220 research outputs found

    The Feeding Value of Silage Made from Peas Grown Alone or in Mixture with Cereals

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    The interest in pea as a forage crop rich in protein does not decrease. In areas frequent summer drought pea (Pisum sativum) as a whole plant for forage gives assured yield and may be used for zero grazing, hay or silage. The winter varieties use winter-spring soil moisture better and give higher yield than the spring varieties, but they lodge, so it is necessary to sow them with supporting cereal crops to increase lodging resistance. The objective of the study was to compare the intake, digestibility, energy value and quality index of two wilted silage made from winter pea, variety Pleven 10, and from pea-cereal crop mixture

    Integrable mixing of A_{n-1} type vertex models

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    Given a family of monodromy matrices {T_u; u=0,1,...,K-1} corresponding to integrable anisotropic vertex models of A_{(n_u)-1}-type, we build up a related mixed vertex model by means of glueing the lattices on which they are defined, in such a way that integrability property is preserved. Algebraically, the glueing process is implemented through one dimensional representations of rectangular matrix algebras A(R_p,R_q), namely, the `glueing matrices' zeta_u. Here R_n indicates the Yang-Baxter operator associated to the standard Hopf algebra deformation of the simple Lie algebra A_{n-1}. We show there exists a pseudovacuum subspace with respect to which algebraic Bethe ansatz can be applied. For each pseudovacuum vector we have a set of nested Bethe ansatz equations identical to the ones corresponding to an A_{m-1} quasi-periodic model, with m equal to the minimal range of involved glueing matrices.Comment: REVTeX 28 pages. Here we complete the proof of integrability for mixed vertex models as defined in the first versio

    Global hypoellipticity and global solvability for vector fields on compact Lie groups

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    We present necessary and sufficient conditions to have global hypoellipticity and global solvability for a class of vector fields defined on a product of compact Lie groups. In view of Greenfield's and Wallach's conjecture, about the non-existence of globally hypoelliptic vector fields on compact manifolds different from tori, we also investigate different notions of regularity weaker than global hypoellipticity and describe completely the global hypoellipticity and global solvability of zero-order perturbations of our vector fields. We also present a class of vector fields with variable coefficients whose operators can be reduced to a normal form, and we prove that the study of the global properties of such operators is equivalent to the study of the respective properties for their normal forms.Comment: 43 page

    Partial Fourier series on compact Lie groups

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    In this note we investigate the partial Fourier series on a product of two compact Lie groups. We give necessary and sufficient conditions for a sequence of partial Fourier coefficients to define a smooth function or a distribution. As applications, we will study conditions for the global solvability of an evolution equation defined on T1×S3\mathbb{T}^1\times\mathbb{S}^3 and we will show that some properties of this evolution equation can be obtained from a constant coefficient equation.Comment: 21 page

    Magnetic and electric dipole moments of the H^3 Δ_1 state in ThO

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    The metastable H^3 Δ_1 state in the thorium monoxide (ThO) molecule is highly sensitive to the presence of a CP -violating permanent electric dipole moment of the electron (eEDM) [E. R. Meyer and J. L. Bohn, Phys. Rev. A 78, 010502 (2008)]. The magnetic dipole moment μ_H and the molecule-fixed electric dipole moment D_H of this state are measured in preparation for a search for the eEDM. The small magnetic moment μH=8.5(5)×10^(−3)μ_B displays the predicted cancellation of spin and orbital contributions in a ^3Δ_1 paramagnetic molecular state, providing a significant advantage for the suppression of magnetic field noise and related systematic effects in the eEDM search. In addition, the induced electric dipole moment is shown to be fully saturated in very modest electric fields (<10 V/cm). This feature is favorable for the suppression of many other potential systematic errors in the ThO eEDM search experiment

    Assessment of fire safety of evacuation routes in industrial premises

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    The paper presents results of the development of new scientific and methodological principles for assessing the fire safety of industrial premises evacuation routes. The basis of these principles is the scientific methodology for managing industrial safety, developed at the department of life safety at the Perm National Research Polytechnic University. Following is discussed in the paper: 1) method of modelling scenarios for fire break-out and development based on Ishikawa diagram, 2) mathematical model describing the stepwise process of fire break-out and development in accordance with diagram topology, 3) indicator of fire safety of evacuation routes, 4) model for estimating the probability of evacuation of people along through the evacuation routes, 5) model for estimating the probability of evacuation from the premises. The developments mentioned above took into account problematic issues related to the behavior of people during a fire (operational actions to turn off equipment or stop the process, speed of human response to fire signals and decision time), movement of people during evacuation inside confined or limited spaces (mines, containers, wells, vessels etc.), remoteness of workplaces from evacuation routes (scaffolding, crane tracks, work at height etc.), reliability of evacuation warning and control systems, absence of a clear algorithm for constructing fire scenarios. The areas of scientific research application are identified. A method for assessing the safety of evacuation routes in relation to fire extinguishing substances of automatic fire extinguishing units that pose a danger to human health is considered. Examples of the application of scientific developments in the assessment of evacuation routes fire safety and modelling a fire scenario at a specific production facility are given

    Optically trapped Feshbach molecules of fermionic 161Dy and 40K

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    We report on the preparation of a pure ultracold sample of bosonic DyK Feshbach molecules, which are composed of the fermionic isotopes 161Dy and 40K. Employing a magnetic sweep across a resonance located near 7.3 G, we produce up to 5000 molecules at a temperature of about 50 nK. For purification from the remaining atoms, we apply a Stern-Gerlach technique based on magnetic levitation of the molecules in a very weak optical dipole trap. With the trapped molecules we finally reach a high phase-space density of about 0.1. We measure the magnetic field dependence of the molecular binding energy and the magnetic moment, refining our knowledge of the resonance parameters. We also demonstrate a peculiar anisotropic expansion effect observed when the molecules are released from the trap and expand freely in the magnetic levitation field. Moreover, we identify an important lifetime limitation that is imposed by the 1064-nm infrared trap light itself and not by inelastic collisions. The light-induced decay rate is found to be proportional to the trap light intensity and the closed-channel fraction of the Feshbach molecule. These observations suggest a one-photon coupling to electronically excited states to limit the lifetime and point to the prospect of loss suppression by optimizing the wavelength of the trapping light. Our results represent important insights and experimental steps on the way to achieve quantum-degenerate samples of DyK molecules and novel superfluids based on mass-imbalanced fermion mixtures

    Spectrum generating algebra for the continuous spectrum of a free particle in Lobachevski space

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    In this paper, we construct a Spectrum Generating Algebra (SGA) for a quantum system with purely continuous spectrum: the quantum free particle in a Lobachevski space with constant negative curvature. The SGA contains the geometrical symmetry algebra of the system plus a subalgebra of operators that give the spectrum of the system and connects the eigenfunctions of the Hamiltonian among themselves. In our case, the geometrical symmetry algebra is so(3,1)\frak{so}(3,1) and the SGA is so(4,2)\frak{so}(4,2). We start with a representation of so(4,2)\frak{so}(4,2) by functions on a realization of the Lobachevski space given by a two sheeted hyperboloid, where the Lie algebra commutators are the usual Poisson-Dirac brackets. Then, introduce a quantized version of the representation in which functions are replaced by operators on a Hilbert space and Poisson-Dirac brackets by commutators. Eigenfunctions of the Hamiltonian are given and "naive" ladder operators are identified. The previously defined "naive" ladder operators shift the eigenvalues by a complex number so that an alternative approach is necessary. This is obtained by a non self-adjoint function of a linear combination of the ladder operators which gives the correct relation among the eigenfunctions of the Hamiltonian. We give an eigenfunction expansion of functions over the upper sheet of two sheeted hyperboloid in terms of the eigenfunctions of the Hamiltonian.Comment: 23 page
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