From crocodile to woman - the multidimensionality and energy dynamic of movement seen in light of the dance therapy form Dansergia

DEFF Research Database (Denmark)

Winther, Helle

2006-01-01

The chapter focuses on movement as primary language, exxploring the multidimensionality and energy dynamics of movement through the connections between the concepts of body and energy. A session from the dance therapy form Dansergia with a woman, here called Clara, is narrated, analysed...... and compared to a daily life scene with the child Nina. These scenes are discussed in relation to phenomenological and energy theoretical aspects in order to open the research field for psychological themes, which include the body and yet do not exclude culture, history, and community. In order to...... respect the nonlinear movement language of the body, data and theory are in this chapter woven closely and organically together to follow the processes of Nina and Clara....

Produção e características físico-químicas dos cachos da videira 'BRS Clara' sob cobertura plástica e sombrite em safra fora de época

Directory of Open Access Journals (Sweden)

Lilian Yukari Yamamoto

2012-03-01

Full Text Available Devido às condições climáticas favoráveis à ocorrência de doenças fúngicas em uvas de mesa, tem-se buscado a adoção de tecnologias que propiciem a redução nos custos de produção, sendo uma alternativa o cultivo de uvas sob cobertura plástica. O objetivo deste trabalho foi avaliar a produção e as características físico-químicas dos cachos da videira 'BRS Clara' enxertada sobre o porta-enxerto IAC-766 'Campinas', em cultivo protegido durante a safra fora de época, visando à redução da aplicação de fungicidas para o controle do míldio. Os experimentos foram realizados em pomares comerciais localizados em Uraí e Marialva-PR. As videiras foram conduzidas no sistema latada, em espaçamento de 4,0 x 4,0 m, em Uraí, e de 2,0 x 5,0 m, em Marialva. O delineamento experimental foi o inteiramente casualizado, com dois sistemas de cultivo protegido (sob cobertura plástica e sob sombrite e sete repetições. No experimento conduzido em Uraí, não foram verificadas diferenças entre os sistemas de cultivo protegido quanto às características produtivas e químicas das bagas, como o teor de sólidos solúveis totais, índice de maturação e pH. Verificou-se a ocorrência do míldio somente nas folhas, sendo a incidência e a severidade menor nas videiras sob cobertura plástica (0,5 e 0,02%, respectivamente. Em Marialva, também não houve influência das coberturas nas características produtivas das videiras. Entretanto, o teor de sólidos solúveis totais das bagas sob cobertura plástica foi superior em relação àquelas sob sombrite (19,6 e 17,2ºBrix, respectivamente. Não foi detectada a ocorrência de míldio em nenhum dos sistemas de cultivo protegido nessa localidade. Conclui-se que o uso da cobertura plástica permite a redução do número de aplicações de fungicidas para o controle do míldio, sem alterar as características produtivas da uva 'BRS Clara'.

La confiabilidad en los sistemas eléctricos competitivos y el modelo colombiano de cargo por confiabilidad

Directory of Open Access Journals (Sweden)

Vélez Luis Guillermo

2012-09-01

Full Text Available El propósito de este artículo es hacer un análisis de la seguridad en el suministro de electricidad en Colombia, considerando el nuevo esquema del Cargo por Confiabilidad, modelo adoptado en Colombia para garantizar las inversiones en generación. Para esto se analiza la diferencia entre escenarios de demanda y de oferta de electricidad. La oferta para las plantas nuevas considera las OEF adquiridas con el cargo; y para las plantas existentes se realizan simulaciones bajo diversos escenarios de ocurrencia del fenómeno de “El Niño”. La demanda fue tomada de las proyecciones de la UPME. Las simulaciones realizadas muestran una apropiada dimensión del tamaño del Cargo por Confiabilidad.

Thermal evaluation by means of simulation of two houses with different materials in the city of La Paz, B.C.S.; Evaluacion termica mediante simulacion de dos casas con materiales diferentes en la ciudad de la Paz, B.C.S.

Energy Technology Data Exchange (ETDEWEB)

Resendiz Pacheco, Oscar; Morillon Galvez, David; Chavez M, Elizabeth; Poujol G, Federico; Flores I, Alfredo [Universidad Autonoma de Baja California Sur (Mexico)

2009-01-15

In this article the evaluation of two houses of social interest in the city of La Paz is presented, in terms of the thermal comfort that could be offered to their users with a minimum cost of energy by means of a simulation of their thermal behavior with the program TRNSYS. One of the houses is constructed in a large extent with adobe, for the walls and brick for the ceilings and the other is a typical construction of social interest built with conventional materials. The obtained results are presented, with which some recommendations that can be made tending to improve comfort and energy saving in houses of social interest. These recommendations consider the type of material as much as the geometry of the houses. [Spanish] En este articulo se presenta la evaluacion de dos casas de interes social para la ciudad de La Paz, en terminos del confort termico que pudieran ofrecer a sus usuarios con un gasto minimo de energia mediante una simulacion de su comportamiento termico con el programa TRNSYS. Una de las casas esta construida en su mayor parte con adobe, para las paredes y ladrillo para los techos y la otra es una construccion tipica de interes social construida de materiales convencionales. Se presentan los resultados obtenidos, con los que se pueden hacer algunas recomendaciones tendientes a mejorar confort y ahorro de energia en casas de interes social. Estas recomendaciones consideran tanto el tipo de material como la geometria de las casas.

Integrated modeling of a turbo-generator: analysis, simulation and compensation; Modelado integrado de un turbogenerador: analisis, simulacion y compensacion

Energy Technology Data Exchange (ETDEWEB)

Hernandez Rodriguez, Isaura Victoria

2008-09-15

generador. Estos esquemas no consideran la interaccion entre los lazos de control de potencia y voltaje, lo que puede degradar la respuesta del turbogenerador. Para remediar esta situacion y desarrollar mejores esquemas de control es necesario contar con modelos matematicos completos del conjunto turbina-generador que reproduzcan fielmente su dinamica en todo el rango de operacion e incluyan los efectos de interaccion. En esta tesis se desarrollo el modelo matematico de un generador sincrono que incluye devanados amortiguadores y saturacion magnetica del hierro del rotor. El modelo se programo modularmente en parametros por unidad, y se integro al modelo existente de una turbina de gas para conformar el modelo completo de un turbogenerador de combustion de 32 MVA. La estabilidad numerica de los modelos del generador y del turbogenerador se demostro mediante experimentos de simulacion en estado estable. Para demostrar el comportamiento dinamico se utilizaron lazos de control de potencia y de voltaje basados en algoritmos PID discretos. Ademas, con los resultados de estos experimentos se diseno un esquema de control basado en dos compensadores difusos, uno para potencia y otro para voltajes, los cuales disminuyen los efectos no deseados de la interaccion entre los lazos de control de los esquemas descentralizados convencionales. Se demostro que el modelo completo del turbogenerador es valido en un amplio rango de operacion y permite disenar y evaluar esquemas de control de alto desempeno que consideren la interaccion entre la turbina y el generador. El modelo del turbogenerador esta siendo utilizado en el Instituto de Investigaciones Electrica para integrar un banco de pruebas en tiempo real para sistemas de control de turbogeneradores.

Facoemulsificação por córnea clara no meridiano mais curvo Phacoemulsification using clear cornea incision in steepest meridian

Directory of Open Access Journals (Sweden)

Fernando Pistarini Gonçalves

2007-03-01

Full Text Available OBJETIVOS: Avaliar o efeito da facoemulsificação com incisão em córnea clara no meridiano mais curvo sobre a magnitude do astigmatismo ceratométrico pré-operatório. Mapear a magnitude do astigmatismo cirurgicamente induzido por incisões nas posições nasal (N, temporal (T, temporal superior (TS e temporal inferior (TI. MÉTODOS: Foi realizado estudo ceratométrico prospectivo em 48 olhos de 48 pacientes, submetidos a facoemulsificação com incisão do meridiano mais curvo. As medidas ceratométricas foram realizadas no pré-operatório e um mês após a realização da cirurgia. O astigmatismo cirurgicamente induzido foi determinado pelo método das coordenadas retangulares em 10 passos, modificado. RESULTADOS: Foram operados 21 olhos direitos e 27 olhos esquerdos e, de acordo com a posição das incisões em córnea clara, foram divididos em: 16 olhos N, 4 olhos T, 22 olhos TS, 6 olhos TI. A média da ametropia cilíndrica pré-operatória foi de 1,06D ± 0,65 e a pós-operatória de 0,89D ± 0,80. Houve diminuição estatisticamente significativa no astigmatismo corneal preexistente (p=0,016. A média total de astigmatismo cirurgicamente induzido foi de 0,94D ± 0,56. Em relação aos grupos o astigmatismo cirurgicamente induzido foi de 1,06D ± 0,66 em N, 0,87D ± 0,20 em T, 0,95D ± 0,55 em TS e 0,61D ± 0,25 em TI. Não houve diferença estatística com relação ao astigmatismo cirurgicamente induzido nos grupos N, T, TS e TI (p=0,426. CONCLUSÃO: A técnica se mostrou efetiva na redução do astigmatismo ceratométrico pré-operatório. A média do astigmatismo cirurgicamente induzido foi de 1,06D ± 0,66 em N, 0,95D ± 0,55 em TS, 0,61D ± 0,25 em T e 0,87D ± 0,20 em TI.PURPOSE: To evaluate the effect of phacoemulsification through clear cornea incision in the steepest meridian (ISM, on the magnitude of preoperative keratometric astigmatism. To map the magnitude of surgically induced astigmatism (SIA by clear cornea incision

Desempenho de um “wetland” vertical aplicado ao tratamento do efluente de um filtro anaeróbio em uma estação de tratamento de águas cinzas claras visando o reúso não potável em edificações residenciais

OpenAIRE

Sarnaglia, Solange Aparecida Alho

2014-01-01

No tratamento de água cinza com vistas ao reúso predial os “wetlands” têm se mostrado como uma opção viável devido à boa remoção de poluentes, ao baixo custo de implantação e operação, além do baixo impacto ambiental quando comparados a outros sistemas. O presente estudo teve como objetivo caracterizar físico-química e microbiologicamente a água cinza clara gerada em um edifício universitário avaliar a influência das cargas hidráulica e orgânica na remoção de matéria orgânica, turbidez e de c...

Effect of controlled human exposure to diesel exhaust and allergen on airway surfactant protein D, myeloperoxidase and club (Clara) cell secretory protein 16.

Science.gov (United States)

Biagioni, B J; Tam, S; Chen, Y-W R; Sin, D D; Carlsten, C

2016-09-01

Air pollution is a major cause of global morbidity and mortality. Air pollution and aeroallergens aggravate respiratory illness, but the variable effects of air pollutants and allergens in the lung are poorly understood. To determine the effects of diesel exhaust (DE) and bronchial allergen challenge as single and dual exposures on aspects of innate immunity in the airway as reflected by surfactant protein D (SPD), myeloperoxidase (MPO) and club (Clara) cell secretory protein 16 (CC16) in 18 atopic individuals. In this double-blind, randomized crossover study, atopic individuals were exposed to DE or filtered air, followed by endobronchial allergen or saline 1 hour after inhalational exposure. Bronchoalveolar lavage, bronchial washings, nasal lavage and blood samples were obtained 48 hours after exposures and assayed for CC16, MPO and SPD by ELISA. In bronchial samples, the concentration of SPD increased from 53.3 to 91.8 ng/mL after endobronchial allergen, with no additional contribution from DE. MPO also increased significantly in response to allergen (6.8 to 14.7 ng/mL), and there was a small additional contribution from exposure to DE. The concentration of CC16 decreased from 340.7 to 151.0 ng/mL in response to DE, with minor contribution from allergen. These changes were not reflected in nasal lavage fluid or plasma samples. These findings suggest that allergen and DE variably influence different aspects of the innate immune response of the lung. SPD and MPO, known markers of allergic inflammation in the lung, are strongly increased by allergen while DE has a minor effect therein. DE induces a loss of CC16, a protective protein, while allergen has a minor effect therein. Results support site- and exposure-specific responses in the human lung upon multiple exposures. © 2016 John Wiley & Sons Ltd.

La simulación como herramienta de aprendizaje en física / Simulation as physics learning tool

Directory of Open Access Journals (Sweden)

Alvarez Vargas, Zulma

2008-08-01

Full Text Available Resumen: En la presente investigación se estudió el efecto de la aplicación de un diseño instruccional apoyado con simulaciones asistidas por el computador, en un grupo de estudiantes que cursaban la asignatura Física a nivel universitario. El diseño de la investigación fue cuasi-experimental, de un solo grupo con pre-postest de carácter transeccional descriptivo, bajo un enfoque cuanti–cualitativo. Los hallazgos de la investigación fueron: (a el mejoramiento de la comprensión de los conceptos cinemáticos en los estudiantes al aplicarse estrategias instruccionales apoyadas en simulaciones asistidas por el computador y (b mejora del rendimiento académico obtenido por los estudiantes al aplicarse estrategias instruccionales basadas en el uso de simulaciones asistidas por el computador.Abstract: The focus of the present research was to investigate the effect of the application of an instructional design supported by computer-based simulations in a group of students enrolled on a Physics course. The study was quasi-experimental, performed in one single group, with pre-post test of transectional descriptive character, in both quantitative and qualitative modes. The results revealed that (a understanding of the concepts within the topic, kinematics, was improved by the instructional strategy using computer-based simulations and (b the academic performance of the students improved with the use of computer-based simulations.

Association of serum Clara cell protein CC16 with respiratory infections and immune response to respiratory pathogens in elite athletes.

Science.gov (United States)

Kurowski, Marcin; Jurczyk, Janusz; Jarzębska, Marzanna; Moskwa, Sylwia; Makowska, Joanna S; Krysztofiak, Hubert; Kowalski, Marek L

2014-04-15

Respiratory epithelium integrity impairment caused by intensive exercise may lead to exercise-induced bronchoconstriction. Clara cell protein (CC16) has anti-inflammatory properties and its serum level reflects changes in epithelium integrity and airway inflammation. This study aimed to investigate serum CC16 in elite athletes and to seek associations of CC16 with asthma or allergy, respiratory tract infections (RTIs) and immune response to respiratory pathogens. The study was performed in 203 Olympic athletes. Control groups comprised 53 healthy subjects and 49 mild allergic asthmatics. Serum levels of CC16 and IgG against respiratory viruses and Mycoplasma pneumoniae were assessed. Allergy questionnaire for athletes was used to determine symptoms and exercise pattern. Current versions of ARIA and GINA guidelines were used when diagnosing allergic rhinitis and asthma, respectively. Asthma was diagnosed in 13.3% athletes, of whom 55.6% had concomitant allergic rhinitis. Allergic rhinitis without asthma was diagnosed in 14.8% of athletes. Mean CC16 concentration was significantly lower in athletes versus healthy controls and mild asthmatics. Athletes reporting frequent RTIs had significantly lower serum CC16 and the risk of frequent RTIs was more than 2-fold higher in athletes with low serum CC16 (defined as equal to or less than 4.99 ng/ml). Athletes had significantly higher anti-adenovirus IgG than healthy controls while only non-atopic athletes had anti-parainfluenza virus IgG significantly lower than controls. In all athletes weak correlation of serum CC16 and anti-parainfluenza virus IgG was present (R = 0.20, p athletes a weak positive correlations of CC16 with IgG specific for respiratory syncytial virus (R = 0.29, p = 0.009), parainfluenza virus (R = 0.31, p = 0.01) and adenovirus (R = 0.27, p = 0.02) were seen as well. Regular high-load exercise is associated with decrease in serum CC16 levels. Athletes with decreased CC16 are

California GAMA Program: Sources and transport of nitrate in shallow groundwater in the Llagas Basin of Santa Clara County, California

International Nuclear Information System (INIS)

Moran, J E; McNab, W; Esser, B; Hudson, G; Carle, S; Beller, H; Kane, S; Tompson, A B; Letain, T; Moore, K; Eaton, G; Leif, R; Moody-Bartel, C; Singleton, M

2005-01-01

A critical component of the State Water Resource Control Board's Groundwater Ambient Monitoring and Assessment (GAMA) Program is to assess the major threats to groundwater resources that supply drinking water to Californians (Belitz et al., 2004). Nitrate is the most pervasive and intractable contaminant in California groundwater and is the focus of special studies under the GAMA program. This report presents results of a study of nitrate contamination in the aquifer beneath the cities of Morgan Hill and Gilroy, CA, in the Llagas Subbasin of Santa Clara County, where high nitrate levels affect several hundred private domestic wells. The main objectives of the study are: (1) to identify the main source(s) of nitrate that issue a flux to the shallow regional aquifer (2) to determine whether denitrification plays a role in the fate of nitrate in the subbasin and (3) to assess the impact that a nitrate management plan implemented by the local water agency has had on the flux of nitrate to the regional aquifer. Analyses of 56 well water samples for major anions and cations, nitrogen and oxygen isotopes of nitrate, dissolved excess nitrogen, tritium and groundwater age, and trace organic compounds, show that synthetic fertilizer is the most likely source of nitrate in highly contaminated wells, and that denitrification is not a significant process in the fate of nitrate in the subbasin except in the area of recycled water application. In addition to identifying contaminant sources, these methods offer a deeper understanding of how the severity and extent of contamination are affected by hydrogeology and groundwater management practices. In the Llagas subbasin, the nitrate problem is amplified in the shallow aquifer because it is highly vulnerable with high vertical recharge rates and rapid lateral transport, but the deeper aquifers are relatively more protected by laterally extensive aquitards. Artificial recharge delivers low-nitrate water and provides a means of long

ORTHOIMAGERY, Santa Clara, CA

Data.gov (United States)

Federal Emergency Management Agency, Department of Homeland Security — Digital orthographic imagery datasets contain georeferenced images of the Earth's surface, collected by a sensor in which object displacement has been removed for...

Santa Clara County, California

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — LAS format files, raw LiDAR data in its native format, classified bare-earth LiDAR DEM and photogrammetrically derived breaklines generated from LiDAR Intensity...

SIMULACIÓN DE UN MODELO DE EQUILIBRIO GENERAL COMPUTABLE PARA VENEZUELA

Directory of Open Access Journals (Sweden)

Luis Enrique Pedauga

2012-01-01

Full Text Available Este artículo presenta los resultados de la simulación de un modelo de equilibrio general computable construido para Venezuela. El uso de este modelo se ejempli-fica mediante la calibración y simulación de una economía abierta con tres agentes institucionales (hogares, empresas y gobierno y tres sectores productivos (petró-leo, manufactura y resto, para una economía abierta. Se considera diferentes re-glas de política. En cada caso se muestra el proceso de calibración y los resultados de las simulaciones utilizando información proveniente de la serie de matrices de contabilidad social para Venezuela entre 1997 y 2005. Se aporta simulaciones de la economía hasta 2009, tanto en los parámetros pertinentes y como algunos ejerci-cios de sensibilidad

Estudio comparativo de flujo de fluido a través de una placa de orificio usando las ecuaciones de Stokes y de Navier-Stokes

Directory of Open Access Journals (Sweden)

Miryam Lucía Guerra-Mazo

2016-05-01

Full Text Available Presenta los resultados de la comparación entre las ecuaciones de Stokes y de Navier-Stokes para la simulación del flujo de agua líquida, a condiciones atmosféricas, a través de una placa orificio concéntrica. A partir de los datos experimentales que fueron tomados en el banco de fluidos, se evaluaron las simulaciones de ambas ecuaciones, usando el software libre Freefem++cs, que se basa en el método de los elementos finitos; las variables evaluadas son velocidad y presión en un intervalo de tiempo. Al analizar los resultados obtenidos con las simulaciones y comparar con los datos experimentales se encontró que las ecuaciones de Navier-Stokes representan mejor el sistema que la ecuación de Stokes.

Nanostructuring of Aluminum Alloy Powders by Cryogenic Attrition with Hydrogen-Free Process Control Agent

Science.gov (United States)

2015-02-01

Nanostructuring of Aluminum Alloy Powders by Cryogenic Attrition with Hydrogen-Free Process Control Agent by Frank Kellogg , Clara Hofmeister...Process Control Agent Frank Kellogg Bowhead Science and Technology Clara Hofmeister Advanced Materials Processing and Analysis Center...NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Frank Kellogg , Clara Hofmeister, Anit Giri, and Kyu Cho 5d. PROJECT NUMBER 5e

Opciones tipo barrera sobre la tasa de cambio Peso/Dólar

Directory of Open Access Journals (Sweden)

Ángela María Pérez Muñoz

2007-12-01

Full Text Available Este artículo es derivado de la investigación titulada Opciones tipo barrera sobretasa de cambio. Se realizó un examen de diversas metodologías existentes parala valoración y medición de los riesgos de las opciones tipo barrera europeas. Larevisión se centró, principalmente, en los métodos numéricos. Las SimulacionesMontecarlo constituyen una metodología para valorar y calcular las coberturas deopciones que dependen de la ruta seguida por los precios del activo subyacentedurante su vida útil. Los resultados generados corroboran que ellas convergensatisfactoriamente en la formulación analítica cuando ésta se ajusta a unaobservación discreta de los precios del activo subyacente. Tales resultados seajustan más cuando se aplica el Método de Control de Varianza de Variables Antitéticas a las Simulaciones Montecarlo. 

Network support for e-Science in Latin America

International Nuclear Information System (INIS)

Stanton, M.; Macahdo, I.; Faerman, M.; Moura, A. L.

2007-01-01

Computer networks in Latin America have connected scientists in the region to their peers in other parts of the world since 1986. Starting with the creation of Internet2 in 1996, a new global research network has been extended throughout the world, providing communications infrastructure for large-scale international scientific collaboration. With the creation of the RedCLARA network and its links to Europe and the US between 2004 and 2005, this global network reached the majority of Latin America countries, setting the stage for much closer collaboration between scientists in Latin America and their counterparts in other countries. In this article we describe the development of the research networking infrastructure currently available within the region together with its inter-regional connections, and how this infrastructure is being used for support of e-science. Particular attention is given to the role of the national research and education networks (NRENs) in the region, and of their association, CLARA, in providing networking support for e-science projects. CLARA and Latin American NRENs are active partners in the EU-supported EELA and RINGrid projects, and also are making significant supporting contributions to the success of other international projects with Latin American partners, in fields such as High-Energy Physics, Astronomy and Astrophysics and Space Geodesy, to single out the early adopters of advanced networking technologies. These contributions are described in the article. The article concludes describing future trends in networking infrastructure in the region, in order to meet foreseeable demands for e-science support. These include the widespread adoption of optical networking and support for grid-based applications, as well as the provisioning of significantly higher international bandwidth to meet the declared needs for international collaboration in a number of fields including those mentioned above. (Author)

77 FR 73490 - Proposed Flood Hazard Determinations

Science.gov (United States)

2012-12-10

... Fruitvale Avenue, Saratoga, CA 95070. Town of Los Gatos Engineering Services, 110 East Main Street, Los Gatos, CA 95030. Unincorporated Areas of Santa Clara Santa Clara Office of Planning, County. 70 West...

A simulation study of rater agreement measures with 2x2 contingency tables

Directory of Open Access Journals (Sweden)

Ana Benavente

2011-01-01

Full Text Available Un estudio de simulacion de medidas de acuerdo entre observadores para tablas de contingencia 2x2. Mediante un estudio de simulacion se aborda una comparacion entre seis medidas obtenidas usando tres enfoques diferentes para la evaluacion del acuerdo. Los coeficientes de acuerdo elegidos fueron sigma de Bennet (1954, Pi de Scott (1955, Kappa de Cohen (1960 y gamma de Gwet (2001; 2008 para representar el enfoque clasico descriptivo, el coeficiente alpha de Aickin (1990, para representar el enfoque de los modelos loglineal y mixtura ("mixture models" y la medida delta de Martin and Femia (2004 para representar el enfoque de los test de eleccion multiple. Los resultados obtenidos confirman que los coeficientes Pi y kappa presentan diferencias notables en relacion a los restantes coeficientes particularmente en presencia de valores extremos de prevalencia y sesgo entre observadores. El mejor comportamento fue observado con los coeficientes alpha de Bennet y delta de Martin and Femia para todos los valores de prevalencia y sesgo entre observadores.

A Novel Routing Algorithm for Vehicular Ad Hoc Networks

Directory of Open Access Journals (Sweden)

Raúl Aquino Santos

2008-01-01

Full Text Available Este trabajo examina la importancia de las redes inalámbricas ad hoc y el algoritmo de enrutamiento con inundación basada en grupos (LORA-CBF para la comunicación inter-vehicular con la finalidad de optimizar el flujo de tráfico e incrementar la seguridad en las autopistas. Se discute el algoritmo de enrutamiento LORA-CBF y se presentan los resultados de simulaciones realizadas en OPNET de una autopista con alta movilidad vehicular. Primero, el modelo de simulación propuesto se valida a pequeña escala con resultados experimentales. Posteriormente, se emplean simulaciones de nuestro modelo comparándolos con Ad Hoc On-Demand Distance Vector (AODV y Dynamic Source Routing (DSR. Finalmente, se emplea un modelo de tráfico microscópico desarrollado en OPNET para simular la movilidad de 250 vehículos en una autopista y se aplica el algoritmo de enrutamiento LORA-CBF en un escenario vehicular.

Analysis, simulation and control of electromagnetic transients in gas insulated substations in SF6 by means of grounding grid; Analisis, simulacion y control de transitorios electromagneticos en subestaciones aisladas en SF6 por medio de redes de tierra

Energy Technology Data Exchange (ETDEWEB)

Hernandez Martinez, Gaston

2007-12-15

The use of SF6 substations is actually an extensive practice in industrial countries. Some of they replace conventional air substations and the others are new designs in the range of 34.5 kV to 1000 kV. During the switching events in a GIS substation, very fast transients overvoltage may appear and originate faults, malfunctions in the electronic and control equipment, besides the risk by electrical discharge in the personnel who are working in the substation. These overvoltage are produced by the collapse of the electric field on GIS terminals during switching events originating Very Fast Transient Overvoltage (VFTO) and the increase of the Transient Enclosure Voltage (TEV). This investigation is focused on diminishing the magnitude of the VFTO and TEV by designing and redesigning grounding grids for gas insulated substations in SF6. The objective of this work is to design a grounding grid for an air substation and redesign it for a GIS substation. The computer simulation uses a detailed model of the substation in SF6 interconnected with an aerial grounding grid and by adding methodologically grounding rods, the VFTO and TEV within the GIS are reduced. The results of the computer simulation show that the designed grounding grid allows considerably diminishing the magnitude of the VFTO; nevertheless this design doesn't appropriately attenuate the TEV magnitude. [Spanish] Hoy en dia, el uso de subestaciones GIS se ha generalizado. Algunas reemplazan a las subestaciones aereas y otras son de nueva creacion y se instalan en tensiones de 34.5kV hasta 1000 kV. Durante las operaciones de maniobra de la subestacion GIS, se presentan sobretensiones transitorias ultra rapidas que pueden dar origen a diversas fallas, a un malfuncionamiento del equipo electronico y de control asi como el riesgo por descarga electrica al personal que labora en la subestacion. Estas sobretensiones se producen debido al colapso del campo electrico en terminales del interruptor ante

Wind power in Mexico: simulation of a wind farm and application of probabilistic safety analysis; La energia del viento en Mexico: Simulacion de un parque eolico y aplicacion de analisis probabilistica de seguridad

Energy Technology Data Exchange (ETDEWEB)

Martin del Campo Marquez, C.; Nelson Edestein, P.F.; Garcia Vazquez, M.A. [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico (Mexico)]. E-mail: cecilia.martin.del.campo@gmail.com; pnelson_007@yahoo.com; maiki27@yahoo.com

2009-10-15

The most important aspects of wind energy in Mexico, including the potential for generating electricity and the major projects planned are presented here. In particular, the generation costs are compared to those of other energy sources. The results from the simulation of a 100MW wind farm in the Tehuantepec Isthmus are also presented. In addition, the environmental impacts related to the wind farm in the mentioned zone are analyzed. Finally, some benefits of using Probabilistic Safety Analysis are discussed with respect to evaluating the risks associated with events that can occur in wind parks, being especially useful for design and maintenance of the parks and the wind turbines themselves. In particular, an event tree was developed to analyze possible accident sequences that could occur when the wind speed is too great. Also, fault trees were developed for each mitigating system considered, in order to determine the relative importance of the wind generator components to the failure sequences, in order to evaluate the yield of suggested improvements and the optimization of maintenance programs. [Spanish] Se presentan los aspectos mas importantes referentes a la energia eolica en Mexico, su potencial de aprovechamiento y los proyectos planeados. Se comparan sus costos de generacion electrica con los de otras fuentes de energia. Se presentan los resultados de la simulacion con el programa WindPro, de un parque eolico de 100 MW localizado en el Istmo de Tehuantepec. Asimismo, se analizan algunos de los impactos ambientales relacionados con la instalacion de paquetes eolicos en la zona mencionada. Finalmente, se discuten las ventajas que pueden aportar los analisis probabilisticas de seguridad para evaluar los riesgos asociados a eventos que pueden ocurrir en los parques eolicos, sino de los resultados de este analisis de utilidad para el diseno y mantenimiento de los parques y de los propios aerogeneradores. Especificamente se desarrollo un arbol de eventos con el

SIMULACIÓN Y EVALUACIÓN

Directory of Open Access Journals (Sweden)

Emilia Sande Lemos

2005-12-01

Full Text Available RESUMEN: Con este artículo se pretende realizar una revisión de la literatura sobre la evaluación de los impactos educativos de las simulaciones. Esta perspectiva de análisis de las simulaciones, ha retenido la atención de diversos investigadores, aunque sin conclusiones muy objetivas, siendo una de las principales la dificultad en crear instrumentos de evaluación para esta metodología de enseñanza y aprendizaje. PALABRAS CLAVE: Evaluación, simulaciones educativas, motivación, memoria a largo plazo.ABSTRACT: The subject of this paper is a bibliographic revue on the learning progress evaluation of simulation methods. At the end one can assume that is not easy to assert an accurate model to create tools to evaluate the different learning achievement obtained with simulations.KEY WORDS: Evaluation, educational simulations, motivation, long term retentationRÉSUMÉ: Dans cet article ont fait un  révision des études sur la évaluation des apprentissages éd~cationnelles dues a la application des simulations.Dans ces études on ne trouve pas des conclusions tres objectives, parce que ont a des dificultés dans la création des instruments pour les apprentissages dues A  les simulations.Avant de décnre ses études nous ferons une bref explication sur la définition de simulation et aussi sur les caractéristiques des simulation éducationnelles.MOTS CLÉ:Evaluation, simulations éducationnelles, motivation, mémorisation a long terme

Assessment of the RLS 90 calculation method for predicting road traffic noise in Colombian conditions

Directory of Open Access Journals (Sweden)

Diego Mauricio Murillo-Gómez

2015-01-01

Full Text Available Este artículo presenta la evaluación del método alemán RLS 90 (Richtlinien für den Lärmschutz an Straben para la predicción del nivel de ruido producido por el tráfico rodado en condiciones colombianas. Para esto, mediciones de ruido ambiental e información de entrada requerida para las simulaciones fueron adquiridas en dos diferentes áreas de la ciudad de Medellín. A partir de la información recolectada en campo, se realizaron simulaciones de ruido utilizando el software comercial SoundPLAN. La influencia de la información de entrada en la precisión de las simulaciones fue evaluada utilizando la incertidumbre total expandida de los mapas de ruido. En adición, RLS 90 fue comparado con una técnica alternativa para la construcción de mapas de ruido basada en el uso de mediciones de ruido e interpolación. Los resultados indican que la implementación del método RLS 90 permite estimar los niveles de ruido automotor con buena precisión en áreas donde el ruido producido por el flujo vehicular es predominante. Comparado con la técnica de interpolación, los hallazgos sugieren que RLS 90 conlleva a una mejor precisión en la elaboración de mapas de ruido. Finalmente, con relación a las variables de entrada utilizadas en RLS90, los resultados apuntan a que los datos asociados con la caracterización de la fuente son las que mayor impacto tienen en la incertidumbre de la simulación.

Functional live cell imaging of the pulmonary neuroepithelial body microenvironment

NARCIS (Netherlands)

De Proost, Ian; Pintelon, Isabel; Brouns, Inge; Kroese, A; Riccardi, Daniela; Kemp, Paul J.; Timmermans, Jean-Pierre; Adriaensen, Dirk

Pulmonary neuroepithelial bodies (NEBs) are densely innervated groups of neuroendocrine cells invariably accompanied by Clara-like cells. Together with NEBs, Clara-like cells form the so-called "NEB microenvironment," which recently has been assigned a potential pulmonary stem cell niche. Conclusive

Dynamic simulation of an office with windows with solar control filter: cases in Mexico and Canada; Simulacion dinamica de una oficina con una ventana con filtro de control solar: casos en Mexico y Canada

Energy Technology Data Exchange (ETDEWEB)

Gijon Rivera, M. A.; Alvarez Garcia, G.; Xaman Villasenor, J. [Centro Nacional de Investigacion y Desarrollo Tecnologico, CENIDET-DGEST-SEP, Cuernavaca, Morelos (Mexico)]. E-mail: gaby@cenidet.edu.mx; I. Beausoleil-Morrison [Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa (Canada)]. E-mail: ibeausol@mae.carleton.ca

2010-11-15

The use of solar passive strategies in buildings with large glazed areas such as new solar control coatings in windows are becoming more important and helpful recently, mainly because those developments can help to reduce heat gains and/or losses through transparent materials, reduce energy consumption, and improving the environment inside buildings. This paper presents an assessment of thermal performance in an office building with a SnS-Cu{sub x}S solar control coating and its influence on indoor conditions. The simulations consider climates of Mexico city and Ottawa as a good representation of two extremely conditions to asses the thermal behaviour inside offices, energy consumption, costs for air conditioning, and the influence of interior heat transfer coefficient correlations on energy consumption. The results are shown with and without the solar control coating adhered in a clear glass and in a double window configuration. The case of the system glass-film is the worst configuration as result of the high temperatures in the internal surface impacting the air point temperature and increasing the energy consumption. In general, the double glass configuration presents the best conditions, showing higher benefits for the case in Mexico City than the case of Ottawa. [Spanish] Resulta importante implementar estrategias pasivas en estudios de edificaciones con grandes areas de ventanas, como es la implementacion de nuevos materiales de control solar en vidrios que ayudan a reducir las ganancias y/o perdidas de calor a traves de los materiales transparentes, y asi reducir el consumo de energia y mejorar las condiciones del confort interior de los edificios. Este estudio realiza una evaluacion del funcionamiento termico de una pelicula selectiva de SnS-Cu{sub x}S que permite algunas ventajas termicas y opticas en el ambiente interno. Las simulaciones dinamicas consideran climas de la Ciudad de Mexico y Ottawa , con resultados que muestran las condiciones de confort

Factores de protección ante el uso de tabaco y alcohol en jóvenes menores de edad

Directory of Open Access Journals (Sweden)

F. ARBINAGA IBARZÁBAL

2002-01-01

Full Text Available El presente trabajo analiza el peso de 23 posibles factores de protección frente al inicio del consumo de tabaco y alcohol en jóvenes escolarizados. Se empleó una muestra de 112 sujetos menores de 18 años. Siete factores resultaron significativos (p<0,05: apego familiar, normas claras en la familia, alta autoestima, alto rendimiento escolar, cumplimiento de normas como ciudadano, normas claras en la escuela, autosatisfacción con el físico. Para el inicio en el consumo de alcohol se obtuvieron ocho factores significativos; apego familiar, normas claras en la familia, miedo a las drogas, alto rendimiento escolar, cumplimiento de normas como ciudadano, normas claras en la escuela, recibir buena formación en la escuela y búsqueda de consejo en la familia ante la realización nuevas actividades. Dichos factores resultaron afectados por las siguientes variables: sexo, antecedentes familiares y consumo en el grupo de iguales.

Evaluación y modificación del Sistema de Tratamiento de Aguas Residuales de la Planta de Matanza del ITCR en Santa Clara, San Carlos

Directory of Open Access Journals (Sweden)

Alma Deloya Martínez

2006-05-01

Full Text Available La planta de matanza de ganado vacuno y porcino del ITCR, Sede San Carlos, en Santa Clara, procesa en promedio 23 reses y 11 cerdos por día. El caudal de aguas residuales promedio generado durante el proceso de matanza varió de un máximo de 72 m3/día hasta un mínimo de 12 m3/día. Las aguas residuales son tratadas en un sistema de tratamiento biológico anaerobio, para controlar la contaminación del agua, según el Reglamento de vertido y reúso de aguas residuales. El sistema original consistió en un tanque de aireación y un sedimentador integrado al tanque de aireación. La aireación se suministraba por rotores mecánicos. Durante el desarrollo del proyecto, se encontró que el principal problema en la operación y control del sistema eran los sólidos suspendidos totales y los sólidos sedimentables, no presentándose problemas de calidad del efluente en términos de DBO, DQO y otros parámetros. Para solucionar el problema de los sólidos, en el efluente del sistema de tratamiento se modificó el sistema aerobio existente a un sistema anaerobio (para reducir la producción de sólidos, usando como ayuda del tratamiento un compuesto biológico, que actúa como floculante y coagulante, lo que mejora la sedimentación de los sólidos. Con la modificación del sistema, se alcanzaron eficiencias de remoción de los sólidos sedimentables en un 95%, de la demanda bioquímica de oxígeno DBO en un 83% y la DQO en un 75%, cumpliéndose con la normativa para todos los parámetros exigidos por el Ministerio de Salud.

Alternativas eficientes para procesamiento y comunicaciones en sistemas de tiempo real

OpenAIRE

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

2017-01-01

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

Et fast greb i rebet

DEFF Research Database (Denmark)

Degerbøl, Stine Klein

2012-01-01

The article concerns the lived experiences of Clara practicing to become a contemporary circus artist. Clara’s narratives reflect contemporary circus as a movement pedagogical practice in relation to aesthetic learning and in relation to the aims of the circus performer education itself. Furtherm......The article concerns the lived experiences of Clara practicing to become a contemporary circus artist. Clara’s narratives reflect contemporary circus as a movement pedagogical practice in relation to aesthetic learning and in relation to the aims of the circus performer education itself...... the establishment of contemporary circus schools. Clara´s narratives are the empirical touchstones while body phenomenology and narrativity are the main inspirations theoretically and methodologically....

La refrigeracion nocturna en edificios de oficinas optimizacion del sistema mecanico

NARCIS (Netherlands)

Lain, M.; Hensen, J.L.M.

2007-01-01

En muchas ocasiones se ha tratado sobre la necesidad de optimizar el sistema mecánico nocturno de refrigeración. En este documento se trata de la utilización de simulaciones por ordenador tanto para el apoyo al diseño de un edificio nuevo y desarrollo de un sistema HVAC, como para la optimización de

Modelos epidémicos con control por vacunación

OpenAIRE

Saralegui Vallejo, Unai

2016-01-01

Existen diferentes tipos de modelos epidémicos no lineales en los que las dinámicas de las sub-poblaciones ( susceptibles, infectados , recobrados , vacunados etc. ) están acopladas. La vacunación puede interpretatrse como un control cuyo objetivo es eliminar la infección. Se estudian estos modelos matemáticamente, para despues comprobar los resultados obtenidos mediante simulaciones.

Wildfire in the valley of the wild roses

Science.gov (United States)

Linda Moon Stumpff

2015-01-01

Santa Clara Indian Pueblo lands are adjacent to the Jemez National Forest, Bandelier National Monument and Valles Caldera National Preserve. This paper explores Pueblo vulnerability and resilience after repeated and devastating fires in this century as a result of drought and climate change. Santa Clara Pueblo holds a rich store of traditional knowledge about the fire-...

Simulaciones hidrodinámicas de flujos complejos

Science.gov (United States)

María Ibáñez Cabanell, José

Son muchos los escenarios astrofísicos en que los procesos hidrodinámicos juegan un papel clave. En la complejidad que encierra la descripción de dichos procesos destaca el de la correcta simulación de flujos complejos donde la presencia de ondas de choque fuertes que, eventualmente, interaccionan entre ellas o también la presencia de inestabilidades (Kelvin-Helmholtz, Rayleigh-Taylor, etc.) suponen un verdadero desafío numérico. Los códigos hidrodinámicos basados en la solución de un problema de valores iniciales discontinuo (problema de Riemann) son, en la actualidad, los más robustos en el campo de la dinámica de fluidos computacional. En esta charla se dará un resumen de los fundamentos de dichas técnicas numéricas (esquemas de alta resolución de captura de choques) y se ilustrará su potencialidad mostrando una amplia gama de resultados en diferentes aplicaciones astrofísicas.

Field-trip guide to the geology of the Lexington Reservoir and Loma Prieta areas in the Santa Cruz Mountains, Santa Clara and Santa Cruz counties, California

Science.gov (United States)

Stoffer, Philip W.; Messina, Paula

2002-01-01

This guide contains a road log and five stop descriptions for a field trip in the southern Santa Cruz Mountains. The trip officially begins at the boat dock parking area on Alma Bridge Road near the dam of Lexington Reservoir. Stop 1 involves a walk up the Limekiln Trail to examine a large landslide in serpentinite that frequently takes out the trail. Stop 2 is at Miller Point picnic area along the shore of the reservoir where exposures of massive, fractured graywacke sandstone are capped with terrace gravel deposits. Stop 3 is along Highland Way in the Santa Cruz Mountains where large landslides have occasionally force the closure of the road. Stop 4A-C are several closely spaced outcrop areas along Loma Prieta Avenue and Summit-Mt. Madonna Road in the Loma Prieta summit area. A walk to scenic vista points provide opportunity to discuss the evolution of regional landscape along the crest of the Sierra Azul. In addition, a variety of rock types are exposed in the Stop 4 area along a series of road cuts, including Cretaceous age conglomerate, turbidites (consisting of interbedded sandstone and shale), and fossiliferous mudstone. Stop 5 involves returning to the boat dock parking area to examine geology and the placement of the Lexington Dam in the Los Gatos Creek canyon.

DCS Hydrology, Santa Clara County, California

Data.gov (United States)

Federal Emergency Management Agency, Department of Homeland Security — Hydrology data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

Ground-Water Quality Data in the Santa Clara River Valley Study Unit, 2007: Results from the California GAMA Program

Science.gov (United States)

Montrella, Joseph; Belitz, Kenneth

2009-01-01

Ground-water quality in the approximately 460-square-mile Santa Clara River Valley study unit (SCRV) was investigated from April to June 2007 as part of the statewide Priority Basin project of the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin project was developed in response to the Groundwater Quality Monitoring Act of 2001 and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The study was designed to provide a spatially unbiased assessment of the quality of raw ground water used for public water supplies within SCRV, and to facilitate a statistically consistent basis for comparing water quality throughout California. Fifty-seven ground-water samples were collected from 53 wells in Ventura and Los Angeles Counties. Forty-two wells were selected using a randomized grid-based method to provide statistical representation of the study area (grid wells). Eleven wells (understanding wells) were selected to further evaluate water chemistry in particular parts of the study area, and four depth-dependent ground-water samples were collected from one of the eleven understanding wells to help understand the relation between water chemistry and depth. The ground-water samples were analyzed for a large number of synthetic organic constituents (volatile organic compounds [VOC], pesticides and pesticide degradates, potential wastewater-indicator compounds, and pharmaceutical compounds), a constituent of special interest (perchlorate), naturally occurring inorganic constituents (nutrients, major and minor ions, and trace elements), radioactive constituents, and microbial constituents. Naturally occurring isotopes (tritium, carbon-13, carbon-14 [abundance], stable isotopes of hydrogen and oxygen in water, stable isotopes of nitrogen and oxygen in nitrate, chlorine-37, and bromine-81), and dissolved noble gases also were measured to help identify the source

Numerical modeling of Etla Valley aquifer, Oax., Mexico: Evolution and remediation scenarios

Energy Technology Data Exchange (ETDEWEB)

Flores-Marquez, E. L; Martinez-Serrano, R. G; Chavez, R. E; Crusillo, Y [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico D.F. (Mexico); Jimenez, G [Facultad de Ingenieria, Benemerita Universidad Autonoma de Puebla, Puebla (Mexico); Camops-Enriquez, O [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico D.F. (Mexico)

2008-01-15

Short-term evolution (for 2001, 2005 and 2015) for the shallow aquifer of Etla Valley, Oaxaca, southern Mexico, was simulated based in a 3D hydrological model elaborated from the available geological, geophysical, geochemical, and hydrologic parameters. The numerical simulations were based on Visual MODFLOW code. These simulations indicate that, if the actual extraction regime is maintained, the drawdown of the potentiometric surface will get worse to the SE of the study area (i. e. beneath Oaxaca city). The prevailing aquifer flow direction favors the ground water pollution by fertilizers and leakage from the sewage network (dumped to the Atoyac river). According to the numerical simulation, remediation of this situation is possible if the wells located in the neighborhood of Oaxaca City are relocated at the recharge zones (i. e. at the feet from Sierra de Juarez). This remediation scenario will allow a recovery of the drawdown of the potentiometric surface. [Spanish] Se presenta un modelo geohidrologico evolutivo 3D a corto plazo (para los anos 2001, 2005 y 2015) del acuifero somero del Valle de Etla, Oaxaca, sureste de Mexico, basado en los parametros disponibles de geologia, geofisica, geoquimica e hidrologia. Las simulaciones numericas fueron realizadas en Visual MODFLOW. Estas simulaciones indican que, si el actual regimen de extraccion es mantenido, el abatimiento de la superficie potenciometrica puede ser mayor en el SE del area de estudio (i. e. cerca de la ciudad de Oaxaca). La contaminacion por fertilizantes y por las fugas de drenaje es favorecida por la direccion de flujo imperante en el acuifero (vaciandose en el rio Atoyac). De acuerdo a las simulaciones numericas, existe una posible remediacion de este proceso, relocalizando los pozos situados en la ciudad de Oaxaca en las zonas de recarga (i. e. en las faldas de la Sierra de Juarez). Este escenario de remediacion permitiria una recuperacion en el nivel de la superficie potenciometrica.

Five-year clinical and functional multislice computed tomography angiographic results after coronary implantation of the fully resorbable polymeric everolimus-eluting scaffold in patients with de novo coronary artery disease

DEFF Research Database (Denmark)

Onuma, Yoshinobu; Dudek, Dariusz; Thuesen, Leif

2013-01-01

This study sought to demonstrate the 5-year clinical and functional multislice computed tomography angiographic results after implantation of the fully resorbable everolimus-eluting scaffold (Absorb BVS, Abbott Vascular, Santa Clara, California).......This study sought to demonstrate the 5-year clinical and functional multislice computed tomography angiographic results after implantation of the fully resorbable everolimus-eluting scaffold (Absorb BVS, Abbott Vascular, Santa Clara, California)....

Design and Development of Basic Physical Layer WiMAX Network Simulation Models

Science.gov (United States)

2009-01-01

Wide Web . The third software version was developed during the period of 22 August to 4 November, 2008. The software version developed during the...researched on the Web . The mathematics of some fundamental concepts such as Fourier transforms, convolutional coding techniques were also reviewed...Mathworks Matlab users’ website. A simulation model was found, entitled Estudio y Simulacion de la capa Jisica de la norma 802.16 ( Sistema WiMAX) developed

Parasitismo intestinal en manipuladores de alimentos

Directory of Open Access Journals (Sweden)

Miguel Nicolás Gómez Vital

1999-01-01

Full Text Available El parasitismo intestinal representa un significativo problema en la salud mundial. Se realiza un estudio epidemiológico descriptivo en manipuladores de alimentos de los principales centros de elaboración de la ciudad de Santa Clara, provincia Villa Clara, durante 1998. Los enteroparásitos patógenos encontrados por orden de frecuencia fueron la Giardia lamblia y la Entamoeba hitolytica; detectados por método directo y de ritchie para dichos parásitos. La técnica de kato katz fue más eficaz para el diagnóstico de los geohelmintos. Se resalta la función del personal médico en centros de trabajo.Intestinal parasitism is a significant problem for world health. An epidemiological and descriptive study was conducted among food handlers at the main centers of elaboration in the city of Santa Clara, Villa Clara province, during 1998. The pathogenic enteroparasites found by order of frequency were Giardia lamblia and Entamoeba hitolytica, which were detected by using Ritchie's and direct method for such parasites. The Katokatz's technique was more efficient for the diagnosis of geohelminth. It was underlined the function of the medical team at the working centers.

Parasitismo intestinal en círculos infantiles

Directory of Open Access Journals (Sweden)

Miguel Gómez Vital

1999-01-01

Full Text Available Se estudiaron 1 113 niños asistentes a 5 círculos infantiles del municipio de Santa Clara, Villa Clara; con el propósito de analizar la incidencia de parasitismo intestinal. Se les procesaron las muestras de heces fecales mediante 3 métodos coproparasitológicos; demostrándose que el 42,2 % de la muestra estaba parasitada. Las especies más frecuentes fueron la Giardia lamblia, el Enterobius vermicularis y la Entamoeba histolytica, con asociaciones de parásitos en varios casos. Estos son más frecuentes a partir del tercer año de vida. Se resalta la influencia positiva del médico y enfermera de la familia en estas instituciones.1 113 children attending 5 day cae centers in Santa Clara, Villa Clara, were studied aimed at analyzing the incidence of intestinal parasitism. Faeces samples were processed by 3 coproparasitological methods and it was proved that 42.2 % of the samples had parasites. The most frequent species found were Giardia lamblia, enterobius vernmicularis and Entamoeba histolytica with associations of parasites in several cases. These are commoner from the third year of life on. The positive influence of the family physician and nurse in these institutions are stressed.

MODELO MATEMÁTICO GENÉRICO ESTOCÁSTICO Y CREDIBILISTICO PARA CICLO CELULAR EN MAMÍFEROS

Directory of Open Access Journals (Sweden)

Chi\\u015F Oana

2010-01-01

Full Text Available Este trabajo presenta un modelo genérico detallado sobre las células de mamíferos, desde el punto de vista matemático. A causa de regulación celular aparecen las oscilaciones, cuyos complejos procesos de retroalimentación se expresan usando un gran número de variables. Las simulaciones matemáticas son muy útiles para entender la transición del comportamiento oscilatorio, de simple a complejo y determinar las condiciones en que se producen. El modelo clásico, que representa el ciclo de división celular de mamífero, fue propuesto por Tyson Lab (http://mpf.biol.vt.edu/Tyson%20Lab.html, y será analizado, considerando los procesos de Wiener y de Liu. Se estudiarán el sistema híbrido de ecuaciones diferenciales, como una combinación de aleatoriedad y borrosidad. De estos acercamientos, pueden evidenciarse diferentes comportamientos. Las simulaciones numéricas se realizaron utilizando el software Maple 13, y se ha dado la interpretación biológica respectiva. A partir del modelo matemático determinístico genérico para las células de mamíferos, se ha construido la dinámica estocástica del sistema correspondiente.

GENERALIZATION OF ZAD STRATEGY: AN APPLICATION TO A DC-DC BUCK CONVERTER

Directory of Open Access Journals (Sweden)

FABIOLA ANGULO GARCIA

2011-01-01

Full Text Available En la última década se ha reportado la estrategia de control Zero Average Dynamics (ZAD como una alternativa al control de los convertidores de potencia, garantizando frecuencia fi ja de conmutación y bajo error. Sin embargo la estabilidad del sistema depende fuertemente de la carga, por lo cual no es robusto. Cuando se pierde la estabilidad la frecuencia fi ja de conmutación se pierde también. En este artículo se presenta la generalización de la técnica ZAD dentro del marco de la teoría de probabilidades. Usando este marco es posible recuperar el ZAD tal como ha sido analizado hasta ahora y se pueden generar nuevas estrategias de control, las cuales son más estables que las usadas en el ZAD. Por este motivo a esta técnica se le ha llamado Generalized Zero Average Dynamics (GZAD. Presentamos algunas simulaciones del GZAD aplicado a un convertidor de potencia reductor. Esta nueva estrategia no puede ser obtenida con el ZAD clásico. Las simulaciones numéricas muestran buen desempeño del controlador con bajo error de regulación y robustez ante cambio en la carga.

El camino hacia la estabilización demográfica y el proceso de envejecimiento en América Latina: una ilustración a partir de algunos países seleccionados

Directory of Open Access Journals (Sweden)

Moema G. B. Fígoli

2003-01-01

Full Text Available El presente artículo incorpora el concepto de inercia demográfica para evaluar el crecimiento poblacional de cinco países de América Latina, suponiendo el tiempo que tomará a la fecundidad alcanzar niveles de reemplazo. Las simulaciones muestran que en países con alta mortalidad, v.g. Haití y Guatemala, la pendiente de la distribución estable decae más rápido que en países con baja mortalidad a medida que aumenta la edad. Este ejercicio teórico muestra en todas las simulaciones que el tamaño de la población de los países de América Latina, que iniciaron su transición demográfica décadas atrás, no experimentará un crecimiento considerable. La población de Brasil y de Argentina, aún al alcanzar su límite teórico, no se duplicará. A pesar de que el límite teórico de las poblaciones analizadas se alcanzará en 400 a 500 años, éstos alcanzarán un estado “cuasi-estable” entre los años 2050 y 2100.

Strategies for dealing with the diversity-validity dilemma in personnel selection: Where are we and where should we go?

Directory of Open Access Journals (Sweden)

Britt De Soete

2013-01-01

Full Text Available El dilema validez-diversidad ha sido un tema dominante en la investigación y la práctica de la selección de personal. Dado que algunos de los instrumentos de selección más válidos presentan grandes diferencias étnicas en sus puntuaciones, los científicos intentan desarrollar estrategias que reduzcan las diferencias de los subgrupos en la selección mientras mantienen simultáneamente la validez de criterio. Este artículo proporciona una revisión basada en la evidencia de la efectividad de seis estrategias utilizadas para manejar el dilema validez-diversidad: (1 usar medidas de capacidad cognitiva “alternativas”, (2 emplear simulaciones, (3 utilizar procedimientos estadísticos para combinar las medidas predictoras y del criterio, (4 reducir la varianza de los predictores irrelevante para el criterio, (5 fomentar reacciones positivas en los candidatos y (6 facilitarles preparación y posibilidades de practicar. Tres estrategias (emplear evaluaciones basadas en simulaciones, desarrollar medidas alternativas de capacidad cognitiva y usar procedimientos estadísticos son las más prometedoras para aminorar el problema. Se discuten áreas potenciales que requieren investigación en un futuro.

Simulación y comparación de la respuesta eléctrica de algunos materiales piezoeléctricos aplicados en la ecografía médica

Directory of Open Access Journals (Sweden)

R. A. Reyes Villagrana

2013-01-01

Full Text Available La acústica se interpreta como la ciencia que estudia las ondas acústicas, vibraciones y sus interacciones con el entorno, tanto en sistemas macroscópicos como microscópicos. En este trabajo se presenta el modelo de un detector acústico piezoeléctrico desarrollado en el programa OrCAD-PSpice, para determinar la máxima amplitud de voltaje utilizando los materiales piezoeléctricos Cuarzo, PZT-5H, PVDF y PSMNZT, con el objetivo de determinar cuál de estos materiales piezoeléctricos tanto naturales, cerámicos, polímeros y cerámicos compuestos genera el máximo voltaje, sin agregar una etapa de acondicionamiento de la señal, y así contar con una herramienta computacional para predecir los voltajes que arrojan los materiales piezoeléctricos aplicando la técnica de transmisión, cuando no se cuenta de manera inmediata con el equipo para determinar éstas comparaciones. Se utiliza al agua como medio de propagación y se proponen diferentes espesores para las simulaciones. Se muestran las gráficas de las simulaciones realizadas, donde el PSMNZT proporcionó un máximo voltaje de 21.272V con un espesor de 10μm.

Floods of December 1966 in southwestern Utah

Science.gov (United States)

Butler, Elmer; Mundorff, J.C.

1970-01-01

Severe floods occurred in parts of southwestern Utah on December 5-6, 1966, as a result of precipitation of about 1 inch to more than 12 inches during December 3-6. The flood on the Virgin River was the greatest since the first settlers arrived in 1860.The peak discharge of the Virgin River at Virgin, Utah, was 22,830 cubic feet per second on December 6; this exceeded the previous maximum discharge of 13,500 cubic feet per second on March 3, 1938, and September 17, 1961, and probably has a recurrence interval of 100 years. At eight other gage sites in the flood area, the peak discharge in December 1966 was the highest of record; the recurrence intervals of some of the peak discharges may be 100 years. The flood peaks were generally of short duration and most streams receded to near base flow within 24 hours.The dissolved-solids content was significantly lower in the Virgin River at Virgin than at St. George, about 25 miles downstream; the water was of the calcium sulfate type at both sites. Data for the Santa Clara River above Winsor Dam and the Santa Clara River near Santa Clara show a significant increase in dissolved solids between the two sites. The water above Winsor Dam was of the calcium bicarbonate type, and the water near Santa Clara was of the calcium bicarbonate sulfate type.The suspended-sediment discharge, during the period December 5-8, 1966, at Santa Clara River above Winsor Dam, near Santa Clara was about foyer times greater than all the suspended-sediment discharge during the preceding 3 years ; the suspended-sediment discharge of the Virgin River at Virgin was greater during the 4-day period than during any one of the preceding 3 years.Nearly all the flood damage in the area occurred in the Virgin River basin. According to the Soil Conservation Service, total damage in the Dixie Soil Conservation District in Washington County was about $835,000; 60 percent of the damage was caused by floodwater and 40 percent by deposited sediment.

Distributed maximum power point tracking in photovoltaic applications: active bypass DC/DC converter

Directory of Open Access Journals (Sweden)

Carlos Andrés Ramos-Paja

2012-01-01

Full Text Available Se propone una estructura de desvío activo para maximizar la producción de potencia en sistemas fotovoltaicos bajo condiciones irregulares de operación, comparando su eficiencia con soluciones individuales y distribuidas basadas en convertidores DC/DC convencionales. Los análisis y simulaciones realistas demuestran las ventajas del nuevo convertidor de desvío activo sobre soluciones basadas en convertidores Boost, Buck y Buck-Boost.

Isotopic Evolution of Wells in the Geothermal Field of Los Azufres, Michoacan, Mexico; Evolucion isotopica de fluidos de pozos del campo geotermico de Los Azufres, Michoacan, Mexico

Energy Technology Data Exchange (ETDEWEB)

Barragan Reyes, Rosa Maria; Portugal Marin, Enrique; Arellano Gomez, Victor Manel; Aragon Aguilar, Alfonso [Instituto de Investigaciones Electricas (Mexico); Sandoval Medina, Fernando [Comision Federal de Electricidad (Mexico)

2002-12-01

Isotopic ({delta}{sup 1}8 O and {delta}D) data from production and reinjection web fluids from the Los Azufres geothermal field were interpreted in order to define reservoir evolution and the occurrence of physical processes as a result of exploitation. The study included data of 30 wells, which were sampled in September, 2000. General results indicate that different phenomena seem to occur in both zones of the field. In the southern zone there are two different trends of behavior: a mixture of fluids evidenced by the {delta}D versus {delta}{sup 1}8 O trend with a positive slope, was interpreted as the result of reservoir vapor separation at a temperature above 220 Celsius degrees, since for temperatures above 220 Celsius degrees deuterium behaves as a volatile component. No well-defined {delta}{sup D} vs {delta}{sup 1}8 O trend was found for the northern zone, but some points seem to fit the same negative slope trend found in the souther zone. The study of reservoir temperatures estimated by different approaches for particular wells through time, as well as temperature results obtained with a heat and flow well simulator, suggest that reservoir boiling occurs in localized areas in both zone of the field. This process is probably due to exploitation. [Spanish] Se interpretaron datos isotopicos ({delta}{sup 1}8 O y {delta}D) de fluidos de pozos productores y de reinyeccion del campo geotermico de Los Azufres, Michoacan, Mexico, para definir la evolucion del yacimiento y la ocurrencia de procesos fisicos como resultado de la explotacion. En el estudio se consideran datos de treinta pozos segun el muestreo realizado en septiembre de 2000. El estudio de la evolucion en el tiempo de las estimaciones de temperatura de yacimiento mediante diferentes tecnicas, asi como la temperatura obtenida de simulacion de pozos, sugiere que ocurre ebullicion en areas localizadas en ambas zonas del campo debido a la explotacion. Los resultados generales indican la existencia de

Pulmonary toxicity of trichloroethylene in mice. Covalent binding and morphological manifestations

International Nuclear Information System (INIS)

Forkert, P.G.; Birch, D.W.

1989-01-01

We examined the time course of trichloroethylene (TCE)-induced pulmonary injury and focused on morphological changes and covalent binding of [ 14 C]TCE soon after administration of a single dose of TCE (2000 mg/kg) to CD-1 male mice. At 1 hr after chemical treatment, Clara cells of the bronchiolar epithelium exhibited necrotic changes involving the mitochondria and endoplasmic reticulum. Dilatation of the endoplasmic reticulum became more severe at 2 hr after TCE administration and, by 4 hr, distended cisternae coalesced to form small vacuoles within the cytoplasmic matrix of the Clara cell. The severity of cellular damage increased progressively between 8 and 12 hr and, by 24 hr, the majority of Clara cells within an airway were severely vacuolated. Covalent binding of [ 14 C]TCE to lung macromolecules was evident at 1 hr, peaked at 4 hr, declined thereafter, and reached a plateau between 12 and 24 hr. Peak binding (142.6 +/- 31.8 nmol/g of wet weight) represented approximately 20% of [ 14 C]TCE distributed to the lung. Although the levels of binding in the liver were at all times greater than those in the lung, liver injury was relatively insignificant. The results demonstrate a positive correlation between the onset of Clara cell injury and the formation of reactive metabolites, as assessed by covalent binding of [ 14 C]TCE

Uso do 1-metilciclopropeno para retardar a maturação de tomate

Directory of Open Access Journals (Sweden)

Krammes Juliana Golin

2003-01-01

Full Text Available Tomates (Lycopersicon esculentum, cultivar 'Santa Clara' e o híbrido 'Carmen' (longa vida, tratados no estádio verde-maduro com 1-metilciclopropeno (1-MCP, apresentaram retardo nos picos de produção de etileno e CO2, redução nas taxas respiratórias, maior acidez titulável, maior retenção de firmeza e retardo no desenvolvimento de cor vermelha em relação a frutos não tratados, durante vida de prateleira a 23ºC. Os teores de sólidos solúveis totais não foram afetados pelo tratamento com 1-MCP. As doses de 1-MCP necessárias para retardar os picos de produção de etileno e CO2 e aumentar a acidez foram de 300 nl L-1 e 500 nl L-1, para tomates 'Santa Clara' e 'Carmen', respectivamente. Todavia, a retenção de firmeza e o retardo na evolução de cor vermelha da casca foram substanciais com a dose 150 nl L-1 para a cultivar 'Santa Clara', e com a dose de 250 nl L-1 para o híbrido 'Carmen'. Estes resultados mostram o grande potencial de emprego comercial do 1-MCP para retardar a maturação de tomates 'Santa Clara' e 'Carmen' em temperaturas ambientes.

Esker Ri Nursing Home, Kilnabinnia, Clara, Offaly.

LENUS (Irish Health Repository)

McKenna, Malachi

2017-03-01

Atypical femur fractures (AFFs) are associated with long-term bisphosphonate (BP) therapy. Early identification of AFF prior to their completion provides an opportunity to intervene, potentially reducing morbidity associated with these fractures. Single-energy X-ray absorptiometry (SE) is an imaging method recently shown to detect incomplete AFF (iAFF) prior to fracture completion.

Floodplain Mapping, SANTA CLARA COUNTY, CALIFORNIA, USA

Data.gov (United States)

Federal Emergency Management Agency, Department of Homeland Security — The Floodplain Mapping/Redelineation study deliverables depict and quantify the flood risks for the study area. The primary risk classifications used are the...

Summer Arctic sea ice albedo in CMIP5 models

OpenAIRE

Koenigk, T.; Devasthale, A.; Karlsson, K.-G.

2014-01-01

Spatial and temporal variations of summer sea ice albedo over the Arctic are analyzed using an ensemble of historical CMIP5 model simulations. The results are compared to the CLARA-SAL product that is based on long-term satellite observations. The summer sea ice albedo varies substantially among CMIP5 models, and many models show large biases compared to the CLARA-SAL product. Single summer months show an extreme spread of ice albedo among models; July values vary between 0....

Simulation and analysis of the tangential flow in the combustion chamber of a steam generator; Simulacion y analisis del flujo tangencial en la camara de combustion de un generador de vapor

Energy Technology Data Exchange (ETDEWEB)

Hernandez Ramirez, Isaias

1997-06-01

supplying ducts, were obtained, with a maximum discrepancy of 5.5 m/s between the data published by McKenty and Gravel (1997) and this analysis, for the case of combustion gases in the interior of the furnace. Temperature profiles were obtained, which were overestimated in the order of 417 Celsius degrees for the case of the temperature of gases in the center of the combustion chamber, when comparing them with the corresponding ones obtained by McKenty and Gravel (1997). It is speculated that this discrepancy must to be due to the omission of the connection of the radiation model to the global computational model and; the contours of concentration of species for the combustion products in the chamber were considered (carbon dioxide, oxygen and nitrogen), obtaining only the qualitative behavior of these. It is proposed as conclusion that the computational model developed in this thesis work can be used for the estimation of flow of fluids patterns, heat transference and transference of mass of a steam generator VU-60 of the tangential type and similar to the one taken as a base for this analysis. One improvement to the computational model developed could be achieved including the radiation effect, which requires a larger memory capacity of the computer hardware than the one available during the elaboration of this thesis. [Espanol] El presente trabajo de tesis describe la simulacion y analisis de la camara de combustion de un generador de vapor VU-60 del tipo tangencial, el cual esta basado en la solucion de la ecuacion generalizada de transporte, empleando modelos matematicos desarrollados para la caracterizacion de fenomenos fisicos para cerrar los sistemas de ecuaciones gobernantes. Para la solucion de los modelos matematicos y ecuaciones gobernantes se empleo el metodo de volumen finito, el cual se basa en el concepto de volumen de control. Se desarrollo un modelo computacional tridimensional por medio del cual se estimaron los perfiles de velocidad, presion, temperatura

Implications of heterogeneity on transport simulations at large scale: the Morroa aquifer case

Directory of Open Access Journals (Sweden)

Anibal Jose Pérez-García

2014-01-01

Full Text Available El acuífero Morroa, localizado en el departamento de Sucre (Colombia, representa la única fuente de suministro de agua potable de cerca de 500.000 habitantes que incluyen la totalidad de los habitantes de la capital del departamento Sincelejo. Aunque se han desarrollado muchos estudios en esta zona que incluyen la recolección de gran cantidad de información relacionada con niveles piezométricos, información estratigráfica, pruebas de bombeo, esta información es difusa, heterogénea y fraccionada. La incertidumbre asociada a esta información afecta cualquier intento de cuantificar la respuesta del acuífero, por esta razón el punto de partida de esta investigación es el desarrollo de una metodología capaz de integrar todas las variables en un modelo conceptual. Para considerar la incertidumbre se generaron múltiples realizaciones del acuífero de tal manera que todas respetan las propiedades estadísticas de la información disponible. Para generar estas realizaciones se utilizaron dos metodologías: (1 SISIM, que es un método basado en estadísticas de dos puntos (semivariograma, y (2 SNESIM, que es un algoritmo basado en el concepto de imágenes de entrenamiento (estadística de puntos múltiples. Resultados de las simulaciones muestran la gran capacidad de este último para reproducir geometrías curvilíneas complejas. En una segunda fase, se desarrollaron simulaciones de flujo y transporte de contaminantes de una manera integrada usando los dos modelos conceptuales obtenidos a través de las dos aproximaciones geoestadísticas. Condiciones de flujo estacionario y un contaminante conservativo fueron asumidos para todas las simulaciones. Los resultados obtenidos muestran una influencia notable de la heterogeneidad en general, así como una gran sensibilidad al método geoestadístico usado para generar la heterogeneidad. Las diferencias observadas tendrían un gran efecto en el diseño de políticas de manejo integral del recurso

Comparison of the energy demand for comfort in houses of social interest in the municipality of Jiutepec, using the methodologies: degrees-day and TRNSYS; Comparacion de la demanda energetica para el confort de viviendas de interes social en el municipio de Jiutepec, utilizando las metodologias de grados-dia y de TRNSYS

Energy Technology Data Exchange (ETDEWEB)

Gijon, Miguel; Alvarez, Gabriela; Aguilar, Jorge; Xaman, Jesus; Sima, Efrain; Flores, Jason (Mexico)

2009-07-15

In this article a thermal-environmental study is presented in order to evaluate the energy demand in the Morelos state. From collected climatologic data in seven automatic weather stations a comparative diagnosis by the application of two methodologies is realized, such as the one of the Degrees-day and the transitory thermal simulation of TRNSYS to determine the energy demand in traditional dwellings of social interest located in different regions of the State. In the methodology of the degrees-day the ambient temperature for two seasons of the year is used (rainy and dry) and the energy demand for the comfort in the Morelos State is evaluated. For the thermal simulation with the TRNSYS the climatic data obtained in monthly averages is used to determine the thermal loads of the house and the energy requirements in the different regions of the State. The results of the energy demand obtained by both methodologies for the municipality of Jiutepec and a statistic analysis of the existing relation between the degrees-day of cooling and the energy demand for cooling that the dynamic simulations deliver are presented. [Spanish] En este articulo se presenta un estudio termico-ambiental a fin de evaluar la demanda de energia en el Estado de Morelos. A partir de datos climatologicos recolectados en siete estaciones meteorologicas automaticas se realiza un diagnostico comparativo por la aplicacion de dos metodologias, como son la de los Grados-dia y la simulacion termica transitoria de TRNSYS para determinar la demanda energetica en viviendas tradicionales de interes social ubicadas en diferentes regiones del Estado. En la metodologia de los grados-dia se utiliza la temperatura ambiental para dos temporadas del ano (lluvias y secas) y se evalua la demanda energetica del Estado de Morelos para el confort. Para la simulacion termica con el TRNSYS se utiliza la informacion climatica obtenida en promedios mensuales para determinar las cargas termicas de la vivienda y los

Efecto de la energía cinética de la lluvia sobre la dinámica de las propiedades físicas y el encostramiento en un suelo arcilloso sin vegetación

OpenAIRE

Regüés-Muñoz, D.; Torri, D

2002-01-01

[ES] El abandono de cultivos causa en ocasiones un deterioro progresivo del suelo. El contexto climático Mediterráneo, por su régimen estacional de precipitaciones, favorece el encostramiento en suelos arcillosos descubiertos durante ciertas tormentas. El objetivo de este trabajo es diferenciar que factores distinguen dichas tormentas críticas, por medio de realizar series de simulaciones de lluvia en campo y laboratorio, combinando diferentes características de la lluvia y condic...

Characterization of maturity and quality of Brazilian apirenic grapes in the São Francisco river Valley Caracterização da maturidade e qualidade de uvas apirênicas brasileiras no Vale do São Francisco

Directory of Open Access Journals (Sweden)

Robson de Jesus Mascarenhas

2012-03-01

Full Text Available The objective of this study was to characterize and correlate maturity and quality of the first varieties of Brazilian seedless grapes 'BRS Clara', 'BRS Linda', 'BRS Morena', and 'Advanced Selection 8' compared with the American variety 'Crimson Seedless' in compliance with the Brazilian Normative/2002 and export standards Advanced Selection 8' is dark reddish, has large clusters, and is a very large ellipsoid berry; 'BRS Morena' is black with medium sized clusters and large berry shaped as ellipsoid to globoid; 'BRS Linda' is light green and has large sized clusters; 'Crimson' is pink and has small clusters with berries varying from medium to large sizes and ellipsoid shaped; and 'BRS Clara' is green yellowish has medium sized clusters and small berry of elongated ellipsoid shape. All varieties evaluated meet the standard for domestic market established as berry size minimum diameter 12 mm. 'BRS Clara' does not meet the export requirements of diameter. Berries of the red grapes 'BRS Morena' and 'Crimson Seedless' are firmer. The pH, titratable acidity, and soluble solids meet the official standards. Larger clusters are less acidic and present higher soluble solids/titratable acidity ratios implying that they are the sweetest type when ripe.O objetivo deste trabalho foi caracterizar e correlacionar a maturidade e qualidade das primeiras variedades de uvas apirênicas 'BRS Clara', 'BRS Linda', 'BRS Morena', mais a 'Seleção Avançada 8' em fase de lançamento, comparado-as com a variedade norte-americana 'Crimson Seedless', conforme as Normativas Brasileiras/2002 e os padrões para exportação. A Seleção Avançada 8 é avermelhada escura, possui cacho grande, com baga muito grande tipo elipsoide; a 'BRS Morena' é preta com cacho médio, baga grande tipo elipsoide a globosa; a 'BRS Linda' é verde clara, de cacho grande; e a 'Crimson', rósea de cacho pequeno, ambas, com bagas médias a grandes e elipsoides; a 'BRS Clara' éverde amarelada

Influence on pregestacional obesity on the pre-eclampsia/eclampsia risk

OpenAIRE

Suárez González, Juan Antonio; Preciado Guerrero, Richard; Gutiérrez Machado, Mario; Cabrera Delgado, María Rosa; Marín Tápanes, Yoani; Cairo González, Vivian

2013-01-01

Introducción: una de las condiciones maternas que con mayor frecuencia complica el periodo de gestación y el parto es la obesidad. Objetivo: determinar la influencia de la obesidad en los resultados maternos y perinatales de gestantes con riesgo de preeclampsia/eclampsia. Métodos: estudio analítico y ambispectivo en el Hospital Universitario Ginecobstétrico "Mariana Grajales" de Santa Clara, provincia de Villa Clara, en el año 2010 en un grupo de gestantes con riesgo de preeclampsia/eclampsia...

Escala Para Medir Agencia Personal y Empoderamiento (ESAGE)

OpenAIRE

Susan Pick; Jenna Sirkin; Isaac Ortega; Pavel Osorio; Rocío Martínez; Ulises Xocolotzin; Martha Givaudan

2007-01-01

Existe en la literatura una discusión muy extensa, aunque no siempre clara, acerca de la importancia del desarrollo humano. Por ello es necesario contar con las capacidades que permitan fomentar su crecimiento y sustentabilidad. Los conceptos de agencia personal y empoderamiento son centrales en esta discusión. La distinción entre ambos no siempre ha sido clara. De hecho, muchas veces se usan indistintamente. Con base en la experiencia empírica de diseñar, implementar y evaluar pr...

Initial thermal state of the Los Humeros, Puebla, Mexico, geothermal field; Estado termico inicial del campo geotermico de Los Humeros, Puebla, Mexico

Energy Technology Data Exchange (ETDEWEB)

Garcia Gutierrez, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: aggarcia@iie.org.mx

2009-01-15

The initial temperatures field is presented for 40 wells in the Los Humeros geothermal reservoir, along with an elevation curve based on the formation temperature or the most probable reservoir temperature. Stabilized temperatures were estimated using the Radial Spherical Heat Flow method, chosen over the Horner method based on the numerical simulation of the circulation and stop processes of well H-26. In this well, the last temperature log series was reproduced, considering circulation losses. The temperatures were used to produce isothermal curves over three geological sections of the field, which represent the initial distribution of temperatures in the reservoir and show the thermal characteristics and the relationships among thermal anomalies and faults in the reservoir. The elevation curve plotted against the initial temperature of the formation was generated based on detection of the main feed zones at each well, which in turn was developed using detailed analyses of diverse information, such as temperature logs, circulation losses, lithology, well completion, and heat velocities. Based on the results, two groups of wells may be distinguished: one between 1000 and 1600 masl with temperatures from 290 to 330 degrees Celsius, and one between 900 and 0 masl with temperatures from 300 to 400 degrees Celsius. [Spanish] En este trabajo se presenta el campo de temperatura inicial del yacimiento geotermico de Los Humeros y una curva de elevacion contra la temperatura de formacion o temperatura mas probable del yacimiento, obtenida para 40 pozos del campo. Las temperaturas estabilizadas se estimaron mediante el metodo de Flujo de Calor Esferico Radial, y su eleccion sobre las temperaturas del metodo de Horner se soporta con simulacion numerica de los procesos de circulacion y paro del pozo H-26, en la cual la ultima serie de registros se reprodujo considerando perdidas de circulacion. Con estas temperaturas se generaron curvas isotermicas para tres secciones

Produção de cultivares de tomateiro em hidroponia e fertirrigação sob razões de nitrogênio e potássio Production of tomato cultivars in hydroponics and fertigation with different ratios between nitrogen and potassium

Directory of Open Access Journals (Sweden)

Gláucio C Genuncio

2010-12-01

Full Text Available Os cultivos protegidos de tomate apresentam elevada demanda por potássio para altas produções e qualidade de frutos, não tendo sido estudada suficientemente a relação de aplicação entre nitrogênio e potássio que proporcione tais resultados. Avaliou-se a produção e qualidade de frutos de quatro cultivares de tomateiro em sistemas de cultivo hidropônico e fertirrigado sob duas razões entre N e K fornecidas às plantas. Dois experimentos foram conduzidos simultaneamente em casa de vegetação, em esquema fatorial 4x2 com quatro repetições, combinando quatro genótipos (cvs. Cereja 261, San Marzano, Santa Clara e o híbrido Cereja Chipano com duas razões N:K (1:1,5 e 1:2 no hidropônico, e 1:2 e 1:3 no fertirrigado. A produção média de frutos comerciais foi de 2,5 e 1,8 kg/planta no sistema hidropônico e fertirrigado, respectivamente, atingindo 3,3 kg/planta na cv. Santa Clara em hidroponia. Em hidroponia, as razões N:K não afetaram a produção de frutos comerciais e o teor de sólidos solúveis, apesar de um aumento de 6,5% na produção na razão N:K 1:2. A razão N:K 1:2 em hidroponia aumentou a massa e o diâmetro médio dos frutos comerciais, reduzindo a concentração de K nos frutos. No sistema fertirrigado, a razão N:K 1:3 estimulou o crescimento vegetativo do tomateiro, mas não afetou a produção e a qualidade dos frutos. As cultivares San Marzano e Santa Clara tiveram maior produção de frutos nos dois sistemas. A produção de frutos e o teor de sólidos solúveis das cvs. San Marzano e Santa Clara foram maiores no sistema hidropônico em comparação ao fertirrigado. O sistema hidropônico propiciou maior produção de frutos que o sistema fertirrigado para as cultivares San Marzano e Santa Clara e, em hidroponia a razão N:K 1:2 forneceu frutos de maior qualidade comercial.Protected tomato cultivation presents a high potassium demand for obtaining high fruit yield and quality, but the ratio between nitrogen

Feeding non-preference by Spodoptera frugiperda and Spodoptera eridania on tomato genotypes

Directory of Open Access Journals (Sweden)

Bruno Henrique Sardinha de Souza

2013-02-01

Full Text Available Larvae of the genus Spodoptera spp. are highly polyphagous and can cause economical losses in several agricultural crops. Given their growing importance in the tomato crop, especially for industry, this work aimed to evaluate the feeding non-preference by larvae of Spodoptera frugiperda (J. E. Smith, 1797 and Spodoptera eridania (Cramer, 1782 on tomato genotypes and classify them by the levels of resistance. The commercial cultivar Santa Clara was set as the susceptible standard and line PI 134417 as the resistant standard to evaluate the lines PI 134418, PI 126931, LA 462 and LA 716. Feeding non-preference tests were performed under non-choice and free-choice conditions to evaluate the genotype attractiveness to larvae at predetermined times after their release, as well as the leaf area consumed. Overall, the genotypes LA 716 and PI 126931 were the least attractive to S. frugiperda, whereas Santa Clara was the most attractive and consumed. For S. eridania, the genotypes PI 126931, LA 462, LA 716 and PI 134418 were the least preferred for feeding, and Santa Clara and PI 134417 were the most attractive and consumed. The genotypes LA 716 and PI 126931 are moderately resistant to S. frugiperda and S. eridania; PI 134418 and LA 462 are moderately resistant to S. eridania; PI 134417 is susceptible to S. frugiperda and S. eridania; and Santa Clara is highly susceptible to both S. frugiperda and S. eridania.

Resultados del tratamiento quirúrgico en aneurismas intracraneales múltiples de la circulación anterior

Directory of Open Access Journals (Sweden)

Armando Alemán Rivera

2001-09-01

Full Text Available Se realiza un análisis de 10 pacientes con aneurismas múltiples de la porción anterior del polígono de Willis, los cuales representan el 10 % de todos los pacientes con aneurismas operados en el Servicio de Neurocirugía del Hospital Universitario «Arnaldo Milián Castro» de Santa Clara, Villa Clara. En 2 pacientes, los sacos aneurismáticos se localizaban bilateralmente. En un enfermo, la operación fue unilateral, mientras que en el otro, donde los aneurismas se localizaban en ambas arterias cerebrales medias, segmento M2 (aneurismas en espejo, el abordaje se realizó en 2 tiempos quirúrgicos. Todos los sacos aneurismáticos se presillaron y se reportó una mortalidad del 10 %An analysis of 10 patients with multiple aneurysms of the anterior portion of the circle of Willis that accounted for 10 % of all patients with aneurysms operated on at the Neurosurgery Service of "Arnaldo Milián Castro" Teaching Hospital of Santa Clara, Villa Clara, was made. The aneurysmatic sacs were bilaterally located in 2 patients. In one patient, the operation was unilateral, whereas in the other one, in whom the aneurysms were located in both middle cerebral arteries, M2 segment (mirror aneurysms, the operation was performed in 2 surgical times. All the aneurysmatic sacs were stapled and a 10 % mortality was re

Simulation of an active filter for compensation of reactive power and suppression of harmonic currents in the phases and in the neuter of an unbalanced three-phase system of 4 wires; Simulacion de un filtro activo para compensacion de potencia reactiva y supresion de corrientes armonicas en las fases y en el neutro de un sistema trifasico de 4 kilos desbalanceado

Energy Technology Data Exchange (ETDEWEB)

Mino Aguilar, Gerardo

1999-05-01

conocimiento en filtros activos de potencia usados en los puntos de acoplamiento comun entre las fuentes de C.A. y las cargas no lineales formadas por convertidores estaticos de CA/CD, para la supresion de corrientes armonicas y compensacion instantanea de la potencia reactiva. Partiendo de los filtros activos que solo afectan las tres corrientes balanceadas de los sistemas trifasicos de 3 hilos, se llega al tema de esta tesis, cuyo objetivo es resolver el problema de la compensacion reactiva y supresion de corrientes armonicas tanto en las tres fases como tambien en el neutro de los sistemas trifasicos de 4 hilos. La contribucion principal de esta tesis es el diseno, analisis y simulacion de un filtro activo que ademas de suprimir corrientes armonicas y compensacion del factor de potencia en las tres fases de un sistema trifasico desbalanceado, tambien tiene la capacidad para remover la corriente que circula en el neutro, debido al desbalance de las corrientes de fase. Este diseno se basa en la extension de la teoria de la potencia reactiva instantanea que incluye la existencia de los componentes de secuencia cero en las corrientes de fase. Se propone en la tesis un novedoso filtro basado en un inversor trifasico de 4 ramas, 3 ramas de fase y una rama de neutro, que hasta el mejor conocimiento del autor no ha sido reportado en la literatura. Se hace uso de un numero extenso de resultados de simulacion para probar la validez de este filtro, cuyo comportamiento es superior a los filtros para supresion de corrientes en el neutro existentes en la literatura, de los cuales tambien se presenta un estudio comparativo. La tesis tambien incluye un analisis matematico y grafico de los componentes simetricos en sistemas balanceados y desbalanceados a efecto de conocer la naturaleza de las corrientes armonicas de secuencia cero. Se incluye un apartado sobre causas y efectos del problema de la contaminacion armonica.

Evaluation of the MiKlip decadal prediction system using satellite based cloud products

Directory of Open Access Journals (Sweden)

Thomas Spangehl

2016-12-01

Full Text Available The decadal hindcast simulations performed for the Mittelfristige Klimaprognosen (MiKlip project are evaluated using satellite-retrieved cloud parameters from the CM SAF cLoud, Albedo and RAdiation dataset from AVHRR data (CLARA-A1 provided by the EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF and from the International Satellite Cloud Climatology Project (ISCCP. The forecast quality of two sets of hindcasts, Baseline-1-LR and Baseline-0, which use differing initialisations, is assessed. Basic evaluation focuses on multi-year ensemble mean fields and cloud-type histograms utilizing satellite simulator output. Additionally, ensemble evaluation employing analysis of variance (ANOVA, analysis rank histograms (ARH and a deterministic correlation score is performed. Satellite simulator output is available for a subset of the full hindcast ensembles only. Therefore, the raw model cloud cover is complementary used. The new Baseline-1-LR hindcasts are closer to satellite data with respect to the simulated tropical/subtropical mean cloud cover pattern than the reference hindcasts (Baseline-0 emphasizing improvements of the new MiKlip initialisation procedure. A slightly overestimated occurrence rate of optically thick cloud-types is analysed for different experiments including hindcasts and simulations using realistic sea surface boundaries according to the Atmospheric Model Intercomparison Project (AMIP. By contrast, the evaluation of cirrus and cirrostratus clouds is complicated by observational based uncertainties. Time series of the 3-year mean total cloud cover averaged over the tropical warm pool (TWP region show some correlation with the CLARA-A1 cloud fractional cover. Moreover, ensemble evaluation of the Baseline-1-LR hindcasts reveals potential predictability of the 2–5 lead year averaged total cloud cover for a large part of this region when regarding the full observational period. However, the hindcasts show only

Los agujeros negros y las ondas del Doctor Einstein

OpenAIRE

Mario Alberto Rodríguez-Meza

2017-01-01

Se describen los principales desarrollos científicos que llevaron a la detección de las ondas gravitacionales por el proyecto ligo: la relatividad general, sus predicciones de agujeros negros y ondas gravitacionales, la relatividad numérica y las simulaciones de la colisión y coalescencia de dos agujeros negros y los desarrollos de diversos detectores de ondas gravitacionales. Finalmente la detección de las ondas gravitacionales confirma la existencia de los enigmáticos agujeros negros.

GENERACION DEL MODELO MATEMATICO BASADO EN LA ADQUISICION DE DATOS DE HUMEDAD UTILIZANDO LA PLATAFORMA LABVIEW Y MATLAB

OpenAIRE

Sendey Vera; Samuel Bustos

2016-01-01

El presente trabajo aplica el modelo matematico que se enfoca a objetivos especificos como es el analilis, simulacion y pronóstico de los factores de humedad del suelo. La investigacion, tiene como base el analisís matemático - estadístico de los factores de humedad del suelo. Ecuador por ser un pais tercer mudista, nuestro recursos ecnonomicos son limitados, es ahi, donde radica nuestra justificacion economica, la cual es generar un modelo matematico para determinar el comportamiento de ...

Feeding non-preference by Spodoptera frugiperda and Spodoptera eridania on tomato genotypes Não preferência para alimentação em genótipos de tomateiro por Spodoptera frugiperda e Spodoptera eridania

Directory of Open Access Journals (Sweden)

Bruno Henrique Sardinha de Souza

2013-02-01

Full Text Available Larvae of the genus Spodoptera spp. are highly polyphagous and can cause economical losses in several agricultural crops. Given their growing importance in the tomato crop, especially for industry, this work aimed to evaluate the feeding non-preference by larvae of Spodoptera frugiperda (J. E. Smith, 1797 and Spodoptera eridania (Cramer, 1782 on tomato genotypes and classify them by the levels of resistance. The commercial cultivar Santa Clara was set as the susceptible standard and line PI 134417 as the resistant standard to evaluate the lines PI 134418, PI 126931, LA 462 and LA 716. Feeding non-preference tests were performed under non-choice and free-choice conditions to evaluate the genotype attractiveness to larvae at predetermined times after their release, as well as the leaf area consumed. Overall, the genotypes LA 716 and PI 126931 were the least attractive to S. frugiperda, whereas Santa Clara was the most attractive and consumed. For S. eridania, the genotypes PI 126931, LA 462, LA 716 and PI 134418 were the least preferred for feeding, and Santa Clara and PI 134417 were the most attractive and consumed. The genotypes LA 716 and PI 126931 are moderately resistant to S. frugiperda and S. eridania; PI 134418 and LA 462 are moderately resistant to S. eridania; PI 134417 is susceptible to S. frugiperda and S. eridania; and Santa Clara is highly susceptible to both S. frugiperda and S. eridania.Lagartas do gênero Spodoptera spp. são altamente polífagas, podendo causar danos econômicos em diversas culturas agrícolas. Em vista de sua emergente importância na cultura do tomate, principalmente o destinado à indústria, este trabalho teve por objetivo avaliar a não preferência, para alimentação, de lagartas de Spodoptera frugiperda (J. E. Smith, 1797 e Spodoptera eridania (Cramer, 1782 por genótipos de tomateiro, e classificá-los quanto aos graus de resistência. Como padrão susceptível, utilizou-se o cultivar comercial Santa

Characterization of AVHRR global cloud detection sensitivity based on CALIPSO-CALIOP cloud optical thickness information: demonstration of results based on the CM SAF CLARA-A2 climate data record

Science.gov (United States)

Karlsson, Karl-Göran; Håkansson, Nina

2018-02-01

The sensitivity in detecting thin clouds of the cloud screening method being used in the CM SAF cloud, albedo and surface radiation data set from AVHRR data (CLARA-A2) cloud climate data record (CDR) has been evaluated using cloud information from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) onboard the CALIPSO satellite. The sensitivity, including its global variation, has been studied based on collocations of Advanced Very High Resolution Radiometer (AVHRR) and CALIOP measurements over a 10-year period (2006-2015). The cloud detection sensitivity has been defined as the minimum cloud optical thickness for which 50 % of clouds could be detected, with the global average sensitivity estimated to be 0.225. After using this value to reduce the CALIOP cloud mask (i.e. clouds with optical thickness below this threshold were interpreted as cloud-free cases), cloudiness results were found to be basically unbiased over most of the globe except over the polar regions where a considerable underestimation of cloudiness could be seen during the polar winter. The overall probability of detecting clouds in the polar winter could be as low as 50 % over the highest and coldest parts of Greenland and Antarctica, showing that a large fraction of optically thick clouds also remains undetected here. The study included an in-depth analysis of the probability of detecting a cloud as a function of the vertically integrated cloud optical thickness as well as of the cloud's geographical position. Best results were achieved over oceanic surfaces at mid- to high latitudes where at least 50 % of all clouds with an optical thickness down to a value of 0.075 were detected. Corresponding cloud detection sensitivities over land surfaces outside of the polar regions were generally larger than 0.2 with maximum values of approximately 0.5 over the Sahara and the Arabian Peninsula. For polar land surfaces the values were close to 1 or higher with maximum values of 4.5 for the parts

Field transformations to multivalued fields

Energy Technology Data Exchange (ETDEWEB)

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

2007-05-15

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

Desempenho de cultivares nacionais de batata para produtividade de tubérculos

Directory of Open Access Journals (Sweden)

Giovani Olegario da Silva

2014-10-01

Full Text Available O objetivo deste trabalho foi verificar o desempenho dos cultivares de batata nacionais BRS Ana e BRS Clara, em comparação com os cultivares importados Ágata e Asterix, em relação à produtividade de tubérculos. Os experimentos foram realizados no município de Canoinhas, SC. Foram avaliados quatro cultivares de batata: BRS Ana, BRS Clara, Asterix e Ágata. O delineamento experimental foi em blocos casualizados, com quatro repetições. As parcelas continham quatro linhas com 20 plantas em cada linha. Cento e dez dias após o plantio foi realizada a colheita e, os tubérculos de cada parcela, avaliados para caracteres relacionados com a produtividade de tubérculos. Os dados foram submetidos à análise de variância e agrupamento de médias, por Skott & Knott, a 5% de probabilidade. Os cultivares de batata nacionais BRS Ana e BRS Clara foram mais produtivos do que os importados Asterix e Ágata; no entanto, são mais tardios, quanto ao ciclo vegetativo.

Application of a hydrodynamic model to a coastal zone; Aplicacion de un modelo hidrodinamico en una zona costera

Energy Technology Data Exchange (ETDEWEB)

Rendon-Villalobos, J. Rodolfo; Vicente-Vidal, Francisco; Vicente-Vidal, Victor M [Centro de Investigaciones en Ciencia Aplicada y Tecnologia Avanzada, Cuernavaca, Morelos, Mexico (Mexico)

1999-09-01

This study describes the results of a numerical simulation of the hydrodynamic behavior of cooling water discharged into the sea from the Tuxpan Power Plant under two different meteorological and oceanographic conditions: case 1, southwesterly variable winds with an average velocity of 3 m s{sup -}1 and case II, northwesterly variable winds with an average velocity of 11.1 m s{sup -}1. The numerical simulations were made using a three-dimensional hydrodynamic model of coastal circulation and heat exchange. The southerly winds induce a sea surface circulation towards the north, which moves the discharged warm water away from the intake. The northerly winds, however, drive the hydrothermal effluent towards the intake. Comparisons between the numerical simulation results and field data show that the model correctly predicts the surface diffusion and dispersion of the hydrothermal effluents measured August 18 to 21, 1992 (case I) and November 24 to 27, 1992 (case II). The model predicts the extent of the areas impacted with cooling water with a precision of {+-}11%. For all the cases analyzed, the real size of the impacted areas that might have adverse effects on the marine ecosystems was not greater than 100 m{sup 2}. Thus, these possible adverse effects are considered to be of local significance only. The simulated vertical profiles of temperature show that the discharged cooling water remains mostly on the surface of the receiving water mass and reaches a maximum depth of 3.5 m. [Spanish] Este estudio describe los resultados de la simulacion numerica de comportamiento hidrodinamico de la descarga al mar del agua de enfriamiento de la Central de Potencia Tuxpan, bajo dos distintas condiciones ambientales meteorologicas y oceanograficas: caso I, viento variable de direccion del suroeste con intensidad promedio de 3 m s-1, y caso II, viento variable del noroeste con intensidad promedio de 11.1 m s-1. Las simulaciones numericas se realizaron mediante un modelo

Desarrollo dirigido por modelos en simulaciones de inteligencia ambiental

OpenAIRE

Campillo Sánchez, Pablo

2017-01-01

La Inteligencia Ambiental es un paradigma que persigue crear entornos donde se ofrecen servicios a los usuarios. En dichos entornos los dispositivos están perfectamente integrados y los servicios se adaptan y son proactivos. En los últimos años, este paradigma se ha aplicado ampliamente como solución para la asistencia de personas mayores en sus hogares con el fin de mejorar su independencia y calidad de vida. Sin embargo, el desarrollo e investigación de este tipo de sistemas es costoso. Ent...

Simulaciones aumentadas: una experiencia contemporánea del territorio

OpenAIRE

Santamarina-Macho, Carlos

2017-01-01

Recientemente han comenzado a popularizarse los denominados juegos de realidad aumentada geolocalizada, aplicaciones tecnológicas que ofrecen una experiencia lúdica combinando el mundo real y virtual. El artículo analiza el modo en el que estas herramientas modifican nuestra experiencia territorial. Partiendo de su caracterización teórica, se describen primeramente algunos procesos de creación de “lugar” en el marco de estas realidades mixtas, para continuar con el análisis de su aplicación p...

Piloto automático para UAV. Optimizacion y Simulacion

OpenAIRE

Vives Caballero, Sergio Jose

2015-01-01

The objective of this project is to adapt an automatic pilot for unmanned aerial vehicles, written in C#, so that it can be used with the flight simulator XPlane, in addition to its test and validation. This way we will obtain a didactic tool to design and validate automatic pilots for unmanned aerial vehicles. Initially the choice of the simulator, aircraft models, programming language, integrated development environment and functions implemented will be justified and some of the existing op...

Diversidad de sistemas planetarios sin gigantes gaseosos en discos de baja masa

OpenAIRE

Ronco, María Paula

2013-01-01

Como indica el título de esta tesis, el objetivo general de nuestro trabajo es poder analizar la diversidad de sistemas planetarios que podrían formarse alrededor de estrellas de tipo solar y sin gigantes gaseosos. Nuestro interés particular es estudiar estos sistemas en discos de baja masa, pues podemos asegurar que en ellos no hay posibilidad de formar planetas gigantes gaseosos. Para poder lograr este análisis desarrollamos simulaciones de N-cuerpos orientadas a estudiar el proceso de form...

Clasificación de presas y evaluación del riesgo con programa HEC-RAS

OpenAIRE

Marín Rubís, Àlex

2006-01-01

Desde el año 2003 el modelo HEC-RAS, desarrollado por el Hydrologic Engineering Center (HEC) del United States Army Corps of Engineers, incorpora entre sus capacidades un módulo que permite la simulación de rotura de presas. El objeto de este trabajo ha sido asegurar la capacidad de HEC-RAS para llevar a cabo este tipo de simulaciones y crear una guía para su uso en entorno GIS (Arcview) mediante la aplicación HEC-GeoRAS.

Influencia de la solidez en un aerogenerador VAWT con rotor H-Darrieus y perfiles simétricos

OpenAIRE

Alonso Gómez, Álvaro

2016-01-01

Mediante el empleo de la Mecánica Computacional de Fluidos, se estudia la influencia que tiene el grado de solidez en el comportamiento de un aerogenerador. Se estudia un aerogenerador de eje vertical con rotor H-Darrieus y tres perfiles simétricos en el que se analizan tres grados de solidez diferentes, generándose por lo tanto tres modelos, para cada uno de los cuales se obtiene la curva de rendimiento correspondiente. Para construir la curva se van realizando simulaciones a diferentes ve...

Caminata del robot humanoide RH-2 en la plataforma de simulación OpenHRP

OpenAIRE

Torre Doblas, Carlos de

2010-01-01

En primer lugar, en este proyecto se trabajará con el simulador OpenHRP3, intentando comprender su funcionamiento interno (carga de archivos, lenguajes, funcionalidades, etc.). También se adaptará el modelo del robot humanoide Rh-2 al entorno del mismo, pudiendo así realizar simulaciones. La verdadera finalidad de este proyecto, y en lo que se ha hecho especial incapié, es simular el robot sosteniendo una caja, validando así las fuerzas que sienten las distintas partes del cuerpo en los momen...

Los agujeros negros y las ondas del Doctor Einstein

Directory of Open Access Journals (Sweden)

Mario Alberto Rodríguez-Meza

2017-01-01

Full Text Available Se describen los principales desarrollos científicos que llevaron a la detección de las ondas gravitacionales por el proyecto ligo: la relatividad general, sus predicciones de agujeros negros y ondas gravitacionales, la relatividad numérica y las simulaciones de la colisión y coalescencia de dos agujeros negros y los desarrollos de diversos detectores de ondas gravitacionales. Finalmente la detección de las ondas gravitacionales confirma la existencia de los enigmáticos agujeros negros.

¿Cómo son los MOOC sobre educación? Un análisis de cursos de temática pedagógica que se ofertan en castellano

OpenAIRE

Calvo Salvador, Adelina; Rodríguez Hoyos, Carlos; Fernández Díaz, Elia María

2016-01-01

RESUMEN: En esta investigación se analizan MOOCs cuya lengua vehicular es el castellano y que versan sobre temáticas pedagógicas/educativas. El análisis, de clara inspiración cualitativa, se centra en 5 dimensiones: 1) Datos básicos (título, temática, objetivo, institución y plataforma que lo aloja), 2) Metodología, 3) Recursos, 4) Tipos de videos y 5) Evaluación. Los resultados muestran las temáticas hegemónicas en los cursos, así como la clara presencia de una metodología magistral, apoyada...

Initial temperature distribution in Los Humeros, Mexico, geothermal field; Distribucion de temperatura inicial en el campo geotermico de Los Humeros, Puebla

Energy Technology Data Exchange (ETDEWEB)

Garcia, A; Arellano, V; Aragon, A; Barragan, R.M; Izquierdo, G [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico); Pizano, A [Comision federal de Electricidad, Los Humeros, Puebla (Mexico)

2000-12-01

The initial formation temperatures surrounding 40 wells from the Los Humeros geothermal field are presented. These temperatures were estimated using the Horner and the sphere methods. A brief discussion on the applicability of each method is presented and previous applications are detailed. Then the more likely reservoir temperature of each well versus elevation is plotted based on the estimations about the main feed zone and the temperature of each well. The boiling with depth curve for pure water is also included. Two longitudinal and one traverse geological sections are presented to illustrate the field initial temperature distribution, the lithology and layers thickness, the basement topography and the wells traversed along each sections. Also, the main feed zones of the wells are indicated. Finally, the last series of measured temperature logs in well H-26 are produced by numerical simulation. This considers the well circulation losses and an assumed initial temperature profile. This profile iteratively modified until the computed profiles match the measured temperature profiles. The last assumed temperature profile is then considered as the best approximation to the undisturbed formation temperature around well H-26 and it is then compared with the stabilized temperatures obtained via the Horner and Sphere methods. [Spanish] Se presentan las temperaturas iniciales o estabilizadas de la formacion circundante a 40 pozos del campo geotermico Los Humeros, las cuales se estimaron mediante los metodos de Horner y el metodo de la esfera. Se presenta una discusion sobre la aplicacion de cada metodo y se detallan las aplicaciones previas del metodo de la esfera. Posteriormente y con base en las estimaciones de las principales zonas de aporte de cada pozo y sus correspondientes temperaturas se grafican las temperaturas mas probables de yacimiento para cada pozo contra la elevacion y se incluye en la misma grafica la curva de ebullicion del agua contra la elevacion. Se

Evolución Dinámica de Cúmulos Estelares Abiertos

Science.gov (United States)

de La Fuente Marcos, R.

Las estrellas que observamos no se formaron aisladamente, sino que lo hicieron en grupos o cúmulos. Estos sistemas estelares recibenel nombre de cúmulos estelares abiertos o galácticos cuando están constituidos por estrellas de la Población I. Los cúmulos abiertos se localizan preferentemente en el plano galáctico, y en muchos de ellos está teniendo lugar aún una activa formación estelar. El propósito principal de esta tesis doctoral es el estudio de la evolución dinámica de estos sistemas estelares por medio de simulaciones numéricas y de la comparación de sus resultados con datos observacionales. Con este fin se analizan los efectos que, sobre la dinámica de los cúmulos, ejercen varios fenómenos de interés astrofísico tales como el campo gravitatorio galáctico, la pérdida de masa causada por la evolución estelar y la presencia de binarias primordiales. En este trabajo se presentan los resultados de más de un centenar de modelos de cúmulos, con poblaciones comprendidas en el intervalo [100, 10.000] estrellas, calculados con NBODY5, un programa estándar en el campo de la Dinámica Estelar Experimental. De los mismos se deduce que el mecanismo principal que rige la dinámica de los cúmulos abiertos es la evolución estelar de su distribución de masas, encontrándose un comportamiento diferencial fuertemente dependiente de la población inicial del cúmulo. Los mecanismos responsables de la desintegración de los cúmulos abiertos son analizados en detalle, proponiéndose un modelo analítico que ajusta razonablemente los resultados de las simulaciones. Además, y con el fin de explicar el elevado número de sistemas múltiples observados en cúmulos abiertos, se estudian los efectos que, sobre los mismos, ejerce la presencia de una cierta fracción de binarias primordiales. El papel de las binarias tambiín depende de la riqueza del cúmulo y sus efectos se interrelacionan con aquellos debidos a la evolución estelar. Por último, se

Library on Crowd Behavior for Agents Treatment on Videogames

Directory of Open Access Journals (Sweden)

M. Proenza

2013-01-01

Full Text Available Abstract This paper covers the investigation process and further design and implementation of a library on crowd behaviors for videogames. Three methods were studied in order to pick up one of them, resulting to be Steering Behaviors method the one selected to be adopted. The library supports simulations with a large number of moving agents. It also copes with polygonal obstacles avoidance. Additionally, simulations can be adapted to many contexts by tuning some parameters. The library consists of an original design mostly based on Command Pattern that allows it to be easily usable and extendable.   Resumen Este documento cubre el proceso de investigación y el diseño e implementación de una biblioteca en los comportamientos de multitud de videojuegos. Tres métodos fueron estudiados con el fin de recoger a uno de ellos, el resultado es el método de dirección Comportamientos que se ha seleccionado para su adopción. La biblioteca admite simulaciones con un gran número de agentes móviles. También hace frente a la evitación obstáculos poligonales. Además, las simulaciones se pueden adaptar a diferentes contextos mediante la regulación de algunos parámetros. La biblioteca consta de un diseño original basado principalmente en modelo de comandos que permite que sea fácilmente utilizable y extensible.

Ambient air/near-field measurements of methane and Volatile Organic Compounds (VOCs) from a natural gas facility in Northern Europe

Science.gov (United States)

Baudic, Alexia; Gros, Valérie; Bonsang, Bernard; Baisnee, Dominique; Vogel, Félix; Yver Kwok, Camille; Ars, Sébastien; Finlayson, Andrew; Innocenti, Fabrizio; Robinson, Rod

2015-04-01

Since the 1970's, the natural gas consumption saw a rapid growth in large urban centers, thus becoming an important energy resource to meet continuous needs of factories and inhabitants. Nevertheless, it can be a substantial source of methane (CH4) and pollutants in urban areas. For instance, we have determined that about 20% of Volatile Organic Compounds (VOCs) in downtown Paris are originating from this emission source (Baudic, Gros et al., in preparation). Within the framework of the "Fugitive Methane Emissions" (FuME) project (Climate-KIC, EIT); 2-weeks gas measurements were conducted at a gas compressor station in Northern Europe. Continuous ambient air measurements of methane and VOCs concentrations were performed using a cavity ring-down spectrometer (model G2201, Picarro Inc., Santa Clara, USA) and two portable GC-FID (Chromatotec, Saint-Antoine, France), respectively. On-site near-field samplings were also carried out at the source of two pipelines using stainless steel flasks (later analyzed with a laboratory GC-FID). The objective of this study aims to use VOCs as additional tracers in order to better characterize the fugitive methane emissions in a complex environment, which can be affected by several urban sources (road-traffic, others industries, etc.). Moreover, these measurements have allowed determining the chemical composition of this specific source. Our results revealed that the variability of methane and some VOCs was (rather) well correlated, especially for alkanes (ethane, propane, etc.). An analysis of selected events with strong concentrations enhancement was performed using ambient air measurements; thus allowing the preliminary identification of different emission sources. In addition, some flasks were also sampled in Paris to determine the local natural gas composition. A comparison between both was then performed. Preliminary results from these experiments will be presented here.

An electric field in a gravitational field

International Nuclear Information System (INIS)

Harpaz, Amos

2005-01-01

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

Slabsim: Simulador de dispositivos ópticos integrados

OpenAIRE

Fernández González, Alberto

2013-01-01

En los diseños y desarrollos de ingeniería, antes de comenzar la construcción e implementación de los objetivos de un proyecto, es necesario realizar una serie de análisis previos y simulaciones que corroboren las expectativas de la hipótesis inicial, con el fin de obtener una referencia empírica que satisfaga las condiciones de trabajo o funcionamiento de los objetivos de dicho proyecto. A menudo, los resultados que satisfacen las características deseadas se obtienen mediante la iteración de...

Simulación numérica : ecuación de difusión

OpenAIRE

Millán, Zulma; Torre, Leonor de la; Oliva, Laura; Berenguer, María del Carmen

2011-01-01

La simulación numérica es una herramienta eficaz en las ciencias aplicadas, para la determinación de soluciones y la predicción del comportamiento de las mismas, sin recurrir a la experimentación. Permite la recreación matemática de procesos físicos que aparecen con frecuencia en el área de Ingeniería. El uso de simulaciones numéricas para estudiar ecuaciones diferenciales en derivadas parciales, en particular la ecuación de difusión, requiere normalmente de un cuidadoso estudio d...

Un Sistema Dinámico Asociado a un Modelo de Propagación y Control del VIH-SIDA

OpenAIRE

Pulecio Montoya, Ana María

2012-01-01

La siguiente investigación se enfoca en el planteamiento y estudio de un sistema de ecuaciones diferenciales no lineales que representan la dinámica de propagación y control del VIH-SIDA. Se realiza un análisis de estabilidad del sistema y se plantean estrategias de control óptimo para el modelo planteado, teniendo en cuenta un funcional de costos y otro de beneficios. Finalmente, se realizan simulaciones numéricas mediante el software Matlab con el fin de ilustrar los resultados obtenido...

Presentación del dossier Evaluación y tratamiento psicológico mediante realidad virtual y otras nuevas tecnologías

OpenAIRE

Gutiérrez Maldonado, José

2009-01-01

Pese a lo que pudiera parecer a primera vista, la realidad virtual no es una tecnología exótica. Las aplicaciones de la realidad virtual se hallan presentes ya en gran cantidad de campos, desde las simulaciones con las que se entrena en el manejo de diferentes tipos de máquinas, hasta sistemas de visualización que ayudan a comprender complejos sistemas conceptuales matemáticos. En medicina existen desde hace años aplicaciones mediante las que es posible aprender y practicar técnicas quirúrgic...

Modelamiento de un yacimiento hipotetico de carbón utilizando el software minesight®.

OpenAIRE

Franco Sepúlveda, Giovanni; Henao Gómez, Cristian Camilo

2012-01-01

Este artículo presenta una compilación de términos generales relacionados con la generación de un proyecto geologico minero usando herramientas ejecutables proporcionadas por Minesight®, que es una de las herramientas para el modelamiento y la panificación minera más utilizadas a nivel mundial, tomando como punto de partida el suministro de datos de campo hasta la finalización con el planeamiento minero, relacionando los diferentes tipos de datos en simulaciones posibles y aplicables a los de...

Análisis y modelización de vigas sándwich sometidas a impactos de baja velocidad

OpenAIRE

Iváñez del Pozo, Inés

2016-01-01

En esta Tesis Doctoral se ha estudiado el comportamiento frente a impactos de baja velocidad de vigas sándwich constituidas por pieles de material compuesto de tipo laminado y núcleo de nido de abeja de aluminio. Existen tres clases de metodologías para hacer frente a este estudio: el análisis experimental, los modelos analíticos y las simulaciones numéricas. La realización de un estudio experimental exhaustivo supone una gran inversión, tanto en términos económicos como tem...

Análisis CFD sobre la influencia de la solidez en aerogeneradores H-Darrieus con perfiles asimétricos NACA 7425

OpenAIRE

Rivero Sánchez, Alonso

2016-01-01

El presente trabajo de fin de grado es un estudio CFD de un aerogenerador de eje vertical tipo H-Darrieus de pequeñas dimensiones, compuesto por tres álabes con perfiles asimétricos NACA 7425. El objetivo principal es analizar la influencia de la solidez en un aerogenerador con estas características, para ello se estudiaran diferentes modelos posibles, rotor completo y perfiles estáticos. En la práctica se han realizado diversas simulaciones para llegar a obtener las curvas características de...

Diseño de interfaces en Matlab para la enseñanza de la Física en titulaciones técnicas

OpenAIRE

Neipp López, Cristian; Hernández Prados, Antonio; Beléndez Vázquez, Augusto; Moreno Marín, Juan Carlos; Beléndez Vázquez, Tarsicio; Rodes Roca, José Joaquín

2004-01-01

El entorno de trabajo “Matlab” es sin lugar a dudas una herramienta imprescindible para un gran número de científicos e ingenieros que pretenden realizar simulaciones numéricas. Esto se debe a que la programación en “Matlab” se puede realizar de manera relativamente sencilla y eficaz, gracias al gran número de funciones ya implementadas en este entorno. Entre otros aspectos interesantes, “Matlab” también permite una rápida y efectiva visualización de los resultados obtenidos...

Estudio cinético del agotamiento de colorantes reactivos en tricomía en fibras de algodón

OpenAIRE

Parra Osorio, Hernán Julio; Parra Osorio, Hernán Julio

2010-01-01

Este estudio de investigación se desarrolla debido a la necesidad de contar con herramientas para hacer un análisis más eficiente del proceso de agotamiento de colorantes reactivos en la tintura del algodón. Dicho estudio nos llevará a predecir la tendencia en forma cuantitativa del nivel de difusión, absorción y reacción del color, y poder así determinar cuál es su comportamiento cinético durante el proceso de tintura. El estudio es corroborado con simulaciones de tintura experimenta...

Comparativa de herramientas de simulación de redes sociales

OpenAIRE

Camino García, Ana María

2016-01-01

Hoy en día, el Análisis de Redes Sociales (ARS) es muy útil, ya que refleja el comportamiento de la sociedad actual. Entre las diferentes técnicas para analizar las redes sociales, hay un interés creciente en el modelado basado en agentes (MBA), ya que permite realizar simulaciones de sistemas complejos. Por lo tanto, las herramientas de simulación cobran gran importancia para el análisis de redes sociales. En este trabajo, se analizan diferentes tipos de herramientas de simulación, con el fi...

Trigeneración en un hospital en Madrid

OpenAIRE

Stoica, Geany Mark Antonio

2014-01-01

En el presente proyecto se tiene como finalidad determinar de forma precisa las posibilidades de trigeneración de un hospital concreto. Basando los cálculos y simulaciones en datos reales facilitados por el propio centro, que analizándolos posteriormente se podrá decidir sobre el tipo de planta y potencia más adecuada a su configuración energética actual. Los objetivos a cumplir en el presente proyecto por tanto son: Estudio de la viabilidad de implantar un sistema de trigeneració...

Efectos de aumentar las pensiones no contributivas de jubilación y las pensiones con complemento a mínimo de jubilación y viudedad a las personas mayores en España.

OpenAIRE

Clemente Polo Andrés; Raimundo Viejo Rubio

2011-01-01

En este artículo se presentan los resultados obtenidos al aumentar algunas de las pensiones más bajas que perciben los hogares mayores de 65 años en España. Las simulaciones se han realizado con un modelo de equilibrio general aplicado y los resultados obtenidos indican que el aumento del déficit público ocasionado por el incremento de las pensiones se podría contrarrestar, sin imponer costes sustanciales a los hogares menores de 65 años, elevando bien los tipos del impuesto sobre la renta o ...

Análisis de las configuraciones de electrónica de potencia empleadas en los sistemas de tracción de vehículos eléctricos

OpenAIRE

García de Pablos, Fidel

2014-01-01

En este documento se han analizado los diferentes tipos de vehículos, los diferentes motores eléctricos y los convertidores electrónicos empleados para la tracción en vehículos eléctricos. A continuación se ha analizado en mayor profundidad en funcionamiento y el control de convertidores continua continua bidireccionales y de un inversor trifásico en puente para el control de motores de continua y conmutados electrónicamente. Esto se ha acompañado de simulaciones por ordenador ...

Comportamiento de sistemas reductores de velocidad para la regulación del tráfico

OpenAIRE

Bernal Carretero, Virginia

2009-01-01

Uno de los objetivos de este proyecto fin de carrera es realizar un estudio de los reductores de velocidad existentes en una ciudad y comprobar si cumplen la actual normativa tanto referente a las dimensiones como a la señalización. Tras realizar el estudio de campo, se realizarán simulaciones con la ayuda del programa informático CarSim® con el objetivo de estudiar el comportamiento dinámico del vehículo al circular por un reductor de velocidad siguiendo las recomendaciones de la normativa a...

Efectos de los cúmulos ionizantes de baja masa en el espectro de regiones H II y galaxias

OpenAIRE

Villaverde Aparicio, Marcos

2012-01-01

Para estudiar estos efectos de muestreo, ver en que caso son relevantes y como influyen en el espectro integrado de líneas de emisión de galaxias espirales, hemos realizado un total de dos millones de simulaciones Monte Carlo de cúmulos con edad cero y metalicidad solar con masas entre 20 y 106 M¿. Las masas de los cúmulos se han asignado muestreado aleatoriamente un función inicial de masas de cúmulos (ICMF). Para cada cúmulo la masa de las estrellas individuales se han obtenido muestreando ...

Tripolar electric field Structure in guide field magnetic reconnection

Science.gov (United States)

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

2018-03-01

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

Tripolar electric field Structure in guide field magnetic reconnection

Directory of Open Access Journals (Sweden)

S. Fu

2018-03-01

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

Gauge fields in a torsion field

International Nuclear Information System (INIS)

Rosu, Ion

2004-01-01

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

Analysis techniques of charging damage studied on three different high-current ion implanters

Science.gov (United States)

Felch, S. B.; Larson, L. A.; Current, M. I.; Lindsey, D. W.

1989-02-01

One of the Greater Silicon Valley Implant Users' Group's recent activities has been to sponsor a round-robin on charging damage, where identical wafers were implanted on three different state-of-the-art, high-current ion implanters. The devices studied were thin-dielectric (250 Å SiO2), polysilicon-gate MOS capacitors isolated by thick field oxide. The three implanters involved were the Varian/Extrion 160XP, the Eaton/Nova 10-80, and the Applied Materials PI9000. Each implanter vendor was given 48 wafers to implant with 100 keV As+ ions at a dose of 1 × 1016 cm-2. Parameters that were varied include the beam current, electron flood gun current, and chamber pressure. The charge-to-breakdown, breakdown voltage, and leakage current of several devices before anneal have been measured. The results from these tests were inconclusive as to the physical mechanism of charging and as to the effectiveness of techniques to reduce its impact on devices. However, the methodology of this study is discussed in detail to aid in the planning of future experiments. Authors' industrial affiliations: S.B. Felch, Varian Research Center, 611 Hansen Way, Palo Alto, CA 94303, USA; L.A. Larson, National Semiconductor Corp., P.O. Box 58090, Santa Clara, CA 95052-8090, USA; M.I. Current, Applied Materials, 3050 Bowers Ave., Santa Clara, CA 95054, USA; D.W. Lindsey, Eaton/NOVA, 931 Benicia Ave, Sunnyvale, CA 94086, USA.

Simulation of Tracer Transport in Porous Media: Application to Bentonites; Simulacion del Transporte de Trazadores en Medios Porosos: Aplicacion al Caso de Arcillas

Energy Technology Data Exchange (ETDEWEB)

Bru, A; Casero, D [CIEMAT, Madrid (Spain)

2001-07-01

We present a formal framework to describe tracer transport in heterogeneous media, such as porous media like bentonites. In these media, mean field approximation is not valid because there exist some geometrical constraints and the transport is anomalous. (Author)

Quantized fields in external field. Pt. 2

International Nuclear Information System (INIS)

Bellissard, J.

1976-01-01

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

Wake fields and wake field acceleration

International Nuclear Information System (INIS)

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

1984-12-01

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

Plan de negocios para la comercialización de empanadas en Lima - Perú

OpenAIRE

UPC, Repositorio Academico; Noltenius, Susanne; Olaechea, Adolfo; Rodríguez, Renzo

2015-01-01

El presente trabajo propone un Plan de Negocios para la comercialización de las empanadas Doña Clara. Se trata de un negocio estructurado, cuya misión, visión, valores y filosofía se exponen en el capítulo 1, basado en un sondeo de mercado que se describe en el capítulo 2, y con estrategias comerciales enunciadas en el capítulo 3. Los objetivos se explican en el capítulo 4 y la proyección de resultados se comenta en el capítulo 5. Empañadas Doña Clara son una propuesta nueva de comercializaci...

Plan de negocios para la comercialización de empanadas en Lima Perú

OpenAIRE

Noltenius, Susanne; Olaechea, Adolfo; Rodríguez, Renzo

2015-01-01

El presente trabajo propone un Plan de Negocios para la comercialización de las empanadas Doña Clara. Se trata de un negocio estructurado, cuya misión, visión, valores y filosofía se exponen en el capítulo 1, basado en un sondeo de mercado que se describe en el capítulo 2, y con estrategias comerciales enunciadas en el capítulo 3. Los objetivos se explican en el capítulo 4 y la proyección de resultados se comenta en el capítulo 5. Empañadas Doña Clara son una propuesta nueva de comercializaci...

A field-sweep/field-lock system for superconducting magnets--Application to high-field EPR.

Science.gov (United States)

Maly, Thorsten; Bryant, Jeff; Ruben, David; Griffin, Robert G

2006-12-01

We describe a field-lock/field-sweep system for the use in superconducting magnets. The system is based on a commercially available field mapping unit and a custom designed broad-band 1H NMR probe. The NMR signal of a small water sample is used in a feedback loop to set and control the magnetic field to high accuracy. The current instrumental configuration allows field sweeps of +/-0.4 T and a resolution of up to 10(-5) T (0.1 G) and the performance of the system is demonstrated in a high-field electron paramagnetic resonance (EPR) application. The system should also be of utility in other experiments requiring precise and reproducible sweeps of the magnetic field such as DNP, ENDOR or PELDOR.

A Field-Sweep/Field-Lock System for Superconducting Magnets-Application to High-Field EPR

Science.gov (United States)

Maly, Thorsten; Bryant, Jeff; Ruben, David; Griffin, Robert G.

2007-01-01

We describe a field-lock/field-sweep system for the use in superconducting magnets. The system is based on a commercially available field mapping unit and a custom designed broad-band 1H-NMR probe. The NMR signal of a small water sample is used in a feedback loop to set and control the magnetic field to high accuracy. The current instrumental configuration allows field sweeps of ± 0.4 T and a resolution of up to 10-5 T (0.1 G) and the performance of the system is demonstrated in a high-field electron paramagnetic resonance (EPR) application. The system should also be of utility in other experiments requiring precise and reproducible sweeps of the magnetic field such as DNP, ENDOR or PELDOR. PMID:17027306

Matching tomographic IMRT fields with static photon fields

International Nuclear Information System (INIS)

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

2001-01-01

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

Rainfall Estimation and Performance Characterization Using an X-band Dual-Polarization Radar in the San Francisco Bay Area

Science.gov (United States)

Cifelli, R.; Chen, H.; Chandra, C. V.

2016-12-01

The San Francisco Bay area is home to over 5 million people. In February 2016, the area also hosted the NFL Super bowl, bringing additional people and focusing national attention to the region. Based on the El Nino forecast, public officials expressed concern for heavy rainfall and flooding with the potential for threats to public safety, costly flood damage to infrastructure, negative impacts to water quality (e.g., combined sewer overflows) and major disruptions in transportation. Mitigation of the negative impacts listed above requires accurate precipitation monitoring (quantitative precipitation estimation-QPE) and prediction (including radar nowcasting). The proximity to terrain and maritime conditions as well as the siting of existing NEXRAD radars are all challenges in providing accurate, short-term near surface rainfall estimates in the Bay area urban region. As part of a collaborative effort between the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory, Colorado State University (CSU), and Santa Clara Valley Water District (SCVWD), an X-band dual-polarization radar was deployed in Santa Clara Valley in February of 2016 to provide support for the National Weather Service during the Super Bowl and NOAA's El Nino Rapid Response field campaign. This high-resolution radar was deployed on the roof of one of the buildings at the Penitencia Water Treatment Plant. The main goal was to provide detailed precipitation information for use in weather forecasting and assists the water district in their ability to predict rainfall and streamflow with real-time rainfall data over Santa Clara County especially during a potentially large El Nino year. The following figure shows the radar's coverage map, as well as sample reflectivity observations on March 06, 2016, at 00:04UTC. This paper presents results from a pilot study from February, 2016 to May, 2016 demonstrating the use of X-band weather radar for quantitative precipitation

Data Series Generation for CPS Plants Simulation; Generacion de Series para Simulacion de Centrales Termosolares

Energy Technology Data Exchange (ETDEWEB)

Ibanez, G.; Valenzuela, R. X.; Ramirez, L.; Polo, J.

2014-02-01

Due to the problems with the environment and other issues arising from the use of oil as the main source of energy, such as unstable politics and economics, there has been a growing interest in the development of alternative forms of energy over the last few years. In this field, the sun is a fundamental element, since any form of existing energy derives from it, directly or indirectly. Taking in to consideration all of these renewable energies, we have decided to focus on solar thermal energy, seeing as it will play a vital role in the future particularly in countries such as Spain that have great solar potential. Amid this form of renewable energy, the parabolic cylinder concentrator power plants are technologies with one of the most promising futures. Power plants with sufficient technological developments to compete with the other forms of energies and that have an extensive margin for improvement. These power plants are the subject of the investigations carried out in this project. This project will try to establish and standardize some of the necessary procedures for the process of data prior to the simulation of energy with these types of power plants. The final objective is to help create a regulation where all these procedures are gathered together, and one that can be used as a guide for future investigations on the viability of these power plants. To achieve this, this project is comprised of various phases where different necessary investigations will be carried out in order to define the different points of the regulation. Firstly, the different casuistries will be investigated when analyzing the behavior of the estimated input data. At this stage, the selected variable (global or direct radiation), as well as the procedure used for the generation of the Monthly Reference Value, will be taken in to account, differentiating it in to two different typologies. The best method for the adjustment of the estimated data obtained from the satellite images will

Field theories with subcanonical fields

International Nuclear Information System (INIS)

Bigi, I.I.Y.

1976-01-01

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

Tripolar electric field Structure in guide field magnetic reconnection

OpenAIRE

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

2018-01-01

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

Hydraulic Model for Drinking Water Networks, Including Household Connections; Modelo hidraulico para redes de agua potable con tomas domiciliarias

Energy Technology Data Exchange (ETDEWEB)

Guerrero Angulo, Jose Oscar [Universidad Autonoma de Sinaloa (Mexico); Arreguin Cortes, Felipe [Instituto Mexicano de Tecnologia del Agua, Jiutepec, Morelos (Mexico)

2002-03-01

This paper presents a hydraulic simulation model for drinking water networks, including elements that are currently not considered household connections, spatially variable flowrate distribution pipelines, and tee secondary network. This model is determined by solving the equations needed for a conventional model following an indirect procedure for the solution of large equations systems. Household connection performance is considered as dependent of water pressure and the way in which users operate the taps of such intakes. This approach allows a better a acquaintance with the drinking water supply networks performance as well as solving problems that demand a more precise hydraulic simulation, such as water quality variations, leaks in networks, and the influence of home water tanks as regulating devices. [Spanish] Se presenta un modelo de simulacion hidraulica para redes de agua potable en el cual se incluyen elementos que no se toman en cuenta actualmente, como las tomas domiciliarias, los tubos de distribucion con gastos espacialmente variado y la red secundaria, resolviendo el numero de ecuaciones que seria necesario plantear en un modelo convencional mediante un procedimiento indirecto para la solucion de grandes sistemas de ecuaciones. En las tomas domiciliarias se considera que su funcionamiento depende de las presiones y la forma en que los usuarios operan las llaves de las mismas. Este planteamiento permite conocer mejor el funcionamiento de las redes de abastecimiento de agua potable y solucionar problemas que requieren de una simulacion hidraulica mas precisa, como el comportamiento de la calidad del agua, las fugas en las redes y la influencia reguladora de los tinacos de las casas.

Evaluación del proceso integral para la obtención de aceite esencial y pectina a partir de la cáscara de naranja Integral evaluation process for obtaining pectin and essential oil

Directory of Open Access Journals (Sweden)

Ivonne Cerón-Salazar

2011-06-01

Full Text Available En este trabajo se presentó la extraccion de aceite esencial y pectina a partir dela cascara de naranja (Citrus sinensis como un proceso integral. Se realizó elproceso de extracción utilizando un simulador comercial adaptandose al procesoreal. Se realizaron pruebas experimentales con un kilogramo de cáscara de naranja procesado a las mismas condiciones de la simulacion con el fin de comparar los rendimientos obtenidos, logrando una concordancia aceptable. Posteriormente se escaló el proceso a una tonelada. Como resultado no solo se demuestran las ventajas del proceso integral, sino tambien la posibilidadde su implementacion a nivel industrial. Se concluye ademas que las tecnicas de simulacion son una herramienta poderosa que permite minimizar tiempo,costos y experimentacion en el diseñode procesos como los de extraccion de aceite esencial y pectina.In this paper, an alternative for essential oil and pectin extraction from orange peel (Citrus sinensis as an integral process was presented. The extraction units were simulated using commercial simulator software for real process conditions. Experimental tests were carried out with a kilogram of orange peel with the same conditions used in of the simulation with the aim of comparing the experimental and calculated yields. Subsequently, the process was scaled to 1000 kg. Advantages of the integrated process and its possibilities of implementation at industrial level were showed. Moreover, it was concluded that simulation techniques are powerful tools that allows minimizing time, costs and experimentation in the design of processes such as essential oil extraction and pectin extraction.

ESTUDIO DEL MODELO DE PROPAGACIÓN SUZUKI PARA REDES MÓVILES

Directory of Open Access Journals (Sweden)

Gina Sierra

2013-12-01

Full Text Available Este artículo presenta brevemente la teoría fundamental del Modelo Suzuki comúnmente usado para modelar la propagación en canales inalámbricos. El modelo toma en cuenta los efectos del sombreado y del multi-trayecto de manera simultánea. Además, se valida el modelo mediante una comparación estadística entre mediciones realizadas en el entorno real y simulaciones realizadas en MATLAB® a través de la generación de series de tiempo Suzuki distribuidas. Las mediciones se realizaron durante diez horas sobre la banda de frecuencias entre 850 MHz y 900 MHz. Con los datos obtenidos en medición durante los primeros cinco minutos, se caracterizó el canal inalámbrico para cada una de las frecuencias muestreadas calculando la media y desviación estándar de la señal recibida. Estos dos parámetros fueron introducidos como variables de entrada para la generación de las respectivas series de tiempo. Para cada frecuencia se realizaron simulaciones prediciendo los niveles de la señal que se obtendrían durante diez horas. Finalmente, se calculó el error cuadrático medio entre los valores medidos y los valores generados en simulación. Los resultados obtenidos demuestran que el modelo es válido como una herramienta de predicción de las características de propagación en comunicaciones móviles.

Seguidor solar adaptativo basado en un controlador lógico programable para paneles fotovoltaicos

Directory of Open Access Journals (Sweden)

Celso de la Cruz Casaño

2012-12-01

Full Text Available Objetivos: Desarrollar un sistema de seguimiento solar adaptativo para paneles solares fotovoltaicos que no necesitan una configuración inicial. Métodos: Se utilizó el método estructuralista, en el cual se observa la realidad, se construye modelos y se analiza la estructura. Se utilizaron bloques de programación del controlador lógico programable (PLC y de modelos de mecanismos para construir el modelo del seguidor solar; además se aplicó teorías de ingeniería de control como la estabilidad de sistemas dinámicos y control adaptativo. La prueba de estabilidad y el funcionamiento correcto se analiza utilizando todo el sistema en conjunto, luego, se validan estos análisis con las simulaciones y experimentaciones. Resultados: Se presentan resultados de simulación y experimentación, en los cuales se hace evidente que el controlador adaptativo mantiene el error de control de seguimiento muy bajo a pesar de las condiciones nubladas. En las simulaciones y experimentaciones no se requirió una configuración inicial; este hecho es uno de los requisitos que se busca alcanzar en los objetivos. La ventaja de la adaptación es que el seguidor solar seguirá la trayectoria del sol aun cuando este se encuentre oculto por las nubes. Conclusiones: El aporte fue brindar un diseño novedoso de un seguidor solar cronológico adaptativo. El algoritmo de control adaptativo evita la configuración inicial del seguidor solar cronológico.

Socrates on philosophy and politics: ancient and contemporary interpretations

OpenAIRE

Gonzalez, Francisco

2012-01-01

Podría decirse que Sócrates le dejó a la tradición filosófica posterior el problema de la relación entre filosofía y política. Ya en la República la propuesta del rey filósofo representa más una tensión que una identidad. Mientras que la respuesta de Aristóteles insiste en una clara distinción entre la política y la sabiduría filosófica, un examen cuidadoso demuestra que esta distinción es menos clara de lo que parece. Heidegger caracteriza la filosofía como la única política auténtica y al f...

Composición química del huevo de tortuga lora (Lepidochelys olivacea) y evaluación de su calidad física y microbiológica durante su almacenamiento

OpenAIRE

Mora Castro, Randall; Chaves Quirós, Ana Cecilia

1997-01-01

Se determinó la composición química de los huevos de tortuga lora (Lepidochelys olivacea) y se evaluó su calidad física y microbiológica durante el almacenamiento a 5 °C y 25 °C y a una humedad relativa de 92 %. Se encontró que los huevos de tortuga lora tienen una masa promedio de 27,9 g y están constituidos por un 58,0 % de yema, un 38,0 % de clara y un 4,0 % de cáscara. La cáscara contiene un 37,0 % de humedad, un 28,2 % de proteína y un 36,0 % de materia mineral. En la clara el compone...

Gravitational Field Shielding by Scalar Field and Type II Superconductors

Directory of Open Access Journals (Sweden)

Zhang B. J.

2013-01-01

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

Structural simulation of natural zeolites; Simulacion estructural de zeolitas naturales

Energy Technology Data Exchange (ETDEWEB)

Sanchez P, E.; Carrera G, L.M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

1997-07-01

The application of X-ray diffraction (XRD) in the study of crystalline structures of the natural and modified zeolites allows the identification, lattice parameter determination and the crystallinity grade of the sample of interest. Until two decades ago, simulation methods of X-ray diffraction patterns were developed with which was possible to do reliable determinations of their crystalline structure. In this work it is presented the first stage of the crystalline structure simulation of zeolitic material from Etla, Oaxaca which has been studied for using it in the steam production industry and purification of industrial water. So that the natural material was modified for increasing its sodium contents and this material in its turn was put in contact with aqueous solutions of Na, Mg and Ca carbonates. All the simulations were done with the Lazy-Pulverix method. The considered phase was clinoptilolite. It was done the comparison with three clinoptilolite reported in the literature. (Author)

Simulacion borrosa de un reactor con reaccion exotermica no lineal

Directory of Open Access Journals (Sweden)

MIGUEL ANGEL RODRIGUEZ BORROTO

2007-01-01

Full Text Available En el presente trabajo se desarrolla un modelo difuso basado en la estructura Takagi-Sugeno-Kang dinámica para un reactor continuo de tanque con agitador (RCTA con reacción química de primer orden exotérmico. A partir de datos experimentales obtenidos mediante simulación del proceso real, se obtiene la base de datos de las variables de entrada y salida del proceso y a partir de la misma se elaboran los archivos de datos de entrenamiento y de verificación del modelo borroso el cual es obtenido mediante la herramienta anfis de MATLAB. El modelo obtenido permite predecir la salida del sistema con errores de predicción muy bajos, por lo que el mismo sienta las bases para el diseño de un controlador predictivo no lineal del mismo en próximas etapas de la investigación

On vector fields having properties of Reeb fields

OpenAIRE

Hajduk, Boguslaw; Walczak, Rafal

2011-01-01

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

Characterization of maturity and quality of Brazilian apirenic grapes in the São Francisco river Valley

Directory of Open Access Journals (Sweden)

Robson de Jesus Mascarenhas

2012-03-01

Full Text Available The objective of this study was to characterize and correlate maturity and quality of the first varieties of Brazilian seedless grapes 'BRS Clara', 'BRS Linda', 'BRS Morena', and 'Advanced Selection 8' compared with the American variety 'Crimson Seedless' in compliance with the Brazilian Normative/2002 and export standards Advanced Selection 8' is dark reddish, has large clusters, and is a very large ellipsoid berry; 'BRS Morena' is black with medium sized clusters and large berry shaped as ellipsoid to globoid; 'BRS Linda' is light green and has large sized clusters; 'Crimson' is pink and has small clusters with berries varying from medium to large sizes and ellipsoid shaped; and 'BRS Clara' is green yellowish has medium sized clusters and small berry of elongated ellipsoid shape. All varieties evaluated meet the standard for domestic market established as berry size minimum diameter 12 mm. 'BRS Clara' does not meet the export requirements of diameter. Berries of the red grapes 'BRS Morena' and 'Crimson Seedless' are firmer. The pH, titratable acidity, and soluble solids meet the official standards. Larger clusters are less acidic and present higher soluble solids/titratable acidity ratios implying that they are the sweetest type when ripe.

Optimización MULTI-GPU de un algoritmo de detección de colisiones. Caso de estudio CUDA

OpenAIRE

Maltese Girón, Mar

2012-01-01

Proyecto Fin de Carrera leído en la Universidad Rey Juan Carlos en el curso académico 2011/2012. Tutores del Proyecto: Alberto Sánchez Campos y Marcos Novalbos Mendiguchía La evolución en la computación gráfica ha sido notoria en los últimos años. Sin embargo a pesar de todos los avances, uno de los principales problemas que nos encontramos hoy en día para lograr simulaciones realistas es la necesidad de incluir en las mismas el funcionamiento de las leyes básicas de la física, co...

Control predictivo económico de vehículos híbridos basados en pilas de combustible

OpenAIRE

Sampietro, Jose Luis; Costa Castelló, Ramon; Puig Cayuela, Vicenç

2015-01-01

Las pilas de combustible que utilizan el hidrógeno como combustible están siendo consideradas, en estos últimos años, como una alternativa a los combustibles fósiles para su uso en automóviles. Dicha tecnología se puede aplicar en los vehículos de propulsión híbrida. Este trabajo introduce el control predictivo económico (EMPC, siglas en inglés) como técnica de gestión óptima de la energía. Finalmente, se presentan simulaciones de varios escenarios, basados en un control EMPC, en donde se ...

Análisis de propulsión iónica en condensadores asimétricos

OpenAIRE

Cubides Alfonso, Fredy Yamith; Lancheros Quiroga, David Leonardo; Chacón-Cardona, César Alexander

2016-01-01

Resumen Presenta una nueva metodología para el estudio del comportamiento en condensadores asimétricos del fenómeno de levitación electromagnética, sometido a altas tensiones (AC y DC). Se realizaron modelos experimentales para un análisis cinemático y simulaciones para observar el campo eléctrico y magnético, y, por último, se hicieron estudios de termografía de los condensadores asimétricos, con el fin de realizar un análisis cuantitativo y cualitativo del fenómeno de levitación electromagn...

Comportamiento hidrosedimentario de una cuenca agroforestal bajo diferentes condiciones climáticas : importancia para establecer planes de manejo

OpenAIRE

Arias Miguélez, Ricardo

2013-01-01

[Resumen] El objetivo de esta tesis es la aplicación, calibración y validación del modelo SWAT (Soil and Water Assessment Tool) para descarga de agua, sedimentos y nitratos en una pequeña cuenca agroforestal, localizada en la provincia de A Coruña (noroeste de España), representativa del clima atlántico. Con los resultados de las simulaciones se evalúa el efecto del cambio climático sobre la respuesta hidrosedimentaria y sobre la exportación de nitratos de la cuenca. De los resultados de este...

Redes neuronales en espectrometría y dosimetría de neutrones

OpenAIRE

Torre López, Jesús Alberto de la

2017-01-01

Este Trabajo de Fin de Grado tiene como objetivo fundamental la realización de experimentos y simulaciones que ayuden a la comprensión acerca de una de las herramientas de predicción de valores más potentes de la inteligencia artificial como son las Redes Neuronales Artificiales. Su aplicación en este trabajo será muy concreta, en el campo de la espectrometría y dosimetría de neutrones, sin embargo, sus posibles aplicaciones abarcan un campo mucho más amplio, lo cual hace de ellas una herr...

La Violación de la Segunda Ley de la Termodinámica por el Método de Elementos Finitos

OpenAIRE

Limache, Alejandro Cesar; Rojas Fredini, Pablo Sebastián; Murillo, Marina H.

2016-01-01

El presente artículo pretende alertar sobre un hecho grave: la Segunda Ley de la Termodinámica es violada como consecuencia de la discretización numérica resultante de la aplicación del Método de Elementos Finitos (FEM, por Finite Element Method). En este trabajo se estudia la consistencia termodinámica de las formulaciones FEM. El estudio está basado en el análisis de la ecuación del calor 1-Dimensional (1D) y 2-Dimensional (2D). Los resultados presentados afectan a todas las simulaciones de...

OntoWEDSS - An Ontology-based Environmental Decision-Support System for the management of Wastewater treatment plants

OpenAIRE

Ceccaroni, Luigi

2001-01-01

Les contribucions d'aquesta tesi uneixen dues disciplines: ciències ambientals (específicament, gestió d'aigües residuals) i informàtica (específicament, intel·ligència artificial). El tractament d'aigües residuals com a disciplina opera fent servir un rang de diferents enfocaments i mètodes que inclouen: control manual, control automàtic on-line, modelat numèric o no-numèric, models estadístics i simulacions. La tesi caracteritza la recerca interdisciplinària de tècniques d'intel·ligència ar...

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

OpenAIRE

Diego Fernando Lemus Polania; Elkin Cataño Velez

2013-01-01

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

Modelación y simulación de un pervaporador acoplado a un proceso de sacarificación-fermentación para la producción de etanol

OpenAIRE

Jairo Antonio Cubillos-Lobo; Felipe Bustamante-Londoño; Alejandro Acosta-Cárdenas

2015-01-01

Actualmente, la integración de procesos es considerada una opción viable para reducir costos en la producción de etanol a partir de biomasa. Simulaciones y resultados experimentales han demostrado los beneficios de la integración de las etapas de sacarificación y fermentación y del acoplamiento del proceso de fermentación a la recuperación in-situ de etanol por pervaporación en la producción de bioetanol; sin embargo, no se han publicado estudios de la integración del proceso de sacarificació...

Règim no permanent en lleres de resposta ràpida. Aplicació del model HEC-RAS

OpenAIRE

Gayá Mascaró, Antoni

2004-01-01

El model numèric HEC-RAS és una eina d'ús públic força generalitzada en els càlculs de qualsevol projecte hidràulic. L'última versió d'aquest programa inclou un mòdul de càlcul en règim no permanent del qual no es té massa experiència pel que fa a les simulacions per hidrogrames d'avinguda curts. Aquesta tesina analitza el comportament d'aquest mòdul en la modelització de l'últim tram de la llera del riu Llobregat.

Trastornos de depresion desde una perspectiva sistemica

OpenAIRE

JUAN LUIS CHORRO; Mª AMPARO COTOLÍ

2000-01-01

La finalidad del artículo es la de proponer un modelo dinámico del proceso de depresión, capaz de explicar tanto la establidad como el cambio de la conducta individual. La motivación se basa en la insuficiencia de las teorías estáticas de la personalidad para explicar el cambio en la evolución de la persona. El modelo propuesto se basa en el modelo general de crecimiento de VanGeert, y se ha realizado simulaciones de la evolución del proceso de depresión bajo distintos supuestos. Los resultad...

TRANSPORTE DE VOZ (VoIP SOBRE REDES IPv4 e IPv6

Directory of Open Access Journals (Sweden)

Fausto Alexander Gamboa

2012-05-01

Full Text Available El presente artículo tiene como finalidad evaluar el comportamiento de la VoIP en redes IPv6 y compararlo con IPv4, de igual manera presentar las arquitecturas que la soportan. Con el fin de que los resultados sean los más cercanos a la realidad, el artículo no solo se soporta en simulaciones si no en implementaciones reales. Dentro de las conclusiones más sobresalientes se encontró que la VoIP6 presenta mejor rendimiento ante el Jitter y el retardo que VoIPv4.

Estrategias didácticas para favorecer el aprendizaje en las carreras de Ingeniería utilizando tecnologías de información y comunicación (TICS)

OpenAIRE

Castro Maldonado, L.

2009-01-01

En el proceso de formación de los estudiantes de carreras de ingeniería existe regularmente un índice considerable de reprobación y deserción. Se analizan los factores que inciden en esta problemática y se proponen distintas estrategias didácticas con TICs (Tecnologías para la Educación) para favorecer el proceso de enseñanza-aprendizaje en las materias de Física clásica. Se utilizó el software “Easy Java Simulations” (EJS) basado en applets para la creación de simulaciones discretas y facili...

Numerical simulation of oil spills in coastal areas using shallow water equations in generalised coordinates

OpenAIRE

Novelli, Guillaume

2011-01-01

La contaminación generada por los vertidos accidentales de petróleo puede ser reducida si se actúa y si se toman las decisiones adecuadas a tiempo. Las simulaciones numéricas de vertidos de petróleo permiten predecir la evolución de las manchas de crudo. En este trabajo, el objetivo principal era de mejorar la precisión y el rango de aplicación del código SIMOIL desarrollando e integrando al código un modelo de predicción de corrientes marinas en aguas costeras. Se han derivado las ecuaciones...

Análisis del papel de la elección en la base de datos reticular observacional en la evaluación de modelos climáticos regionales

OpenAIRE

Montávez, Juan Pedro; Gómez Navarro, Juan José; Jerez, Sonia; Baró, Rocío; Lorente Plazas, Raquel; García Valero, Juan Andrés; Jiménez Guerrero, Pedro

2012-01-01

Ponencia presentada en: VIII Congreso de la Asociación Española de Climatología celebrado en Salamanca entre el 25 y el 28 de septiembre de 2012. [ES]En este trabajo se presentan los resultados de la evaluación de la habilidad de todos los miembros de dos conjuntos de simulaciones regionales climáticas para la reproducción de la precipitación y temperaturas máximas y mínimas utilizando tres bases de datos reticulares diferentes (SPAIN02, AEMET y E-OBS), que tienen una resolución e...

Eficiencia financiera del índice IPC mexicano a la luz de su impacto en la competitividad de las sociedades de inversión y ETF’s que lo replican en su política de inversión

Directory of Open Access Journals (Sweden)

Martínez Torre-Enciso, María Isabel

2013-01-01

Full Text Available El presente artículo prueba la propiedad de eficiencia financiera del índice IPC (como aproximación de la cartera del mercado bursátil mexicanoal utilizar el estadístico de prueba propuesto por Kandel y Stambaugh en dos simulaciones de eventos discretos, una con datos muestrales y otra con datos remuestreados con bootstraping. Los resultados sugieren que, a pesar de que la propiedad estudiada se mantiene en términos estadísticos, la proporción de fechas cuestiona la utilidad práctica del IPC, sugiriendo la necesidad de pruebas más robustas.

Supervisión bancaria europea: análisis crítico de los tests de estrés

OpenAIRE

Fruet Cardozo, J. Vicente; Jimber del Río, Juan Antonio; Millán de la Lastra, José Ramón

2013-01-01

La crisis financiera mundial ha traído como consecuencia que inevitablemente se haya focalizado la atención en el proceso de supervisión macroeconómica y financiera a nivel global. Los Test de Estrés son realizados por los supervisores nacionales, el Banco de España en el caso español, y también por la Autoridad Bancaria Europea (ABE). Estas iniciativas no son más que simulaciones hechas sobre el papel acerca de la capacidad de los bancos y cajas para enfrentarse a un deterioro ge...

Collective decision-making under the influence of bribers and temporal constraints

OpenAIRE

Bannikova, Marina

2016-01-01

Estudio la conexión entre la corrupción y las características estructurales de los parlamentos: número de asientos, el número de partidos representados, y reglas de decisión adoptadas. Con la aplicación de enfoques analíticos y computacionales, además de simulaciones, muestro que el número medio de diputados que deben ser sobornados disminuye a medida que el número de partidos aumenta, por lo que el soborno se siente alentado por un número cada vez mayor de partes. También investigo dos f...

El software de simulación en Física: herramienta para el aprendizaje de contenidos

OpenAIRE

Alzugaray, Gloria E.; Carreri, Ricardo A.; Marino, Luis A.

2010-01-01

Diversas experiencias educativas relacionadas con el empleo de simulaciones educativas de uso libre llevaron a los autores de este trabajo a estudiar y elaborar alternativas didácticas constructivistas para la enseñanza de las ciencias experimentales. Esto requirió de la selección y evaluación de dichos materiales, considerando aspectos y características tecnológicas, semióticas/ estéticas así como también el contexto pedagógico de aplicación y por último la implementación y evaluación de dis...

Repair of tracheal epithelium by basal cells after chlorine-induced injury

Directory of Open Access Journals (Sweden)

Musah Sadiatu

2012-11-01

Full Text Available Abstract Background Chlorine is a widely used toxic compound that is considered a chemical threat agent. Chlorine inhalation injures airway epithelial cells, leading to pulmonary abnormalities. Efficient repair of injured epithelium is necessary to restore normal lung structure and function. The objective of the current study was to characterize repair of the tracheal epithelium after acute chlorine injury. Methods C57BL/6 mice were exposed to chlorine and injected with 5-ethynyl-2′-deoxyuridine (EdU to label proliferating cells prior to sacrifice and collection of tracheas on days 2, 4, 7, and 10 after exposure. Airway repair and restoration of a differentiated epithelium were examined by co-localization of EdU labeling with markers for the three major tracheal epithelial cell types [keratin 5 (K5 and keratin 14 (K14 for basal cells, Clara cell secretory protein (CCSP for Clara cells, and acetylated tubulin (AcTub for ciliated cells]. Morphometric analysis was used to measure proliferation and restoration of a pseudostratified epithelium. Results Epithelial repair was fastest and most extensive in proximal trachea compared with middle and distal trachea. In unexposed mice, cell proliferation was minimal, all basal cells expressed K5, and K14-expressing basal cells were absent from most sections. Chlorine exposure resulted in the sloughing of Clara and ciliated cells from the tracheal epithelium. Two to four days after chlorine exposure, cell proliferation occurred in K5- and K14-expressing basal cells, and the number of K14 cells was dramatically increased. In the period of peak cell proliferation, few if any ciliated or Clara cells were detected in repairing trachea. Expression of ciliated and Clara cell markers was detected at later times (days 7–10, but cell proliferation was not detected in areas in which these differentiated markers were re-expressed. Fibrotic lesions were observed at days 7–10 primarily in distal trachea. Conclusion

On Jacobi-fields

International Nuclear Information System (INIS)

Bruening, E.

1981-01-01

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

7 CFR 920.12 - District.

Science.gov (United States)

2010-01-01

.... (e) District 5 shall include the counties of San Joaquin, Calaveras, Tuolumne, Merced, Stanislaus, Contra Costa, El Dorado, Amador, Sacramento, Alpine, San Francisco, Alameda, San Mateo, Santa Clara...

75 FR 44989 - In the Matter of Certain Semiconductor Chips Having Synchronous Dynamic Random Access Memory...

Science.gov (United States)

2010-07-30

... following respondents: NVIDIA Corporation of Santa Clara, California; Asustek Computer, Inc. of Taipei... exclusion order and cease- and-desist orders against respondents NVIDIA Corp.; Hewlett-Packard Co.; ASUS...

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

Science.gov (United States)

Casadevall, Arturo; Fang, Ferric C

2015-09-08

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

Optimal field splitting for large intensity-modulated fields

International Nuclear Information System (INIS)

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

2004-01-01

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

Estudio de la evolución y nuevas técnicas de análisis por elementos finitos aplicadas al diseño de pavimentos cerámicos

Directory of Open Access Journals (Sweden)

Dunai, L.

2009-12-01

Full Text Available The traditional design process of ceramic floorings, based on the manufacturing of prototypes, is a slow and expensive process, which reduce the productivity and creativity of the enterprises. A new approach to face this challenge is by means of virtual models, which offer the same information as a physic prototype at a very lower cost, when they are tested under manufacturing and quality simulations. The most used simulation technique is FEA (finite element analysis. In this paper we introduce the finite element method and summarize the main applications of these techniques in the general ceramic industry, and particularly in the ceramic tile sector. We analyze its evolution and current state, citing the most relevant works. Finally we expose the new approach of the Research Center on Graphic Technologies of Universidad Politécnica de Valencia in this field, based in the employment of three dimensional elements, multi-criteria evaluation and the generation of specific design software based on parametric examinations to enhance the geometry and structure of ceramic floorings.

El proceso tradicional de diseño de nuevos pavimentos cerámicos, basado en la fabricación de prototipos físicos, es un proceso lento y costoso, que merma la productividad y creatividad de las empresas. Una nueva forma de afrontar este proceso es mediante la creación de modelos virtuales por computador, los cuales ofrecen la misma información que un prototipo real a un coste muy inferior cuando se los somete a simulaciones de fabricación y calidad. La técnica computacional más usada para estas simulaciones es el AEF (análisis por elementos finitos. En este trabajo se introduce el AEF y se resumen las principales aplicaciones de este análisis en la industria cerámica en general, y en particular en el sector de los pavimentos. Se analizan su evolución y estado actual, citando los trabajos más relevantes. Finalmente se expone el nuevo planteamiento del

A general field-covariant formulation of quantum field theory

International Nuclear Information System (INIS)

Anselmi, Damiano

2013-01-01

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

Two field formulation of closed string field theory

International Nuclear Information System (INIS)

Bogojevic, A.R.

1990-09-01

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

Field Model: An Object-Oriented Data Model for Fields

Science.gov (United States)

Moran, Patrick J.

2001-01-01

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

Trapped field recovery of bulk superconductor magnets by static field magnetization

Energy Technology Data Exchange (ETDEWEB)

Deng, Z., E-mail: zigang@kaiyodai.ac.jp [Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo 135-8533 (Japan); Tsuzuki, K.; Miki, M.; Felder, B.; Hara, S.; Izumi, M. [Laboratory of Applied Physics, Department of Marine Electronics and Mechanical Engineering, Tokyo University of Marine Science and Technology, Tokyo 135-8533 (Japan)

2011-11-15

A series of initial trapped fields after ZFC or FC magnetization are used to simulate the attenuated trapped field. It is possible and easy to recover the lost trapped field and regain the best trapped field performance as before. In the re-magnetization process, the initial magnetic flux inside the bulk magnets will help to recover the trapped field. The optimum recovery field is recommended to be 2.5 times the saturation field of the bulk at LN2 temperature. Thanks to the trapped field of bulk high-temperature superconductors, they can be used as field-pole magnets in the high temperature superconducting (HTS) rotating machines. For example, an output power of 10 kW at 720 rpm was realized by an average trapped field of 0.56 T of eight melt-textured GdBa{sub 2}Cu{sub 3}O{sub y} (Gd-123) bulks at liquid nitrogen temperature in TUMSAT in 2004. Similarly to the HTS machines involving 1G or 2G wires, the trapped field of the bulk is possibly sensitive and even can be attenuated by the AC component field during the operation. Hence, it is necessary to recover the trapped field once being decreased to some extent in the practical application. From this point, we have investigated the trapped field recovery of HTS bulk magnets by static field magnetization in the paper. A series of different initial trapped fields after zero-field-cooling or field-cooling magnetization are used to simulate the attenuated trapped field. By comparing the trapped field peak and its distribution, the trapped field was found to be able to recover by the static field magnetization method with a stronger excitation field and the initial trapped flux inside the bulk also has an influence on the recovery process. The optimum recovery field was found to be about 2.5 times the saturated trapped field of the bulk at liquid nitrogen temperature, by which the bulk can regain the former best trapped field performance.

7 CFR 920.131 - Redistricting of kiwifruit districts.

Science.gov (United States)

2010-01-01

... include the counties of San Francisco, San Mateo, Santa Cruz, Contra Costa, Alameda, Santa Clara, Monterey, San Benito, San Joaquin, Calaveras, Alpine, Mono, Tuolumne, Stanislaus, Merced, Mariposa, Madera, and...

How fields vary.

Science.gov (United States)

Krause, Monika

2018-03-01

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

77 FR 39726 - Land Acquisitions: Pueblo of Santa Clara

Science.gov (United States)

2012-07-05

... Indian Affairs, 1001 Indian School Road NW., Albuquerque, NM 87104-2303; Telephone (505) 563-3337, sandy...., Sec. 17, lots 1 to 8, inclusive; Sec. 18, lots 5 to 12, inclusive; Sec. 19, lots 12 to 17, inclusive...

78 FR 67210 - Santa Clara Pueblo Disaster #NM-00038

Science.gov (United States)

2013-11-08

.../2013 Effective Date: 10/29/2013 Physical Loan Application Deadline Date: 12/30/2013 Economic Injury...- Profit organizations that provide essential services of governmental nature may file disaster loan... Non-Profit Organizations Without Credit Available Elsewhere 2.875 For Economic Injury: Non-Profit...

fields

Directory of Open Access Journals (Sweden)

Brad J. Arnold

2014-07-01

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

MAGNETIC FIELD MEASUREMENTS FOR FAST-CHANGING MAGNETIC FIELDS

International Nuclear Information System (INIS)

2004-01-01

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

Magnetic field reconnexion in a sheared field

International Nuclear Information System (INIS)

Ugai, M.

1981-01-01

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

Comparison between 3D conventional techniques, field-in-field and electronic tissue compensation for mantle fields planning

International Nuclear Information System (INIS)

Martins, Lais P.; Silva, Leonardo P.; Trindade, Cassia; Garcia, Paulo L.; Santos, Maira R.; Batista, Delano V.S.

2012-01-01

External radiotherapy treatment for Hodgkin's lymphoma over diaphragm region requires large radiation fields with protections applied to larynx, humerus head and lungs. The size and shape of the field, which covers different depths, make it difficult to distribute a homogeneous dose. Techniques such as field-in-field and electronic tissue compensation may be used to make dose homogeneous and compensate the obliquity from the tissue. Three types of planning were performed for diagnose of nodular sclerosis Hodgkin's lymphoma: one plan with two fields, AP-PA (AP plan), another with four fields field-in- field (FF plan), and a third one with two fields and electronic tissue compensation (ETC plan). Results showed better gradient, cover of PTV and dose distribution for the ETC plan, besides the advantage from this technique of does not require protection blocks. In the meanwhile, AP and FF plans require simpler dosimetry and fewer MU. Related to the uniformity of dose distribution, AP plan showed hot areas in the neck region, FF plan showed hot areas in the shoulder region and ETC plan showed most uniform distribution without hot areas. The electronic tissue compensation is a useful tool for large and shaped fields as the mantle field, however higher MU and complex dosimetry should be taken in account. (author)

Trapped field recovery of bulk superconductor magnets by static field magnetization

Science.gov (United States)

Deng, Z.; Tsuzuki, K.; Miki, M.; Felder, B.; Hara, S.; Izumi, M.

2011-11-01

Thanks to the trapped field of bulk high-temperature superconductors, they can be used as field-pole magnets in the high temperature superconducting (HTS) rotating machines. For example, an output power of 10 kW at 720 rpm was realized by an average trapped field of 0.56 T of eight melt-textured GdBa2Cu3Oy (Gd-123) bulks at liquid nitrogen temperature in TUMSAT in 2004. Similarly to the HTS machines involving 1G or 2G wires, the trapped field of the bulk is possibly sensitive and even can be attenuated by the AC component field during the operation. Hence, it is necessary to recover the trapped field once being decreased to some extent in the practical application. From this point, we have investigated the trapped field recovery of HTS bulk magnets by static field magnetization in the paper. A series of different initial trapped fields after zero-field-cooling or field-cooling magnetization are used to simulate the attenuated trapped field. By comparing the trapped field peak and its distribution, the trapped field was found to be able to recover by the static field magnetization method with a stronger excitation field and the initial trapped flux inside the bulk also has an influence on the recovery process. The optimum recovery field was found to be about 2.5 times the saturated trapped field of the bulk at liquid nitrogen temperature, by which the bulk can regain the former best trapped field performance.

7 CFR 917.14 - District.

Science.gov (United States)

2010-01-01

... District. (g) Contra Costa District includes and consists of Contra Costa County. (h) Santa Clara District... Ventura County. (l) Stockton District includes and consists of San Joaquin County, Amador County...

FIRST Quantum-(1980)-Computing DISCOVERY in Siegel-Rosen-Feynman-...A.-I. Neural-Networks: Artificial(ANN)/Biological(BNN) and Siegel FIRST Semantic-Web and Siegel FIRST ``Page''-``Brin'' ``PageRank'' PRE-Google Search-Engines!!!

Science.gov (United States)

Rosen, Charles; Siegel, Edward Carl-Ludwig; Feynman, Richard; Wunderman, Irwin; Smith, Adolph; Marinov, Vesco; Goldman, Jacob; Brine, Sergey; Poge, Larry; Schmidt, Erich; Young, Frederic; Goates-Bulmer, William-Steven; Lewis-Tsurakov-Altshuler, Thomas-Valerie-Genot; Ibm/Exxon Collaboration; Google/Uw Collaboration; Microsoft/Amazon Collaboration; Oracle/Sun Collaboration; Ostp/Dod/Dia/Nsa/W.-F./Boa/Ubs/Ub Collaboration

2013-03-01

Belew[Finding Out About, Cambridge(2000)] and separately full-decade pre-Page/Brin/Google FIRST Siegel-Rosen(Machine-Intelligence/Atherton)-Feynman-Smith-Marinov(Guzik Enterprises/Exxon-Enterprises/A.-I./Santa Clara)-Wunderman(H.-P.) [IBM Conf. on Computers and Mathematics, Stanford(1986); APS Mtgs.(1980s): Palo Alto/Santa Clara/San Francisco/...(1980s) MRS Spring-Mtgs.(1980s): Palo Alto/San Jose/San Francisco/...(1980-1992) FIRST quantum-computing via Bose-Einstein quantum-statistics(BEQS) Bose-Einstein CONDENSATION (BEC) in artificial-intelligence(A-I) artificial neural-networks(A-N-N) and biological neural-networks(B-N-N) and Siegel[J. Noncrystalline-Solids 40, 453(1980); Symp. on Fractals..., MRS Fall-Mtg., Boston(1989)-5-papers; Symp. on Scaling..., (1990); Symp. on Transport in Geometric-Constraint (1990)

Sleep apnea leading to Parkinson’s disease – an important association

Directory of Open Access Journals (Sweden)

Shafqat MN

2017-06-01

Full Text Available Muhammad Nabeel Shafqat,1 Muhammad Aadil,2 Maria Shoaib3 1Department of Medicine, University of Medical Sciences “Serafin Ruiz de Zarate” Villa Clara (UCMVC, Villa Clara, Cuba; 2Department of Psychiatry, Rush University Medical Center, Chicago, IL, USA; 3Department of Medicine, Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan We read with great interest the recently published article “Sleep apnea and the subsequent risk of Parkinson disease: a 3-year nationwide population-based study” by Chou et al.1 The study is a step forward in understanding the underlying pathophysiology of Parkinson’s disease, the authors have deduced sleep apnea as one of the possible risk factors. View the original paper by Chou and colleagues.

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

International Nuclear Information System (INIS)

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

1996-01-01

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

Innovation technological energetics in rural communities. Case of study community of “Manantiales”, Villa Clara, Cuba

Directory of Open Access Journals (Sweden)

Raul Olalde Font

2016-10-01

Full Text Available This investigation is framed in the analysis of impacts in the local development starting from the taking of decisions on projects of rural energy in Cuban communities that have as economic main activity the agricultural sector, illustrated the results of a case study where the technological most viable options are selected under the optics of the improvement of indicators of community resources. The methods and used materials are characteristic of a field work with application model are characterized for the taking of decisions in the energy area and their sources SURE, as geographical region the community isolated rural “Manantiales” linked to the agrarian sector in the republic of Cuba and the present period review in the thematic one approached. The main indicators are sketched in each resource of the rural community under the optics of the SURE in their version 3.0, as well the characterization of the prediction of the impacts at each technological option on the resources, is exhibited a mean of impacts and the classification of the technologies according to the level of achievements contribute to the indicators of community resources, obtaining as a result that the hydro energy technology is the most viable option with a value of 100 points in the scale from 0 to 100, followed by the GRID with 91.11 and of the photovoltaic systems based on silicon panels with 90.57, in this case all technologies contribute a significant level of achievements to the local community development.

Moral Action in Everyday Life: An Ethics Process to Foster Interest & Determination in the Workplace

OpenAIRE

Sekerka, Leslie E.

2006-01-01

Business Ethics in a Global World: China, India, and Beyond - Santa Clara University -March 10, 2006 - Leslie E. Sekerka, Ph.D.Assistant Professor, Organizational Behavior & EthicsNaval Postgraduate School Monterey, CA

Sensitivity-based virtual fields for the non-linear virtual fields method

Science.gov (United States)

Marek, Aleksander; Davis, Frances M.; Pierron, Fabrice

2017-09-01

The virtual fields method is an approach to inversely identify material parameters using full-field deformation data. In this manuscript, a new set of automatically-defined virtual fields for non-linear constitutive models has been proposed. These new sensitivity-based virtual fields reduce the influence of noise on the parameter identification. The sensitivity-based virtual fields were applied to a numerical example involving small strain plasticity; however, the general formulation derived for these virtual fields is applicable to any non-linear constitutive model. To quantify the improvement offered by these new virtual fields, they were compared with stiffness-based and manually defined virtual fields. The proposed sensitivity-based virtual fields were consistently able to identify plastic model parameters and outperform the stiffness-based and manually defined virtual fields when the data was corrupted by noise.

Field in field technique in two-dimensional planning for whole brain irradiation; Tecnica field in field em planejamentos bidimensionais para irradiacao de cerebro total

Energy Technology Data Exchange (ETDEWEB)

Castro, A.L.S.; Campos, T.P.R., E-mail: radioterapia.andre@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Departamento de Engenharia Nuclear

2016-11-01

Radiotherapy is the most used clinical method used for brain metastases treatment, the most frequent secondary tumors provided by breast, lung and melanomas as primary origin. The protocols often use high daily doses and, depending on the irradiation technique there is high probability of complications in health tissues. In order to minimize adverse effects, it is important the dosimetric analysis of three-dimensional radiotherapy planning through tomographic images or, concerning to the 2D simulations, by the application of techniques that optimize dose distribution by increasing the homogeneity. The study aimed to compare the 2D and 3D conformal planning for total brain irradiation in a individual equivalent situation and evaluate the progress of these planning applying the field in field technique. The methodology consisted of simulating a two-dimensional planning, reproduce it on a set of tomographic images and compare it with the conformal plan for two fields and four fields (field in field). The results showed no significant difference between 2D and 3D planning for whole brain irradiation, and the field in field technique significantly improved the dose distribution in brain volume compared with two fields for the proposal situation. As conclusion, the two-dimensional plane for the four fields described was viable for whole brain irradiation in the treatment of brain metastases at the proposal situation. (author)

Magnetic Field

DEFF Research Database (Denmark)

Olsen, Nils

2015-01-01

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

Ambient Field Analysis at Groningen Gas Field

Science.gov (United States)

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

2016-12-01

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

Una nota sobre escultura castellana del siglo XIII: Juan González, el pintor de las imágenes de Burgos, y el sepulcro de doña Mayor Guillén de Guzmán en el convento de Santa Clara de Alcocer (Guadalajara

Directory of Open Access Journals (Sweden)

Gutiérrez Baños, Fernando

2015-03-01

Full Text Available In 2009 Christie’s London brought to light the contract for the tomb of doña Mayor Guillén de Guzmán († c. 1263, former mistress of king Alfonso X the Wise. The contract comes from the convent of Poor Clares of Alcocer (Guadalajara, where the tomb itself remained until completely destroyed in 1936 at the beginning of the Spanish Civil War. Dated in Burgos in 1276, the document provides a full description of the work to be carried out. This allows us to compare it with other contemporary tombs, underlining the highly innovative features of that created for doña Mayor. In addition, the document provides access to the personality of the artist responsible for this work: a certain until now unknown Juan González, who introduces himself as el pintor de las imágenes de Burgos (‘the painter of images of Burgos’.En 2009 Christie’s de Londres dio a conocer el contrato del sepulcro de doña Mayor Guillén de Guzmán († c. 1263, antigua amante del rey Alfonso X el Sabio. El contrato procede del convento de Santa Clara de Alcocer (Guadalajara, donde el propio sepulcro se conservó hasta su completa destrucción en 1936 al estallar la Guerra Civil. Datado en Burgos en 1276, el documento nos proporciona una completa descripción de la obra a realizar. Esto nos permitirá compararla con otros sepulcros contemporáneos, subrayando los rasgos altamente innovadores del sepulcro de doña Mayor. Por otra parte, el documento nos permitirá acceder a la personalidad del artista responsable de la obra: un cierto Juan González, desconocido hasta la fecha, que se presenta como el pintor de las imágenes de Burgos.

The effect of breed on fatty acid composition of subcutaneous ...

African Journals Online (AJOL)

User

2015-02-23

Agilent Auto Analyzer 7683 B series, Agilent Technologies, Santa Clara, Calif, USA) into ..... laboratory facilities and financial support. ... supplementation on fatty acid composition and gene expression in adipose tissue of growing ...

Invariant gauge families inherent in Abelian-gauge field theory. [Scalar dipole ghost field, free-field equations

Energy Technology Data Exchange (ETDEWEB)

Yokoyama, Kan-ichi; Kubo, Reijiro

1974-12-01

The framework of the Nakanishi-Lautrup formalism should be enlarged by introducing a scalar dipole ghost field B(x), which is called gauge on field, together with its pair field. By taking free Lagrangian density, Free-field equations can be described. The vacuum is defined by using a neutral vector field U..mu..(x). The state-vector space is generated by the adjoining conjugates of U..mu..sup((+))(x), and auxiliary fields B(x), B/sub 1/(x) and B/sub 2/(x), which were introduced in the form of the Lagrangian density. The physical states can be defined by the supplementary conditions of the form B/sub 1/sup((+))(x) 1 phys>=B/sub 2/sup((+))(x) 1 phys>=0. It is seen that all the field equations and all the commutators are kept form-invariant, and that the gauge parameter ..cap alpha.. is transformed into ..cap alpha..' given by ..cap alpha..'=..cap alpha..+lambda, with epsilon unchanged. The Lagrangian density is specified only by the gauge invariant parameter epsilon. The gauge structure of theory has universal meaning over whole Abelian-gauge field. C-number gauge transformation and the gauge structure in the presence of interaction are also discussed.

Internal magnetic field measurements in a translating field-reversed configuration

International Nuclear Information System (INIS)

Armstrong, W.T.; Chrien, R.E.; McKenna, K.F.; Rej, D.J.; Sherwood, E.G.; Siemon, R.E.; Tuszewski, M.

1984-01-01

Magnetic field probes have been employed to study the internal field structure of Field-Reversed Configurations (FRCs) translating past the probes in the FRX-C/T device. Internal closed flux surfaces can be studied in this manner with minimal perturbation because of the rapid transit of the plasma (translational velocity v/sub z/ approx. 10 cm/μs). Data have been taken using a low-field (5 kG), 5-mtorr-D 2 gas-puff mode of operation in the FRC source coil which yields an initial plasma density of approx. 1 x 10 15 cm -3 and x/sub s/ approx. 0.04. FRCs translate from the approx. 25 cm radius source coil into a 20 cm radius metal translation vessel. Two translation conditions are studied: (1) translation into a 4 kG guide field (matched guide-field case), resulting in similar plasma parameters but with x/sub s/ approx. .45, and (2) translation into a 1 kG guide field (reduced guide-field case), resulting in expansion of the FRC to conditions of density approx. 3 x 10 14 , external field B 0 approx. 2 kG and x/sub s/ approx. 0.7. The expected reversed B/sub z/ structure is observed in both cases. However, the field measurements indicate a possible sideways offset of the FRC from the machine axis in the matched case. There is also evidence of island structure in the reduced guide-field case. Fluctuating levels of B/sub theta/ are ovserved with amplitudes less than or equal to B 0 /3 in both cases. Field measurements on the FRC symmetry axis in the reduced guide-field case indicate β on the separatrix of β/sub s/ approx. = 0.3 (indexed to the external field) has been achieved. This decrease of β/sub s/ with increased x/sub s/ is expected, and desirable for improved plasma confinement

Hydrogen Field Test Standard: Laboratory and Field Performance

Science.gov (United States)

Pope, Jodie G.; Wright, John D.

2015-01-01

The National Institute of Standards and Technology (NIST) developed a prototype field test standard (FTS) that incorporates three test methods that could be used by state weights and measures inspectors to periodically verify the accuracy of retail hydrogen dispensers, much as gasoline dispensers are tested today. The three field test methods are: 1) gravimetric, 2) Pressure, Volume, Temperature (PVT), and 3) master meter. The FTS was tested in NIST's Transient Flow Facility with helium gas and in the field at a hydrogen dispenser location. All three methods agree within 0.57 % and 1.53 % for all test drafts of helium gas in the laboratory setting and of hydrogen gas in the field, respectively. The time required to perform six test drafts is similar for all three methods, ranging from 6 h for the gravimetric and master meter methods to 8 h for the PVT method. The laboratory tests show that 1) it is critical to wait for thermal equilibrium to achieve density measurements in the FTS that meet the desired uncertainty requirements for the PVT and master meter methods; in general, we found a wait time of 20 minutes introduces errors methods, respectively and 2) buoyancy corrections are important for the lowest uncertainty gravimetric measurements. The field tests show that sensor drift can become a largest component of uncertainty that is not present in the laboratory setting. The scale was calibrated after it was set up at the field location. Checks of the calibration throughout testing showed drift of 0.031 %. Calibration of the master meter and the pressure sensors prior to travel to the field location and upon return showed significant drifts in their calibrations; 0.14 % and up to 1.7 %, respectively. This highlights the need for better sensor selection and/or more robust sensor testing prior to putting into field service. All three test methods are capable of being successfully performed in the field and give equivalent answers if proper sensors without drift are

Transport and concentration controls for chloride, strontium, potassium and lead in Uvas Creek, a small cobble-bed stream in Santa Clara County, California, U.S.A. 1. Conceptual model

Science.gov (United States)

Kennedy, V.C.; Jackman, A.P.; Zand, S.M.; Zellweger, G.W.; Avanzino, R.J.

1984-01-01

Stream sediments adsorb certain solutes from streams, thereby significantly changing the solute composition; but little is known about the details and rates of these adsorptive processes. To investigate such processes, a 24-hr. injection of a solution containing chloride, strontium, potassium, sodium and lead was made at the head of a 640-m reach of Uvas Creek in west-central Santa Clara County, California. Uvas Creek is a cobble-bed pool-and-riffle stream draining the eastern slopes of the Santa Cruz Mountains. By September 12, 1973, after a long dry season, Uvas Creek had a low (0.0215 m3s-1 average) flow which varied diurnally, from 0.018 to 0.025 m3s-1. Because stream discharge varied while the injection rate was constant, the concentration of tracers (injected solutes), after mixing in the stream, varied inversely with discharge. Chloride, a nonreactive solute, served as a tracer of water movement. Analysis of extensive chloride concentration data at five sites below the injection point during and after the injection demonstrated that there was considerable underflow of water through the stream gravels; however, the extent of underflow varied greatly within the study reach. Pre-injection water, displaced by tracer-laden water percolating through the gravels, diluted tracers in the stream channel, giving the mistaken impression of groundwater inflow at some points. Accurate measurement of total discharge in such streams requires prolonged tracer injection unless a reach can be found where underflow is negligible. Strontium and potassium were adsorbed by the bed sediments to a moderate extent and lead was strongly adsorbed. A high proportion of these metals could be removed by adsorption from percolating underflow because of extensive and intimate contact with bed sediments. After channel clearing following injection cutoff, 51% of the added strontium and 96% of the lead remained in the study reach, whereas only 19% of the chloride remained. Packets of sized

Electric fields and field-aligned current generation in the magnetosphere

International Nuclear Information System (INIS)

Alexeev, I.I.; Belenkaya, E.S.; Kalegaev, V.V.; Lyutov, Yu.G.

1993-01-01

The authors present a calculation of the electric potential, field-aligned currents, and plasma convection caused by the penetration of the solar wind electric field into the magnetosphere. Ohm's law and the continuity equation of ionospheric currents are used. It is shown that the large-scale convection system is reversed in the plasma sheet flanks. In this region the plasma flow is antisunward earthward of the neutral line and sunward tailward of it. The interplanetary magnetic field (IMF) B z dependences on the dimension of the magnetopause open-quotes windowsclose quotes which are intersected by open field lines, on the potential drop across the polar cap, and on the distance to the neutral line are determined. Because of the IMF effect and the effect of seasonal or daily variations of the geomagnetic field which violate its symmetry relative to the equatorial plane, there may arise a potential drop along field lines which causes field-aligned currents. The values and directions of these currents, the field-aligned potential drop, and a self-consistent solution for the potential at the ionosphere level for high field-aligned conductivity have been determined. 41 refs., 7 figs

Comparison between 3D conventional techniques, field-in-field and electronic tissue compensation for mantle fields planning; Comparacao entre tecnica 3D convencional, field-in-field e compensacao eletronica para planejamento de manto

Energy Technology Data Exchange (ETDEWEB)

Martins, Lais P.; Silva, Leonardo P.; Trindade, Cassia; Garcia, Paulo L.; Santos, Maira R.; Batista, Delano V.S., E-mail: pm.lais@gmail.com [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil)

2012-12-15

External radiotherapy treatment for Hodgkin's lymphoma over diaphragm region requires large radiation fields with protections applied to larynx, humerus head and lungs. The size and shape of the field, which covers different depths, make it difficult to distribute a homogeneous dose. Techniques such as field-in-field and electronic tissue compensation may be used to make dose homogeneous and compensate the obliquity from the tissue. Three types of planning were performed for diagnose of nodular sclerosis Hodgkin's lymphoma: one plan with two fields, AP-PA (AP plan), another with four fields field-in- field (FF plan), and a third one with two fields and electronic tissue compensation (ETC plan). Results showed better gradient, cover of PTV and dose distribution for the ETC plan, besides the advantage from this technique of does not require protection blocks. In the meanwhile, AP and FF plans require simpler dosimetry and fewer MU. Related to the uniformity of dose distribution, AP plan showed hot areas in the neck region, FF plan showed hot areas in the shoulder region and ETC plan showed most uniform distribution without hot areas. The electronic tissue compensation is a useful tool for large and shaped fields as the mantle field, however higher MU and complex dosimetry should be taken in account. (author)

Cosmic Magnetic Fields

Science.gov (United States)

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

2018-05-01

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

Integrated field modelling[Oil and gas fields

Energy Technology Data Exchange (ETDEWEB)

Nazarian, Bamshad

2002-07-01

This research project studies the feasibility of developing and applying an integrated field simulator to simulate the production performance of an entire oil or gas field. It integrates the performance of the reservoir, the wells, the chokes, the gathering system, the surface processing facilities and whenever applicable, gas and water injection systems. The approach adopted for developing the integrated simulator is to couple existing commercial reservoir and process simulators using available linking technologies. The simulators are dynamically linked and customised into a single hybrid application that benefits from the concept of open software architecture. The integrated field simulator is linked to an optimisation routine developed based on the genetic algorithm search strategies. This enables optimisation of the system at field level, from the reservoir to the process. Modelling the wells and the gathering network is achieved by customising the process simulator. This study demonstrated that the integrated simulation improves current capabilities to simulate the performance of the entire field and optimise its design. This is achieved by evaluating design options including spread and layout of the wells and gathering system, processing alternatives, reservoir development schemes and production strategies. Effectiveness of the integrated simulator is demonstrated and tested through several field-level case studies that discuss and investigate technical problems relevant to offshore field development. The case studies cover topics such as process optimisation, optimum tie-in of satellite wells into existing process facilities, optimal well location and field layout assessment of a high pressure high temperature deepwater oil field. Case study results confirm the viability of the total field simulator by demonstrating that the field performance simulation and optimal design were obtained in an automated process with treasonable computation time. No significant

Eneseanalüüs paneb raha voolama / Tarvo Vaarmets

Index Scriptorium Estoniae

Vaarmets, Tarvo

2008-01-01

Ilmunud ka: Delovõje Vedomosti 20. veebr. lk. 29. USA Santa Clara ülikooli professor Meir Statman kõneles Hansapanga investeerimiskonverentsil eneseanalüüsi olulisusest börsile investeerimisel. Kommenteerib Kristjan Lepik

78 FR 39326 - Notice Pursuant To the National Cooperative Research and Production Act of 1993-Opendaylight...

Science.gov (United States)

2013-07-01

... Clara, CA; Cyan Inc., Petaluma, CA; Dell Inc., Round Rock, TX; Ericsson Inc., San Jose, CA; Fujitsu...Daylight's planned activity is to (a) Advance the creation, evolution, promotion, and support of an open...

Comparing concentration methods: parasitrap® versus Kato-Katz for ...

African Journals Online (AJOL)

Comparing concentration methods: parasitrap® versus Kato-Katz for studying the prevalence of Helminths in Bengo province, Angola. Clara Mirante, Isabel Clemente, Graciette Zambu, Catarina Alexandre, Teresa Ganga, Carlos Mayer, Miguel Brito ...

Impact of local electrostatic field rearrangement on field ionization

Science.gov (United States)

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

2018-03-01

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

Potential of Field Education as Signature Pedagogy: The Field Director Role

Science.gov (United States)

Lyter, Sharon C.

2012-01-01

In light of the assertion that field education is the signature pedagogy of social work education, this Internet-based study explores field director demographics and questions the fulfillment of this potential, examining BSW and MSW field education through the lens of the field director position. Field directors (159) and deans/directors (150)…

Traça Tuta absoluta (Meyrick em cultivares de tomateiro tratadas com extratos aquosos de Trichilia pallida Swartz Tuta absoluta (Meyrick on tomato cultivars treated with aqueous extracts of Trichilia pallida Swartz

Directory of Open Access Journals (Sweden)

José Djair Vendramim

2001-09-01

Full Text Available A traça Tuta absoluta (Meyrick é atualmente uma das principais pragas do tomateiro no Brasil. Com o objetivo de obter um método de controle eficiente e não poluente, avaliou-se a atividade dos extratos aquosos de folhas e ramos de Trichilia pallida Swartz associados a duas cultivares de tomateiro (Santa Clara e IPA-5 sobre essa praga. Acompanhou-se o desenvolvimento do inseto em folhas de cada uma das cultivares previamente submersas nos extratos a 1% de concentração, avaliando-se a duração e viabilidade das fases larval e pupal e o peso de pupas. A cultivar IPA-5 provocou alongamento da fase larval e, quando associada aos extratos de folhas e de ramos, reduziu a viabilidade pupal do inseto. Os extratos de folhas e de ramos também alongaram o período larval de T. absoluta, na cultivar Santa Clara. O extrato de folhas foi mais prejudicial ao desenvolvimento da traça do que o extrato de ramos dessa planta, reduzindo a viabilidade larval em ambas as cultivares.The tomato pinworm Tuta absoluta (Meyrick is one of the main tomato pests in Brazil. With the objective of obtaining an efficient and not pollutant method of control, the activity of aqueous extracts of Trichilia pallida Swartz leaves and twigs on this pest was studied associated to the tomato cultivars Santa Clara and IPA-5. The development of the insect was observed on leaves of each cultivar, previously treated with extracts at 1% of concentration. Length and viability of larval and pupal stages and pupal weight were evaluated. The larval period of the insect was more prolonged on 'IPA-5' and, when associated with leaf and twig extracts, reduced pupal viability. Leaf and twig extracts also prolonged the larval stage in 'Santa Clara'. The leaf extract affected more negatively the insect development than the twig extract, reducing larval viability on both cultivars.

Comportamiento estacional del Anopheles (nyssorhynchus darlingi root 1926 en localidades de Loreto y Madre de Dios, Perú 1999- 2000

Directory of Open Access Journals (Sweden)

Walter León C

2003-03-01

Full Text Available Objetivos: Determinar el comportamiento estacional del Anopheles darlingi en las localidades de Santa Clara (Loreto y Villa Luz (Madre de Dios. Materiales y métodos: En las localidades de Santa Clara y Villa Luz, entre agosto de 1999 y junio de 2000 se realizó mensualmente la inspección de criaderos, colecta de larvas de Anopheles darlingi por el método del cucharón y colecta de mosquitos adultos por el método cebo humano (intradomicilio y peri domicilió, trampa Shannon y refugio animal (extradomicilio. Se calcularon los indicadores: criadero positivo y densidad larvaria por cucharonada, índice de picadura hombre noche (IPHN, índice de picadura hombre hora (IPHH, índice esporozoítico y tasa de paridad. Resultados: El IPHN en ambas localidades se incrementó en la estación lluviosa con los valores más altos en mayo (Santa Clara y febrero (Villa Luz. En Santa Clara, el comportamiento de la picadura del Anopheles darlingi de agosto a diciembre de 1999, fue unimodal presentándose el pico de IPHH entre las 19.00 y 21.00 horas; sin embargo, de marzo a junio de 2000, el comportamiento fue bimodal con dos picos del IPHH: entre las 19.00 y 22.00 horas, y entre las 2.00 y 4.00 horas. En Villa Luz, el comportamiento de la picadura, de agosto a junio de 1999, se mantuvo unimodal, con el pico de IPHH entre las 21.00 y 24.00 horas. Las especies inmaduras de Anopheles darlingi representaron menos del 20% de las larvas encontradas en los criaderos permanentes. Conclusiones: El Anopheles darlingi presenta mayor densidad poblacional en meses de estación lluviosa, con comportamientos de picadura distintos según localidad y estación. Los criaderos evaluados no serían criaderos tan importantes de esta especie.

Vinculación del médico y enfermera de la familia con la microbrigada social

Directory of Open Access Journals (Sweden)

Alicia Hernández Cabeza

1999-01-01

Full Text Available Se realiza un estudio descriptivo, retrospectivo del quinquenio 1990-1995, en el Consultorio 34-3, del área de salud "XX Aniversario" de Santa Clara, Villa Clara, para conocer la vinculación del trabajo del médico y la enfermera de la familia a la microbrigada social de un barrio insalubre sometido a acciones físico-constructivas y de animación social y algunos cambios introducidos por los investigadores. El análisis de los resultados se realizó mediante la aplicación de métodos cuantitativos técnicas de investigación cualitativas, arribando a las siguientes conclusiones: la creación de la microbrigada social vinculada al equipo de salud constituye el acontecimiento más relevante de la barriada en los últimos años. Se constatan cambios positivos en el estilo de vida, y en el estado de salud de la población. Las modificaciones en los riesgos sociales son el resultado del trabajo de participación comunitaria y social bajo el liderazgo del grupo profiláctico multidisciplinario.A descriptive and retrospective study of the five-year term 1990-1995 wqas carried out at the family physician´s office 34-3 of the XX Anniversary health area, in Santa Clara, Villa Clara, to know the link existind between the family physician and nurse and the social microgrigade in an insalubrious neighborhood which is under a physical, construction and social animation process. Some changes were introduced by the investigators. The analysis of the results was made by the application of quantitative methods and qualitibe techniques of investigation. The following conclusions were reached: the creation of a social microbrigade connected with the health team is the most important event of the neighborhood in the last years. Positive changes were observed in the lifes tyle and in the health status of the population. The modifications of the social risks are the result of the community and social participation under the leadership of the multidisciplinary

Simulation models generator. Applications in scheduling

Directory of Open Access Journals (Sweden)

Omar Danilo Castrillón

2013-08-01

Rev.Mate.Teor.Aplic. (ISSN 1409-2433 Vol. 20(2: 231–241, July 2013 generador de modelos de simulacion 233 will, in order to have an approach to reality to evaluate decisions in order to take more assertive. To test prototype was used as the modeling example of a production system with 9 machines and 5 works as a job shop configuration, testing stops processing times and stochastic machine to measure rates of use of machines and time average jobs in the system, as measures of system performance. This test shows the goodness of the prototype, to save the user the simulation model building

Gestión óptima de la energía en vehículos híbridos basados en pilas de combustible utilizando control predictivo económico

OpenAIRE

Sampietro, Jose Luis; Costa Castelló, Ramon; Puig Cayuela, Vicenç

2016-01-01

Las pilas de combustible que utilizan el hidrégeno como combustible están siendo consideradas, en estos últimos años, como una alternativa a los combustibles fósiles para su uso en automóviles. Dicha tecnología se puede utilizar en los vehículos eléctricos o de propulsión híbrida ya en uso. Este trabajo introduce el control predictivo económico (EMPC, siglas en inglés) como técnica de gestión óptima de la energía. Finalmente, se presentan simulaciones de varios escenarios, basados en un contr...

Pago y sostenibilidad de la deuda pública: ejercicios de simulación para algunas economías latino americanas

Directory of Open Access Journals (Sweden)

Andrés Ramírez Hassan

2006-10-01

Full Text Available Se desarrolla el marco teorico implicito en la restricción presupuestaria intertemporal del gobierno. A partir de este se realizan una serie de simulaciones sobre el problema de sostenibilidad de la deuda publica, y los sacrificios fiscales necesarios para juzgar el actual nivel de endeudamiento sostenible. Se observa que Colombia ubicada en el contexto analizado se encuentra en un lugar intermedio con respecto al esfuerzo fiscal necesario para sostener la deuda publica, concretamente se requiere un superavit primario promedio equivalente al 2.51% del PIB. Esta magnitud es inferior a la requerida por Argentina y Brasil, pero superior a los requerimientos de Venezuela, Chile y Mexico

Modelado molecular de la interacción de fármacos antitumorales y nucleasas con el ADN

OpenAIRE

Bueren Calabuig, Juan Antonio

2011-01-01

Premio Extraordinario de Doctorado de la UAH en 2013 Los métodos computacionales están convirtiéndose en herramientas muy importantes en ciertas áreas de la investigación como la caracterización de sitios de unión de ligandos a proteínas, acoplamiento de pequeñas moléculas en sitios de unión al ADN y proteínas y simulaciones de dinámica molecular. Los resultados obtenidos aportan información que, a veces, está más allá de las posibilidades puramente experimentales y pueden usarse para gui...

Control system design for the deethanizer absorber tower pressure in the light end unit of the Nico Lopez refinery; Diseno del sistema de control para la presion en la torre absorvedora deetanizadora de la unidad de finales ligeros de la refineria Nico Lopez

Energy Technology Data Exchange (ETDEWEB)

Morales Corral, Camilo [Refineria Nico Lopez, Ciudad Habana (Cuba)]. E-mail: Camilo.morales@refhab.cupet.cu; Pedre Mendoza, Isabel [DAISA, Ciudad Habana (Cuba)]. E-mail: Isabel@daisa.copextel.com.cu; Garcini Leal, Hector J. [Instituto Superior Politecnico Jose A. Echeverria, La Habana (Cuba)]. E-mail: garcini,novi@electrica.cujae.edu.cu; Fernandez, Luis M. [Instituto de Cibernetica, Matematica y Fisica, La Habana (Cuba)]. E-mail: luis@icmf.inf.cu; Benitez Gonzalez, Ivon Oristela [Instituto Superior Politecnico Jose A. Echeverria, La Habana (Cuba)

2010-11-15

This paper is about pressure feed forward control. It is for an absorber tower of the Light End Unit. This one is in the Havana Oil Refinery. Control loop was designed using identification technic and simulation software. Moreover the design control loop has been validated and his quality has been determined. [Spanish] En el presente trabajo se aborda un control anticipatorio de presion. Fue desarrollado para la torre absorvedora de la Unidad de Finales Ligeros. La cual pertenece a la refineria de La Habana. Fue disenado un lazo de control empleando tecnicas de identificacion y programas de simulacion. Ademas el lazo disenado es validado y se determina su calidad.

Modelado y Simulación de la Actividad Eléctrica de Células Ventriculares

Directory of Open Access Journals (Sweden)

Karen Cardona

2008-01-01

Full Text Available En este artículo se simula el potencial de acción ventricular mediante el modelo matemático derrollado por Luo y Rudy; este modelo contiene 22 canales iónicos representados por ecuaciones diferenciales no lineales, lo cual nos permite demostrar mediante el desarrollo de simulaciones basadas en los mismos, que la longitud del ciclo básico (Basic Cycle Length, BCL cambia el valor máximo de la derivada máxima de potencial de acción (V max. Por otra parte, se puede demostrar que la duración del potencial de acción (Action Potential duration, APD es afectada.

Comportamiento dinámico de asteroides en la resonancia 2:1

Science.gov (United States)

López García, F.; Brunini, A.

El propósito de este trabajo es mostrar los resultados obtenidos del estudio del movimiento de asteroides cercanos a la conmensurabilidad 2:1 con el movimiento medio de Júpiter, analizando el comportamiento de órbitas de asteroides reales y ficticios. Se analizan los tiempos de Lyapunov obtenidos a partir de la integración de las ecuaciones del movimiento. Se han estudiado la órbitas utilizando el modelo de cinco cuerpos y se han considerado los casos planar y espacial. Las simulaciones numéricas se realizaron utilizando integradores simpléticos y el intervalo de tiempo de integración fue de T = 107 años.

Engineering field theory

CERN Document Server

Baden Fuller, A J

2014-01-01

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

Lossi legendist, tamme teekonnast ja maali mõistatusest / Alar Läänelaid

Index Scriptorium Estoniae

Läänelaid, Alar, 1951-

2006-01-01

Dendrokronoloogilisest dateerimisest (aastarõngasdateerimine), mis on toonud selgust Alatskivi lossi söögisaali laekaunistuse dateerimisse, Hans van Esseni maali "Vaikelu homaariga" ning Clara Peetersi "Vaikelu jahisaagiga" valmimisaja ja ehtsuse kindlaksmääramisse

Advanced paratransit system : an application of digital map, automated vehicle scheduling and vehicle location systems

Science.gov (United States)

1997-05-01

This report documents and evaluates an advanced Paratransit system demonstration project. The Santa Clara Valley Transportation Agency (SCVTA), via OUTREACH, implemented such a system, comprised of an automated trip scheduling system (ATSS) and autom...

Normal Levels of Urinary CC16 Protein. Comments on Beamer et al. Association of Children’s Urinary CC16 Levels with Arsenic Concentrations in Multiple Environmental Media. Int. J. Environ. Res. Public Health 2016, 13, 521.

Directory of Open Access Journals (Sweden)

Víctor García-Nieto

2016-10-01

Full Text Available In 1937, Max Clara described a new type of cell in the human lung, which was later determined to be an exocrine secretory cell type containing granules composed of proteins [1].[...

Wide-field fundus autofluorescence corresponds to visual fields in chorioretinitis patients

Directory of Open Access Journals (Sweden)

Seidensticker F

2011-11-01

Full Text Available Florian Seidensticker1, Aljoscha S Neubauer1, Tamer Wasfy1,2, Carmen Stumpf1, Stephan R Thurau1,*, Anselm Kampik1, Marcus Kernt1,*1Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany; 2Department of Ophthalmology, Tanta University, Tanta, Egypt *Both authors contributed equally to this workBackground and objectives: Detection of peripheral fundus autofluorescence (FAF using conventional scanning laser ophthalmoscopes (SLOs is difficult and requires pupil dilation. Here we evaluated the diagnostic properties of wide-field FAF detected by a two-laser wavelength wide-field SLO in uveitis patients.Study design/materials and methods: Observational case series of four patients suffering from different types of posterior uveitis/chorioretinitis. Wide-field FAF images were compared to visual fields. Panretinal FAF was detected by a newly developed SLO, which allows FAF imaging of up to 200° of the retina in one scan without the need for pupil dilation. Visual fields were obtained by Goldmann manual perimetry.Results: Findings from wide-field FAF imaging showed correspondence to visual field defects in all cases.Conclusion: Wide-field FAF allowed the detection of visual field defect-related alterations of the retinal pigment epithelium in all four uveitis cases.Keywords: fundus autofluorescence (FAF, Optomap, wide-field scanning laser ophthalmoscopy, imaging, uveitis, visual field

Seasonal and habitat abundance and distribution of some forensically important blow flies (Diptera: Calliphoridae) in Central California.

Science.gov (United States)

Brundage, Adrienne; Bros, Shannon; Honda, Jeffrey Y

2011-10-10

Seasonal and habitat calliphorid abundance and distribution were examined weekly for two years (2001-2003) in Santa Clara County, California, using sentinel traps baited with bovine liver. Of the 34,389 flies examined in three defined habitats (rural, urban, and riparian), 38% of the total catch represented Compsomyiops callipes (Bigot) and 23% represented Phormia regina (Meigen). Other flies collected in this survey included Calliphora vomitoria (Linnaeus), Calliphora latifrons (Hough), Lucilia sericata (Meigen), Lucilia cuprina (Wiedemann), and Lucilia mexicana (Macquart), which is a new record for the area. Multivariate MANOVA and ANOVA (P ≤ 0.05) analysis indicate significant seasonal habitat preference for all fly species examined. This information may be used to identify potentially forensically impo rtant fly species within Santa Clara County, California. Published by Elsevier Ireland Ltd.

Equidad distributiva del ingreso pesquero en la reserva de la biosfera Alto golfo de California y delta del Río Colorado en México

Directory of Open Access Journals (Sweden)

Carlos Israel VÁZQUEZ LEÓN

2012-01-01

Full Text Available Se analiza la distribución del ingreso y se estima el grado de equidad durante 1994 y 2002 en tres comunidades colindantes a la reserva de la biosfera alto golfo de California y delta del río Colorado (RBAGC: Puerto Peñasco, el Golfo de Santa Clara, en Sonora, y San Felipe, en Baja California. Se considera a la rbagc como política pública enfocada a la sustentabilidad en la región. Se concluye que hay diferencias entre los pescadores antes y después de la introducción del plan de manejo, y que la inequidad en el Golfo de Santa Clara ha aumentado, siendo esta comunidad la que se ubica dentro de la reserva y con mayor dependencia de la pesca.

Comparison of duloxetine and SSRI as a treatment option of painful physical symptoms associated with major depressive disorder

Directory of Open Access Journals (Sweden)

Haider M

2017-10-01

Full Text Available Miqdad Haider,1 Muhammad Nabeel Shafqat2 1Department of Medicine, Fatima Memorial Hospital, Fatima Memorial College of Medicine and Dentistry, Lahore, Pakistan; 2Department of Medicine, University of Medical Sciences “Serafin Ruiz de Zarate” Villa Clara (UCMVC, Villa Clara, CubaWe would like to write about the recently published article “An observational study of duloxetine versus selective serotonin reuptake inhibitors (SSRIs monotherapy for the treatment of painful physical symptoms in Japanese patients with major depressive disorder: primary analysis” by Kuga et al, which we read with great interest.1 The study is a good step toward finding the best treatment option for painful physical symptoms (PPSs in patients with major depressive disorder (MDD.View the original paper by Kuga and colleagues. 

Accelerating field step-up transformer in wake-field accelerators

International Nuclear Information System (INIS)

Chojnacki, E.; Gai, W.; Schoessow, P.; Simpson, J.

1991-01-01

In the wake-field scheme of particle acceleration, a short, intense drive bunch of electrons passes through a slow-wave structure, leaving behind high rf power in its wake field. The axial accelerating electric field associated with the rf can be quite large, > 100 MeV/m, and is used to accelerate a much less intense ''witness'' beam to eventual energies > 1 TeV. The rf power is deposited predominantly in the fundamental mode of the structure, which, for dielectric-lined waveguide as used at Argonne, is the TM 01 mode. In all likelihood on the field amplitude will be limited only by rf breakdown of the dielectric material, the limit of which is currently unknown in the short time duration, high frequency regime of wake-field acceleration operation. To obtain such strong electric fields with given wake-field rf power, the dimensions of the dielectric-lined waveguide have to be fairly small, OD of the order of a cm and ID of a few mm, and this gives rise to the generation of strong deflection modes with beam misalignment. While a scheme exists to damp such deflection modes on a bunch-to-bunch time scale, head-tail beam deflection could still be a problem and BNS damping as well as FODO focusing are incomplete cures. Presented here are details of a scheme by which the rf power is generated by in a large-diameter wake-field tube, where deflection mode generation by the intense drive beam is tolerable, and then fed into a small-diameter acceleration tube where the less intense witness beam is accelerated by the greatly enhanced axial electric field. The witness beam generates little deflection-mode power itself, even in the small acceleration tube, thus a final high-quality, high-energy electron beam is produced

Background Independent Open String Field Theory and Constant B-Field

OpenAIRE

Nemeschansky, D.; Yasnov, V.

2000-01-01

We calculate the background independent action for bosonic and supersymmetric open string field theory in a constant B-field. We also determine the tachyon effective action in the presence of constant B-field.

Acceleration of auroral particles by magnetic-field aligned electric fields

International Nuclear Information System (INIS)

Block, L.P.

1988-01-01

Measurements on the S3-3 and Viking satellites appear to show that at least a large fraction of magnetic field-aligned potential drops are made up of multiple double layers. Solitons and double layers in U-shaped potential structures give rise to spiky electric fields also perpendicular to the magnetic field in agreement with satellite measurements. The large scale potential structures associated with inverted V-events are built up of many similar short-lived structures on a small scale. Viking measurements indicate that electric fields parallel to the magnetic field are almost always directed upward

Selfdecomposable Fields

DEFF Research Database (Denmark)

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

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

Selfdecomposable Fields

DEFF Research Database (Denmark)

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

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

Suppression of sound radiation to far field of near-field acoustic communication system using evanescent sound field

Science.gov (United States)

Fujii, Ayaka; Wakatsuki, Naoto; Mizutani, Koichi

2016-01-01

A method of suppressing sound radiation to the far field of a near-field acoustic communication system using an evanescent sound field is proposed. The amplitude of the evanescent sound field generated from an infinite vibrating plate attenuates exponentially with increasing a distance from the surface of the vibrating plate. However, a discontinuity of the sound field exists at the edge of the finite vibrating plate in practice, which broadens the wavenumber spectrum. A sound wave radiates over the evanescent sound field because of broadening of the wavenumber spectrum. Therefore, we calculated the optimum distribution of the particle velocity on the vibrating plate to reduce the broadening of the wavenumber spectrum. We focused on a window function that is utilized in the field of signal analysis for reducing the broadening of the frequency spectrum. The optimization calculation is necessary for the design of window function suitable for suppressing sound radiation and securing a spatial area for data communication. In addition, a wide frequency bandwidth is required to increase the data transmission speed. Therefore, we investigated a suitable method for calculating the sound pressure level at the far field to confirm the variation of the distribution of sound pressure level determined on the basis of the window shape and frequency. The distribution of the sound pressure level at a finite distance was in good agreement with that obtained at an infinite far field under the condition generating the evanescent sound field. Consequently, the window function was optimized by the method used to calculate the distribution of the sound pressure level at an infinite far field using the wavenumber spectrum on the vibrating plate. According to the result of comparing the distributions of the sound pressure level in the cases with and without the window function, it was confirmed that the area whose sound pressure level was reduced from the maximum level to -50 dB was

In vitro establishment of Eugenia squarrose: an endemic species in danger of extinction from Santa Clara (Cuba

Directory of Open Access Journals (Sweden)

Elisa Quiala

2004-01-01

Full Text Available The tissue culture techniques can be supplemented with others that are carried out in the cultivation in situ and being applied in combined way to give solution to the extinction of different species. Eugenia squarrosa (Ekman & Urban it is an endemic species of Cuba in extinction danger due to the urbanization of their natural habitat, which have been reduced to a few hectares. The aim of this work was to achieve the establishment in vitro of this species. Seeds and young branches were collected starting from plants in its natural habitat. The effect of three concentrations of NaOCl (2.0, 2.5, 3.0% during 20 minutes in the disinfection of the seeds was studied. For the disinfection of the buds a treatment with alcohol to 70% was used during two minutes previously to the disinfection with NaOCl. The effect of three concentrations of this NaOCl was studied (1.0, 2.0, 3.0% during 10 minutes. The present microbiota was characterized in the contaminated branch. The 100% of disinfection of the seeds was achieved in all the treatments studied. The bigger explants percentage free of contaminant (88.6% was obtained in the treatment with 3% of NaOCl. However the biggest percentage of survival (45.7% was obtained when 2.0% of NaOCl was used. The establishment in vitro of the species was achieved starting from seeds and buds collected of field plants. Key Words: biodiversity, micropropagation, threatened species

Prequantum classical statistical field theory: background field as a source of everything?

International Nuclear Information System (INIS)

Khrennikov, Andrei

2011-01-01

Prequantum classical statistical field theory (PCSFT) is a new attempt to consider quantum mechanics (QM) as an emergent phenomenon, cf. with De Broglie's 'double solution' approach, Bohmian mechanics, stochastic electrodynamics (SED), Nelson's stochastic QM and its generalization by Davidson, 't Hooft's models and their development by Elze. PCSFT is a comeback to a purely wave viewpoint on QM, cf. with early Schrodinger. There is no quantum particles at all, only waves. In particular, photons are simply wave-pulses of the classical electromagnetic field, cf. SED. Moreover, even massive particles are special 'prequantum fields': the electron field, the neutron field, and so on. PCSFT claims that (sooner or later) people will be able to measure components of these fields: components of the 'photonic field' (the classical electromagnetic field of low intensity), electronic field, neutronic field, and so on. At the moment we are able to produce quantum correlations as correlations of classical Gaussian random fields. In this paper we are interested in mathematical and physical reasons of usage of Gaussian fields. We consider prequantum signals (corresponding to quantum systems) as composed of a huge number of wave-pulses (on very fine prequantum time scale). We speculate that the prequantum background field (the field of 'vacuum fluctuations') might play the role of a source of such pulses, i.e., the source of everything.

Accuracy limits of the equivalent field method for irregular photon fields

International Nuclear Information System (INIS)

Sanz, Dario Esteban

2002-01-01

A mathematical approach is developed to evaluate the accuracy of the equivalent field method using basic clinical photon beam data. This paper presents an analytical calculation of dose errors arising when field equivalencies, calculated at a certain reference depth, are translated to other depths. The phantom scatter summation is expressed as a Riemann-Stieltjes integral and two categories of irregular fields are introduced: uniform and multiform. It is shown that multiform fields produce errors whose magnitudes are nearly twice those corresponding to uniform fields in extreme situations. For uniform field shapes, the maximum, local, relative dose errors, when the equivalencies are calculated at 10 cm depth on the central axis and translated to a depth of 30 cm, are 3.8% and 8.8% for 6 MV and cobalt-60 photon beams, respectively. In terms of maximum dose those errors are within 1-2%. This supports the conclusion that the equivalencies between rectangular fields, which are examples of uniform fields, are applicable to dose ratio functions irrespective of beam energy. However, the magnitude of such errors could be of importance when assessing the exit dose for in vivo monitoring. This work provides a better understanding of the influence of the irregular field shapes on the accuracy of the equivalent field method. (author)

Field Campaign Guidelines

Energy Technology Data Exchange (ETDEWEB)

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

2015-12-01

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

Field quality issues in iron-dominated dipoles at low fields

International Nuclear Information System (INIS)

Brown, B.C.

1996-10-01

In order to help assess the usable dynamic range of iron-dominated dipoles, field shape data at low field on several Fermi-lab accelerator dipole designs are presented. Emphasis is placed on the systematic and random values of the low field sextupole since it is the first ''allowed'' field error. The Main Injector dipoles provide four times smaller sextupole and more than 20 times less sextupole hysteresis than earlier designs for the Main Ring

78 FR 52981 - Investigations Regarding Eligibility to Apply for Worker Adjustment Assistance

Science.gov (United States)

2013-08-27

...-- Tulsa, OK 08/02/13 08/01/13 Wholesale Customer Application Support Team (Workers). 82953 Abbott Laboratories, Santa Clara, CA........ 08/02/13 08/01/13 including on-site leased workers from ATR Int'l (State...

Dielectric properties study of surface engineered nanoTiO2/epoxy ...

Indian Academy of Sciences (India)

2018-02-02

Feb 2, 2018 ... 2Department of Physics, Sri Sathya Sai Institute of Higher Learning, Vidyagiri, ... the surface modifiers were not successful in obtaining the improved dielectric .... lent Technologies Inc., Santa Clara, CA) at a frequency range.

La comunidad en el aula y el aula en la comunidad: Un modelo (The Community in the Classroom and the Classroom in the Community: A Model).

Science.gov (United States)

Varona, Lucia T.

1999-01-01

Describes an advanced conversational Spanish language course based on community experiences, multicultural education, and collaborative research taught at the University of Santa Clara in California. The class combined authentic materials with real-life experiences. (Author/VWL)

Quantum field theory

International Nuclear Information System (INIS)

Ryder, L.H.

1985-01-01

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

COMPORTAMIENTO MECANICO DE LA AORTA ASCENDENTE: CARACTERZACION EXPERIMENTAL Y SIMULACION NUMERICA.

OpenAIRE

GARCIA HERRERA, CLAUDIO; GARCIA HERRERA, CLAUDIO

2008-01-01

En este trabajo se realiza una caracterización experimental y numérica del comportamiento mecánico de la pared de la aorta humana. Se destaca la importancia (le este tema debido al creciente interés cii coiiocer las propiedades y la respuesta mecánica de 193p.

Detailed thermal simulation of fenestration; Simulacion termica detallada de una ventana

Energy Technology Data Exchange (ETDEWEB)

Fissore Sch, Adelqui; Tartari, Paula [Universidad de Concepcion (Chile). Facultad de Ingenieria. Dept. de Ingenieria Mecanica]. E-mail: afissore@udec.cl; ptartari@udec.cl; Hernandez C, Gaston [Universidad del Bio-Bio, Concepcion (Chile). Facultad de Ingenieria. Dept. de Ingenieria Mecanica]. E-mail: ghernand@ubiobio.cl

2000-07-01

In this paper a new model for heat balance of a window is proposed. The objective of the model is to solve accurately the heat balance on a single glass window in a moderate climate. This procedure will allow the designer to calculate the main parameters of a fenestration (surface, orientation, overhangs, etc.), minimizing the energy consumption for a specific enclosure (including heating, air conditioning and lighting). The present study is mainly focused on problems related with the internal long wave radiation calculations, and secondly on the effect of internal convection coefficient on the heat balance. A comparison between the results obtained using this model and those obtained with other current models is included in the second part of the paper. The importance of using the right internal convection coefficient on the heat balance of fenestration for this kind of application is also analyzed. (author)

Earth's electric field

International Nuclear Information System (INIS)

Kelley, M.C.

1978-01-01

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

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

International Nuclear Information System (INIS)

Afolabi, T. J.

2003-01-01

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

Phase field

International Nuclear Information System (INIS)

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

2015-01-01

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

Field emission electronics

CERN Document Server

Egorov, Nikolay

2017-01-01

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

Use of along-track magnetic field differences in lithospheric field modelling

DEFF Research Database (Denmark)

Kotsiaros, Stavros; Finlay, Chris; Olsen, Nils

2015-01-01

. Experiments in modelling the Earth's lithospheric magnetic field with along-track differences are presented here as a proof of concept. We anticipate that use of such along-track differences in combination with east–west field differences, as are now provided by the Swarm satellite constellation......We demonstrate that first differences of polar orbiting satellite magnetic data in the along-track direction can be used to obtain high resolution models of the lithospheric field. Along-track differences approximate the north–south magnetic field gradients for non-polar latitudes. In a test case......, using 2 yr of low altitude data from the CHAMP satellite, we show that use of along-track differences of vector field data results in an enhanced recovery of the small scale lithospheric field, compared to the use of the vector field data themselves. We show that the along-track technique performs...

Rapid change of field line connectivity and reconnection in stochastic magnetic fields

International Nuclear Information System (INIS)

Huang, Yi-Min; Bhattacharjee, A.; Boozer, Allen H.

2014-01-01

Magnetic fields without a direction of continuous symmetry have the generic feature that neighboring field lines exponentiate away from each other and become stochastic, and hence the ideal constraint of preserving magnetic field line connectivity becomes exponentially sensitive to small deviations from ideal Ohm's law. The idea of breaking field line connectivity by stochasticity as a mechanism for fast reconnection is tested with numerical simulations based on reduced magnetohydrodynamics equations with a strong guide field line-tied to two perfectly conducting end plates. Starting from an ideally stable force-free equilibrium, the system is allowed to undergo resistive relaxation. Two distinct phases are found in the process of resistive relaxation. During the quasi-static phase, rapid change of field line connectivity and strong induced flow are found in regions of high field line exponentiation. However, although the field line connectivity of individual field lines can change rapidly, the overall pattern of field line mapping appears to deform gradually. From this perspective, field line exponentiation appears to cause enhanced diffusion rather than reconnection. In some cases, resistive quasi-static evolution can cause the ideally stable initial equilibrium to cross a stability threshold, leading to formation of intense current filaments and rapid change of field line mapping into a qualitatively different pattern. It is in this onset phase that the change of field line connectivity is more appropriately designated as magnetic reconnection. Our results show that rapid change of field line connectivity appears to be a necessary, but not a sufficient condition for fast reconnection.

The Swarm Initial Field Model for the 2014 Geomagnetic Field

Science.gov (United States)

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

2015-01-01

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

Classical field theory

CERN Document Server

Franklin, Joel

2017-01-01

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

Heavy ion transfer reactions

Indian Academy of Sciences (India)

array (CLARA), extensive investigations of nuclear structure and reaction dynamics have been carried out. In the present paper aspects of these studies will be presented, focussing more closely on the reaction mechanism, in particular on the ...

Nuclear Magnetic Resonance Trackbed Moisture Sensor System

Science.gov (United States)

2018-02-01

In this initial phase, conducted from March 2015 through December 2016, Vista Clara and its subcontractor Zetica Rail successfully developed and tested a man-portable, non-invasive spot-check nuclear magnetic resonance (NMR) moisture sensor that dire...

Field-Induced Rheology in Uniaxial and Biaxial Fields

International Nuclear Information System (INIS)

MARTIN, JAMES E.

1999-01-01

Steady and oscillatory shear 3-D simulations of electro- and magnetorheology in uniaxial and biaxial fields are presented, and compared to the predictions of the chain model. These large scale simulations are three dimensional, and include the effect of Brownian motion. In the absence of thermal fluctuations, the expected shear thinning viscosity is observed in steady shear, and a striped phase is seen to rapidly form in a uniaxial field, with a shear slip zone in each sheet. However, as the influence of Brownian motion increases, the fluid stress decreases, especially at lower Mason numbers, and the striped phase eventually disappears, even when the fluid stress is still high. In a biaxial field, an opposite trend is seen, where Brownian motion decreases the stress most significantly at higher Mason numbers. to account for the uniaxial steady shear data they propose a microscopic chain model of the role played by thermal fluctuations on the rheology of ER and MR fluids that delineates the regimes where an applied field can impact the fluid viscosity, and gives an analytical prediction for the thermal effect. In oscillatory shear, a striped phase again appears in uniaxial field, at strain amplitudes greater than(approx) 0.15, and the presence of a shear slip zone creates strong stress nonlinearities at low strain amplitudes. In a biaxial field, a shear slip zone is not created, and so the stress nonlinearities develop only at expected strain amplitudes. The nonlinear dynamics of these systems is shown to be in good agreement with the Kinetic Chain Model

Novel Electrochemical Phenomena in Magnetic Fields(Research in High Magnetic Fields)

OpenAIRE

Mogi, Iwao; Kamiko, Masao

1996-01-01

Recent two topics are given of electrochemical studies in steady magnetic fields at the High Field Laboratory of Tohoku University. One is the magnetic-field-induced diffusion-limited-aggregation in the pattern formation of silver electrodeposits . The other is the magnetic field effect on the learning effect in a dopant-exchange process of an organic conducting polymer polypyrrole.

Orbital effect of the magnetic field in dynamical mean-field theory

Science.gov (United States)

Acheche, S.; Arsenault, L.-F.; Tremblay, A.-M. S.

2017-12-01

The availability of large magnetic fields at international facilities and of simulated magnetic fields that can reach the flux-quantum-per-unit-area level in cold atoms calls for systematic studies of orbital effects of the magnetic field on the self-energy of interacting systems. Here we demonstrate theoretically that orbital effects of magnetic fields can be treated within single-site dynamical mean-field theory with a translationally invariant quantum impurity problem. As an example, we study the one-band Hubbard model on the square lattice using iterated perturbation theory as an impurity solver. We recover the expected quantum oscillations in the scattering rate, and we show that the magnetic fields allow the interaction-induced effective mass to be measured through the single-particle density of states accessible in tunneling experiments. The orbital effect of magnetic fields on scattering becomes particularly important in the Hofstadter butterfly regime.

Pulsed magnetic field generation suited for low-field unilateral nuclear magnetic resonance systems

Science.gov (United States)

Gaunkar, Neelam Prabhu; Selvaraj, Jayaprakash; Theh, Wei-Shen; Weber, Robert; Mina, Mani

2018-05-01

Pulsed magnetic fields can be used to provide instantaneous localized magnetic field variations. In presence of static fields, pulsed field variations are often used to apply torques and in-effect to measure behavior of magnetic moments in different states. In this work, the design and experimental performance of a pulsed magnetic field generator suited for low static field nuclear magnetic resonance (NMR) applications is presented. One of the challenges of low bias field NMR measurements is low signal to noise ratio due to the comparable nature of the bias field and the pulsed field. Therefore, a circuit is designed to apply pulsed currents through an inductive load, leading to generation of pulsed magnetic fields which can temporarily overpower the effect of the bias field on magnetic moments. The designed circuit will be tuned to operate at the precession frequency of 1H (protons) placed in a bias field produced by permanent magnets. The designed circuit parameters may be tuned to operate under different bias conditions. Therefore, low field NMR measurements can be performed for different bias fields. Circuit simulations were used to determine design parameters, corresponding experimental measurements will be presented in this work.

Effective field theories

International Nuclear Information System (INIS)

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

1992-05-01

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

On field line resonances of hydromagnetic Alfven waves in dipole magnetic field

International Nuclear Information System (INIS)

Chen, Liu; Cowley, S.C.

1989-07-01

Using the dipole magnetic field model, we have developed the theory of field line resonances of hydromagnetic Alfven waves in general magnetic field geometries. In this model, the Alfven speed thus varies both perpendicular and parallel to the magnetic field. Specifically, it is found that field line resonances do persist in the dipole model. The corresponding singular solutions near the resonant field lines as well as the natural definition of standing shear Alfven eigenfunctions have also been systematically derived. 11 refs

Unitary field theories

International Nuclear Information System (INIS)

Bergmann, P.G.

1980-01-01

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

Retrieving Storm Electric Fields From Aircraft Field Mill Data. Part 2; Applications

Science.gov (United States)

Koshak, W. J.; Mach, D. M.; Christian, H. J.; Stewart, M. F.; Bateman, M. G.

2005-01-01

The Lagrange multiplier theory and "pitch down method" developed in Part I of this study are applied to complete the calibration of a Citation aircraft that is instrumented with six field mill sensors. When side constraints related to average fields are used, the method performs well in computer simulations. For mill measurement errors of 1 V/m and a 5 V/m error in the mean fair weather field function, the 3-D storm electric field is retrieved to within an error of about 12%. A side constraint that involves estimating the detailed structure of the fair weather field was also tested using computer simulations. For mill measurement errors of 1 V/m, the method retrieves the 3-D storm field to within an error of about 8% if the fair weather field estimate is typically within 1 V/m of the true fair weather field. Using this side constraint and data from fair weather field maneuvers taken on 29 June 2001, the Citation aircraft was calibrated. The resulting calibration matrix was then used to retrieve storm electric fields during a Citation flight on 2 June 2001. The storm field results are encouraging and agree favorably with the results obtained from earlier calibration analyses that were based on iterative techniques.

Fractal vector optical fields.

Science.gov (United States)

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

2016-07-15

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

Functional visual fields: relationship of visual field areas to self-reported function.

Science.gov (United States)

Subhi, Hikmat; Latham, Keziah; Myint, Joy; Crossland, Michael D

2017-07-01

The aim of this study is to relate areas of the visual field to functional difficulties to inform the development of a binocular visual field assessment that can reflect the functional consequences of visual field loss. Fifty-two participants with peripheral visual field loss undertook binocular assessment of visual fields using the 30-2 and 60-4 SITA Fast programs on the Humphrey Field Analyser, and mean thresholds were derived. Binocular visual acuity, contrast sensitivity and near reading performance were also determined. Self-reported overall and mobility function were assessed using the Dutch ICF Activity Inventory. Greater visual field loss (0-60°) was associated with worse self-reported function both overall (R 2 = 0.50; p function (R 2 = 0.61, p function in multiple regression analyses. Superior and inferior visual field areas related similarly to mobility function (R 2 = 0.56, p function in multiple regression analysis. Mean threshold of the binocular visual field to 60° eccentricity is a good predictor of self-reported function overall, and particularly of mobility function. Both the central (0-30°) and peripheral (30-60°) mean threshold are good predictors of self-reported function, but the peripheral (30-0°) field is a slightly better predictor of mobility function, and should not be ignored when considering functional consequences of field loss. The inferior visual field is a slightly stronger predictor of perceived overall and mobility function than the superior field. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

Magnetic field systems employing a superconducting D.C. field coil

International Nuclear Information System (INIS)

Bartram, T.C.; Hazell, P.A.

1977-01-01

Method and equipment for transferring energy to or from a direct-current superconducting field coil to change the magnetic field generated by the coil in which a second direct-current superconducting coil is used as a storage coil, and energy transfer between the field coil and the storage coil is effected automatically in dependence upon a control program. Preferably, the control program acts upon a variable transformer which is coupled by respective rectifier/inverters to the field and storage coils and also serves for intital supply of energy to the coils

Plasma behaviors in the open field region of reversed-field theta-pinch

International Nuclear Information System (INIS)

Aso, Yoshiyuki; Hirano, Keiichi.

1983-03-01

A characteristic behavior of the plasma in an open field region of reversed field theta pinch has been studied with the guide field (GF) which extends the field line along the axial direction. The experimental result suggests that the rotaional instability may be induced in FRC after the plasma touches the wall at the ends of the open field. (author)

Visual field

Science.gov (United States)

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

78 FR 54487 - Abbott Laboratories; Diagnostic-Hematology; Including On-Site Leased Workers From Manpower...

Science.gov (United States)

2013-09-04

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-82,379] Abbott Laboratories... February 22, 2013, applicable to workers of Abbott Laboratories, Diagnostic--Hematology division, including... Clara, California location of Abbott Laboratories, Diagnostic--Hematology Division. The Department has...

NSA Profs. Barma and Piombo Publish Jointly in International Peacekeeping

OpenAIRE

2016-01-01

National Security Affairs (NSA) News Two NSA faculty, Profs. Naazneen Barma and Jessica Piombo have authored an article with Naomi Levy of Santa Clara University, titled “Disentangling Aid Dynamics in Statebuilding and Peacebuildin: A Causal Framework.”

Detection of electric field around field-reversed configuration plasma

International Nuclear Information System (INIS)

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

2010-01-01

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

Magnetic response to applied electrostatic field in external magnetic field

Energy Technology Data Exchange (ETDEWEB)

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

2014-04-15

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

Finite discrete field theory

International Nuclear Information System (INIS)

Souza, Manoelito M. de

1997-01-01

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

The role of magnetic-field-aligned electric fields in auroral acceleration

International Nuclear Information System (INIS)

Block, L.P.; Faelthammar, C.G.

1990-01-01

Electric field measurements on the Swedish satellite Viking have confirmed and extended earlier observations on S3-3 and provided further evidence of the role of dc electric fields in auroral acceleration processes. On auroral magnetic field lines the electric field is strongly fluctuating both transverse and parallel to the magnetic field. The significance of these fluctuations for the auroral acceleration process is discussed. A definition of dc electric fields is given in terms of their effects on charged particles. Fluctuations below several hertz are experienced as dc by typical auroral electrons if the acceleration length is a few thousand kilometers. For ions the same is true below about 0.1 Hz. The magnetic-field-aligned (as well as the transverse) component of the electric field fluctuations has a maximum below 1 Hz, in a frequency range that appears as dc to the electrons but not to the ions. This allows it to cause a selective acceleration, which may be important in explaining some of the observed characteristics of auroral particle distributions. The electric field observations on Viking support the conclusion that magnetic-field-aligned potential drops play an important role in auroral acceleration, in good agreement with particle observations boht on Viking and on the DE satellites. They also show that a large part, or even all, of the accelerating potential drop may be accounted for by numerous weak (about a volt) electric double layers, in agreement with earlier observations on the S3-3 satellite and with an early theoretical suggestion by L. Block

Blockspin transformations for finite temperature field theories with gauge fields

International Nuclear Information System (INIS)

Kerres, U.

1996-08-01

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

Gravitation and vacuum field

International Nuclear Information System (INIS)

Tevikyan, R.V.

1986-01-01

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

Subcutaneous to visceral fat ratio: a possible risk factor for metabolic syndrome and cardiovascular diseases

Directory of Open Access Journals (Sweden)

Shafqat MN

2018-04-01

Full Text Available Muhammad Nabeel Shafqat,1 Miqdad Haider,2 1Department of Medicine, University of Medical Sciences “Serafin Ruiz de Zarate” Villa Clara (UCMVC, Villa Clara, Cuba; 2Department of Internal Medicine, Fatima Memorial Hospital, Fatima Memorial College of Medicine and Dentistry, Lahore, PakistanWe would like to comment, with great interest, about the recently published article “Visceral-to-subcutaneous fat ratio as a predictor of the multiple metabolic risk factors for subjects with normal waist circumference in Korea” by Oh et al,1 which we found very interesting and valuable. This study is a good step to determine the predictive value of visceral-to-subcutaneous fat ratio (VSR in persons with normal waist circumference for the diagnosis of risk factors for metabolic syndrome.View the original paper by Oh and colleagues.

Echoes from the Field: An Ethnographic Investigation of Outdoor Science Field Trips

Science.gov (United States)

Boxerman, Jonathan Zvi

As popular as field trips are, one might think they have been well-studied. Nonetheless, field trips have not been heavily studied, and little research has mapped what actually transpires during field trips. Accordingly, to address this research gap, I asked two related research questions. The first question is a descriptive one: What happens on field trips? The second question is explanatory: What field trip events are memorable and why? I employed design research and ethnographic methodologies to study learning in naturally occurring contexts. I collaborated with middle-school science teachers to design and implement more than a dozen field trips. The field trips were nested in particular biology and earth sciences focal units. Students were tasked with making scientific observations in the field and then analyzing this data during classroom activities. Audio and video recording devices captured what happened during the field trips, classroom activities and discussions, and the interviews. I conducted comparative microanalysis of videotaped interactions. I observed dozens of events during the field trips that reverberated across time and place. I characterize the features of these events and the objects that drew interest. Then, I trace the residue across contexts. This study suggests that field trips could be more than one-off experiences and have the potential to be resources to seed and enrich learning and to augment interest in the practice of science.

Omnigenous magnetic fields

International Nuclear Information System (INIS)

Stupakov, G.V.

1982-01-01

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

Penetration of the renewable sources of energy in Mexico: group of approach to determine the exogenous parameters of the LEAP simulation model (Annexe 10 in 'A vision of year 2030 on the use of the renewable energies in Mexico'); Penetracion de las fuentes renovables de energia en Mexico: grupo de enfoque para determinar los parametros exogenos del modelo de simulacion LEAP (Anexo 10 en 'Una vision al 2030 de la utilizacion de las energias renovables en Mexico')

Energy Technology Data Exchange (ETDEWEB)

Pernudi, Montserrat; Alonso C, Antonio [Analitica Consultores S.A. de C.V., Mexico D.F. (Mexico)

2005-08-15

The LEAP simulation model requires the values of some exogenous variables: At international level, the population increase, the economic growth and the international oil prices; at domestic level, the population increase, the economic growth, the energy intensity, the elasticity of demand of energy-price, and the elasticity of energy demand-gross national product. The use of the LEAP model for the estimation of the penetration of the renewable energies in Mexico comprises of the requirements established in the study. To estimate the future long term values of variables as the exogenous ones required by this model by means of expert opinion can be, given the nature of same, equally or more complicated and speculative than to directly consider the future rates of penetration of the renewable energies. In order to reflect on the future values of these variables a group of approach with experts was integrated. [Spanish] El modelo de simulacion LEAP requiere los valores de algunas variables exogenas: A nivel internacional, el crecimiento demografico, el crecimiento economico y los precios internacionales del petroleo; a nivel nacional, el crecimiento demografico, el crecimiento economico, la intensidad energetica, la elasticidad de demanda de energia-precio, y la elasticidad de demanda de energia-producto interno bruto. El uso del modelo LEAP para la estimacion de la penetracion de las energias renovables en Mexico forma parte de los requerimientos establecidos en el estudio. Estimar los futuros valores a largo plazo de variables como las exogenas requeridas por dicho modelo mediante opinion experta puede resultar, dada la naturaleza de las mismas, tan o mas complicado y especulativo que estimar las futuras tasas de penetracion de las energias renovables directamente. Para reflexionar sobre los futuros valores de dichas variables se integro un grupo de enfoque con expertos.

Random Fields

Science.gov (United States)

Vanmarcke, Erik

1983-03-01

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

Crescere errando: minori immigrati non accompagnati" (Clara Silva - Giovanna Campani

Directory of Open Access Journals (Sweden)

Olivia Salimbeni

2005-12-01

Full Text Available La presenza in Italia di minori immigrati non accompagnati è un fenomeno recente e tuttavia in forte crescita. Questo testo raccoglie i risultati di quella che potremmo definire la seconda di tre tappe di una ricerca europea incentrata sullo studio del fenomeno dei minori immigrati non accompagnati, avviata nel 2000 e da poco terminata. L’indagine è stata svolta nel quadro di finanziamento del 'Programma Daphne' della Commissione Europea e ha riguardato nelle prime due fasi tre realtà europee, Italia, Germania e Finlandia e nella terza altre realtà quali il Portogallo, la Spagna, la Francia e la Grecia.

Em torno da luz cristalina: clara voz de Pedro Salinas

Directory of Open Access Journals (Sweden)

Cristiano Moreira

2015-06-01

Full Text Available http://dx.doi.org/10.5007/2176-8552.2016n20p147 O texto que segue pretende ler a poesia de Pedro Salinas e Jorge Guillén diante de uma perspectiva que faz da voz uma iluminação e uma resistência diante do tempo histórico e da predominância de uma leitura simples das imagens. Assim, alguns poemas escolhidos permitem uma leitura contemporânea a respeito da voz, seguindo o conceito de Stimmung recuperado por Giorgio Agamben e as lições de poesia de Paul Valéry, e formam aspectos imprescindíveis para ler a poesia destes poetas. Ao manter em sua produção uma conversação com seus predecessores, Pedro Salinas joga com o logos e faz da phoné matéria prima para sua obra.

Santa Clara de Nanay: the MAL-ED cohort in Peru.

Science.gov (United States)

Yori, Pablo Peñataro; Lee, Gwenyth; Olórtegui, Maribel Paredes; Chávez, César Banda; Flores, Julian Torres; Vasquez, Angel Orbe; Burga, Rosa; Pinedo, Silvia Rengifo; Asayag, César Ramal; Black, Robert E; Caulfield, Laura E; Kosek, Margaret

2014-11-01

The Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development (MAL-ED) cohort study communities in Peru are located in Loreto province, in a rural area 15 km from the city of Iquitos. This riverine population of approximately 5000 individuals is fairly representative of Loreto. The province lags behind the rest of the country in access to water and sanitation, per capita income, and key health indicators including infant mortality (43.0 vs 16.0 per 1000 nationwide) and under-5 mortality (60.6 vs 21.0 per 1000). Total fertility rates are higher than elsewhere in the country (4.3 vs 2.6). Nationwide, the prevalence of human immunodeficiency virus is estimated at 0.45%, the prevalence of tuberculosis is 117 per 100 000, and the incidence of malaria is 258 per 100 000. Stunting in this community is high, whereas acute undernutrition is relatively uncommon. The population suffers from high rates of diarrheal disease. Prevalent enteric pathogens include Ascaris, Giardia, enterotoxigenic Escherichia coli, Shigella, and Campylobacter. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

ANÁLISIS DE INCERTIDUMBRE DE UN MODELO PARA LECHUGAS (Lactuca sativa L. CULTIVADAS EN INVERNADERO

Directory of Open Access Journals (Sweden)

Irineo Lorenzo López-Cruz

2013-01-01

Full Text Available Un análisis de incertidumbre para un modelo de crecimiento de un cultivo permite evaluar la variabilidad en sus parámetros y deducir una distribución de incertidumbre para cada variable que el modelo predice. Estos estudios se han practicado raramente en modelos para cultivos bajo invernadero. En el presente trabajo se presenta una metodología para llevar a cabo un análisis de incertidumbre para un modelo de un cultivo bajo invernadero y se aplica para determinar la variabilidad de los parámetros del modelo NICOLET desarrollado para explicar el crecimiento de lechugas (Lactuca sativa L.. Se definieron funciones de densidad de probabilidad para todos los parámetros del modelo y se asignaron sus valores mediante muestreo Monte Carlo, aleatorio e hipercubo latino, mediante un total de N = 2000 muestras. Posteriormente se ejecutaron 2000 simulaciones para calcular las salidas del modelo NICOLET para cada escenario. Finalmente, se analizó la distribución de las variables carbono en las vacuolas, carbono en la estructura, peso seco total y contenido de nitratos, mediante el cálculo de sus histogramas y medidas estadísticas. Las simulaciones se realizaron con el programa para análisis de incertidumbre y sensibilidad Simlab, disponible para el ambiente de programación Matlab. La variable carbono en las vacuolas presentó la mayor incertidumbre ya que su coeficiente de variación (CV en ambos muestreos, aleatorio e hipercubo latino, fue de 35.27 y 35.67 %, respectivamente, seguida del contenido de nitratos (CV = 18.16 % y CV = 19.07 %, el carbono estructural (CV = 5.52 % y CV = 5.67 % y el peso seco total (CV = 4.80 % y CV = 4.82 %.

Electric field confinement effect on charge transport in organic field-effect transistors

NARCIS (Netherlands)

Li, X.; Kadashchuk, A.; Fishchuk, I.I.; Smaal, W.T.T.; Gelinck, G.H.; Broer, D.J.; Genoe, J.; Heremans, P.; Bässler, H.

2012-01-01

While it is known that the charge-carrier mobility in organic semiconductors is only weakly dependent on the electric field at low fields, the experimental mobility in organic field-effect transistors using silylethynyl-substituted pentacene is found to be surprisingly field dependent at low

Swimming pool attendance and respiratory symptoms and allergies among Dutch children

NARCIS (Netherlands)

Jacobs, J.H.; Fuertes, E.; Krop, E.J.M.; Spithoven, J.; Tromp, P.; Heederik, D.J.J.

2012-01-01

OBJECTIVES To describe associations among swimming, respiratory health, allergen sensitisation and Clara cell protein 16 (CC16) levels in Dutch schoolchildren. Trichloramine levels in swimming pool air were determined to assess potential exposure levels. METHODS Respiratory health and pool

Electric field with bipolar structure during magnetic reconnection without a guide field

Science.gov (United States)

Guo, Jun

2014-05-01

We present a study on the polarized electric field during the collisionless magnetic reconnection of antiparallel fields using two dimensional particle-in-cell simulations. The simulations demonstrate clearly that electron holes and electric field with bipolar structure are produced during magnetic reconnection without a guide field. The electric field with bipolar structure can be found near the X-line and on the separatrix and the plasma sheet boundary layer, which is consistent with the observations. These structures will elongate electron's time staying in the diffusion region. In addition, the electric fields with tripolar structures are also found in our simulation.

Merging of magnetic fields with field-aligned plasma flow components

International Nuclear Information System (INIS)

Mitchell, H.G. Jr.; Kan, J.R.

1978-01-01

The Sonnerup merging model for an incompressible plasma is extended to allow a flow component along the field lines in the inflow regions. Solutions are found to exist as long as the difference between the quantities B. V for the two inflow regions does not exceed a critical magnitude dependent on the inflow field magnitudes and plasma densities. All such solutions satisfy Vasyliunas' definition of merging, but some classes of solution have radically altered geometries, i.e. geometries in which the inflow regions are much smaller than the outflow regions. The necessary but not sufficient condition for these unusual geometries is that the field-aligned flow component in at least one inflow region be super-Alfvenic. A solution for the case of a vacuum field in one inflow region is obtained in which any flow velocity is allowed in the non-vacuum inflow region, although super-Alfvenic flow can still result in an unusual geometry. For symmetric configurations, the usual geometry, that of Petschek and Sonnerup, is retained as long as both field-aligned flow components in the inflow regions are less than twice the inflow Alfven speed. For the case of a vacuum field on one side and fields approximating the boundary between the solar wind and the earth's dayside magnetosphere, the usual geometry is retained for flow less than about 2.5 times the local Alfven speed. (author)

Overlay control methodology comparison: field-by-field and high-order methods

Science.gov (United States)

Huang, Chun-Yen; Chiu, Chui-Fu; Wu, Wen-Bin; Shih, Chiang-Lin; Huang, Chin-Chou Kevin; Huang, Healthy; Choi, DongSub; Pierson, Bill; Robinson, John C.

2012-03-01

Overlay control in advanced integrated circuit (IC) manufacturing is becoming one of the leading lithographic challenges in the 3x and 2x nm process nodes. Production overlay control can no longer meet the stringent emerging requirements based on linear composite wafer and field models with sampling of 10 to 20 fields and 4 to 5 sites per field, which was the industry standard for many years. Methods that have emerged include overlay metrology in many or all fields, including the high order field model method called high order control (HOC), and field by field control (FxFc) methods also called correction per exposure. The HOC and FxFc methods were initially introduced as relatively infrequent scanner qualification activities meant to supplement linear production schemes. More recently, however, it is clear that production control is also requiring intense sampling, similar high order and FxFc methods. The added control benefits of high order and FxFc overlay methods need to be balanced with the increased metrology requirements, however, without putting material at risk. Of critical importance is the proper control of edge fields, which requires intensive sampling in order to minimize signatures. In this study we compare various methods of overlay control including the performance levels that can be achieved.

Conformal invariant quantum field theory and composite field operators

International Nuclear Information System (INIS)

Kurak, V.

1976-01-01

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

Channel-closing effects in strong-field ionization by a bicircular field

Science.gov (United States)

Milošević, D. B.; Becker, W.

2018-03-01

Channel-closing effects, such as threshold anomalies and resonantlike intensity-dependent enhancements in strong-field ionization by a bicircular laser field are analyzed. A bicircular field consists of two coplanar corotating or counter-rotating circularly polarized fields having different frequencies. For the total detachment rate of a negative ion by a bicircular field we observe threshold anomalies and explain them using the Wigner threshold law and energy and angular momentum conservation. For the corotating bicircular case, these effects are negligible, while for the counter-rotating case they are pronounced and their position depends on the magnetic quantum number of the initial state. For high-order above-threshold ionization of rare-gas atoms by a counter-rotating bicircular laser field we observe very pronounced intensity-dependent enhancements. We find all four types of threshold anomalies known from collision theory. Contrary to the case of linear polarization, channel-closing effects for a bicircular field are visible also in the cutoff region of the electron energy spectrum, which is explained using quantum-orbit theory.

The Coriolis field

Science.gov (United States)

Costa, L. Filipe; Natário, José

2016-05-01

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

Field-aligned currents during northward interplanetary magnetic field: Morphology and causes

DEFF Research Database (Denmark)

Vennerstrøm, Susanne; Moretto, T.; Rastatter, L.

2005-01-01

[1] We present the results of a global MHD simulation of solar wind magnetosphere interaction during northward IMF. In particular, we emphasize the effect of the IMF By component on the reconnection geometry and the mapping along field lines to the polar ionosphere, through field-aligned currents....... We find that the existence and geometry of the polar cap is closely connected to the IMF By component. During strictly northward IMF the simulated magnetosphere can remain essentially closed because the solar wind field lines reconnect in both hemispheres, thereby creating newly reconnected closed...... both on open and closed field lines and are created by the shear of the newly reconnected field lines against the mantle field as they are convected tailward by the solar wind. When the IMF rotates from northward toward east, the magnetospheric mapping regions of the NBZ currents likewise rotates...

Macroscopic electrical field distribution and field-induced surface stresses of needle-shaped field emitters

Energy Technology Data Exchange (ETDEWEB)

Moy, Charles K.S., E-mail: charles.moy@sydney.edu.au [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia); School of Civil Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Ranzi, Gianluca [ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia); School of Civil Engineering, The University of Sydney, Sydney, NSW 2006 (Australia); Petersen, Timothy C. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); Ringer, Simon P. [Australian Centre for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006 (Australia); ARC Centre of Excellence for Design in Light Metals, The University of Sydney, Sydney, NSW 2006 (Australia)

2011-05-15

One major concern since the development of the field ion microscope is the mechanical strength of the specimens. The macroscopic shape of the imaging tip greatly influences field-induced stresses and there is merit in further study of this phenomenon from a classical perspective. Understanding the geometrical, as opposed to localized electronic, factors that affect the stress might improve the quality and success rate of atom probe experiments. This study uses macroscopic electrostatic principles and finite element modelling to investigate field-induced stresses in relation to the shape of the tip. Three two-dimensional idealized models are considered, namely hyperbolic, parabolic and sphere-on-orthogonal-cone; the shapes of which are compared to experimental tips prepared by electro-polishing. Three dimensional morphologies of both a nano-porous and single-crystal aluminium tip are measured using electron tomography to quantitatively test the assumption of cylindrical symmetry for electro-polished tips. The porous tip was prepared and studied to demonstrate a fragile specimen for which such finite element studies could determine potential mechanical failure, prior to any exhaustive atom probe investigation. -- Research highlights: {yields} We use electrostatic principles and finite element to model field-induced stresses. {yields} We study two-dimensional idealized needle-shaped field emitters. {yields} Stress distribution of hyperbolic, parabolic and sphere-on-orthogonal-cone tips mapped. {yields} Electron tomography to obtain the morphology of three-dimensional aluminium tips. {yields} Studies of the morphology of the porous tip demonstrate a fragile specimen.

Field-In-Field Technique With Intrafractionally Modulated Junction Shifts for Craniospinal Irradiation

International Nuclear Information System (INIS)

Yom, Sue S.; Frija, Erik K. C.; Mahajan, Anita; Chang, Eric; Klein, Kelli C.; Shiu, Almon; Ohrt, Jared; Woo, Shiao

2007-01-01

Purpose: To plan craniospinal irradiation with 'field-in-field' (FIF) homogenization in combination with daily, intrafractional modulation of the field junctions, to minimize the possibility of spinal cord overdose. Methods and Materials: Lateral cranial fields and posterior spinal fields were planned using a forward-planned, step-and-shoot FIF technique. Field junctions were automatically modulated and custom-weighted for maximal homogeneity within each treatment fraction. Dose-volume histogram analyses and film dosimetry were used to assess results. Results: Plan inhomogeneity improved with FIF. Planning with daily modulated junction shifts provided consistent dose delivery during each fraction of treatment across the junctions. Modulation minimized the impact of a 5-mm setup error at the junction. Film dosimetry confirmed that no point in the junction exceeded the anticipated dose. Conclusions: Field-in-field planning and modulated junction shifts improve the homogeneity and consistency of daily dose delivery, simplify treatment, and reduce the impact of setup errors

Retrieving Storm Electric Fields from Aircrfaft Field Mill Data: Part II: Applications

Science.gov (United States)

Koshak, William; Mach, D. M.; Christian H. J.; Stewart, M. F.; Bateman M. G.

2006-01-01

The Lagrange multiplier theory developed in Part I of this study is applied to complete a relative calibration of a Citation aircraft that is instrumented with six field mill sensors. When side constraints related to average fields are used, the Lagrange multiplier method performs well in computer simulations. For mill measurement errors of 1 V m(sup -1) and a 5 V m(sup -1) error in the mean fair-weather field function, the 3D storm electric field is retrieved to within an error of about 12%. A side constraint that involves estimating the detailed structure of the fair-weather field was also tested using computer simulations. For mill measurement errors of 1 V m(sup -l), the method retrieves the 3D storm field to within an error of about 8% if the fair-weather field estimate is typically within 1 V m(sup -1) of the true fair-weather field. Using this type of side constraint and data from fair-weather field maneuvers taken on 29 June 2001, the Citation aircraft was calibrated. Absolute calibration was completed using the pitch down method developed in Part I, and conventional analyses. The resulting calibration matrices were then used to retrieve storm electric fields during a Citation flight on 2 June 2001. The storm field results are encouraging and agree favorably in many respects with results derived from earlier (iterative) techniques of calibration.

Manipulation of positron orbits in a dipole magnetic field with fluctuating electric fields

Science.gov (United States)

Saitoh, H.; Horn-Stanja, J.; Nißl, S.; Stenson, E. V.; Hergenhahn, U.; Pedersen, T. Sunn; Singer, M.; Dickmann, M.; Hugenschmidt, C.; Stoneking, M. R.; Danielson, J. R.; Surko, C. M.

2018-01-01

We report the manipulation of positron orbits in a toroidal dipole magnetic field configuration realized with electric fields generated by segmented electrodes. When the toroidal circulation motion of positrons in the dipole field is coupled with time-varying electric fields generated by azimuthally segmented outer electrodes, positrons undergo oscillations of their radial positions. This enables quick manipulation of the spatial profiles of positrons in a dipole field trap by choosing appropriate frequency, amplitude, phase, and gating time of the electric fields. According to numerical orbit analysis, we applied these electric fields to positrons injected from the NEPOMUC slow positron facility into a prototype dipole field trap experiment with a permanent magnet. Measurements with annihilation γ-rays clearly demonstrated the efficient compression effects of positrons into the strong magnetic field region of the dipole field configuration. This positron manipulation technique can be used as one of essential tools for future experiments on the formation of electron-positron plasmas.

MR equipment acquisition strategies: low-field or high-field scanners

International Nuclear Information System (INIS)

Marti-Bonmati, L.; Kormano, M.

1997-01-01

Magnetic resonance (MR) field strength is one of the key aspects to consider when purchasing MR equipment. Other aspects include the gradient system, coil design, computer and pulse sequence availability, purchase cost, local reimbursement policies, and current opinion within the medical community. Our objective here is to evaluate the decision-influencing aspects of the MR market, with a focus on some specific areas such as high resolution studies, examination times, special techniques, instrumentation, open design magnets, costs and reimbursement policies, academic and industrial interests, contrast media, clinical efficacy, and finally, clinicians' preferences. Certainly the advantage of high-field is a higher signal-to-noise ratio and improved resolution. With a high-field unit, higher spatial resolution images and higher temporal resolution images can be obtained. Typical imaging times needed to produce clinically diagnostic images are about 3 times longer at 0.1 T than at 1.0 or 1.5 T. High-field-related advanced techniques, such as functional imaging, spectroscopy and microscopy, may become clinically useful in the near future. As long as there is an unlimited demand for MR examinations, it appears financially profitable to run a high-field system, despite the associated higher costs. However, if demand for MR becomes saturated, low-field systems will cause less financial strain on the reimbursement organisation and service provider. Recent emphasis on cost containment, the development of interventional techniques, the increased use of MR for patients in intensive care and operating suites, the deployment of magnets in office suites, and the development of new magnet configurations, all favour the supplementary use of low-field systems. Hence, MR units of all field strengths have a role in radiology. (orig.)

Quantum noise in the mirror–field system: A field theoretic approach

International Nuclear Information System (INIS)

Hsiang, Jen-Tsung; Wu, Tai-Hung; Lee, Da-Shin; King, Sun-Kun; Wu, Chun-Hsien

2013-01-01

We revisit the quantum noise problem in the mirror–field system by a field-theoretic approach. Here a perfectly reflecting mirror is illuminated by a single-mode coherent state of the massless scalar field. The associated radiation pressure is described by a surface integral of the stress-tensor of the field. The read-out field is measured by a monopole detector, from which the effective distance between the detector and mirror can be obtained. In the slow-motion limit of the mirror, this field-theoretic approach allows to identify various sources of quantum noise that all in all leads to uncertainty of the read-out measurement. In addition to well-known sources from shot noise and radiation pressure fluctuations, a new source of noise is found from field fluctuations modified by the mirror’s displacement. Correlation between different sources of noise can be established in the read-out measurement as the consequence of interference between the incident field and the field reflected off the mirror. In the case of negative correlation, we found that the uncertainty can be lowered than the value predicted by the standard quantum limit. Since the particle-number approach is often used in quantum optics, we compared results obtained by both approaches and examine its validity. We also derive a Langevin equation that describes the stochastic dynamics of the mirror. The underlying fluctuation–dissipation relation is briefly mentioned. Finally we discuss the backreaction induced by the radiation pressure. It will alter the mean displacement of the mirror, but we argue this backreaction can be ignored for a slowly moving mirror. - Highlights: ► The quantum noise problem in the mirror–field system is re-visited by a field-theoretic approach. ► Other than the shot noise and radiation pressure noise, we show there are new sources of noise and correlation between them. ► The noise correlations can be used to suppress the overall quantum noise on the mirror. �

Quantum noise in the mirror-field system: A field theoretic approach

Energy Technology Data Exchange (ETDEWEB)

Hsiang, Jen-Tsung, E-mail: cosmology@gmail.com [Department of Physics, National Dong-Hwa University, Hua-lien, Taiwan, ROC (China); Wu, Tai-Hung [Department of Physics, National Dong-Hwa University, Hua-lien, Taiwan, ROC (China); Lee, Da-Shin, E-mail: dslee@mail.ndhu.edu.tw [Department of Physics, National Dong-Hwa University, Hua-lien, Taiwan, ROC (China); King, Sun-Kun [Institutes of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan, ROC (China); Wu, Chun-Hsien [Department of Physics, Soochow University, Taipei, Taiwan, ROC (China)

2013-02-15

We revisit the quantum noise problem in the mirror-field system by a field-theoretic approach. Here a perfectly reflecting mirror is illuminated by a single-mode coherent state of the massless scalar field. The associated radiation pressure is described by a surface integral of the stress-tensor of the field. The read-out field is measured by a monopole detector, from which the effective distance between the detector and mirror can be obtained. In the slow-motion limit of the mirror, this field-theoretic approach allows to identify various sources of quantum noise that all in all leads to uncertainty of the read-out measurement. In addition to well-known sources from shot noise and radiation pressure fluctuations, a new source of noise is found from field fluctuations modified by the mirror's displacement. Correlation between different sources of noise can be established in the read-out measurement as the consequence of interference between the incident field and the field reflected off the mirror. In the case of negative correlation, we found that the uncertainty can be lowered than the value predicted by the standard quantum limit. Since the particle-number approach is often used in quantum optics, we compared results obtained by both approaches and examine its validity. We also derive a Langevin equation that describes the stochastic dynamics of the mirror. The underlying fluctuation-dissipation relation is briefly mentioned. Finally we discuss the backreaction induced by the radiation pressure. It will alter the mean displacement of the mirror, but we argue this backreaction can be ignored for a slowly moving mirror. - Highlights: Black-Right-Pointing-Pointer The quantum noise problem in the mirror-field system is re-visited by a field-theoretic approach. Black-Right-Pointing-Pointer Other than the shot noise and radiation pressure noise, we show there are new sources of noise and correlation between them. Black-Right-Pointing-Pointer The noise

7 CFR 1412.47 - Planting flexibility.

Science.gov (United States)

2010-01-01

..., Imperial, Kern, Kings, Madera, Merced, Riverside, Sacramento, San Benito, San Joaquin, Santa Clara..., Henrico, Henry, Highland, Isle of Wight, James City, King and Queen, King George, King William, Lancaster..., persimmon, persian melon, pimentos, pineapple, pistachios, plantain, plumcots, plums, pomegranates, potatoes...

Mechanisms of Very Late Bioresorbable Scaffold Thrombosis : The INVEST Registry

NARCIS (Netherlands)

Yamaji, Kyohei; Ueki, Yasushi; Souteyrand, Geraud; Daemen, Joost; Wiebe, Jens; Nef, Holger; Adriaenssens, Tom; Loh, Joshua P; Lattuca, Benoit; Wykrzykowska, Joanna J.; Gomez-Lara, Josep; Timmers, Leo; Motreff, Pascal; Hoppmann, Petra; Abdel-Wahab, Mohamed; Byrne, Robert A.; Meincke, Felix; Boeder, Niklas; Honton, Benjamin; O'Sullivan, Crochan J; Ielasi, Alfonso; Delarche, Nicolas; Christ, Günter; Lee, Joe K T; Lee, Michael; Amabile, Nicolas; Karagiannis, Alexios; Windecker, Stephan; Räber, Lorenz

2017-01-01

BACKGROUND: Very late scaffold thrombosis (VLScT) occurs more frequently after bioresorbable scaffold (Absorb BVS 1.1, Abbott Vascular, Santa Clara, California) implantation than with metallic everolimus-eluting stents. OBJECTIVES: The purpose of this study was to elucidate mechanisms underlying

Comparación cariotípica de cinco especies de Lutzmoyia (Diptera: Culícidae, pertenecientes al grupo verrucarum y a la serie Townsendi, de Colombia

Directory of Open Access Journals (Sweden)

J. Escovar

2001-07-01

Full Text Available Identificar las características citogenéticas de cinco especies nativas de Lutzomyia, correspondientes al grupo Verrucarum y a la serie Townsendi, para efectos de una clara tipificación citotaxonómica de los insectos seleccionados.

Quantized Dirac field interacting with a classical Maxwell field

International Nuclear Information System (INIS)

Kolsrud, M.

1987-10-01

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

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

Directory of Open Access Journals (Sweden)

Diego Fernando Lemus Polania

2013-01-01

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

Experimentar con TIC y reflexionar sobre su uso a partir de las apreciaciones de los estudiantes

Directory of Open Access Journals (Sweden)

Giacosa, Norah

2012-12-01

Full Text Available Se presentan resultados de una investigación educativa centrada en las apreciaciones de un grupo de estudiantes universitarios que participaron de una propuesta pedagógica innovadora en la enseñanza del Electromagnetismo y la Óptica. Dicha propuesta integró experiencias en entornos virtuales para ser realizadas con simulaciones computacionales de acceso libre. Del análisis de las respuestas proporcionadas en las encuestas escritas, surge que los estudiantes valoran principalmente el poder comparar los resultados obtenidos analíticamente con los proporcionados por el simulador, comprender mejor los fenómenos y las leyes físicas y experimentar, de manera simulada, con equipamiento de difícil acceso

Efectos de la simulación en la comprensión de la ley de los grandes números

Directory of Open Access Journals (Sweden)

Gabriel Yáñez Canal

2013-01-01

Full Text Available En este trabajo se presentan algunos de los resultados obtenidos en una investigación que indagaba por los procesos de razonamiento probabilístico de doce estudiantes entre 12 y 15 años de un colegio público en un municipio en el departamento de Santander (Colombia, alrededor de la Ley de los Grandes Números. Después de vivir una experiencia directa, los estudiantes realizaron simulaciones utilizando Probability Explorer. Los resultados sugieren que para tomar conciencia de la variabilidad en el corto plazo y de la estabilidad a largo plazo de las frecuencias relativas deben realizarse actividades bidireccionales que involucren el espacio muestral y los resultados obtenidos.

TECNOLOGIA A FIBRA OPTICA: UNIVERSIDAD NACIONAL DE COLOMBIA SEDE MEDELLIN, "UN REFERENTE LATINOAMERICANO"

Directory of Open Access Journals (Sweden)

RODRIGO ACUÑA

2008-01-01

Full Text Available En este artículo se muestran algunos resultados de las investigaciones realizadas por el grupo de Fotónica y Opto-electrónica de la Universidad Nacional de Colombia, Sede Medellín. Se hace una breve reseña de la creación del grupo y se describen las principales aplicaciones desarrolladas, las cuales convierten al grupo en un referente Latinoamericano en el área. Se ilustran aplicaciones de las redes de Bragg en fibra óptica en sensores, simulaciones computacionales de guías de onda ópticas y la construcción de fuentes de luz láser a fibra óptica.

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

International Nuclear Information System (INIS)

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

1998-01-01

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

Covariant electromagnetic field lines

Science.gov (United States)

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

2017-08-01

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

Gauge theories of Yang-Mills vector fields coupled to antisymmetric tensor fields

International Nuclear Information System (INIS)

Anco, Stephen C.

2003-01-01

A non-Abelian class of massless/massive nonlinear gauge theories of Yang-Mills vector potentials coupled to Freedman-Townsend antisymmetric tensor potentials is constructed in four space-time dimensions. These theories involve an extended Freedman-Townsend-type coupling between the vector and tensor fields, and a Chern-Simons mass term with the addition of a Higgs-type coupling of the tensor fields to the vector fields in the massive case. Geometrical, field theoretic, and algebraic aspects of the theories are discussed in detail. In particular, the geometrical structure mixes and unifies features of Yang-Mills theory and Freedman-Townsend theory formulated in terms of Lie algebra valued curvatures and connections associated to the fields and nonlinear field strengths. The theories arise from a general determination of all possible geometrical nonlinear deformations of linear Abelian gauge theory for one-form fields and two-form fields with an Abelian Chern-Simons mass term in four dimensions. For this type of deformation (with typical assumptions on the allowed form considered for terms in the gauge symmetries and field equations), an explicit classification of deformation terms at first-order is obtained, and uniqueness of deformation terms at all higher orders is proven. This leads to a uniqueness result for the non-Abelian class of theories constructed here

Determination of the saturation magnetization, anisotropy field, mean field interaction, and switching field distribution for nanocrystalline hard magnets

International Nuclear Information System (INIS)

McCallum, R. William

2005-01-01

For a uniaxial nanocrystalline magnetic material, the determination of the saturation magnetization, M s , requires measurements of the magnetization at fields which exceed the anisotropy field. For a typical RE-Tm compound, where RE=rare earth and Tm=transition metal, this may require fields above 7 T if the approach to saturation law is used. However for an isotropic material composed of a random distribution of non-interacting uniaxial grains, both M s and the anisotropy filed, H a , may be determined by fitting the Stoner-Wohlfarth (SW) model (Philos. Trans. Roy. Soc. 240 (1948) 599) to the reversible part of the demagnetization curve in the first quadrant. Furthermore, using the mean field interaction model of Callen, Liu and Cullen [2], a quantitative measure of the interaction strength for interacting particles may be determined. In conjunction with an analytical fit to the first quadrant demagnetization curve of the SW model, this allows M s , H a and the mean field interaction constant of a nanocrystalline magnet to be determined from measurements below 5 T. Furthermore, comparison of the model solution for the reversible magnetization with experimental data in the 2nd and 3rd quadrants allows the accurate determination of the switching field distribution. In many cases the hysteresis loop may be accurately described by a normal distribution of switching fields

Extraction of the Electric Field in Field Plate Assisted RESURF Devices

NARCIS (Netherlands)

Boksteen, B.K.; Dhar, S.; Heringa, A.; Koops, G.E.J.; Hueting, Raymond Josephus Engelbart

2012-01-01

It has previously been reported that the lateral electric field (Ex) in the drain extension of thin SOI HV (700V) field plate assisted RESURF devices can be extracted from their ID-VD characteristics in the subthreshold regime. In this work the prerequisites for valid field extraction and the

Field emitters with low turn on electric field based on carbon fibers

International Nuclear Information System (INIS)

Wang Qilong; Mu Hui; Zhang Xiaobing; Lei Wei; Wang Jinchan; Zhao Hongping

2007-01-01

Field emitters of vertical carbon fibers on a silicon substrate are fabricated by catalytic chemical vapor deposition. After an ageing process of 150 min, field emission measurement of the fibers is carried out in a vacuum chamber with a base pressure of 5.0 x 10 -4 Pa. The experimental results display that field emission performance of the carbon fibers depends strongly on the vacuum level during the experiments. After the field emission measurement, damage to the carbon fiber field emitters is observed from the scanning electron microscopic images

Far field acceleration

International Nuclear Information System (INIS)

Fernow, R.C.

1995-07-01

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

Mosquitoes and other aquatic insects in fallow field biotopes and rice paddy fields.

Science.gov (United States)

Ohba, S Y; Matsuo, T; Takagi, M

2013-03-01

Fallow field biotopes that develop from abandoned rice fields are man-made wetlands that provide new habitats for various aquatic animals. Although consideration of such biotopes generally focuses on their positive aspects, this study evaluated the negative aspects of establishing fallow field biotopes with regard to mosquito breeding sites. To determine whether fallow field biotopes become breeding habitats for vector mosquitoes, we evaluated mosquito fauna in fallow field biotopes and adjacent rice fields. We found larvae of Anopheles lesteri, Anopheles sinensis and Culex tritaeniorhynchus (all: Diptera: Culicidae) in the biotopes. Although abundances of mosquito larvae in the biotopes and rice fields were statistically similar, mosquito abundances in rice fields increased dramatically in August when the water level reduced after the rainy season. The abundance and variety of the mosquitoes' natural predators were greater in biotopes than in rice fields because the former are a permanent and stable aquatic environment. A generalized linear mixed model showed a negative effect of predator diversity on mosquito larvae abundance in both habitats. Although fallow field biotopes become breeding habitats for vector mosquitoes, establishing biotopes from fallow fields in order to protect various aquatic animals, including mosquito insect predators, may help to control mosquito breeding. © 2012 The Royal Entomological Society.

Low-field MRI can be more sensitive than high-field MRI

Science.gov (United States)

Coffey, Aaron M.; Truong, Milton L.; Chekmenev, Eduard Y.

2013-12-01

MRI signal-to-noise ratio (SNR) is the key factor for image quality. Conventionally, SNR is proportional to nuclear spin polarization, which scales linearly with magnetic field strength. Yet ever-stronger magnets present numerous technical and financial limitations. Low-field MRI can mitigate these constraints with equivalent SNR from non-equilibrium ‘hyperpolarization' schemes, which increase polarization by orders of magnitude independently of the magnetic field. Here, theory and experimental validation demonstrate that combination of field independent polarization (e.g. hyperpolarization) with frequency optimized MRI detection coils (i.e. multi-turn coils using the maximum allowed conductor length) results in low-field MRI sensitivity approaching and even rivaling that of high-field MRI. Four read-out frequencies were tested using samples with identical numbers of 1H and 13C spins. Experimental SNRs at 0.0475 T were ∼40% of those obtained at 4.7 T. Conservatively, theoretical SNRs at 0.0475 T 1.13-fold higher than those at 4.7 T were possible despite an ∼100-fold lower detection frequency, indicating feasibility of high-sensitivity MRI without technically challenging, expensive high-field magnets. The data at 4.7 T and 0.0475 T was obtained from different spectrometers with different RF probes. The SNR comparison between the two field strengths accounted for many differences in parameters such as system noise figures and variations in the probe detection coils including Q factors and coil diameters.

Near-field and far-field modeling of scattered surface waves. Application to the apertureless scanning near-field optical microscopy

International Nuclear Information System (INIS)

Muller, J.; Parent, G.; Fumeron, S.; Jeandel, G.; Lacroix, D.

2011-01-01

The detection of surface waves through scanning near-field optical microscopy (SNOM) is a promising technique for thermal measurements at very small scales. Recent studies have shown that electromagnetic waves, in the vicinity of a scattering structure such as an atomic force microscopy (AFM) tip, can be scattered from near to far-field and thus detected. In the present work, a model based on the finite difference time domain (FDTD) method and the near-field to far-field (NFTFF) transformation for electromagnetic waves propagation is presented. This model has been validated by studying the electromagnetic field of a dipole in vacuum and close to a dielectric substrate. Then simulations for a tetrahedral tip close to an interface are presented and discussed.

Electron-Cloud Wake Fields

CERN Document Server

Rumolo, Giovanni

2002-01-01

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

Perfil sensorial da bebida café (Coffea arabica L. determinado por análise tempo-intensidade Sensorial profile of beverage coffee (Coffea arabica L. determined by analysis time-intensity

Directory of Open Access Journals (Sweden)

Marlene A. M. Monteiro

2005-12-01

Full Text Available O presente trabalho teve como objetivo avaliar o gosto amargo, sabor fermentado e sabor queimado de nove amostras (mole/clara, dura/clara, rio/clara, mole/expresso, dura/expresso, rio/expresso, mole/escura, dura/escura e rio/escura da bebida café (Coffea arabica L. por meio da análise Tempo-Intensidade (TI. Foram avaliados seis parâmetros da curva: tempo para atingir a intensidade máxima (TImáx, intensidade máxima do estímulo (Imáx, tempo correspondente ao ponto onde a intensidade máxima começa a declinar (Td, tempo de duração da intensidade máxima (Platô, área sob a curva (Área e tempo total de duração do estímulo (Ttot. A análise demonstrou que as amostras de torra escura tiveram maior intensidade máxima (Imáx e tempo de duração do estímulo (Ttot para gosto amargo e sabor queimado, sendo que as amostras de torra clara apresentaram menor intensidade destes estímulos. Em relação ao sabor fermentado, a amostra rio/expresso foi a que apresentou maior intensidade.The present work had as objective to evaluate the bitter taste, fermented flavor and burned flavor of nine samples (soft/light, hard/light, rio/light, soft/express, hard/express, rio/express, soft/dark, hard/dark and rio/dark of the drink coffee (Coffea arabica L. through the analysis Time-Intensity (TI. Six parameters of the curve were evaluated: time to reach the maximum intensity (TImáx, maximum intensity of the incentive (Imáx, time corresponding to the point where the maximum intensity begins to refuse (Td, time of duration of the maximum intensity (Plateau, area under the curve (Área and total time of duration of the incentive (Ttot. The analysis demonstrated that the samples of dark toast had larger maximum intensity (Imáx and time of duration of the incentive (Ttot for bitter taste and burned flavor, while the samples of light toast presented smaller intensity of these stimulus. For the fermented flavor, the sample rio/express was the one that

Forces in electromagnetic field and gravitational field

OpenAIRE

Weng, Zihua

2008-01-01

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

Magnetic Field Effects on the Plume of a Diverging Cusped-Field Thruster

KAUST Repository

Matlock, Taylor

2010-07-25

The Diverging Cusped-Field Thruster (DCFT) uses three permanent ring magnets of alternating polarity to create a unique magnetic topology intended to reduce plasma losses to the discharge chamber surfaces. The magnetic field strength within the DCFT discharge chamber (up to 4 kG on axis) is much higher than in thrusters of similar geometry, which is believed to be a driving factor in the high measured anode efficiencies. The field strength in the near plume region is large as well, which may bear on the high beam divergences measured, with peaks in ion current found at angles of around 30-35 from the thruster axis. Characterization of the DCFT has heretofore involved only one magnetic topology. It is then the purpose of this study to investigate changes to the near-field plume caused by altering the shape and strength of the magnetic field. A thick magnetic collar, encircling the thruster body, is used to lower the field strength outside of the discharge chamber and thus lessen any effects caused by the external field. Changes in the thruster plume with field topology are monitored by the use of normal Langmuir and emissive probes interrogating the near-field plasma. Results are related to other observations that suggest a unified conceptual framework for the important near-exit region of the thruster.

Narrowing the field

DEFF Research Database (Denmark)

Knudsen, Bo Nissen

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

Out-of-Field Cell Survival Following Exposure to Intensity-Modulated Radiation Fields

International Nuclear Information System (INIS)

Butterworth, Karl T.; McGarry, Conor K.; Trainor, Colman; O'Sullivan, Joe M.; Hounsell, Alan R.; Prise, Kevin M.

2011-01-01

Purpose: To determine the in-field and out-of-field cell survival of cells irradiated with either primary field or scattered radiation in the presence and absence of intercellular communication. Methods and Materials: Cell survival was determined by clonogenic assay in human prostate cancer (DU145) and primary fibroblast (AGO1552) cells following exposure to different field configurations delivered using a 6-MV photon beam produced with a Varian linear accelerator. Results: Nonuniform dose distributions were delivered using a multileaf collimator (MLC) in which half of the cell population was shielded. Clonogenic survival in the shielded region was significantly lower than that predicted from the linear quadratic model. In both cell lines, the out-of-field responses appeared to saturate at 40%-50% survival at a scattered dose of 0.70 Gy in DU-145 cells and 0.24 Gy in AGO1522 cells. There was an approximately eightfold difference in the initial slopes of the out-of-field response compared with the α-component of the uniform field response. In contrast, cells in the exposed part of the field showed increased survival. These observations were abrogated by direct physical inhibition of cellular communication and by the addition of the inducible nitric oxide synthase inhibitor aminoguanidine known to inhibit intercellular bystander effects. Additional studies showed the proportion of cells irradiated and dose delivered to the shielded and exposed regions of the field to impact on response. Conclusions: These data demonstrate out-of-field effects as important determinants of cell survival following exposure to modulated irradiation fields with cellular communication between differentially irradiated cell populations playing an important role. Validation of these observations in additional cell models may facilitate the refinement of existing radiobiological models and the observations considered important determinants of cell survival.

Dynamical Mean Field Approximation Applied to Quantum Field Theory

CERN Document Server

Akerlund, Oscar; Georges, Antoine; Werner, Philipp

2013-12-04

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

Background field coils for the High Field Test Facility

International Nuclear Information System (INIS)

Zbasnik, J.P.; Cornish, D.N.; Scanlan, R.M.; Jewell, A.M.; Leber, R.L.; Rosdahl, A.R.; Chaplin, M.R.

1980-01-01

The High Field Test Facility (HFTF), presently under construction at LLNL, is a set of superconducting coils that will be used to test 1-m-o.d. coils of prototype conductors for fusion magnets in fields up to 12 T. The facility consists of two concentric sets of coils; the outer set is a stack of Nb-Ti solenoids, and the inner set is a pair of solenoids made of cryogenically-stabilized, multifilamentary Nb 3 Sn superconductor, developed for use in mirror-fusion magnets. The HFTF system is designed to be parted along the midplane to allow high-field conductors, under development for Tokamak fusion machines, to be inserted and tested. The background field coils were wound pancake-fashion, with cold-welded joints at both the inner and outer diameters. Turn-to-turn insulation was fabricated at LLNL from epoxy-fiberglass strip. The coils were assembled and tested in our 2-m-diam cryostat to verify their operation

Nonperturbative construction of massive Yang-Mills fields without the Higgs field

Science.gov (United States)

Kondo, Kei-Ichi

2013-01-01

In order to understand the so-called decoupling solution for gluon and ghost propagators in QCD, we give a nonperturbative construction of a massive vector field describing a non-Abelian massive spin-one particle, which has the correct physical degrees of freedom and is invariant under a modified Becchi-Rouet-Stora-Tyutin transformation, in a massive Yang-Mills model without the Higgs field, i.e., the Curci-Ferrari model. The resulting non-Abelian massive vector boson field is written by using a nonlinear but local transformation from the original fields in the Curci-Ferrari model. As an application, we write down a local mass term for the Yang-Mills field and a dimension-two condensate, which are exactly invariant under the modified Becchi-Rouet-Stora-Tyutin transformation, Lorentz transformation, and color rotation.

Polarimetry of random fields

Science.gov (United States)

Ellis, Jeremy

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

76 FR 19788 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Telemanagement Forum

Science.gov (United States)

2011-04-08

... notifications were filed for the purpose of extending the Act's provisions limiting the recovery of antitrust...-LLC, Dubai, UNITED ARAB EMIRATES; Ciminko, Luxembourg, LUXEMBOURG; Cloud Scope Technologies, Inc... computing and networking services, Amsterdam, NETHERLANDS; Savvion, Santa Clara, CA; Site of Knowledge Group...

77 FR 45373 - Certain Semiconductor Chips and Products Containing Same; Termination of the Investigation With a...

Science.gov (United States)

2012-07-31

... Corporation of Milpitas, California (``LSI''); Mediatek Inc. of Hsin-Chu, Taiwan (``Mediatek''); NVIDIA Corp. of Santa Clara, California (``NVIDIA''); STMicroelectronics N.V. of Geneva, Switzerland; and... respondents on the basis of Rambus's settlements with Broadcom, Freescale, MediaTek, and NVIDIA. LSI and...

Differential gene expression in anterior pituitary glands from anestrous and cycling postpartum beef cows

Science.gov (United States)

Oligionucleotide microarrays (GeneChip Bovine Genome Arrays, Affymetrix Inc., Santa Clara, CA) were used to evaluate gene expression profiles in anterior pituitary glands collected from 4 anestrous and 4 cycling postpartum primiparous beef cows to provide insight into genes associated with transitio...

Induction of cell cycle arrest and apoptosis by Ormenis eriolepis a ...

African Journals Online (AJOL)

Induction of cell cycle arrest and apoptosis by Ormenis eriolepis a Morrocan endemic plant in various human cancer cell lines. Lamiae Belayachi, Clara Aceves-Luquero, Nawel Merghoub, Silvia Fernández de Mattos, Saaïd Amzazi, Priam Villalonga, Youssef Bakri ...

Stochastic Discount Factor Approach to International Risk-Sharing:A Robustness Check of the Bilateral Setting

NARCIS (Netherlands)

Hadzi-Vaskov, M.; Kool, C.J.M.

2007-01-01

This paper presents a robustness check of the stochastic discount factor approach to international (bilateral) risk-sharing given in Brandt, Cochrane, and Santa-Clara (2006). We demonstrate two main inherent limitations of the bilateral SDF approach to international risk-sharing. First, the discount

Normobaric Hypoxia Induces Mild Damage to Epithelium of Terminal Bronchioles in Rabbits (Ultrastructural Study)

Czech Academy of Sciences Publication Activity Database

Uhlík, J.; Konrádová, V.; Vajner, L.; Adášková, Jana

2005-01-01

Roč. 50, č. 10 (2005), s. 432-438 ISSN 0375-8427 Source of funding: V - iné verejné zdroje Keywords : airways * Clara cells * ciliated cells * electron microscopy Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.621, year: 2005

Inequality and Development Challenges | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

2013-08-30

Inequality and Development Challenges. Couverture du livre Inequality and Development Challenges. Editor(s):. Maria Clara Couto Soares, Mario Scerri et Rasigan Maharajh. Publisher(s):. Routledge, CRDI. August 30, 2013. ISBN: 9780415710329. 372 pages. e-ISBN: 9781552505571. Download PDF · Read the e-book.

A source representation of microseisms constrained by HV spectral ratio observations

Science.gov (United States)

Dreger, D.; Rhie, J.

2006-12-01

The microseisms are generated by pressure variation on the sea floor caused by incident and reflected ocean waves, and dominant background noises at short periods. The observations of microseism wave fields in deep sedimentary basins (e.g., Santa Clara Valley) show that the maximum period of the horizontal to vertical (H/V) spectral ratio correlates with basin thickness. A similar correlation has been found in teleseismic arrival times and P-wave amplitude as well as local-earthquake S-wave relative amplification [Dolenc et al., 2005]. This observation infers that a study of microseism wave field, combined with other seismic data sets, can probably be used to invert for the velocity structures of the deep basins. To make this inversion possible, it is necessary to understand the excitation and propagation characteristics of microseisms. We will perform forward computations of microseism wave fields for source representations such as CLVDs and single-forces with the USGS 3D velocity model. Various spatial extensions as well as the frequency content of the source will be tested to match observed shifts in dominant H/V spectral ratio. The optimal source representation of the microseisms will be the first step to accomplish inversions for 3D seismic velocity structure in sedimentary basins using microseisms.

Unified field theory

International Nuclear Information System (INIS)

Prasad, R.

1975-01-01

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

Pair-breaking effects by parallel magnetic field in electric-field-induced surface superconductivity

International Nuclear Information System (INIS)

Nabeta, Masahiro; Tanaka, Kenta K.; Onari, Seiichiro; Ichioka, Masanori

2016-01-01

Highlights: • Zeeman effect shifts superconducting gaps of sub-band system, towards pair-breaking. • Higher-level sub-bands become normal-state-like electronic states by magnetic fields. • Magnetic field dependence of zero-energy DOS reflects multi-gap superconductivity. - Abstract: We study paramagnetic pair-breaking in electric-field-induced surface superconductivity, when magnetic field is applied parallel to the surface. The calculation is performed by Bogoliubov-de Gennes theory with s-wave pairing, including the screening effect of electric fields by the induced carriers near the surface. Due to the Zeeman shift by applied fields, electronic states at higher-level sub-bands become normal-state-like. Therefore, the magnetic field dependence of Fermi-energy density of states reflects the multi-gap structure in the surface superconductivity.

Muonium spin exchange as a Poisson process: magnetic field dependence in transverse fields

International Nuclear Information System (INIS)

Senba, Masayoshi; British Columbia Univ., Vancouver, BC

1993-01-01

The muonium spin exchange has been investigated as a function of transverse magnetic field strength, where the Poisson nature of collisions is exploited to simplify the calculation. In intermediate fields where the so-called two-frequency muonium signal is observed, the muonium relaxation due to spin exchange is 1.5 times faster than in low fields. In even higher fields, the observed relaxation rate drops back to the low field value. Since the relaxation rate due to a chemical reaction is field independent, such a distinct field dependence in spin exchange can be used in distinguishing experimentally spin exchange from chemical reactions. The time evolution of the muon spin polarization in the presence of muonium spin exchange has been expressed in a simple analytical closed form. (author)

Evaluation of tomato varieties on P absorption and its use efficiency

International Nuclear Information System (INIS)

Alvarez Villanueva, Felipe Carlos; Cotrim Duete, Robson Rui; Muraoka, Takashi; Cotrim Duete, Washington Luiz; Abreu Junior, Cassio Hamilton

1999-01-01

The differences on the uptake of P from the soil and fertilizer (triple superphosphate) and on nutrient use by two commercial tomato (Lycopersicum esculentum Will) varieties, Santa Clara and Santa Cruz Kada, were evaluated by 32 P technique. The experiment was carried out in two Brazilian soils, Dark Red Latosol from Piracicaba, Sao Paulo and calcareous Yellow Latosol from Irec Bahia, using pots with 2.5 kg soil. The radioisotope was added to the soil as KH2PO4 solution, with 3.7 MBq/pot. The dry matter weight, plant P content, L and A values were utilized for comparing the tomato varieties. There was a clear response to P fertilization. The Santa Cruz variety had higher dry matter weight and lower concentration than Santa Clara variety, but there was no difference on the total P taken up, indicating that the Santa Cruz variety

8 de março: conquistas e controvérsias The 8th of March: Gains and Controversies

Directory of Open Access Journals (Sweden)

EVA ALTERMAN BLAY

2001-01-01

Full Text Available O Dia Internacional da Mulher foi proposto por Clara Zetkin em 1910 no II Congresso Internacional de Mulheres Socialistas. Nos anos posteriores a 1970 este Dia passou a ser associado a um incêndio que ocorreu em Nova Iorque em 1911. Neste artigo procuro recuperar a história do Dia 8 de Março e as distorções que têm sido feitas sobre ele e sobre a luta feminista.Clara Zetkin suggested the creation of the International Women's Day during the 2nd Socialist Women's International Conference in 1910. After 1970 this date became increasingly associated with a fire that took place in New York City in 1911. In this paper I review the history of the 8th of March, pointing out some of the distortions of its meanings and the repercussions these distortions have had for an understanding of feminist struggles.

Mixed-symmetry fields in AdS(5), conformal fields, and AdS/CFT

Energy Technology Data Exchange (ETDEWEB)

Metsaev, R.R. [Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky prospect 53, Moscow 119991 (Russian Federation)

2015-01-15

Mixed-symmetry arbitrary spin massive, massless, and self-dual massive fields in AdS(5) are studied. Light-cone gauge actions for such fields leading to decoupled equations of motion are constructed. Light-cone gauge formulation of mixed-symmetry anomalous conformal currents and shadows in 4d flat space is also developed. AdS/CFT correspondence for normalizable and non-normalizable modes of mixed-symmetry AdS fields and the respective boundary mixed-symmetry anomalous conformal currents and shadows is studied. We demonstrate that the light-cone gauge action for massive mixed-symmetry AdS field evaluated on solution of the Dirichlet problem amounts to the light-cone gauge 2-point vertex of mixed-symmetry anomalous shadow. Also we show that UV divergence of the action for mixed-symmetry massive AdS field with some particular value of mass parameter evaluated on the Dirichlet problem amounts to the action of long mixed-symmetry conformal field, while UV divergence of the action for mixed-symmetry massless AdS field evaluated on the Dirichlet problem amounts to the action of short mixed-symmetry conformal field. We speculate on string theory interpretation of a model which involves short low-spin conformal fields and long higher-spin conformal fields.

Field Report

DEFF Research Database (Denmark)

Gorm Hansen, Louise Lyngfeldt

2012-01-01

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

Working in the magnetic field of ultrahigh field MRI

International Nuclear Information System (INIS)

Leitgeb, N.; Gombotz, H.

2013-01-01

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

Quantized fields in interaction with external fields. Pt. 1

International Nuclear Information System (INIS)

Bellissard, J.

1975-01-01

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

A Unified Field Theory of Gravity, Electromagnetism, and the Yang-Mills Gauge Field

Directory of Open Access Journals (Sweden)

Suhendro I.

2008-01-01

Full Text Available In this work, we attempt at constructing a comprehensive four-dimensional unified field theory of gravity, electromagnetism, and the non-Abelian Yang-Mills gauge field in which the gravitational, electromagnetic, and material spin fields are unified as intrinsic geometric objects of the space-time manifold S4 via the connection, with the general- ized non-Abelian Yang-Mills gauge field appearing in particular as a sub-field of the geometrized electromagnetic interaction.

Vector optical fields with polarization distributions similar to electric and magnetic field lines.

Science.gov (United States)

Pan, Yue; Li, Si-Min; Mao, Lei; Kong, Ling-Jun; Li, Yongnan; Tu, Chenghou; Wang, Pei; Wang, Hui-Tian

2013-07-01

We present, design and generate a new kind of vector optical fields with linear polarization distributions modeling to electric and magnetic field lines. The geometric configurations of "electric charges" and "magnetic charges" can engineer the spatial structure and symmetry of polarizations of vector optical field, providing additional degrees of freedom assisting in controlling the field symmetry at the focus and allowing engineering of the field distribution at the focus to the specific applications.

Field Trips. Beginnings Workshop.

Science.gov (United States)

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

2001-01-01

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

Strong Magnetic Field Characterisation

Science.gov (United States)

2012-04-01

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

Hyperbolic-symmetry vector fields.

Science.gov (United States)

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

2015-12-14

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

RFID Antenna Near-field Characterization Using a New 3D Magnetic Field Probe

Directory of Open Access Journals (Sweden)

Kassem Jomaa

2017-05-01

Full Text Available In this paper the design of a new 3D magnetic field (H-field probe with a near-field scanning system is presented, then the near electromagnetic fields radiated by a Library RFID system is characterized. The proposed system is developed in order to determine the magnetic near-field emitted by electronic devices. The designed isotropic H-field probe consists of three orthogonal and identical loops each of diameter of 6 mm having 3 turns. The antenna factor of the designed probe is presented for a frequency range from 10 MHz to 1 GHz. The designed probe is tested and validated using a standard passive circuit as a device under test. An RFID reader antenna is also designed and simulated on HFSS (high frequency structural simulator and the radiated magnetic field, obtained by simulations, is then compared to the real measured one above the fabricated circuit. The obtained levels are checked if they satisfy the European and ICNIRP Electromagnetic Fields Guidelines.

Representation of magnetic fields with toroidal topology in terms of field-line invariants

International Nuclear Information System (INIS)

Lewis, H.R.

1990-01-01

Beginning with Boozer's representation of magnetic fields with toroidal topology [Phys. Fluids 26, 1288 (1983)], a general formalism is presented for the representation of any magnetic field with toroidal topology in terms of field-line invariants. The formalism is an application to the magnetic field case of results developed recently by Lewis et al. (submitted for publication to J. Phys. A) for arbitrary time-dependent Hamiltonian systems with one degree of freedom. Every magnetic field with toroidal topology can be associated with time-dependent Hamiltonian systems with one degree of freedom and every time-dependent Hamiltonian system with one degree of freedom can be associated with magnetic fields with toroidal topology. In the Hamiltonian context, given any particular function I(q,p,t), Lewis et al. derived those Hamiltonians for which I(q,p,t) is an invariant. In addition, for each of those Hamiltonians, they derived a function canonically conjugate to I(q,p,t) that is also an invariant. They applied this result to the case where I(q,p,t) is expressed as a function of two canonically conjugate functions. This general Hamiltonian formalism provides a basis for representing magnetic fields with toroidal topology in terms of field-line invariants. The magnetic fields usually contain plasma with flow and anisotropic pressure. A class of fields with or without rotational symmetry is identified for which there are magnetic surfaces. The formalism is developed for application to the case of vacuum magnetic fields

Análisis de la respuesta mecánica de recubrimientos elaborados mediante proyección térmica por plasma usando la medición de esfuerzos residuales y el método de elementos finitos a escala estructural: efecto de la red de poros Mechanical responses of plasma sprayed coatings from residual stress measurements and finite element analysis: effect of the pore network architecture

Directory of Open Access Journals (Sweden)

Claudia Constanza Palacio Espinosa

2011-12-01

Full Text Available En el presente trabajo se estudia la respuesta mecánica de recubrimientos elaborados mediante proyección térmica por plasma ante la presencia de esfuerzos residuales y campos de esfuerzos generados por deformaciones. Para lograr este propósito, se midieron los esfuerzos residuales durante el proceso de elaboración de recubrimientos de TiO2-Cu y se evaluó el efecto de la red de poros en la estructura de la capa obtenida a partir de imágenes de alta resolución de Microscopía Electrónica de Barrido (MEB obtenidas de los recubrimientos de Al2O3-13TiO2, las cuales fueron posteriormente procesadas y discretizadas para su análisis mediante el Método de Elementos Finitos (MEF. Algunos parámetros operacionales empleados para elaborar los recubrimientos, tales como el flujo de gases y la corriente eléctrica, necesarios para formar el plasma, mostraron tener influencia en el contenido de poros, densidad de grietas y orientación de las mismas y en la magnitud de los esfuerzos residuales provocados. Los esfuerzos residuales determinados a partir de mediciones de deflexión durante la elaboración de los recubrimientos de TiO2-Cu, permitieron identificar su naturaleza, mientras que las simulaciones numéricas mostraron la gran influencia de la red de poros sobre el campo de esfuerzos de los recubrimientos de Al2O3-13TiO2. Del mismo modo, mediante MEF se evaluaron otras composiciones teóricas a través de la modificación de las propiedades mecánicas intrínsecas de las fases constituyentes. Para los casos considerados, las simulaciones mostraron la pobre influencia que tiene la presencia de los constituyentes secundarios en el campo de esfuerzos de los recubrimientos.This study aims a better understanding residual stress and stress field within composite plasma sprayed coatings submitted to strains. In order to reach out this objective, residual stress techniques can be implemented for measurements during elaboration of coatings and finite

A Unified Field Theory of Gravity, Electromagnetism, and theA Unified Field Theory of Gravity, Electromagnetism, and the Yang-Mills Gauge Field

Directory of Open Access Journals (Sweden)

Suhendro I.

2008-01-01

Full Text Available In this work, we attempt at constructing a comprehensive four-dimensional unified field theory of gravity, electromagnetism, and the non-Abelian Yang-Mills gauge field in which the gravitational, electromagnetic, and material spin fields are unified as intrinsic geometric objects of the space-time manifold $S_4$ via the connection, with the generalized non-Abelian Yang-Mills gauge field appearing in particular as a sub-field of the geometrized electromagnetic interaction.

Towers of Function Fields over Non-prime Finite Fields

DEFF Research Database (Denmark)

Bassa, Alp; Beelen, Peter; Garcia, Arnaldo

2015-01-01

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

Molten corium concrete interaction: investigation of heat transfer in two-phase flow

International Nuclear Information System (INIS)

Amizic, Milan

2014-01-01

In the context of severe accident research for the second and the third generation of nuclear power plants, there are still open issues concerning some aspects of the concrete cavity ablation during the molten corium - concrete interaction (MCCI). The determination of heat transfer along the interfacial region between the molten corium pool and the ablating basemat concrete is crucial for the assessment of concrete ablation progression and eventually the basemat melt through. For the purpose of experimental investigation of thermal hydraulics inside a liquid pool agitated by gas bubbles, the CLARA project has been launched. The CLARA experiments are performed using simulant materials and they reveal the influence of superficial gas velocity, liquid viscosity and pool geometry on the heat transfer coefficient between the internally heated liquid pool and vertical and horizontal pool walls maintained at uniform temperature. The first test campaign has been conducted with the small pool configuration (50 cm * 25 cm * 25 cm). The tests have been performed with liquids covering a wide range of dynamic viscosity from approximately 1 mPa s to 10000 mPa s and the superficial gas velocity is varied up to 8 cm/s. This thesis comprises a brief description of MCCI phenomenology, literature reviews on the existing heat transfer correlations for two phase flow and the void fraction, a description of CLARA setup, experimental results and their interpretation. The experimental results are compared with existing models and some new models for the assessment of heat transfer coefficient in two-phase flow. (author) [fr

Aguaclara, una alternativa para el tratamiento de agua para consumo humano. Aguaclara - an alternativefor drinking water treatment.

Directory of Open Access Journals (Sweden)

Gilberto Arturo Díaz Ordóñez

2011-05-01

Full Text Available Agua Para el Pueblo con el apoyo técnico del Programa AguaClara de la Universidad de Cornell, facilita asistencia técnica a comunidades rurales mayores de 2,000 habitantes y pequeñas y medianas ciudades con poblaciones menores de 50,000 habitantes, para la construcción de plantas de tratamiento denominadas AguaClara. Este esfuerzo institucional es una respuesta para optimizar la desinfección del agua con cloro en aquellos sistemas de agua ya construidos y que por razones naturales o antropicas se han visto afectados con problemas de alta turbiedad en los suministros de agua. La tecnología consiste en la floculación hidráulica, la sedimentación de alto rendimiento y la desinfección con alta eficiencia, sin el uso de la filtración o energía eléctrica para asegurar una entrega de agua de acuerdo a la Norma Técnica Nacional de Calidad del Agua de Honduras. La gestión de las plantas de tratamiento AguaClara va más allá de los aspectos constructivos y enfatiza simultáneamente la organización comunitaria, la capacitación de los diferentes actores, la readecuación de las tarifas, la operación y mantenimiento del sistema incluyendo la planta de tratamiento, así como la mitigación de las vulnerabilidades del sistema de agua y la protección sanitaria y ambiental en general de los entornos comunitarios donde se construyen las plantas de tratamiento.

The Galactic magnetic fields

International Nuclear Information System (INIS)

Han Jinlin

2006-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1976-10-01

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

Electromagnetic fields and their impacts

Science.gov (United States)

Prša, M. A.; Kasaš-Lažetić, K. K.

2018-01-01

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

Disintegration and field evaporation of thiolate polymers in high electric fields

International Nuclear Information System (INIS)

Nickerson, B.S.; Karahka, M.; Kreuzer, H.J.

2015-01-01

High electrostatic fields cause major changes in polymers, structural (e.g. electrostriction) and electronic (e.g. reduction of the “band gap” with final metallization). Using density functional theory we have studied field effects on amino-alkane-thiols and perfluoro-alkane-thiols adsorbed on a metal substrate. Our results agree well with the APT fragmentation spectra obtained by Stoffers, Oberdorfer and Schmitz and shed light on disintegration pathways. We demonstrate that in SAMs the HOMO/LUMO gap is again reduced as a function of the field strength and vanishes at evaporation. We also follow the field dependence of the dielectric constant and polarizability. - Highlights: • Simple model of thiolate polymers is used to understand trends leading to field evaporation. • Potential energy curves followed by dipole moment, electric polarizability and dielectric constant are examined. • Features including coil, tilt and electrostriction are featured alongside evaporated species and HOMO/LUMO gap.

Disintegration and field evaporation of thiolate polymers in high electric fields

Energy Technology Data Exchange (ETDEWEB)

Nickerson, B.S., E-mail: brenden.nickerson@dal.ca; Karahka, M.; Kreuzer, H.J.

2015-12-15

High electrostatic fields cause major changes in polymers, structural (e.g. electrostriction) and electronic (e.g. reduction of the “band gap” with final metallization). Using density functional theory we have studied field effects on amino-alkane-thiols and perfluoro-alkane-thiols adsorbed on a metal substrate. Our results agree well with the APT fragmentation spectra obtained by Stoffers, Oberdorfer and Schmitz and shed light on disintegration pathways. We demonstrate that in SAMs the HOMO/LUMO gap is again reduced as a function of the field strength and vanishes at evaporation. We also follow the field dependence of the dielectric constant and polarizability. - Highlights: • Simple model of thiolate polymers is used to understand trends leading to field evaporation. • Potential energy curves followed by dipole moment, electric polarizability and dielectric constant are examined. • Features including coil, tilt and electrostriction are featured alongside evaporated species and HOMO/LUMO gap.

Geophysical Field Theory

International Nuclear Information System (INIS)

Eloranta, E.

2003-11-01

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

Quark pair creation in color electric fields and effects of magnetic fields

International Nuclear Information System (INIS)

Tanji, Noato

2010-01-01

The time evolution of a system where a uniform and classical SU(3) color electric field and quantum fields of quarks interact with each other is studied focusing on non-perturbative pair creation and its back reaction. We characterize a color direction of an electric field in a gauge invariant way, and investigate its dependence. Momentum distributions of created quarks show plasma oscillation as well as quantum effects such as the Pauli blocking and interference. Pressure of the system is also calculated, and we show that pair creation moderates degree of anisotropy of pressure. Furthermore, enhancement of pair creation and induction of chiral charge under a color magnetic field which is parallel to an electric field are discussed.

Mean fields and self consistent normal ordering of lattice spin and gauge field theories

International Nuclear Information System (INIS)

Ruehl, W.

1986-01-01

Classical Heisenberg spin models on lattices possess mean field theories that are well defined real field theories on finite lattices. These mean field theories can be self consistently normal ordered. This leads to a considerable improvement over standard mean field theory. This concept is carried over to lattice gauge theories. We construct first an appropriate real mean field theory. The equations determining the Gaussian kernel necessary for self-consistent normal ordering of this mean field theory are derived. (orig.)

Magnetic Field Calculator

Data.gov (United States)

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

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

Energy Technology Data Exchange (ETDEWEB)

Garcia Castrejon, Juan Carlos

2008-09-15

The steam flow induced vibrations in turbines is a common problem during the operation of 300 MW turbines and it is one of the problems that requires solution to develop 1 GW steam turbines. The flow induced vibration is caused because there is an interaction between blades and the flow field. Blades are subjected to the forces caused by the flow field, but also the flow field is affected by the blades and its movement. The nozzle wakes cause uneven pressure field downstream and produces alternating forces on blades which lead to blade vibrations. Some of the vibrations originated in this way may damage the blades and affect the turbine performance. The forces acting on blades (and causing forced vibrations) as a result of the variations in the flow field in the axial rotor-stator clearance are studied in this project. These forces were determined applying computer fluid dynamics (CFD) in two turbine stages. The CFD analysis was carried out in the Curtis stage and in the last stage, using 2D and 3D models. An important part of the analysis is focused on discussing the pressure field variation, because this variation caused the forces acting on blades. The flow field was resolved using CFD and the computed pressure field was integrated around the blades to get the forces acting on blades. These computed dynamical forces were analyzed using a FFT analysis and the results were used in the blade useful life estimation and in the investigation of the failure causes of these blades. In every turbine stage the RNG - turbulence model and the sliding mesh method was used to deal with the blade motion. The 3D models were resolved using parallel computation in a cluster of 6 AMD 64 Opteron processors of 2412.36 MHz and 8 Gb of RAM. The results of the simulation in both stages get the pressure field behavior in the axial rotor-stator clearance and determine the force acting on the blades. These results showed that both, the pressure field and the force magnitude acting on

When Are Users Comfortable Sharing Locations with Advertisers?

Science.gov (United States)

2010-10-01

allowing small businesses and national chains (e.g., Starbucks ) to offer recurring, frequency-based, and loyalty-based coupons to over three million...Mobile Business, 2002. [8] Clara Mancini, Keerthi Thomas, Yvonne Rogers, Blaine A. Price , Lukazs Jedrzejczyk, Arosha K. Bandara, Adam N. Joinson, and

75 FR 33822 - Los Esteros Critical Energy Facility Low-Effect Habitat Conservation Plan for the Bay Checkerspot...

Science.gov (United States)

2010-06-15

..., California. Emissions from power plants, vehicles, and industrial development result in deposition of... and Serpentine Endemic Plant Species, Santa Clara County, CA AGENCY: Fish and Wildlife Service... comment. SUMMARY: We, the U.S. Fish and Wildlife Service, have received an application from the Calpine...

Comparative analysis method of permanent metallic stents (XIENCE) and bioresorbable poly-L-lactic (PLLA) scaffolds (Absorb) on optical coherence tomography at baseline and follow-up

NARCIS (Netherlands)

T. Nakatani (Tomoya); Y. Sotomi (Yohei); Y. Ishibashi (Yuki); M.J. Grundeken (Maik); H. Tateishi (Hiroki); E. Tenekecioglu (Erhan); Y. Zeng (Yaping); P. Suwannasom (Pannipa); E.S. Regar (Eveline); M. Radu (Maria); L. Räber (Lorenz); H.G. Bezerra (Hiram); M.A. Costa (Marco); Fitzgerald, P. (Peter); F. Prati (Francesco); R.A. Costa (Ricardo); J. Dijkstra (Jouke); T. Kimura (Takeshi); K. Kozuma (Ken); K. Tanabe (Kengo); T. Akasaka (Takashi); C. di Mario (Carlo); P.W.J.C. Serruys (Patrick); Y. Onuma (Yoshinobu); G. Guagliumi (Giulio)

2016-01-01

textabstractAims: Fully bioresorbable Absorb poly-L-lactic-acid (PLLA) scaffolds (Abbott Vascular, Santa Clara, CA, USA) are a novel approach for the treatment of coronary narrowing. Due to the translucency of the material (PLLA), the optical coherence tomography (OCT) measurement methods used in

77 FR 26789 - Certain Semiconductor Chips Having Synchronous Dynamic Random Access Memory Controllers and...

Science.gov (United States)

2012-05-07

... patents. 73 FR 75131. The principal respondent was NVIDIA Corporation of Santa Clara, California (``NVIDIA''). Joining NVIDIA as respondents were approximately twenty of NVIDIA's customers. The Commission found a... accused products in the United States: NVIDIA; Hewlett-Packard Co. of Palo Alto, California; ASUS Computer...

Distal coronary hemoperfusion during percutaneous transluminal coronary angioplasty

NARCIS (Netherlands)

Muinck, Ebo Derk de

1994-01-01

In this thesis several aspects of passive and active coronary perfusion during coronary angioplasty are investigated. The autoperfusion balloon catheters that were evaluated are the Stack® and the RX-60® catheters (Advanced Cardiovascular Systems, inc., Santa Clara, California, U.S.A). The coronary

Strengthening German Programs through Community Engagement and Partnerships with Saturday Morning Schools

Science.gov (United States)

Hellebrandt, Josef

2014-01-01

German university programs can increase enrollments and diversify their curricula through academic community partnerships with surrounding schools. This article informs about two community-supported initiatives between the German Studies Program at Santa Clara University and the South Bay Deutscher Schulverein, a Saturday Morning School in…