5,656 research outputs found
Analysis of the retail survey of products that carry welfare- claims and of non-retailer led assurance schemes whose logos accompany welfare-claims.
This report serves two aims. Firstly, this report contains analysis of the retail audit
(sub-deliverable 1.2.2.1) of welfare-friendly food products in the 6 study countries.
The report gives the results of an emerging comparative analysis of the ‘market’ for
welfare-friendly food products in the 6 study countries. It also outlines ‘non-retailer’
led schemes1 whose products occurred in the study. In this way, an emerging picture
of the actual product ranges, that make claims about welfare-friendliness, will be
drawn based on fieldwork carried out from November 2004 until April 2005. Also,
the report explores how the different legislative and voluntary standards on animal
welfare compare across different countries and how these actively advertise their
welfare-friendlier component to consumers through food packaging. <br/
Cartan-Hannay-Berry Phases and Symmetry
We give a systematic treatment of the treatment of the classical Hannay-Berry phases for mechanical
systems in terms of the holonomy of naturally constructed connections on bundles associated to the system.
We make the costructions using symmetry and reduction and, for moving systems, we use the Cartan
connection. These ideas are woven with the idea of Montgomery [1988] on the averaging of connections to
produce the Hannay-Berry connection
The retail of welfare-friendly products: A comparative assessment of the nature of the market for welfare-friendly products in six European Countries
This paper attempts to describe the market for welfare-friendly foodstuffs within larger retailing trends in six study countries in Europe (Norway, Sweden, Italy, France, the Netherlands and the UK). This is based on the findings to date from the work carried out by the work package 1.2 whose aims are to study the current and potential market for welfare-friendly foodstuffs. The aims of the current empirical stages of work package 1.2 are focussed on – what do retailers communicate to consumers about animal welfare? How is animal welfare framed? Are welfare-claims used on their own or within broader issues of quality
Stability Analysis of a Rigid Body with Attached Geometrically Nonlinear Rod by the Energy-Momentum Method
This paper applies the energy-momentum method to the problem of nonlinear stability of relative equilibria of a rigid body with attached flexible appendage in a uniformly rotating state. The appendage is modeled as a geometrically exact rod which allows for finite bending, shearing and twist in three dimensions. Application of the energy-momentum method to this example depends crucially on a
special choice of variables in terms of which the second variation block diagonalizes into blocks associated with rigid body modes and internal vibration modes respectively. The analysis yields a nonlinear stability result which states that relative equilibria are nonlinearly stable provided that; (i) the angular velocity is bounded above by the square root of the minimum eigenvalue of an associated
linear operator and, (ii) the whole assemblage is rotating about the minimum axis of inertia
Reduction, Symmetry and Phases in Mechanics
Various holonomy phenomena are shown to be instances of the reconstruction procedure
for mechanical systems with symmetry. We systematically exploit this point of view for fixed
systems (for example with controls on the internal, or reduced, variables) and for slowly moving
systems in an adiabatic context. For the latter, we obtain the phases as the holonomy for a
connection which synthesizes the Cartan connection for moving mechanical systems with the
Hannay-Berry connection for integrable systems. This synthesis allows one to treat in a natural
way examples like the ball in the slowly rotating hoop and also non-integrable mechanical systems
The geometry and analysis of the averaged Euler equations and a new diffeomorphism group
We present a geometric analysis of the incompressible averaged Euler
equations for an ideal inviscid fluid. We show that solutions of these
equations are geodesics on the volume-preserving diffeomorphism group of a new
weak right invariant pseudo metric. We prove that for precompact open subsets
of , this system of PDEs with Dirichlet boundary conditions are
well-posed for initial data in the Hilbert space , . We then use
a nonlinear Trotter product formula to prove that solutions of the averaged
Euler equations are a regular limit of solutions to the averaged Navier-Stokes
equations in the limit of zero viscosity. This system of PDEs is also the model
for second-grade non-Newtonian fluids
Discrete Routh Reduction
This paper develops the theory of abelian Routh reduction for discrete
mechanical systems and applies it to the variational integration of mechanical
systems with abelian symmetry. The reduction of variational Runge-Kutta
discretizations is considered, as well as the extent to which symmetry
reduction and discretization commute. These reduced methods allow the direct
simulation of dynamical features such as relative equilibria and relative
periodic orbits that can be obscured or difficult to identify in the unreduced
dynamics. The methods are demonstrated for the dynamics of an Earth orbiting
satellite with a non-spherical correction, as well as the double
spherical pendulum. The problem is interesting because in the unreduced
picture, geometric phases inherent in the model and those due to numerical
discretization can be hard to distinguish, but this issue does not appear in
the reduced algorithm, where one can directly observe interesting dynamical
structures in the reduced phase space (the cotangent bundle of shape space), in
which the geometric phases have been removed. The main feature of the double
spherical pendulum example is that it has a nontrivial magnetic term in its
reduced symplectic form. Our method is still efficient as it can directly
handle the essential non-canonical nature of the symplectic structure. In
contrast, a traditional symplectic method for canonical systems could require
repeated coordinate changes if one is evoking Darboux' theorem to transform the
symplectic structure into canonical form, thereby incurring additional
computational cost. Our method allows one to design reduced symplectic
integrators in a natural way, despite the noncanonical nature of the symplectic
structure.Comment: 24 pages, 7 figures, numerous minor improvements, references added,
fixed typo
A block diagonalization theorem in the energy-momentum method
We prove a geometric generalization of a block diagonalization theorem first found by the authors for
rotating elastic rods. The result here is given in the general context of simple mechanical systems with a
symmetry group acting by isometries on a configuration manifold. The result provides a choice of
variables for linearized dynamics at a relative equilibrium which block diagonalizes the second variation of
an augmented energy these variables effectively separate the rotational and internal vibrational modes. The
second variation of the effective Hamiltonian is block diagonal. separating the modes completely. while the
symplectic form has an off diagonal term which represents the dynamic interaction between these modes.
Otherwise, the symplectic form is in a type of normal form. The result sets the stage for the development
of useful criteria for bifurcation as well as the stability criteria found here. In addition, the techniques
should apply to other systems as well, such as rotating fluid masses
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