613 research outputs found

    4-H Project Guide: Poultry Production

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    Any boy or girl who wishes to enroll in the 4-H Poultry Project must be 10 years old on or before May 31; and must not have reached the age of 21 on January 1 of the current year. This boy or girl must be enrolled in the project before May 31. The 4-H member may have chickens, turkeys, ducks, or geese as the poultry project. The chicks should be bought at a reliable local hatchery each year. The first-year member should raise one hundred or more baby chicks. The following years, the member should enlarge the project. In taking care of the poultry project, the boy or girl should have the following things to do: the member should sell the eggs and birds and purchase the feed; improve the poultry houses and equipment; and keep a record of the money spent on the flock and received from the flock. A record also should be made of the amount and cost of equipment such as self-feeders, water fountains, and other similar equipment and supplies

    Influence of damping on the vanishing of the electro-optic effect in chiral isotropic media

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    Using first principles, it is demonstrated that radiative damping alone cannot lead to a nonvanishing electro-optic effect in a chiral isotropic medium. This conclusion is in contrast with that obtained by a calculation in which damping effects are included using the standard phenomenological model. We show that these predictions differ because the phenomenological damping equations are valid only in regions where the frequencies of the applied electromagnetic fields are nearly resonant with the atomic transitions. We also show that collisional damping can lead to a nonvanishing electrooptic effect, but with a strength sufficiently weak that it is unlikely to be observable under realistic laboratory conditions

    Influence of radiative damping on the optical-frequency susceptibility

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    Motivated by recent discussions concerning the manner in which damping appears in the electric polarizability, we show that (a) there is a dependence of the nonresonant contribution on the damping and that (b) the damping enters according to the "opposite sign prescription." We also discuss the related question of how the damping rates in the polarizability are related to energy-level decay rates

    Large-eddy simulation of the lid-driven cubic cavity flow by the spectral element method

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    This paper presents the large-eddy simulation of the lid-driven cubic cavity flow by the spectral element method (SEM) using the dynamic model. Two spectral filtering techniques suitable for these simulations have been implemented. Numerical results for Reynolds number Re=12â€Č000\text{Re}=12'000 are showing very good agreement with other experimental and DNS results found in the literature

    Parallel tempering in full QCD with Wilson fermions

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    We study the performance of QCD simulations with dynamical Wilson fermions by combining the Hybrid Monte Carlo algorithm with parallel tempering on 10410^4 and 12412^4 lattices. In order to compare tempered with standard simulations, covariance matrices between sub-ensembles have to be formulated and evaluated using the general properties of autocorrelations of the parallel tempering algorithm. We find that rendering the hopping parameter Îș\kappa dynamical does not lead to an essential improvement. We point out possible reasons for this observation and discuss more suitable ways of applying parallel tempering to QCD.Comment: 16 pages, 3 figure

    Solving Problems of Practice in Education

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    The authors identify and discuss the many complexities involved in the translation of scientific information in the social sciences into forms usable for solving problems of practice in education. As a means of appropriately handling these complexities and the issues that arise, they prescribe a series of stages to be followed from the advent of a practitioner's situational problem to the design of a response to it. They assert that unless the process of translation is conducted with the prescribed level of understanding, appreciation, and rigor, the application of knowledge will be inaccurate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68934/2/10.1177_107554708400600103.pd

    Thermodynamics of SU(3) gauge theory on anisotropic lattices

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    Finite temperature SU(3) gauge theory is studied on anisotropic lattices using the standard plaquette gauge action. The equation of state is calculated on 163×816^{3} \times 8, 203×1020^{3} \times 10 and 243×1224^{3} \times 12 lattices with the anisotropy ÎŸâ‰Ąas/at=2\xi \equiv a_s / a_t = 2, where asa_s and ata_t are the spatial and temporal lattice spacings. Unlike the case of the isotropic lattice on which Nt=4N_t=4 data deviate significantly from the leading scaling behavior, the pressure and energy density on an anisotropic lattice are found to satisfy well the leading 1/Nt21/N_t^2 scaling from our coarsest lattice, Nt/Ο=4N_t/\xi=4. With three data points at Nt/Ο=4N_t/\xi=4, 5 and 6, we perform a well controlled continuum extrapolation of the equation of state. Our results in the continuum limit agree with a previous result from isotropic lattices using the same action, but have smaller and more reliable errors.Comment: RevTeX, 21 pages, 17 PS figures. A quantitative test about the benefit of anisotropic lattices added, minor errors corrected. Final version for PR

    Comparative Study of full QCD Hadron Spectrum and Static Quark Potential with Improved Actions

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    We investigate effects of action improvement on the light hadron spectrum and the static quark potential in two-flavor QCD for a−1≈1a^{-1} \approx 1 GeV and mPS/mV=0.7−0.9m_{PS}/m_V = 0.7-0.9. We compare a renormalization group improved action with the plaquette action for gluons, and the SW-clover action with the Wilson action for quarks. We find a significant improvement in the hadron spectrum by improving the quark action, while the gluon improvement is crucial for a rotationally invariant static potential. We also explore the region of light quark masses corresponding to mPS/mV≄0.4m_{PS}/m_V \geq 0.4 on a 2.7 fm lattice using the improved gauge and quark action. A flattening of the potential is not observed up to 2 fm.Comment: LaTeX, 35 pages, 22 eps figures, uses revtex and eps

    Quantum coherence in a degenerate two-level atomic ensemble: for a transition Fe=0↔Fg=1F_e=0\leftrightarrow F_g=1

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    For a transition Fe=0↔Fg=1F_e=0\leftrightarrow F_g=1 driven by a linearly polarized light and probed by a circularly light, quantum coherence effects are investigated. Due to the coherence between the drive Rabi frequency and Zeeman splitting, electromagnetically induced transparency, electromagnetically induced absorption, and the transition from positive to negative dispersion are obtained, as well as the populations coherently oscillating in a wide spectral region. At the zero pump-probe detuning, the subluminal and superluminal light propagation is predicted. Finally, coherent population trapping states are not highly sensitive to the refraction and absorption in such ensemble.Comment: 9 pages, 6 figure
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