Search results for "flux [antineutrino]"
showing 10 items of 59 documents
Upper limit on the cosmic-ray photon flux above 1019 eV using the surface detector of the Pierre Auger Observatory
2008
A method is developed to search for air showers initiated by photons using data recorded by the surface detector of the Auger Observatory. The approach is based on observables sensitive to the longitudinal shower development, the signal risetime and the curvature of the shower front. Applying this method to the data, upper limits on the flux of photons of 3.8 x 10-3, 2.5 x 10-3; and 2.2 x 10-3 km-2 sr-1 yr-1 above 1019 eV, 2 x 1019 eV; and 4 x 1019 eV are derived, with corresponding limits on the fraction of photons being 2.0%, 5.1%, and 31% (all limits at 95% c.l.). These photon limits disfavor certain exotic models of sources of cosmic rays. The results also show that the approach adopted…
Model for ion transport in bipolar membranes.
1990
A simple theory for multi-ionic transport, nonequilibrium water dissociation, and space-charge effects in bipolar membranes is developed on the basis of some of the concepts used in the solid-state n-p junction. Ion transport is described in terms of the Nernst-Planck flux equation and nonequilibrium water dissociation is accounted for by the Onsager theory of the second Wien effect. The model is expected to be of interest for biological and synthetic membranes, and can explain a number of observed effects.
FULLY RESOLVED QUIET-SUN MAGNETIC FLUX TUBE OBSERVED WITH THE SUNRISE/IMAX INSTRUMENT
2010
Until today, the small size of magnetic elements in quiet Sun areas has required the application of indirect methods, such as the line-ratio technique or multi-component inversions, to infer their physical properties. A consistent match to the observed Stokes profiles could only be obtained by introducing a magnetic filling factor that specifies the fraction of the observed pixel filled with magnetic field. Here, we investigate the properties of a small magnetic patch in the quiet Sun observed with the IMaX magnetograph on board the balloon-borne telescope Sunrise with unprecedented spatial resolution and low instrumental stray light. We apply an inversion technique based on the numerical s…
An angular-selective electron source for the KATRIN experiment
2014
The KATRIN experiment is going to search for the average mass of the electron antineutrino with a sensitivity of 0.2 eV/c2. It uses a retardation spectrometer of MAC-E filter type to accurately measure the shape of the electron spectrum at the endpoint of tritium beta decay. In order to achieve the planned sensitivity the transmission properties of the spectrometer have to be understood with high precision for all initial conditions. For this purpose an electron source has been developed that emits single electrons at adjustable total energy and adjustable emission angle. The emission is pointlike and can be moved across the full flux tube that is imaged onto the detector. Here, we demonstr…
Spectrum of the QCD flux tube in 3d SU(2) lattice gauge theory
2009
Abstract Evidence from the lattice suggests that formation of a flux tube between a q q ¯ pair in the QCD vacuum leads to quark confinement. For large separations between the quarks, it is conjectured that the flux tube has a behavior similar to an oscillating bosonic string, supported by lattice data for the groundstate q q ¯ potential. We measure the excited states of the flux tube in 3d SU ( 2 ) gauge theory with three different couplings inside the scaling region. We compare our results to predictions of effective string theories.
Long range rapidity correlations and the ridge in A+A collisions
2009
We discuss results for n-gluon correlations that form the basis of the Glasma flux tube picture of early times in heavy ion collisions. Our formalism is valid to all orders in perturbation theory at leading logarithmic accuracy in x and includes both QCD bremsstrahlung and the many body screening and recombination effects that are important at large parton densities. Long range rapidity correlations, as seen in the near-side ridge in heavy ion collisions, are a chronometer of these early time strong color field dynamics. They also contain information on how radial flow develops in heavy ion collisions.
A simple algorithm to estimate evapotranspiration from DAIS data: Application to the DAISEX campaigns
2005
DOI:10.1016/j.jhydrol.2005.03.027; The knowledge of evapotranspiration is of great interest in many applications such as assessing irrigation water use. In this paper, a methodology is presented to estimate evapotranspiration using the surface energy balance model S-SEBI (Simplified Surface Energy Balance Index) and the evaporative fraction. The method is applicable under the assumptions of constant atmospheric conditions and sufficient wet and dry pixels over the image. The model uses remotely sensed parameters such as albedo, MSAVI (Modified Soil Adjusted Vegetation Index) and surface temperature and emissivity images. The methodology has been applied over the Barrax test site, located in…
3D MHD MODELING of TWISTED CORONAL LOOPS
2016
We perform MHD modeling of a single bright coronal loop to include the interaction with a non-uniform magnetic field. The field is stressed by random footpoint rotation in the central region and its energy is dissipated into heating by growing currents through anomalous magnetic diffusivity that switches on in the corona above a current density threshold. We model an entire single magnetic flux tube, in the solar atmosphere extending from the high-beta chromosphere to the low-beta corona through the steep transition region. The magnetic field expands from the chromosphere to the corona. The maximum resolution is ~30 km. We obtain an overall evolution typical of loop models and realistic loo…
The Influence of the Digitalisation of the Distribution Channel in the Process of Bypassing Wholesalers: The Case of a Distribution Triad
2022
• ObjectivesThe wholesaler, a traditional player in distribution, has been going through a new phase in its evolution over the last twenty years. Driven by the digitalisation of activities, upstream and downstream players are trying to bypass it and new players such as commercial platforms are appearing. In order to understand this phenomenon, this research analyses how the wholesaler manages to keep a part of the flows between the actors of the distribution channel.• MethodA qualitative analysis by individual interviews within the building materials sector highlights the appropriation of informational flows by manufacturers leading to the phenomenon of partial disintermediation which affec…
Caractérisation expérimentale de la variabilité phénotypique du système racinaire nodulé de génotypes contrastés de pois (Pisum sativum L.), en phase…
2013
One of the challenges in plant breeding pea is to offer adapted genotypes to non-optimal environmental conditions. One of the factors limiting the agronomic performance of the pea is related to the environment plant sensitivity. Nodulated root system traits determine this sensitivity. The characterization of phenotypic traits combinations of the nodulated root system in different peas genotypes is interesting to suggest new plant breeding traits. The objective of this work was to experimentally characterize the phenotypic variability of the nodulated root system of 10 pea genotypes. The analysis was conducted under controlled conditions. The plants were grown in the absence of nitrates. Phe…