180 research outputs found
Second-order closures for compressible turbulence
This viewgraph presentation discusses project description, turbulence models, and computational engine and results for second-order closures for compressible turbulence
Impact calculation and multicriteria classification of multiple combined sewer overflows: methodology applied to a catchment area of Grand Lyon
Approche multi-échelles pour étudier les impacts de l'évolution de l'occupation du sol et de la gestion des eaux pluviales sur l'hydrologie de bassins versants périurbains. Application au bassin de l'Yzeron (150 km2)
Study of the Flow Temperature and Ring Design Influence on the Response of a New Reduced-Size Calorimetric Cell for Nuclear Heating Quantification
Measurement of the Crab Flux Above 60 GeV with the CELESTE Cherenkov Telescope
We have converted the former solar electrical plant THEMIS (French Pyrenees)
into an atmospheric Cherenkov detector called CELESTE, which records gamma rays
above 30 GeV (7E24 Hz). Here we present the first sub-100 GeV detection by a
ground based telescope of a gamma ray source, the Crab nebula, in the energy
region between satellite measurements and imaging atmospheric Cherenkov
telescopes. At our analysis threshold energy of 60 +/- 20 GeV we measure a
gamma ray rate of 6.1 +/- 0.8 per minute. Allowing for 30% systematic
uncertainties and a 30% error on the energy scale yields an integral gamma ray
flux of I(E>60 GeV) = 6.2^{+5.3}_{-2.3} E-6 photons m^-2 s^-1. The analysis
methods used to obtain the gamma ray signal from the raw data are detailed. In
addition, we determine the upper limit for pulsed emission to be <12% of the
Crab flux at the 99% confidence level, in the same energy range. Our result
indicates that if the power law observed by EGRET is attenuated by a cutoff of
form e^{-E/E_0} then E_0 < 26 GeV. This is the lowest energy probed by a
Cherenkov detector and leaves only a narrow range unexplored beyond the energy
range studied by EGRET.Comment: 34 pages, accepted by the Astrophysical Journa
Hyperon production in proton-sulphur collisions at 200 GeV/c
The WA94 experiment uses the production of strange particles and antiparticles to investigate the properties of hot hadronic matter created in heavy--ion interactions. \PgL, \PagL, \PgXm\ and \PagXp\ particle yields and transverse mass spectra are presented for pS interactions. These results are compared with those from SS interactions. Our results are also compared with those from pW and SW interactions of the WA85 experiment
Strangeness enhancement at mid-rapidity in Pb-Pb collisions at 158 GeV/c
, , , and negative particle yields and transverse mass spectra have been measured at central rapidity in Pb-Pb and p-Pb collisions at 158 GeV/. The yields in Pb-Pb interactions % are presented as a function of the collision centrality and compared with those obtained from p-Pb collisions. Strangeness enhancement in Pb-Pb relative to p-Pb collisions increases with the strangeness content of the particle. Going from p-Pb to Pb-Pb, the strange particle yields increase faster than linearly with the number of participants up to , thereafter the increase becomes %linear with . Yields are studied as a function of the number of nucleons participating in the collision , which is estimated with the Glauber model. From p-Pb to Pb-Pb collisions the particle yields per participant increase substantially. The enhancement is more pronounced for multistrange particles, and exceeds an order of magnitude for the . For a number of participants, , greater than , however, all yields per participant appear to be constant
Coccinelle : un appareil de dépouillement automatique
Cet appareil est caractérisé par un dispositif original de corrélation des impulsions résultant de l'analyse d'une photographie par un balayage télévision qui permet de détecter les éléments linéaires et par une stratégie d'association de ces éléments en traces par approximations successives
Coccinelle : un appareil de dépouillement automatique
A pattern recognition and measurement machine is described. Two essential features are a pulse correlation circuit which detects all linear elements, and the machine works with increasing accuracy as the gathered information increases.Cet appareil est caractérisé par un dispositif original de corrélation des impulsions résultant de l'analyse d'une photographie par un balayage télévision qui permet de détecter les éléments linéaires et par une stratégie d'association de ces éléments en traces par approximations successives
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