The control of wave energy converters using active bipolar damping

A novel method for controlling wave energy converters using active bipolar damping is described and compared with current control methods. The performance of active bipolar damping is modelled numerically for two distinct types of wave energy converter and it is found that in both cases the power capture can be significantly increased relative to optimal linear damping. It is shown that this is because active bipolar damping has the potential for providing a quasi-spring or quasi-inertia, which improves the wave energy converter's tuning and amplitude of motion, resulting in the increase in power capture observed. The practical implementation of active bipolar damping is also discussed. It is noted that active bipolar damping does not require a reactive energy store and thereby reduces the cost and eliminates losses due to the cycling of reactive energy. It is also noted that active bipolar damping could be implemented using a single constant pressure double-acting hydraulic cylinder and so potentially represents a simple, efficient, robust and economic solution to the control of wave energy converters.

Delivery of Methylene Blue and meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate from cross-linked poly(vinyl alcohol) hydrogels: A potential means of photodynamic therapy of infected wounds

Poly(vinyl alcohol)-borate complexes were evaluated as a potentially novel drug delivery platform suitable for in vivo use in photodynamic antimicrobial chemotherapy (PACT) of wound infections. An optimised formulation (8.0%w/w PVA, 2.0% w/w borax) was loaded with 1.0 mg ml(-1) of the photosensitisers Methylene Blue (MB) and meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP). Both drugs were released to yield receiver compartment concentrations (>5.0 mu g ml(-1)) found to be phototoxic to both planktonic and bicifilm-grown methicillin-resistant Staphylococcus aureus (MRSA), a common cause of wound infections in hospitals. Newborn calf serum, used to simulate the conditions prevalent in an exuding wound, did not adversely affect the properties of the hydrogels and had no significant effect on the rate of TMP-mediated photodynamic kill of MRSA, despite appreciably reducing the fluence rate of incident light. However, MB-mediated photodynamic kill of MRSA was significantly reduced in the presence of calf serum and when the clinical isolate was grown in a biofilm. Results support the contention that delivery of MB or TMP using gel-type vehicles as part of PACT could make a contribution to the photodynamic eradication of MRSA from infected wounds. (C) 2009 Elsevier B.V. All rights reserved.

Continuity and Change in the European Union’s Approach to Enlargement::Turkey and Central and Eastern Europe compared

Existing studies of European Union (EU) enlargement provide few answers to questions concerning continuity and change in the dynamics of the process. This article identifies a number of conditioning factors that have shaped the EU’s approach to eastern enlargement and traces elements of continuity and change in the EU’s handling of Turkey’s membership aspirations. The article focuses on three established factors – member state preferences, supranational activism and EU capacity – and two less prominent factors – public opinion and narrative frame

Presentism and ontological symmetry

In this paper, I argue that there is an inconsistency between two presentist doctrines: that of ontological symmetry and asymmetry of fixity. The former refers to the presentist belief that the past and future are equally unreal. The latter refers to the A-Theoretic intuition that the past is closed or actual, and the future is open or potential. My position in this paper is that the presentist is unable to account for the temporal asymmetry that is so fundamentally a part of her theory. In Section I, I briefly outline a recent defence of presentism due to Craig, and argue that a flaw in this defence highlights the tension between the presentist's doctrines of ontological symmetry and asymmetry of fixity. In Section II, I undertake an investigation, on the presentist's behalf, in order to determine whether she is capable of reconciling these two doctrines. In the course of the investigation, I consider different asymmetries, other than that of ontology, which might be said fundamentally to constitute temporal asymmetry, and the asymmetry of fixity in particular. In Section III, I also consider whether the presentist is able to avail herself of some of the standard B-Theoretic accounts of the asymmetry of fixity, and argue that she cannot. Finally, I conclude that temporal asymmetry cannot be accounted for (or explained) other than through the postulation of an ontological asymmetry.

Avandia (TM) - From molecule to market for type 2 diabetes.

Type 2 diabetes is a disease fast approaching epidemic proportions throughout the world. From insulin sensitizers to PPARg agonists, the lecture will outline the successful medicinal chem. and biol. strategy underpinning the discovery and selection of Avandia, an innovative new medicine for this disease.

Report of the 17th F.I.D.E. Congress (1996)

?. National Constitutional Law vis-à-vis European Integration. B. Energy and Environmental Protection in a European Perspective. C. Procedures and Sanctions in Economic Administrative Law

School Ethos and Governor Relationships

This paper argues that an understanding of ethos is essential for appreciating the process of policy implementation in schools. Whilst educational literature consistently refers to the importance of ethos as a means of understanding the distinctive nature of schools, there is little exploration of school ethos as an effective mediator of policy. Drawing on qualitative data collected in three primary schools it will be demonstrated how ethos can act as a bridge or a barrier to the successful construction of the model of collaborative relationships between school governors and heads, as set out by the education reform legislation of the late 1980s

Local differences, perceptions and IB claimants: implications for policy delivery

Geographical unevenness in labour market and social conditions is one reason why the 'local' has been emphasised increasingly in the delivery of labour market policy in the UK. This article explores the extent to which there are local differences in labour market conditions using the characteristics and experiences of Incapacity Benefit (IB) claimants in Northern Ireland as an example. It then offers some comments on the potential for policy initiatives to cope with these spatial variations. Evidence from a survey of 803 IB claimants is used, supplemented by focus group material derived from discussions with Personal Advisers (PAs). The article shows that whilst there are important variations between areas, largely in the quantity and quality of jobs, and the perceptions that IB claimants hold of their local labour markets, there are also similarities in the general types of labour market barriers they face across areas. There is some evidence, however, to conclude that these barriers in urban areas are particularly pronounced and that some IB claimants in these places face severer obstacles to re-integration in the labour market than those in rural areas. The article also suggests that policy delivery to cope with these geographical differences faces two problems. First, capacity to respond to local differences is limited by strong systemic impulses towards centralisation. Secondly, and paradoxically, local differences erode capacity to respond to severer urban problems because social/institutional capacity within providers and policy-deliverers in these places is limited by high staff turnover and a crowded institutional landscape.