Wake skew angle variation with rotor thrust for wind turbines in yaw based on the MEXICO experiment

The primary objective of the MEXICO (Model Experiments in Controlled Conditions) project was to generate experimental data from which the uncertainties of the computational tools employed to predict wind turbine performance and loads. Pressure sensors were used for pressure measurements while PIV was used with the major aim of tracking the tip vortex trajectory. The aerodynamic forces on the blades were derived found from the pressure measurements and were used in an inverse free wake lifting line model to compute the positions of the tip vortices. From these the wake skew angle was derived. A relationship between the skew angle and the thrust coefficient was thus drawn.peer-reviewe

Marine stepping‐stones: Connectivity of Mytilus edulis populations between offshore energy installations

Recent papers have suggested that epifaunal organisms use artificial structures as stepping‐stones to spread to areas that are too distant to reach in a single generation. With thousands of artificial structures present in the North Sea, we test the hypothesis that these structures are connected by water currents and act as an interconnected reef. Population genetic structure of the blue mussel, Mytilus edulis, was expected to follow a pattern predicted by a particle tracking model (PTM). Correlation between population genetic differentiation, based on microsatellite markers, and particle exchange was tested. Specimens of M. edulis were found at each location, although the PTM indicated that locations >85 km offshore were isolated from coastal subpopulations. The fixation coefficient FST correlated with the number of arrivals in the PTM. However, the number of effective migrants per generation as inferred from coalescent simulations did not show a strong correlation with the arriving particles. Isolation by distance analysis showed no increase in isolation with increasing distance and we did not find clear structure among the populations. The marine stepping‐stone effect is obviously important for the distribution of M. edulis in the North Sea and it may influence ecologically comparable species in a similar way. In the absence of artificial shallow hard substrates, M. edulis would be unlikely to survive in offshore North Sea waters

Improving assessments of data-limited populations using life-history theory

Funder: Research EnglandFunder: UK Joint Nature Conservation Committee (DEFRA)Predicting how populations may respond to climate change and anthropogenic pressures requires detailed knowledge of demographic traits, such as survival and reproduction. However, the availability of these data varies greatly across space and taxa. Therefore, it is common practice to conduct population assessments by filling in missing values from surrogate species or other populations of the same species. Using these independent surrogate values concurrently with observed data neglects the life‐history trade‐offs that connect the different aspects of a population's demography. Consequently, this approach introduces biases that could ultimately lead to erroneous management decisions. We use a Bayesian hierarchical framework to combine fragmented multi‐population data with established life‐history theory and reconstruct population‐specific demographic data across a substantial part of a species breeding range. We apply our analysis to a long‐lived colonial species, the black‐legged kittiwake Rissa tridactyla, that is classified as globally Vulnerable and is highly threatened by increasing anthropogenic pressures, including offshore renewable energy development. We then use a projection analysis to examine how the reconstructed demographic parameters may improve population assessments, compared to models that combine observed data with independent surrogate values. Demographic parameters reconstructed using a hierarchical framework can be utilised in a range of population modelling approaches. They can also be used as reference estimates to assess whether independent surrogate values are likely to over or underestimate missing demographic parameters. We show that surrogate values from independent sources are often used to fill in missing parameters that have large potential demographic impact, and that resulting biases are driven in unpredictable directions thus precluding assessments from being consistently precautionary. Synthesis and applications. Our study dramatically increases the spatial coverage of population‐specific demographic data for black‐legged kittiwakes. The reconstructed demographic parameters presented can also be used immediately to reduce uncertainty in the consenting process for offshore wind development in the United Kingdom and Ireland. More broadly, we show that the reconstruction approach used here provides a new avenue for improving evidence‐based management and policy action for animal and plant populations with fragmented and error prone demographic data

Surviving in Europe : geopolitics of biodiversity conservation illustrated by a proxy species Viola uliginosa

Building strategies for continental-scale conservation is challenging due to evolutionary and geopolitical problems. How do policy choices arise from this setting? In this study, we integrate ecological research with policy analysis to examine the problem field with a case study research. We use a violet species endemic to Europe, Viola uliginosa, as a proxy for a significant European Union (EU)-Russian biodiversity pattern and its conservation. The violet's core populations locate in Belarus, Ukraine, and Russia, and all populations in the EU are peripheral. The species is endangered in 12 EU member states and in decline in many places elsewhere. To analyze the choices of conservation, we gathered data on its ecology, distribution, and conservation mechanisms across Europe, putting additional emphasis on the EU enlargement and long-term site histories in Finland. We found that the survival of the species in the EU depends on the enlargement negotiations, conflicts between the EU biodiversity and agricultural policies, selection of the species to national Red Lists and the Habitats Directive, and contingent site histories depending on the conservation activities by civic actors and the member states. While the evolutionary aspect emphasizes the genetic differentiation potential of peripheral populations, the geopolitical aspect characterizes the EU as simultaneous spaces of a monotopia, borderlands, and polycentric development. We conclude that intersections between these geopolitical spaces can be used with evolutionary perspectives to identify local, European, and network-driven policy choices of conservation.Peer reviewe

Interviews for the assessment of long-term incapacity for work: a study on adherence to protocols and principles

<p>Abstract</p> <p>Background</p> <p>Assessments for long-term incapacity for work are performed by Social Insurance Physicians (SIPs) who rely on interviews with claimants as an important part of the process. These interviews are susceptible to bias. In the Netherlands three protocols have been developed to conduct these interviews. These protocols are expert- and practice-based. We studied to what extent these protocols are adhered to by practitioners.</p> <p>Methods</p> <p>We compared the protocols with one another and with the ICF and the biopsychosocial approach. The protocols describe semi-structured interviews with comparable but not identical topics. All protocols prescribe that the client's opinion on his capacity for work, and his arguments, need to be determined and assessed. We developed a questionnaire to elicit the adherence SIPs have to the protocols, their underlying principles and topics. We conducted a survey among one hundred fifty-five experienced SIPs in the Netherlands.</p> <p>Results</p> <p>Ninety-eight SIPs responded (64%). All respondents used some form of protocol, either one of the published protocols or their own mix. We found no significant relation between training and the use of a particular protocol. Ninety percent use a semi-structured interview. Ninety-five percent recognise having to verify what the claimant says and eighty-three percent feel the need to establish a good relation (p = 0.019). Twelve topics are basically always addressed by over eighty percent of the respondents. The claimant's opinion of being fit for his own work or other work, and his claim of incapacity and his health arguments for that claim, reach a hundred percent. Description of claimants' previous work reaches ninety-nine percent.</p> <p>Conclusion</p> <p>Our study shows professional consensus among experienced Dutch SIPs about the principle of assessment on arguments, the principle of conducting a semi-structured interview and the most crucial interview topics. This consensus can be used to further develop a protocol for interviewing in the assessment of incapacity for work in social insurance. Such a protocol can improve the quality of the assessments in terms of transparency and reproducibility, as well as by enabling clients to better prepare themselves for the assessments.</p

Evidence-based guidelines in the evaluation of work disability: an international survey and a comparison of quality of development

<p>Abstract</p> <p>Background</p> <p>In social insurance, the evaluation of work disability is becoming stricter as priority is given to the resumption of work, which calls for a guarantee of quality for these evaluations. Evidence-based guidelines have become a major instrument in the quality control of health care, and the quality of these guidelines' development can be assessed using the AGREE instrument. In social insurance medicine, such guidelines are relatively new. We were interested to know what guidelines have been developed to support the medical evaluation of work disability and the quality of these guidelines.</p> <p>Methods</p> <p>Five European countries that were reported to use guidelines were approached, using a recent inventory of evaluations of work disability in Europe. We focused on guidelines that are disease-oriented and formally prescribed in social insurance medicine. Using the AGREE instrument, these guidelines were appraised by two researchers. We asked two experts involved in guideline development to indicate if they agreed with our results and to provide explanations for insufficient scores.</p> <p>Results</p> <p>We found six German and sixteen Dutch sets of disease-oriented guidelines in official use. The AGREE instrument was applicable, requiring minor adaptations. The appraisers reached consensus on all items. Each guideline scored well on 'scope and purpose' and 'clarity and presentation'. The guidelines scored moderately on 'stakeholder involvement' in the Netherlands, but insufficiently in Germany, due mainly to the limited involvement of patients' representatives in this country. All guidelines had low scores on 'rigour of development', which was due partly to a lack of documentation and of existing evidence. 'Editorial independence' and 'applicability' had low scores in both countries as a result of how the production was organised.</p> <p>Conclusion</p> <p>Disease-oriented guidelines in social insurance medicine for the evaluation of work disability are a recent phenomenon, so far restricted to Germany and the Netherlands. The AGREE instrument is suitably applicable to assess the quality of guideline development in social insurance medicine, but some of the scoring rules need to be adapted to the context of social insurance. Existing guidelines do not meet the AGREE criteria to a sufficient level. The way patients' representatives can be involved needs further discussion. The guidelines would profit from more specific recommendations and, for providing evidence, more research is needed on the functional capacity of people with disabilities.</p

Developing policies for the end-of-life of energy infrastructure: Coming to terms with the challenges of decommissioning

Energy sector policies have focused historically on the planning, design and construction of energy infrastructures, while typically overlooking the processes required for the management of their end-of-life, and particularly their decommissioning. However, decommissioning of existing and future energy infrastructures is constrained by a plethora of technical, economic, social and environmental challenges that must be understood and addressed if such infrastructures are to make a net-positive contribution over their whole life. Here, we introduce the magnitude and variety of these challenges to raise awareness and stimulate debate on the development of reasonable policies for current and future decommissioning projects. Focusing on power plants, the paper provides the foundations for the interdisciplinary thinking required to deliver an integrated decommissioning policy that incorporates circular economy principles to maximise value throughout the lifecycle of energy infrastructures. We conclude by suggesting new research paths that will promote more sustainable management of energy infrastructures at the end of their life

Key Safety Principles for operation of experimental and developmental Airborne Wind Energy Systems

The members of Airborne Wind Europe commit to adhere to the following Key Safety Principles for operation of experimental and developmental Airborne Wind Energy Systems (AWES). The aim is to minimise the risk of a hazardous or catastrophic incident by reducing the probability and the consequence of such an incident. Catastrophic incidents are incidents that could result in one or more fatalities. Hazardous incidents are incidents with one failure away from catastrophic incident or that could result in third party human harm. These principles do not replace any legal or technical safety requirements imposed on AWES developer