenous populations. This study investigated the effects of exposure of mixed, subsurface microbial communities to vapor phase petroleum constituents or vapors of petroleum mixtures. Soil slurries were prepared and plated onto mineral salts agar plates and exposed to vapor phase contaminants at equilibrium with pure product. Representative n-alkane, branched alkane, cycloalkane, and aromatic compounds were tested as well as petroleum product mixtures. Vapor exposure altered the numbers and morphologies of the colonies enumerated when compared to controls. However, even at high, equilibrium vapor concentrations, microbial degrader populations were not completely inhibited

  18. Bionanomaterials and Bioinspired Nanostructures for Selective Vapor Sensing

    Science.gov (United States)

    Potyrailo, Radislav; Naik, Rajesh R.

    2013-07-01

    At present, monitoring of air at the workplace, in urban environments, and on battlefields; exhaled air from medical patients; air in packaged food containers; and so forth can be accomplished with different types of analytical instruments. Vapor sensors have their niche in these measurements when an unobtrusive, low-power, and cost-sensitive technical solution is required. Unfortunately, existing vapor sensors often degrade their vapor-quantitation accuracy in the presence of high levels of interferences and cannot quantitate several components in complex gas mixtures. Thus, new sensing approaches with improved sensor selectivity are required. This technological task can be accomplished by the careful design of sensing materials with new performance properties and by coupling these materials with the suitable physical transducers. This review is focused on the assessment of the capabilities of bionanomaterials and bioinspired nanostructures for selective vapor sensing. We demonstrate that these sensing materials can operate with diverse transducers based on electrical, mechanical, and optical readout principles and can provide vapor-response selectivity previously unattainable by using other sensing materials. This ability for selective vapor sensing provides opportunities to significantly impact the major directions in development and application scenarios of vapor sensors.

  19. New Regenerative Cycle for Vapor Compression Refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Mark J. Bergander

    2005-08-29

    The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available geothermal heat pumps manufactured by US and foreign companies. Other objectives are to optimize the design parameters and to determine the economic viability of the new technology. Background (as stated in the proposal): The proposed technology closely relates to EERE mission by improving energy efficiency, bringing clean, reliable and affordable heating and cooling to the residential and commercial buildings and reducing greenhouse gases emission. It can provide the same amount of heating and cooling with considerably less use of electrical energy and consequently has a potential of reducing our nations dependence on foreign oil. The theoretical basis for the proposed thermodynamic cycle was previously developed and was originally called a dynamic equilibrium method. This theory considers the dynamic equations of state of the working fluid and proposes the methods for modification of T-S trajectories of adiabatic transformation by changing dynamic properties of gas, such as flow rate, speed and acceleration. The substance of this proposal is a thermodynamic cycle characterized by the regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The essential new features of the process are: (1) The application of two-step throttling of the working fluid and two-step compression of its vapor phase. (2) Use of a compressor as the initial step compression and a jet device as a second step, where throttling and compression are combined. (3) Controlled ratio of a working fluid at the first and

  20. Enhanced Attenuation Technologies: Passive Soil Vapor Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, K.; Looney, B.; Kamath, R.; Adamson, D.; Newell, C.

    2010-03-15

    Passive soil vapor extraction (PSVE) is an enhanced attenuation (EA) approach that removes volatile contaminants from soil. The extraction is driven by natural pressure gradients between the subsurface and atmosphere (Barometric Pumping), or by renewable sources of energy such as wind or solar power (Assisted PSVE). The technology is applicable for remediating sites with low levels of contamination and for transitioning sites from active source technologies such as active soil vapor extraction (ASVE) to natural attenuation. PSVE systems are simple to design and operate and are more cost effective than active systems in many scenarios. Thus, PSVE is often appropriate as an interim-remedial or polishing strategy. Over the past decade, PSVE has been demonstrated in the U.S. and in Europe. These demonstrations provide practical information to assist in selecting, designing and implementing the technology. These demonstrations indicate that the technology can be effective in achieving remedial objectives in a timely fashion. The keys to success include: (1) Application at sites where the residual source quantities, and associated fluxes to groundwater, are relatively low; (2) Selection of the appropriate passive energy source - barometric pumping in cases with a deep vadose zone and barrier (e.g., clay) layers that separate the subsurface from the atmosphere and renewable energy assisted PSVE in other settings and where higher flow rates are required. (3) Provision of sufficient access to the contaminated vadose zones through the spacing and number of extraction wells. This PSVE technology report provides a summary of the relevant technical background, real-world case study performance, key design and cost considerations, and a scenario-based cost evaluation. The key design and cost considerations are organized into a flowchart that dovetails with the Enhanced Attenuation: Chlorinated Organics Guidance of the Interstate Technology and Regulatory Council (ITRC). The PSVE