From Coherent Modes to Turbulence and Granulation of Trapped Gases

The process of exciting the gas of trapped bosons from an equilibrium initial state to strongly nonequilibrium states is described as a procedure of symmetry restoration caused by external perturbations. Initially, the trapped gas is cooled down to such low temperatures, when practically all atoms are in Bose-Einstein condensed state, which implies the broken global gauge symmetry. Excitations are realized either by imposing external alternating fields, modulating the trapping potential and shaking the cloud of trapped atoms, or it can be done by varying atomic interactions by means of Feshbach resonance techniques. Gradually increasing the amount of energy pumped into the system, which is realized either by strengthening the modulation amplitude or by increasing the excitation time, produces a series of nonequilibrium states, with the growing fraction of atoms for which the gauge symmetry is restored. In this way, the initial equilibrium system, with the broken gauge symmetry and all atoms condensed, can be excited to the state, where all atoms are in the normal state, with completely restored gauge symmetry. In this process, the system, starting from the regular superfluid state, passes through the states of vortex superfluid, turbulent superfluid, heterophase granular fluid, to the state of normal chaotic fluid in turbulent regime. Both theoretical and experimental studies are presented.Comment: Latex file, 25 pages, 4 figure

Controlling the net: European approaches to content and access regulation

This article has been accepted for publication in the journal, Journal of Information Science [© CILIP] and the final (edited, revised and typeset) version of this paper will be published in Journal of Information Science, by SAGE Publications Ltd, All rights reserved. © CILIP. For more information please visit: http://jis.sagepub.co.uk

Flexible friends? Lone parents and retail

This paper considers a so far unappreciated sector of the labour market - lone parents. The number of lone parents has increased dramatically in recent years. Consideration of lone parents allows for a discussion of two key issues within the contemporary labour market: the attempts by government to increase the number of lone parents in work; and relatedly, governmental initiatives which have sought to reform the tax and benefit system to make work more attractive and also address the need for work-life balance for parents. The paper considers these issues by reporting a small-scale piece of research that sought to address the viability of the supermarket sector as a suitable employer for lone parents. The results suggest that the increasing numbers of students entering the labour market means that supermarkets are unlikely to consider lone parents as an important, discrete source of labour

Lone parents, the New Deal and the opportunities and barriers to retail employment

The number of lone parents has increased considerably in recent years and the UK Labour Government has reacted by encouraging them to move from welfare and into work. This group face multi-dimensional and complex barriers to employment that the government has attempted to rectify through the introduction of various initiatives such as the National Childcare Strategy, the Working Families Tax Credit and the New Deal. The availability of appropriate employment opportunities is central to this strategy. Retail employment is perceived to be one such opportunity. This article examines the Glasgow supermarket sector as a suitable employer for clients of the New Deal for Lone Parents programme. The findings demonstrate that lone parents still experience significant barriers to work, even in a sector that is considered a viable employment option

MONTE CARLO SIMULATIONS OF ELECTRON DRIFT VELOCITIES IN THE NOBLE GASES AND THEIR MIXTURES

No abstract availabl

Does horizontal transmission invalidate cultural phylogenies?

Phylogenetic methods have recently been applied to studies of cultural evolution. However, it has been claimed that the large amount of horizontal transmission that sometimes occurs between cultural groups invalidates the use of these methods. Here, we use a natural model of linguistic evolution to simulate borrowing between languages. The results show that tree topologies constructed with Bayesian phylogenetic methods are robust to realistic levels of borrowing. Inferences about divergence dates are slightly less robust and show a tendency to underestimate dates. Our results demonstrate that realistic levels of reticulation between cultures do not invalidate a phylogenetic approach to cultural and linguistic evolution