Burst statistics in Alcator C-Mod SOL turbulence

Bursty fluctuations in the scrape-off layer (SOL) of Alcator C-Mod have been analyzed using gas puff imaging data. This reveals many of the same fluctuation properties as Langmuir probe measurements, including normal distributed fluctuations in the near SOL region while the far SOL plasma is dominated by large amplitude bursts due to radial motion of blob-like structures. Conditional averaging reveals burst wave forms with a fast rise and slow decay and exponentially distributed waiting times. Based on this, a stochastic model of burst dynamics is constructed. The model predicts that fluctuation amplitudes should follow a Gamma distribution. This is shown to be a good description of the gas puff imaging data, validating this aspect of the model.Comment: 8 pages, 6 figure

Characterization of ISP Traffic: Trends, User Habits, and Access Technology Impact

In the recent years, the research community has increased its focus on network monitoring which is seen as a key tool to understand the Internet and the Internet users. Several studies have presented a deep characterization of a particular application, or a particular network, considering the point of view of either the ISP, or the Internet user. In this paper, we take a different perspective. We focus on three European countries where we have been collecting traffic for more than a year and a half through 5 vantage points with different access technologies. This humongous amount of information allows us not only to provide precise, multiple, and quantitative measurements of "What the user do with the Internet" in each country but also to identify common/uncommon patterns and habits across different countries and nations. Considering different time scales, we start presenting the trend of application popularity; then we focus our attention to a one-month long period, and further drill into a typical daily characterization of users activity. Results depict an evolving scenario due to the consolidation of new services as Video Streaming and File Hosting and to the adoption of new P2P technologies. Despite the heterogeneity of the users, some common tendencies emerge that can be leveraged by the ISPs to improve their servic

Daños por magulladura en frutos de pepita: Factores que influyen en su aparición y control de daños con frutos electrónicos

La demanda de frutas y hortalizas en Europa es cada vez más exigente en términos de calidad. En frutos de pepita, como la manzana y la pera, los principales parámetros de calidad son el calibre, la firmeza, el color, la calidad gustativa y la ausencia de defectos; los daños mecánicos son los defectos que producen mayores pérdidas. En manzana, se ha comprobado que las magulladuras son el daño mecánico más frecuente, que influye decisivamente en el precio de venta y en la aceptación del consumidor. En los últimos cinco años, un equipo investigador del Departamento de Ingeniería Rural de la Universidad Politécnica de Madrid, dirigido por la Profesora M. Ruiz-Altisent, ha estudiado en profundidad los diversos factores que influyen en la aparición de daños por magulladura en frutos de pepita y la manera de evitarlo

Efectos de las características de la piel y pulpa sobre la respuesta al impacto y la magulladura en frutos de pepita en relación con factores de cultivo.

Los factores de cultivo tienen una influencia significativa en las características de la piel y pulpa de frutos de pepita. La susceptibilidad a magulladura aumenta con posteriores fechas de recolección y disminuye al aumentar la firmeza de la pulpa

Effects of skin characteristics on impact response and bruising of apples and pears

Skin properties have an important influence on impact parameters and bruising. Skin deformation at puncture (a measure of the turgidity of the fruit skin) is negatively correlated with bruise volume in Golden apples after cold storage

Insights on the provision of frequency support by wind power and the impact on energy systems

This paper implements and compares between the key concepts to enable wind power short-term frequency support from electrical and mechanical loads perspectives. Pitch de-loading, kinetic energy extraction and wind turbine (WTG) over-speeding are investigated, where each concept is integrated as a supplementary controller to the conventional controls of WTG. Different patterns of wind speed are examined, step-change and real intermittent of high resolution. The examined aggregated synchronous area has a relatively high wind penetration with frequency support. The overall dynamic inertia of the system is assessed to analyze the impact of the integrated support methods and their key parameters. The coordination between synchronous areas and wind farms, which are interconnected through a multi-terminal high voltage direct current network (MT-HVDC) is examined. A definition of the virtual inertia of MT-HVDC grid is proposed. Results show that pitch de-loading secures support reserve most of the time, and kinetic energy extraction provides sustainable support for a short time, while accelerative de-loading could reach a compromise. The three methods are adaptable with the MT-HVDC holistic frequency support controller, with a small advantage of kinetic energy extraction on the virtual inertia of the MT-HVDC. Matlab/Simulink® is the simulation environment

Daños por magulladura en frutos de pepita

La demanda de frutas y hortalizas es cada vez más exigente en términos de calidad. En frutos de pepita, los principales parámetros de calidad son el calibre, la firmeza, el color, la calidad gustativa y la ausencia de defectos; los daños mecánicos son los defectos que producen mayores pérdidas. En manzana, se ha comprobado que las magulladuras son el daño mecánico más frecuente, que influye decisivamente en el precio de venta y en la aceptación del consumidor. En los últimos cinco años, un equipo investigador del Departamento de Ingeniería Rural de la Universidad Politécnica de Madrid, dirigido por la Profesora M. Ruiz-Altisent, ha estudiado en profundidad los diversos factores que influyen en la aparición de daños por magulladura en frutos de pepita y la manera de evitarlos

Neutron-diffraction study of field-induced transitions in the heavy-fermion compound Ce2RhIn8

We present neutron diffraction measurements in high magnetic fields (0 to 14.5 T) and at low temperatures (2.5, 2.3, 0.77 and 0.068 K) on single crystals of the tetragonal heavy fermion antiferromagnet Ce2RhIn8. For B//[110] the field dependence of selected magnetic and nuclear reflections reveals that the material undergoes several transitions, the temperature dependence of which suggests a complex B-T phase diagram. We present the detailed evolution of the integrated intensities of selected reflections and discuss the associated field-induced transitions.Comment: 12 pages, 3 figures Proceeding Euro-conference "Properties of Condensed Matter probed by x-ray and neutron scattering"; to appear in Physica