6,330 research outputs found
Weak interactions and quasi-stable particle energy loss
We discuss the interplay between electromagnetic energy loss and weak
interactions in the context of quasistable particle particle propagation
through materials. As specific examples, we consider staus, where weak
interactions may play a role, and taus, where they don't.Comment: 4 pages, 4 figures, to appear in the proceedings of the Second
Workshop on TeV Particle Astrophysics (August 2006, Madison, WI
Anisotropic Lifshitz Point at
We present the critical exponents , and
for an -axial Lifshitz point at second order in an expansion.
We introduced a constraint involving the loop momenta along the -dimensional
subspace in order to perform two- and three-loop integrals. The results are
valid in the range . The case corresponds to the usual
Ising-like critical behavior.Comment: 10 pages, Revte
Indicacao de cultivares de feijao para o Estado de Alagoas.
A cultura do feijao, no Estado, e explorada, na sua grande maioria, por pequenos produtores, em regime de subsistencia, com pouca adocao de tecnicas de cultivo e utilizacao de semente de baixo potencial produtivo. A indicacao de cultivares bem adaptadas ao meio e com caracteristicas favoraveis se constitui em objeto do presente estudo. O ensaio foi conduzido no Campo Experimental de Santana do Ipanema, AL, em solo Litolico Eutrofico, de textura arenosa. Foram testadas dez cultivares de feijao, em consorcio com 3 de feijao. O delineamento usado foi o de blocos ao acaso, com 4 repeticoes, tendo cada parcela uma area util de 12 2. Efetuou-se a adubacao basica, com aplicacao de 30-60-20 kg/ha de N, P2O5 e K2O, respectivamente, nas formas de sulfato de amonio, superfosfato simples e cloreto de potassio. As cultivares introduzidas, Gordo e Bagajo, destacaram-se das demais, com rendimentos superiores as regionais Vagem Roxa, Rim de Porco, Santana do Ipanema e Lages, cujas producoes foram: 1068, 865, 640, 613 e 591 kg/ha, respectivamente, em cultivo consorciado. Observou-se tambem que as cultivares que apresentaram com comportamento em consorcio, assim se mostraram quando isoladas
Exportação de nutrientes pelas videiras cvs. Itália e Benitaka cultivads no Vale do São Francisco.
Astrophysical Neutrino Event Rates and Sensitivity for Neutrino Telescopes
Spectacular processes in astrophysical sites produce high-energy cosmic rays
which are further accelerated by Fermi-shocks into a power-law spectrum. These,
in passing through radiation fields and matter, produce neutrinos. Neutrino
telescopes are designed with large detection volumes to observe such
astrophysical sources. A large volume is necessary because the fluxes and
cross-sections are small. We estimate various telescopes' sensitivities and
expected event rates from astrophysical sources of high-energy neutrinos. We
find that an ideal detector of km^2 incident area can be sensitive to a flux of
neutrinos integrated over energy from 10^5 and 10^{7} GeV as low as 1.3 *
10^(-8) * E^(-2) (GeV/cm^2 s sr) which is three times smaller than the
Waxman-Bachall conservative upper limit on potential neutrino flux. A real
detector will have degraded performance. Detection from known point sources is
possible but unlikely unless there is prior knowledge of the source location
and neutrino arrival time.Comment: Section added +modification
Reptilia, Squamata, Colubridae, <i>Rhinobothryum lentiginosum</i> (Scopoli 1785): First record from state of Acre, Brazil
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