1,332 research outputs found

    Influence of Winter Cow Feeding Strategies on Cow Response

    Get PDF
    The objective of this study was to investigate the effects of the primary maternal prepartum dietary energy source (forage vs. concentrate) during mid- and late-gestation on dam body weight (BW), body condition score (BCS), pregnancy rate, and economic responses

    Comparison of Winter Cow Feeding Strategies on Offspring Performance and Meat Quality

    Get PDF
    The objective of this study was to investigate the effects of maternal prepartum dietary energy source (forage vs. concentrate) during mid- and late-gestation on offspring growth performance, carcass characteristics and meat quality

    Exploring the Thermodynamics of a Universal Fermi Gas

    Full text link
    From sand piles to electrons in metals, one of the greatest challenges in modern physics is to understand the behavior of an ensemble of strongly interacting particles. A class of quantum many-body systems such as neutron matter and cold Fermi gases share the same universal thermodynamic properties when interactions reach the maximum effective value allowed by quantum mechanics, the so-called unitary limit [1,2]. It is then possible to simulate some astrophysical phenomena inside the highly controlled environment of an atomic physics laboratory. Previous work on the thermodynamics of a two-component Fermi gas led to thermodynamic quantities averaged over the trap [3-5], making it difficult to compare with many-body theories developed for uniform gases. Here we develop a general method that provides for the first time the equation of state of a uniform gas, as well as a detailed comparison with existing theories [6,14]. The precision of our equation of state leads to new physical insights on the unitary gas. For the unpolarized gas, we prove that the low-temperature thermodynamics of the strongly interacting normal phase is well described by Fermi liquid theory and we localize the superfluid transition. For a spin-polarized system, our equation of state at zero temperature has a 2% accuracy and it extends the work of [15] on the phase diagram to a new regime of precision. We show in particular that, despite strong correlations, the normal phase behaves as a mixture of two ideal gases: a Fermi gas of bare majority atoms and a non-interacting gas of dressed quasi-particles, the fermionic polarons [10,16-18].Comment: 8 pages, 5 figure
    corecore