383 research outputs found
Geologia de la Cubeta d’Inca (Mallorca): Cartografía geológica e interpretación de datos del subsuelo
3-Core Fiber Modal Analysis
Multicore fibers (MCFs) are expected as a good candidate for overcoming the capacity limit of current optical communication systems. This paper describes the modal analysis of a 3-core MCF taking into account some geometrical and material degrees of freedom. A reasonable tailoring of the modal distribution is shown to be achievable
Characterization of Active Integrated Multicore Waveguides
This study includes the experimental both passive and active characterization of multicore waveguides written in phosphate glass codoped with erbium and ytterbium, with the aim of designing and optimizing photonic devices based on this type of structures.
 
Structural controls on basin- and crustal-scale fluid flow and resulting mineral reactions
This preface summarizes the main contents of the special issue Structural Controls on Basin- and Crustal-Scale Fluid Flow and Resulting Mineral Reactions, organized by topic. The description of contributions starts with those addressing crustal-scale processes, followed by studies of relatively shallower fluid flow mechanisms and their consequences. The final subsection summarizes contributions on structural controls on mineral reactions, as well as those evaluating how they impact geothermal reservoir properties
Dextroposição cardíaca e pectus excavatum em cão
The authors present a case of dextroposition and pectus excavatum in a female Pekingese dog, approximately 30 days old. They document the case with radiographies, cineangiodardiography and a picture taken after the necropsy, associating than with the clinical symptoms.Registrou-se caso de dextroposição ardíaca em 1 cão da raça pequines, fêmea, com aproximadamente 30 dias de idade, que se apresentava prostado, com sintomas de asfixia, mucosa cianótica e temperatura retal de 39,2"C. Os exames radiológicos e os dados de necropsia revelaram também a presença de pectus excavatum, causa, segundo os AA. do deslocamento cardíaco que, por sua vez, ocasionava compressão do pulmão direito, determinando o quadro clínico apresentado pelo animal. Conforme pode ser apurado, pelo exame da literatura especializada, a relação entre a dextroposição cardíaca e o pectus excavatum não havia sido ainda assinalada
A novel technique for sterilization using a power self-regulated single-mode microwave cavity
In this paper, a novel technique to achieve precise temperatures in food sterilization has been proposed. An accurate temperature profile is needed in order to reach a commitment between the total removal of pathogens inside the product and the preservation of nutritional and organoleptic characteristics. The minimal variation of the target temperature in the sample by means of a monitoring and control software platform, allowing temperature stabilization over 100 °C, is the main goal of this work. A cylindrical microwave oven, under pressure conditions and continuous control of the microwave supply power as function of the final temperature inside the sample, has been designed and developed with conditions of single-mode resonance. The uniform heating in the product is achieved by means of sample movement and the self-regulated power control using the measured temperature. Finally, for testing the sterilization of food with this technology, specific biological validation based on Bacillus cereus as a biosensor of heat inactivation has been incorporated as a distribution along the sample in the experimental process to measure the colony-forming units (CFUs) for different food samples (laboratory medium, soup, or fish-based animal by-products). The obtained results allow the validation of this new technology for food sterilization with precise control of the microwave system to ensure the uniform elimination of pathogens using high temperatures.This work was supported by the Ministerio de Economía y Competitividad under the project with reference DPI2014-61857-EXP
An integrated pump-controlled variable coupler fabricated by ultrafast laser writing
The design and fabrication of a integrated symmetric directional coupler dependent o the pumping power and operating at a 1534 nm wavelength is reported. The twin-core waveguide was inscribed into Er3+/Yb3+ co-doped phosphate glass by a femtosecond laser direct writing technique. By optical pumping, the coupling ratio can be modulated due to the changes induced in the refractive index of the material. The experimental results demonstrated that the coupling ratio can be tuned continuously from 100/0 to 50/50 by increasing the pump’s power from 0 to 350 mW. The developed twin-core coupler has promising applications for on-chip all-optical signal processing and communication systems
Uso de un modelo basado en eventos para evaluar la conductividad hidráulica en una cuenca de pequeñas dimensiones
Los suelos de cultivo situados en pendiente y
desarrollados sobre esquistos del Complejo de Órdenes en
Galicia, se consideran sensibles a la acción de la
escorrentía y a la erosión hídrica. Ello se debe al efecto
conjunto de un clima húmedo con precipitaciones elevadas
durante la estación invernal, a suelos de textura franca o
franco-limosa que pueden encostrarse y a la topografía
ondulada. Para luchar eficazmente en contra de los efectos
adversos de la erosión y la escorrentía es importante
conocer aquellos períodos de la estación húmeda en que la
intensidad de la infiltración es de menor cuantía, en
ausencia de cubierta vegetal. En este contexto se utilizó un
modelo determinista con base física (LISEM), que
funciona asociado a un SIG de tipo raster (PCRaster), para
predecir la erosión y la escorrentía. Mediante el modelo
LISEM se estimó la conductividad hidráulica a saturación
(Ks) en una pequeña cuenca agrícola mediante el método
de prueba y error, usando datos de precipitación y caudal.
Las series de datos experimentales corresponden a ocho
eventos medidos en la cuenca de 10,7 ha denominada
Abelar durante el período 1997/1998. Dado que LISEM
requiere una cantidad importante de parámetros de entrada,
se utilizaron diferentes fuentes de información para obtener
estos datos, incluyendo el calibrado del modelo,
experiencia previas y nuevas observaciones de campo. En
los ocho eventos estudiados la conductividad media de la
cuenca se obtuvo usando un procedimiento de prueba y
error. Para ello se activó una opción del modelo que
permite estimar para cada evento la fracción de la
conductividad hidráulica saturada considerada como
óptima. De este modo, mediante la interfaz de LISEM, se
modificó el porcentaje Ks con respecto al valor de
referencia, hasta alcanzar un ajuste visual razonable entre
el caudal medido y el simulado. Tras los ajustes, el valor
del parámetro E de Nash-and-Sutcliffe (1970) obtenido fue
de 0,51 y el valor medio del coeficiente de correlación
entre datos medidos y simulados en r2 = 0,69. El valor más
bajo de Ks fue 2,48 mm/h y se obtuvo durante un evento
considerado como excepcional. En los restantes siete
eventos este óptimo osciló entre 3,73 y 12,01 mm/h. La
conductividad hidráulica puede presentar una disminución
importante en otoño. Sin embargo, las menores
intensidades de infiltración a escala de cuenca tienden a
ocurrir a finales de invierno y comienzos de la primavera.
En base a estos resultados, se recomienda que las acciones
que puedan contribuir a reducir la escorrentía y por tanto la
erosión del suelo apliquen durante dicho período, dado que
en él los valores de conductividad hidráulica se alejan del
óptimo durante un intervalo importante / The combination of a wet climate with
elevated winter precipitation, loamy-silt or loamy soils
prone to crusting and rolling terrain makes the cultivated
slopes of soils developed over Ordenes schist parent
material in Galicia sensible to soil erosion and overland
flow. To efficiently counteract erosion and runoff, it is
important to know when the infiltration rate in the winter
season is lowest, in the absence of soil cover. For this
purpose, a deterministic, physically-based soil erosion and
runoff model (LISEM) coupled to a raster GIS (PCRaster)
was used. With the aid of the LISEM model, saturated
hydraulic conductivity (Ks) in a small agricultural
catchment was estimated by the trial-and-error method
from precipitation and discharge data. Experimental data
sets were measured during eight events in the 10,7 ha-sized
catchment of O Abelar in the winter season of 1997/1998.
Since LISEM demands a number of input data, they were
retrieved from several sources, including calibration,
literature and additional field observations. The catchmentaveraged
saturated hydraulic conductivity was inversely
modelled by trail-and-error for all eight events. For this
purpose a model option to estimate the fraction of the
optimal saturated hydraulic conductivity was used. The
effective percentage of saturated hydraulic conductivity
within the LISEM interface was adjusted until a reasonable
visually fit was reached between measured and modelled
discharge. The model fits had an average Nash-and-
Sutcliffe (1970) E of 0,51 and an average r2 of 0,69
between measured and simulated data was obtained. The
lowest value of Ks was 2,48 mm/h which was reached
during an event considered to be exceptional. For seven out
of eight events this figure was between 3,73 and 12,01
mm/h. The hydraulic conductivity can already drop
significantly during late-autumn events. However, in
general late winter-early spring is the time with the lowest
infiltration rate on catchment level. Thus, management
measures to mitigate runoff and erosion are recommend to
be applied especially during this period, since hydraulic conductivity is least optimal for a more prolonged timeGalicia. Consellería de Economía e Industria; PGIDT01 AGR10302 PRMinisterio de Ciencia y Tecnología; REN2000-04445-C02-01-H
Modelización de guías de onda multinúcleo
Las guías de onda multinúcleo están adquiriendo cada vez más importancia debido a su potencial para incrementar la capacidad de transmisión de información de los sistemas ópticos así como para aumentar la potencia de dispositivos ópticos activos. Cuando los núcleos se encuentran acoplados, la propagación de las señales ópticas a lo largo de estas estructuras se modeliza expresando el campo electromagnético en forma de superposición de los modos de la estructura, conocidos como supermodos. Para modelizar la propagación de las señales ópticas en medios activos se utilizan las ecuaciones de la propagación de las potencias de los supermodos acopladas a las ecuaciones de las densidades de población de los iones activos que provocan la amplificación. En este trabajo se presentan los fundamentos de esta modelización, haciendo hincapié en el impacto de diversos factores como la competición modal, los batidos de potencia entre núcleos, la dependencia de la distribución de los supermodos con la variación del factor de ganancia y la existencia de zonas de índice deprimido
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