96 research outputs found
Diurnal behavior of dairy cows on alfalfa pastures supplemented with corn silage and concentrate
Evidence for a mixed mass composition at the `ankle' in the cosmic-ray spectrum
We report a first measurement for ultra-high energy cosmic rays of the
correlation between the depth of shower maximum and the signal in the water
Cherenkov stations of air-showers registered simultaneously by the fluorescence
and the surface detectors of the Pierre Auger Observatory. Such a correlation
measurement is a unique feature of a hybrid air-shower observatory with
sensitivity to both the electromagnetic and muonic components. It allows an
accurate determination of the spread of primary masses in the cosmic-ray flux.
Up till now, constraints on the spread of primary masses have been dominated by
systematic uncertainties. The present correlation measurement is not affected
by systematics in the measurement of the depth of shower maximum or the signal
in the water Cherenkov stations. The analysis relies on general characteristics
of air showers and is thus robust also with respect to uncertainties in
hadronic event generators. The observed correlation in the energy range around
the `ankle' at differs significantly from
expectations for pure primary cosmic-ray compositions. A light composition made
up of proton and helium only is equally inconsistent with observations. The
data are explained well by a mixed composition including nuclei with mass . Scenarios such as the proton dip model, with almost pure compositions, are
thus disfavoured as the sole explanation of the ultrahigh-energy cosmic-ray
flux at Earth.Comment: Published version. Added journal reference and DOI. Added Report
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Estimativas de herdabilidade e tendĂȘncias genĂ©ticas para caracterĂsticas de crescimento e reprodutivas em bovinos da raça Nelore: Estimates of heritability and genetic trends for growth and reproduction traits in Nelore cattle
Interação genótipo-ambiente sobre os pesos aos 205 e 365 dias de idade em bovinos da raça Nelore em diferentes regiÔes do Brasil
Biology and population features of a rare species of Pseudopimelodidae from the Upper ParanĂĄ River Basin
Implantação de pastagens sob sistema monocultivo e integrado com lavoura utilizando biofertilizante de cama de aviårio como adubação de cobertura
Estimation of genetic parameters for growth traits in TabapuĂŁ cattle using a multi-trait model
Estimativas de parĂąmetros genĂ©ticos para caracterĂsticas de crescimento em ovinos da raça Somalis Brasileira
Fatores genéticos e de ambiente sobre o intervalo de partos de cabras leiteiras no semi-årido nordestino
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