Indium foil with beryllia washer improves transistor heat dissipation

Indium foil, used as an interface material in transistor mountings, greatly reduces the thermal resistance of beryllia washers. This method improves the heat dissipation of power transistors in a vacuum environment

Excitations of the ν=5/2\nu=5/2 Fractional Quantum Hall State and the Generalized Composite Fermion Picture

We present a generalization of the composite Fermion picture for a muticomponent quantum Hall plasma which contains particle with different effective charges. The model predicts very well the low-lying states of a $\nu=5/2$ quantum Hall state found in numerical diagonalization.Comment: 5 pages, 3 figure

Nuclear Energy in the UK: Safety Culture and Industrial Organisation

In this paper we seek to explore the relationship between professionalism and nuclear safety in the UK. We consider the history of civil nuclear energy in Britain and the near complete shift in emphasis from state owned enterprises to the private sector. We show how in recent years government has acknowledged that a truly liberalised electricity industry is unable to deliver the construction of new nuclear power stations as part of a future low carbon electricity system. Throughout, however, the intention has been for policy merely to incentivise the private sector rather than to steer industry strategy directly. Having said that, the line between strong incentives and weak control can be hard to see. We present illustrative examples, real and fictional, that give insight into the UK nuclear safety culture and we discuss the wider nature of UK society with respect to corruption. We conclude that the unique basis of safety regulation in the UK, essentially permissive rather than prescriptive, has a key role to play in promoting and maintaining nuclear professionalism

Control surface spanwise placement in active flutter suppression systems

A method is developed that determines the placement of an active control surface for maximum effectiveness in suppressing flutter. No specific control law is required by this method which is based on the aerodynamic energy concept. It is argued that the spanwise placement of the active controls should coincide with the locations where maximum energy per unit span is fed into the system. The method enables one to determine the distribution, over the different surfaces of the aircraft, of the energy input into the system as a result of the unstable fluttering mode. The method is illustrated using three numerical examples

Snake eels (Ophichthidae) of the remote St. Peter and St. Paul’s Archipelago (Equatorial Atlantic) : Museum records after 37 years of shelf life

Despite of its major zoogeographical interest, the biological diversity of central Atlantic oceanic islands are still poorly known because of its remoteness. Incomplete species inventories are a hindrance to macroecology and conservation because knowledge on species distribution are important for identifying patterns and processes in biodiversity and for conservation planning. Records of the snake-eel family Ophichthidae for the St. Peter and St. Paul’s Archipelago, Brazil, are presented for the first time after revision of material collected and deposited in a museum collection 37 yrs ago. Specimens of Apterichtus kendalli and Herpetoichthys regius were collected using rotenone on sand bottoms and one Myrichthys sp. was observed and photographed swimming over a rocky reef. Remarkably, these species were not seen or collected in the St. Peter and St. Paul’s Archipelago ever since despite the substantial increase of biological expeditions over the past two decades, suggesting that the unjustified rotenone sampling prohibition in Brazil is hindering advancement of the nation’s biological diversity knowledge.info:eu-repo/semantics/publishedVersio

Including the urban heat island in spatial heat health risk assessment strategies: a case study for Birmingham, UK

Background Heatwaves present a significant health risk and the hazard is likely to escalate with the increased future temperatures presently predicted by climate change models. The impact of heatwaves is often felt strongest in towns and cities where populations are concentrated and where the climate is often unintentionally modified to produce an urban heat island effect; where urban areas can be significantly warmer than surrounding rural areas. The purpose of this interdisciplinary study is to integrate remotely sensed urban heat island data alongside commercial social segmentation data via a spatial risk assessment methodology in order to highlight potential heat health risk areas and build the foundations for a climate change risk assessment. This paper uses the city of Birmingham, UK as a case study area. Results When looking at vulnerable sections of the population, the analysis identifies a concentration of "very high" risk areas within the city centre, and a number of pockets of "high risk" areas scattered throughout the conurbation. Further analysis looks at household level data which yields a complicated picture with a considerable range of vulnerabilities at a neighbourhood scale. Conclusions The results illustrate that a concentration of "very high" risk people live within the urban heat island, and this should be taken into account by urban planners and city centre environmental managers when considering climate change adaptation strategies or heatwave alert schemes. The methodology has been designed to be transparent and to make use of powerful and readily available datasets so that it can be easily replicated in other urban areas

The epiphyllous habit in the hepatic genus Frullania

We report for the first time 11 species of Frullania growing as epiphylls in New Zealand, New Caledonia, and Colombia . Also listed are 29 Frullania species that have previously been recorded growing as epiphylls in other regions of the world. The highest diversity of Frullania epiphyllous species are in the floristic regions of New Zealand, New Caledonia, Macraonesia, and Madagascar. Frullania epiphylls range in altitude from sea-level to 2500m and can be categorised into facultative or accidental epiphylls. The number of Frullania species currently recorded growing as epiphylls will no doubt increase as more revisions of the genus in different floristic regions take place. This number may also increase if botanists were to explore leaf surfaces as a potential substrate for Frullania species, in addition to bark and rock habitats that have traditionally been described as microhabitats for the genus