Numerical study of heat transfer in a distorted rod bundle

The effect of rod distortion on the flow and heat transfer in a rod (fuel) bundle similar to those in an Advanced Gas-cooled Reactor (AGR) is investigated using carefully constructed CFD models. The results are of relevance to various other engineering applications, for example heat exchangers. The distorted element contracts gradually over the first half of the element, reaching a minimum at half high then subsequently increasing back to its normal value over the second half of the element. In this paper, the results for forced convection are presented. Changes in the rod profiles divert flow to regions of less resistance, resulting in strong cross flow recirculation regions. The resultant three dimensional flow is also accompanied by large scale swirling flow around the fuel pins. The hotspot at any height coincides with the leeward side of the cross flow. It is rather surprising that the peak can temperature at the location of worst bundle distortion (i.e middle height) is actually slightly lower than that of intact fuel. The overall peak can temperature in the damaged bundle is however much higher than that in the intact fuel, and this occurs towards the top of the bundle

Genome-wide signatures of complex introgression and adaptive evolution in the big cats.

The great cats of the genus Panthera comprise a recent radiation whose evolutionary history is poorly understood. Their rapid diversification poses challenges to resolving their phylogeny while offering opportunities to investigate the historical dynamics of adaptive divergence. We report the sequence, de novo assembly, and annotation of the jaguar (Panthera onca) genome, a novel genome sequence for the leopard (Panthera pardus), and comparative analyses encompassing all living Panthera species. Demographic reconstructions indicated that all of these species have experienced variable episodes of population decline during the Pleistocene, ultimately leading to small effective sizes in present-day genomes. We observed pervasive genealogical discordance across Panthera genomes, caused by both incomplete lineage sorting and complex patterns of historical interspecific hybridization. We identified multiple signatures of species-specific positive selection, affecting genes involved in craniofacial and limb development, protein metabolism, hypoxia, reproduction, pigmentation, and sensory perception. There was remarkable concordance in pathways enriched in genomic segments implicated in interspecies introgression and in positive selection, suggesting that these processes were connected. We tested this hypothesis by developing exome capture probes targeting ~19,000 Panthera genes and applying them to 30 wild-caught jaguars. We found at least two genes (DOCK3 and COL4A5, both related to optic nerve development) bearing significant signatures of interspecies introgression and within-species positive selection. These findings indicate that post-speciation admixture has contributed genetic material that facilitated the adaptive evolution of big cat lineages

Portugal e os BRIC: numa perspectiva da diplomacia pública e da autopoiesis

O sistema internacional post-­‐11 de Setembro vem acelerar a movimentação em torno da sociedade civil, alterando, consequentemente, o próprio conceito espácio-­temporal da actuação da diplomacia, na sua acepção clássica, na arena internacional enquanto instrumento pacífico de execução da política externa. Assiste-se a uma complexidade crescente no processo de edificação da nova ordem mundial cujo epicentro se circunscreve numa espécie de sub-­‐mundialização à escala doméstica de cada Estado quer pela (in)capacidade da elite governante em responder aos estímulos provenientes do ambiente externo ao ritmo vertiginoso da velocidade dos fluxos de informação entre os mais diversos actores das relações internacionais. Daí que a prática da diplomacia tradicional tal como a conhecemos caminha para além da evolução teórica, situando-­se cada vez mais em termos concretos num mundo inconstante de caminho incerto com regimes antagónicos de convergências pontuais e imprevisíveis que levam à emergência de outras formas de actuação como sendo o caso da diplomacia pública que representa um recurso estratégico vital para os estados enquanto actores das relações internacionais e concretamente para o caso de Portugal nas suas relações com os BRIC onde se pretende melhorar e influenciar a imagem de um país quer internamente quer externamente como um país/marca num mundo competitivo

The potential monetary benefits of reclaiming hazardous waste sites in the Campania region: an economic evaluation

BACKGROUND: Evaluating the economic benefit of reducing negative health outcomes resulting from waste management is of pivotal importance for designing an effective waste policy that takes into account the health consequences for the populations exposed to environmental hazards. Despite the high level of Italian and international media interest in the problem of hazardous waste in Campania little has been done to reclaim the land and the waterways contaminated by hazardous waste. OBJECTIVE: This study aims to reduce the uncertainty about health damage due to waste exposure by providing for the first time a monetary valuation of health benefits arising from the reclamation of hazardous waste dumps in Campania. METHODS: First the criteria by which the landfills in the Campania region, in particular in the two provinces of Naples and Caserta, have been classified are described. Then, the annual cases of premature death and fatal cases of cancers attributable to waste exposure are quantified. Finally, the present value of the health benefits from the reclamation of polluted land is estimated for each of the health outcomes (premature mortality, fatal cancer and premature mortality adjusted for the cancer premium). Due to the uncertainty about the time frame of the benefits arising from reclamation, the latency of the effects of toxic waste on human health and the lack of context specific estimates of the Value of Preventing a Fatality (VPF), extensive sensitivity analyses are performed. RESULTS: There are estimated to be 848 cases of premature mortality and 403 cases of fatal cancer per year as a consequence of exposure to toxic waste. The present value of the benefit of reducing the number of waste associated deaths after adjusting for a cancer premium is euro11.6 billion. This value ranges from euro5.4 to euro20.0 billion assuming a time frame for benefits of 10 and 50 years respectively. CONCLUSION: This study suggests that there is a strong economic argument for both reclaiming the land contaminated with hazardous waste in the two provinces of Naples and Caserta and increasing the control of the territory in order to avoid the creation of new illegal dump sites

It's not too Late for the Harpy Eagle (Harpia harpyja): High Levels Of Genetic Diversity and Differentiation Can Fuel Conservation Programs

Article on the harpy eagle (Harpia harpyja) and how high levels of genetic diversity and differentiation can fuel conservation programs

Public, private and personal: Qualitative research on policymakers' opinions on smokefree interventions to protect children in 'private' spaces

<p>Abstract</p> <p>Background</p> <p>Governments use law to constrain aspects of private activities for purposes of protecting health and social wellbeing. Policymakers have a range of perceptions and beliefs about what is public or private. An understanding of the possible drivers of policymaker decisions about where government can or should intervene for health is important, as one way to better guide appropriate policy formation. Our aim was to identify obstacles to, and opportunities for, government smokefree regulation of private and public spaces to protect children. In particular, to seek policymaker opinions on the regulation of smoking in homes, cars and public parks and playgrounds in a country with incomplete smokefree laws (New Zealand).</p> <p>Methods</p> <p>Case study, using structured interviews to ask policymakers (62 politicians and senior officials) about their opinions on new smokefree legislation for public and private places. Supplementary data was obtained from the Factiva media database, on the views of New Zealand local authority councillors about policies for smokefree outdoor public places.</p> <p>Results</p> <p>Overall, interviewees thought that government regulation of smoking in private places was impractical and unwise. However, there were some differences on what <it>was </it>defined as 'private', particularly for cars. Even in public parks, smoking was seen by some as a 'personal' decision, and unlikely to be amenable to regulation. Most participants believed that educative, supportive and community-based measures were better and more practical means of reducing smoking in private places, compared to regulation.</p> <p>Conclusions</p> <p>The constrained view of the role of regulation of smoking in public and private domains may be in keeping with current political discourse in New Zealand and similar Anglo-American countries. Policy and advocacy options to promote additional smokefree measures include providing a better voice for childrens' views, increasing information to policymakers about the harms to children from secondhand smoke and the example of adult smoking, and changing the culture for smoking around children.</p