22,435 research outputs found

    Speciation and fate of copper in sewage treatment works with and without tertiary treatment: The effect of return flows

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    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2013 Taylor & Francis.The removal of metals from wastewaters is becoming an important issue, with new environmental quality standards putting increased regulatory pressure on operators of sewage treatment works. The use of additional processes (tertiary treatment) following two-stage biological treatment is frequently seen as a way of improving effluent quality for nutrients and suspended solids, and this study investigates the impact of how back washes from these tertiary processes may impact the removal of copper during primary sedimentation. Seven sites were studied, three conventional two-stage biological treatment, and four with tertiary processes. It was apparent that fluxes of copper in traditional return flows made a significant contribution to the load to the primary treatment tanks, and that<1% of this was in the dissolved phase. Where tertiary processes were used, back wash liquors were also returned to the primary tanks. These return flows had an impact on copper removal in the primary tanks, probably due to their aerobic nature. Returning such aerobic back wash flows to the main process stream after primary treatment may therefore be worth consideration. The opportunity to treat consolidated liquor and sludge flows in side-stream processes to remove toxic elements, as they are relatively concentrated, low volume flow streams, should also be evaluated

    Serological surveillance reveals patterns of exposure to H5 and H7 influenza A viruses in European poultry

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    Influenza A viruses of H5 and H7 subtype in poultry can circulate subclinically, and subsequently mutate from low to high pathogenicity with potentially devastating economic and welfare consequences. European Union Member States undertake surveillance of commercial and backyard poultry for early detection and control of subclinical H5 and H7 influenza A infection. This surveillance has moved towards a risk‐based sampling approach in recent years; however quantitative measures of relative risk associated with risk factors utilised in this approach are necessary for optimisation. This study describes serosurveillance for H5 and H7 influenza A in domestic and commercial poultry undertaken in the European Union from 2004 to 2010, where a random sampling and thus representative approach to serosurveillance was undertaken. Using these representative data, this study measured relative risk of seropositivity across poultry categories and spatially across the EU. Data were analysed using multivariable logistic regression. Domestic waterfowl, game birds, fattening turkeys, ratites, backyard poultry and the “other” poultry category holdings had relatively increased probability of H5 and/or H7 influenza A seropositivity, compared to laying‐hen holdings. Amongst laying‐hen holdings, free‐range rearing was associated with increased probability of H7 seropositivity. Spatial analyses detected ‘hotspots’ for H5 influenza A seropositivity in western France and England, and H7 influenza A seropositivity in Italy and Belgium, which may be explained by the demographics and distribution of poultry categories. Findings suggest certain poultry category holdings are at increased risk of subclinical H5 and/or H7 influenza A circulation, and free‐range rearing increases the likelihood of exposure to H7 influenza A. These findings may be used in further refining risk‐based surveillance strategies, and prioritising management strategies in influenza A outbreaks

    Final Report of the Commission on Presidential Disability and the Twenty-Fifth Amendment

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    This Report examines the Twenty-Fifth Amendment to identify potential difficulties in presidential succession and makes recommendations

    Epistemic policy networks in the European Union’s CBRN risk mitigation policy

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    This paper offers insights into an innovative and currently flagship approach of the European Union (EU) to the mitigation of chemical, biological, radiological, and nuclear (CBRN) risks. Building on its long-time experience in the CBRN field, the EU has incorporated methods familiar to the students of international security governance: it is establishing regional networks of experts and expertise. CBRN Centers of Excellence, as they are officially called, aim to contribute to the security and safety culture in different parts of Africa, the Middle East, South East Asia, and South East Europe, in the broadly construed CBRN area. These regional networks represent a modern form of security cooperation, which can be conceptualized as an epistemic policy networks approach. It offers flexibility to the participating states, which have different incentives to get involved. At the same, however, the paper identifies potential limitations and challenges of epistemic policy networks in this form

    E-Voting in an ubicomp world: trust, privacy, and social implications

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    The advances made in technology have unchained the user from the desktop into interactions where access is anywhere, anytime. In addition, the introduction of ubiquitous computing (ubicomp) will see further changes in how we interact with technology and also socially. Ubicomp evokes a near future in which humans will be surrounded by “always-on,” unobtrusive, interconnected intelligent objects where information is exchanged seamlessly. This seamless exchange of information has vast social implications, in particular the protection and management of personal information. This research project investigates the concepts of trust and privacy issues specifically related to the exchange of e-voting information when using a ubicomp type system

    The Changing Face of Youth Employment in Europe

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    This article examines trends in youth employment across the EU-15 countries during 2002-6 and 2007-11. Drawing upon microdata from the EU-Labour Force Survey it examines changes in contract-type, hours worked and occupation by level of education. Although the financial crisis creates a discontinuity in numbers employed, and despite certain country specificities, we observe common structural changes across the two periods. We find an increasing shift from permanent full-time to temporary part-time contracts, the ‘hollowing out’ of traditional mid-skill level occupations and evidence of ‘occupational filtering down’ whereby the higher-educated are substituted for the lower-educated in low-skilled occupations. We observe some growth in ‘professionals’ following the crisis, but little evidence of the rise of a new knowledge economy. This raises questions concerning the most appropriate policy approaches to education and training and labour market regulation if European nations are to provide high-quality employment opportunities for their young people

    Scientific, Technical and Economic Committee for Fisheries. Review of economic data collected in relation to the DCF and harmonisation of sampling strategies (STECF-11-19)

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    The STECF Expert Working Group (EWG) on reflections on the review of economic data collected in relation to the DCF and harmonisation of sampling strategies (EWG 11-18) met in Salerno, from 17th to 21st October 2011. The EWG dealt with a broad range of issues that are important in the improvement of the collection of economic data and in the evolution of the DCF. STECF reviewed the report during its Plenary meeting on 7-11 November 2011

    Optimal Scheduling of Trains on a Single Line Track

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    This paper describes the development and use of a model designed to optimise train schedules on single line rail corridors. The model has been developed with two major applications in mind, namely: as a decision support tool for train dispatchers to schedule trains in real time in an optimal way; and as a planning tool to evaluate the impact of timetable changes, as well as railroad infrastructure changes. The mathematical programming model described here schedules trains over a single line track. The priority of each train in a conflict depends on an estimate of the remaining crossing and overtaking delay, as well as the current delay. This priority is used in a branch and bound procedure to allow and optimal solution to reasonable size train scheduling problems to be determined efficiently. The use of the model in an application to a 'real life' problem is discussed. The impacts of changing demand by increasing the number of trains, and reducing the number of sidings for a 150 kilometre section of single line track are discussed. It is concluded that the model is able to produce useful results in terms of optimal schedules in a reasonable time for the test applications shown here
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