225 research outputs found
The Feeding Value of Silage Made from Peas Grown Alone or in Mixture with Cereals
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
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
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
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 and we will show
that some properties of this evolution equation can be obtained from a constant
coefficient equation.Comment: 21 page
R-matrix presentation for (super)-Yangians Y(g)
We give a unified RTT presentation of (super)-Yangians Y(g) for so(n), sp(2n)
and osp(m|2n).Comment: 9 page
Magnetic and electric dipole moments of the H^3 Δ_1 state in ThO
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
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
Radiative decays of quarkonium states, momentum operator expansion and nilpotent operators
We present the method of calculation of radiative decays of composite
quark-antiquark systems with different J^{PC}: (Q\bar Q)_{in} -> gamma (Q\bar
Q)_{out}. The method is relativistic invariant, it is based on the double
dispersion relation integrals over the masses of composite mesons, it can be
used for the high spin particles and provides us with the gauge invariant
transition amplitudes. We apply this method to the case when the photon is
emitted by a constituent in the intermediate state (additive quark model). We
perform the momentum operator expansion of the spin amplitudes for the decay
processes. The problem of nilpotent spin operators is discussed.Comment: 21 pages, 1 figur
Spectrum generating algebra for the continuous spectrum of a free particle in Lobachevski space
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
and the SGA is . We start with a
representation of 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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