Schmidt balls around the identity

Robustness measures as introduced by Vidal and Tarrach [PRA, 59, 141-155] quantify the extent to which entangled states remain entangled under mixing. Analogously, we introduce here the Schmidt robustness and the random Schmidt robustness. The latter notion is closely related to the construction of Schmidt balls around the identity. We analyse the situation for pure states and provide non-trivial upper and lower bounds. Upper bounds to the random Schmidt-2 robustness allow us to construct a particularly simple distillability criterion. We present two conjectures, the first one is related to the radius of inner balls around the identity in the convex set of Schmidt number n-states. We also conjecture a class of optimal Schmidt witnesses for pure states.Comment: 7 pages, 1 figur

The fundamental parameters of the roAp star 10 Aql

Due to the strong magnetic field and related abnormal surface layers existing in rapidly oscillating Ap stars, systematic errors are likely to be present when determining their effective temperatures, which potentially compromises asteroseismic studies of these pulsators. Using long-baseline interferometry, our goal is to determine accurate angular diameters of a number of roAp targets to provide a temperature calibration for these stars. We obtained interferometric observations of 10 Aql with the visible spectrograph VEGA at the CHARA array. We determined a limb-darkened angular diameter of 0.275+/-0.009 mas and deduced a linear radius of 2.32+/-0.09 R_sun. We estimated the star's bolometric flux and used it, in combination with its parallax and angular diameter, to determine the star's luminosity and effective temperature. For two data sets of bolometric flux we derived an effective temperature of 7800+/-170 K and a luminosity of 18+/-1 L_sun or of 8000+/-210 K and 19+/-2 L_sun. We used these fundamental parameters together with the large frequency separation to constrain the mass and the age of 10 Aql, using the CESAM stellar evolution code. Assuming a solar chemical composition and ignoring all kinds of diffusion and settling of elements, we obtained a mass of 1.92 M_sun and an age of 780 Gy or a mass of 1.95 M_sun and an age of 740 Gy, depending on the considered bolometric flux. For the first time, we managed to determine an accurate angular diameter for a star smaller than 0.3 mas and to derive its fundamental parameters. In particular, by only combining our interferometric data and the bolometric flux, we derived an effective temperature that can be compared to those derived from atmosphere models. Such fundamental parameters can help for testing the mechanism responsible for the excitation of the oscillations observed in the magnetic pulsating stars

Perfil fermentativo da silagem de jaca in natura e acrescida de uréia.

Objetivou-se avaliar o perfil fermentativo das silagens de jaca in natura e aditivada com 1% de uréia. Utilizou-se silos experimentais feitos de cano de PVC, 10 cm de diâmetros x 40 cm de comprimento. As aberturas dos silos ocorreram aos 1, 3, 5, 7, 14, 28 e 56 dias após a ensilagem. Os teores de matéria seca (MS) e proteína bruta (PB) foram elevados significativamente (P<0,05) com a adição de uréia. O pH encontrado em ambos os tratamentos foi considerado ideal para uma silagem. Os valores de nitrogênio amoniacal (N-NH3/NT) encontrados foram baixos nos tratamentos, e a N-NH3, assim como a PB, apresentaram comportamento quadrático (P<0,05). A matéria seca dos dois tratamentos decresceu linearmente (P<0,05). A adição de uréia contribui para o aumento do teor de PB, e não comprometeu as características qualitativas de uma silagem bem conservada

Composição bromatológica do co-produto do desfibramento do sisal submetido a amonização.

Objetivou-se avaliar o efeito da adição de três concentrações de uréia pecuária sobre a composição bromatológica do co-produto do desfibramento do sisal

Balanço de nitrogênio em ovinos alimentados com silagens de seis variedades de milho precoce ou super-precoce.

Zootec 2011