Critical Evaluation of Euler-Euler and Euler-Lagrangian Modelling Strategies in a 2-D Gas Fluidized Bed

Two-phase granular systems are commonly encountered in industry, and fluidized beds are particularly important due to their excellent heat and mass transfer characteristics. Here, we critically evaluate the differences between two modelling strategies, Euler-Euler and Euler-Lagrangian models. Euler-Euler simulations were performed using MFIX and an in-house code was used for Euler-Lagrangian simulations. A 2D bed of width, height and transverse thickness of respectively, 0.2 m, 0.5 m and 0.01 m, served as a test case. The settled bed height was H0 = 0.2 m. Particles of density ρ = 1000 kg/m³ and diameter dp = 1.2 mm were fluidized with air. The drag-law proposed by Benyahia et al. (10) was used in both models. Comparison between the simulation results was based on both instantaneous and time-averaged properties. A particular focus of this study was the influence of the coefficients of restitution and friction on the simulation results

The silence of self-knowledge

Gareth Evans famously affirmed an explanatory connection between answering the question whether p and knowing whether one believes that p. This is commonly interpreted in terms of the idea that judging that p constitutes an adequate basis for the belief that one believes that p. This paper formulates and defends an alternative, more modest interpretation, which develops from the suggestion that one can know that one believes that p in judging that p

Analysing public service outsourcing: the value of a regulatory perspective

This article draws on findings from two longitudinal case studies of voluntary organisations engaged in delivering social care services via purchaser – provider relations with local authorities. The study focuses on changes to contractual relations, employment conditions in provider organisations and service quality. The article argues the influence of the market on these changes can only be adequately comprehended by rooting the analysis in an understanding of the way in which surrounding regulatory frameworks shape its structure and operation. In doing so, it reveals how in an era of shifting market conditions characterised by greater competition and dramatic local authority cuts, a ‘soft’ regulatory framework offers little support to partnership relations between voluntary organisations and local authorities. Instead, the regulatory environment undermines financial security among voluntary organisations, degrades employment conditions in them and raises concerns regarding their service quality

Vortex Rings in two Component Bose-Einstein Condensates

We study the structure of the vortex core in two-component Bose-Einstein condensates. We demonstrate that the order parameter may not vanish and the symmetry may not be restored in the core of the vortex. In this case such vortices can form vortex rings known as vortons in particle physics literature. In contrast with well-studied superfluid $^4He$, where similar vortex rings can be stable due to Magnus force only if they move, the vortex rings in two-component BECs can be stable even if they are at rest. This beautiful effect was first discussed by Witten in the cosmic string context, where it was shown that the stabilization occurs due to condensation of the second component of the field in the vortex core. This second condensate trapped in the core may carry a current along the vortex ring counteracting the effect of string tension that causes the loop to shrink. We speculate that such vortons may have been already observed in the laboratory. We also speculate that the experimental study of topological structures in BECs can provide a unique opportunity to study cosmology and astrophysics by doing laboratory experiments.Comment: 21 pages, 2 figure

The potential of trading activity income to fund third sector organisations operating in deprived areas

In the United Kingdom, as in other countries, Third Sector Organisations (TSOs) have been drawn towards income sources associated with trading activities (Teasdale, 2010), but many remain reliant on grant funding to support such activities (Chell, 2007). Using a multivariate analysis approach and data from the National Survey of Charities and Social Enterprises (NSCSE), it is found that trading activities are used relatively commonly in deprived areas. These organisations are also more likely to attempt to access public sector funds. This suggests policy-makers need to consider the impact of funding cuts on TSOs in the most deprived areas as TSOs are unlikely achieve their objectives without continuing support

Dynamics of power in contemporary media policy-making

Despite the growing interest in the organization and regulation of media industries, there is relatively little public discussion of the material processes through which media policy is developed. At a time of considerable change in the global media environment, new actors and new paradigms are emerging that are set to shift the balance of power between public and private interests in the policy-making process. This article focuses on some core challenges to the pluralist conception of public policy-making that still dominates today and considers whether key aspects of UK and American media policy-making can be said to be competitive, accessible, transparent or rational. Based on interviews with a wide range of ‘stakeholders’, the article assesses the power dynamics that underlie media policy-making and argues that the process is skewed by the taken-for-granted domination of market ideology

The Grounds and Extent of Legal Responsibility

To question that is the title of this symposium, What Do Compensatory Damages Compensate?, requires consideration of the basic grounds and purposes of legal responsibility. The question is usefully brought into sharper focus by the specific questions and puzzles posed to the contributors to stimulate thought and discussion