6,845 research outputs found

    Probing the ZZgamma and Zgammagamma Couplings Through the Process e+e- --> nu anti-nu gamma

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    We study the sensitivity for testing the anomalous triple gauge couplings ZZγZZ\gamma and ZγγZ\gamma\gamma via the process e+eννˉγe^+e^-\to \nu \bar\nu \gamma at high energy linear colliders. For integrated luminosities of 500 fb1fb^{-1} and center of mass energies between 0.5 and 1.5 TeVTeV, we find that this process can provide tests of the triple neutral gauge boson couplings of order 10410^{-4}, one order of magnitude lower than the standard model prediction.Comment: 12 pages, 6 figure

    Aplicabilidad del test MABC en escolares con síndrome de down

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    El presente estudio analiza la aplicabilidad de tests de coordinación y habilidad motriz, diseñados para la población infantil general, en escolares de Educación Física Especial. Para el estudio se selecciona una muestra de niños y niñas con síndrome de Down, de 9 y 10 años, del colegio de educación especial ¿María Corredentora¿ de Madrid. Se utilizan las pruebas del Test MABC para el tramo de 4 a 6 años de edad (con algunas adaptaciones) y la escala de observación ECOMI tomada como criterio de validez. Resultados y conclusiones: El módulo de 4 a 6 años del test MABC es aplicable, con ligeras modificaciones, para evaluar las habilidades motrices fundamentales de niños y niñas con síndrome de Down. El conjunto de las pruebas muestra coeficientes de fiabilidad y validez adecuados. El grado de desarrollo motor de estos niños (9 y 10 años), mediante la comparación con el baremo de MABC, es inferior al promedio de la población española de escolares de 4 a 6 años

    Noise reduction using wavelet cycle spinning: analysis of useful periodicities in the z-transform domain

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    Cycle spinning (CS) and a'trous algorithms are different implementations of the undecimated wavelet transform (UWT). Both algorithms can be used for UWT and even though the resulting wavelet coefficients are different, they keep a correspondence. This paper describes an analysis of the CS algorithm performed in the z-transform domain, showing the similarities and differences with the a'trous implementation. CS generates more wavelet coefficients than a'trous, but the number of significative and different coefficients is the same in both cases because of the occurrence of a periodic repetition in CS coefficients. Mathematical expressions for the relationship between CS and a'trous coefficients and for CS coefficient periodicities are provided in the z-transform domain. In some wavelet denoising applications, periodicities (present in the coefficients of the CS procedure) can also be found in the performance measure of the processed signals. In particular, in ultrasonic CS denoising applications, periodicities have been appreciated in the signal-to-noise ratio (SNR) of the ultrasonic denoised signals. These periodicities can be used to optimize the number of CS coefficients for an efficient implementation. Two examples showing the periodicities in the SNR are included. A selection of several reduced sets of CS wavelet coefficients has been utilized in the examples, and the SNRs resulting after denoising are analyzed.This work was partially supported by Spanish MCI Project DPI2011-22438 and MEC Project TIN2013-47272-C2-1-R. The translation of this paper was funded by the Universitat Politecnica de Valencia, Spain.Rodríguez-Hernández, MA.; San Emeterio, JL. (2016). Noise reduction using wavelet cycle spinning: analysis of useful periodicities in the z-transform domain. Signal, Image and Video Processing. 10(3):519-526. https://doi.org/10.1007/s11760-015-0762-8S519526103Daubechies, I.: Ten Lectures on Wavelets. 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    Effect of cooling rate during solidification on the hard phases of M23C6-type of cast CoCrMo alloy

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    Microstructural morphology of CoCrMo alloy by control of the cooling rate during the solidification was investigated. Samples were obtained using both an induction furnace for slow cooling rate and electric arc furnace for fast cooling rate. Microstructural characterizations were performed with metallographic techniques. It was found that the difference between the formation temperature of hard secondary phases of M23C6-type carbides determine the reduction of carbide size by increasing the cooling rate

    Effect of cooling rate during solidification on the hard phases of M23C6-type of cast CoCrMo alloy

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    Microstructural morphology of CoCrMo alloy by control of the cooling rate during the solidification was investigated. Samples were obtained using both an induction furnace for slow cooling rate and electric arc furnace for fast cooling rate. Microstructural characterizations were performed with metallographic techniques. It was found that the difference between the formation temperature of hard secondary phases of M23C6-type carbides determine the reduction of carbide size by increasing the cooling rate

    Los Pitagóricos en soporte hipermedia

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    Se presenta el diseño e implementación de un CD-ROM interactivo sobre Pitágoras y los pitagóricos. De esta forma, a partir de una referencia concreta se han construido diversas partes de las matemáticas como Aritmética, Geometría, Proporcionalidad y Estadística. Pretende abarcar todo lo referente al teorema de Pitágoras incluyendo, además del propio teorema, situaciones históricas, diferentes demostraciones, colecciones de ejercicios, problemas, extensiones del teorema y juegos, curiosidades, relación con otras ciencias como Arte, Música, Astronomía, etc. De este modo se proporciona una visión globalizadora de las matemáticas distinta de la de ser una ciencia formada por contenidos aislados

    Anomalous Roughening of Viscous Fluid Fronts in Spontaneous Imbibition

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    We report experiments on spontaneous imbibition of a viscous fluid by a model porous medium in the absence of gravity. The average position of the interface satisfies Washburn's law. Scaling of the interface fluctuations provides a dynamic exponent z \simeq 3, indicative of global dynamics driven by capillary forces. The complete set of exponents clearly shows that interfaces are not self-affine, exhibiting distinct local and global scaling, both for time (b=0.64\pm 0.02, b* =0.33 \pm 0.03) and space (a=1.94 \pm 0.20, a_loc=0.94 \pm 0.10). These values are compatible with an intrinsic anomalous scaling scenario.Comment: 4 pages, 5 figure

    The effect of pre-strain on fatigue for a high strength low alloy (HSLA) steel

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    The effect of initial plastic strain cycle fatigue lives of HSLA specimens is investigated. Specimens were monotonically, quasi-statically loaded under strain control in tension to produce plastic strains (prestrain conditions s0 = 0, s1 = 4,6, s2 = 35,6 and s3 = 66,7 % deformation). Surface analysis on the annealed Zn coat on the prestrain surfaces shows that, the higher the deformation the bigger and deeper the cracks on the Zn coat. Results show that the higher prestrain the higher fatigue resistance for all stress applied, specimens with s3 shows the highest fatigue resistance for these experimental conditions

    Spatio-temporal analysis of the degradation of salts-affected soils in the lacustre system of Texcoco Valley (Mexico)

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    El Valle de Texcoco, uno de los cinco lagos que conformaban el gran lago de Tenochticlan en el periodo colonial de la ciudad de México (año 1520), es hoy en día una de las regiones del planeta con mayor superficie de suelos afectados por salinidad extrema (>10 000 ha). La salinidad de los suelos es un grave problema en regiones áridas o semiáridas, ya que afecta a la productividad agrícola y la calidad de las aguas, con graves consecuencias socioeconómicas, como la desertificación y migración a las ciudades. Además, las sales se disuelven con facilidad en el suelo, por lo que se requieren herramientas de monitorización precisas que permitan evaluar la alta variabilidad espacio-temporal de los suelos afectados por sales. Este trabajo tiene como objetivo evaluar el estado de los suelos afectados por salinidad en el valle de Texcoco, así como los cambios de uso de suelo acontecidos en los últimos 30 años. Para ello se emplearán técnicas de GIS, imágenes de satélite Landsat desde la década de los 80 hasta la actualidad (1985-2015), y radiómetros de campo para identificar las firmas espectrales de los suelos en condiciones de laboratorio. Una vez procesadas las imágenes de satélite Landsat (corrección radiométrica y atmosférica, y aplicación de filtros), se identificaron diferentes cubiertas o usos de suelo: agua, vegetación semi-natural, tierras de cultivo, suelos sin vegetación y suelos salinos. Se calcularon diferentes índices radiométricos para distinguir la vegetación de las tierras de cultivo y de los suelos salinos. El sistema de clasificación no supervisada mostró cambios de uso de la tierra en el 80% de la superficie en 30 años. Disminuye el agua potable y las tierras agrícolas e incrementan en más de un 20% los suelos degradados por sales o de uso urbano. Se trata de una región con riesgo extremo por pérdida y degradación de las tierras de cultivo por efecto de la salinidadThe Valley of Texcoco, one of the five lakes that formed the great lake of Tenochticlan in the colonial period of Mexico City (year 1520), is today one of the regions with the largest surface area of soils affected by extreme salinity (>10 000 ha). The salinity of soil is a serious problem in arid or semi-arid regions. It affects to agricultural productivity and water quality, with serious socioeconomic consequences, such as desertification and migration of the rural populations to the cities. So, salts dissolve easily in the soil, so precise monitoring tools are necessary to evaluate the high spatiotemporal variability by salts-affected soils. The aim is to evaluate the state of salts-affected soils in the Texcoco Valley, as well as the land use changes in the last 30 years. GIS, Landsat satellite images from the 1980s to the present (1985-2015), and field radiometers will be used to identify the spectral signatures of salts-affected soils under laboratory conditions. Once processed the multispectral images (radiometric and atmospheric correction, and filters application), different land uses were identified: water, semi-natural vegetation, agricultural lands, soil without vegetation and saline soils. Different radiometric indices were used to differentiate vegetation from agricultural and saline soils. The unsupervised classification system showed changes at 80% of the surface in land use in 30 years. Clear water and agricultural land decreased and increased at 20% the soils degraded by salts or urban use. It is a region with extreme risk due to the salts-affected soil
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