On cost-effective reuse of components in the design of complex reconfigurable systems

Design strategies that benefit from the reuse of system components can reduce costs while maintaining or increasing dependability—we use the term dependability to tie together reliability and availability. D3H2 (aDaptive Dependable Design for systems with Homogeneous and Heterogeneous redundancies) is a methodology that supports the design of complex systems with a focus on reconfiguration and component reuse. D3H2 systematizes the identification of heterogeneous redundancies and optimizes the design of fault detection and reconfiguration mechanisms, by enabling the analysis of design alternatives with respect to dependability and cost. In this paper, we extend D3H2 for application to repairable systems. The method is extended with analysis capabilities allowing dependability assessment of complex reconfigurable systems. Analysed scenarios include time-dependencies between failure events and the corresponding reconfiguration actions. We demonstrate how D3H2 can support decisions about fault detection and reconfiguration that seek to improve dependability while reducing costs via application to a realistic railway case study

Connectivity, neutral theories and the assessment of species vulnerability to global change in temperate estuaries

One of the main adaptation strategies to global change scenarios, aiming to preserve ecosystem functioning and biodiversity, is to maximise ecosystem resilience. The resilience of a species metapopulation can be improved by facilitating connectivity between local populations, which will prevent demographic stochasticity and inbreeding. The objective of this investigation is to estimate the degree of connectivity among estuarine species along the north-eastern Iberian coast, in order to assess community vulnerability to global change scenarios. To address this objective, two connectivity proxy types have been used based upon genetic and ecological drift processes: 1) DNA markers for the bivalve cockle (Cerastoderma edule) and seagrass Zostera noltei, and 2) the decrease in the number of species shared between two sites with geographic distance; neutral biodiversity theory predicts that dispersal limitation modulates this decrease, and this has been explored in estuarine plants and macroinvertebrates. Results indicate dispersal limitation for both saltmarsh plants and seagrass beds community and Z. noltei populations; this suggests they are especially vulnerable to expected climate changes on their habitats. In contrast, unstructured spatial pattern found in macroinvertebrate communities and in C. edule genetic populations in the area suggests that estuarine soft-bottom macroinvertebrates with planktonic larval dispersal strategies may have a high resilience capacity to moderate changes within their habitats. Our findings can help environmental managers to prioritise the most vulnerable species and habitats to be restored

Application Dependent End-of-Life Threshold Definition Methodology for Batteries in Electric Vehicles

The end-of-life event of the battery system of an electric vehicle is defined by a fixed end-of-life threshold value. However, this kind of end-of-life threshold does not capture the application and battery characteristics and, consequently, it has a low accuracy in describing the real end-of-life event. This paper proposes a systematic methodology to determine the end-of-life threshold that describes accurately the end-of-life event. The proposed methodology can be divided into three phases. In the first phase, the health indicators that represent the aging behavior of the battery are defined. In the second phase, the application specifications and battery characteristics are evaluated to generate the end-of-life criteria. Finally, in the third phase, the simulation environment used to calculate the end-of-life threshold is designed. In this third phase, the electric-thermal behavior of the battery at different aging conditions is simulated using an electro-thermal equivalent circuit model. The proposed methodology is applied to a high-energy electric vehicle application and to a high-power electric vehicle application. The stated hypotheses and the calculated end-of-life threshold of the high-energy application are empirically validated. The study shows that commonly assumed 80 or 70% EOL thresholds could lead to mayor under or over lifespan estimations.The iModBatt project has received funding from the European Union’s Horizon 2020 Programme for research and innovation under Grant Agreement No. 770054

Assessing the suitability of a range of benthic indices in the evaluation of environmental impact of fin and shellfish aquaculture located in sites across Europe

The European Union-funded ECASA project (Ecosystem Approach for Sustainable Aquaculture) studied the impacts from aquaculture on ecosystems from northern Norway to Greece. The objectives of this investigation were to identify quantitative indicators of the effects of aquaculture on marine communities, and to assess their applicability over a range of ecosystems and aquaculture production systems. The study included 6 Mediterranean and 4 Atlantic sites, 7 ofwhich produced finfish (seabream, seabass, tuna, salmon and cod), and 2 bivalve molluscs (oysters, mussels, and clams); one site produced both fish and bivalves. Cultivation methods included finfish cages, long-lines and trestles. Similar sampling methodologies were employed at the 10 study sites, obtaining sediment, hydrodynamic, and benthic faunal data. The horizontal impact from organic enrichment extended 50m from the farms, with contradictory responses in several indicators (individual abundance, biomass) and a more consistent response of the Infaunal Trophic Index (ITI) and AZTI'sMarine Biotic Index (AMBI). By means of Partial Redundancy Analysis, it was demonstrated that the environmental variables explained 53.2% of the variability in the macrofaunal variables (individual abundance, species richness, diversity, AMBI and ITI), whilst the explained variance was partialled out within three groups of variables: (i) ‘hydrography’ (depth, distance to farm, average current speed), which explained 11.5% of the variance; (ii) ‘sediment’ (Eh and percentages of silt and total organic matter), which explained 5.4%; and (iii) ‘cages’ (years of production and annual production), which explained 15.2%. The shared variance explained by interactions among these groups was 21.1%. These results, together with multiple regression analysis, provide an accurate assessment of the degree of impact from aquaculture. In conclusion, the use of several benthic indicators, in assessing farm impacts, together with the investigation of dynamics of the studied location, water depth, years of farm activity, and total annual production, must be included when interpreting the response of benthic communities to organic enrichment from aquaculture

An objective framework to test the quality of candidate indicators of good environmental status

This is the final version. Available from the publisher via the DOI in this record.Large efforts are on-going within the EU to prepare the Marine Strategy Framework Directive's (MSFD) assessment of the environmental status of the European seas. This assessment will only be as good as the indicators chosen to monitor the 11 descriptors of good environmental status (GEnS). An objective and transparent framework to determine whether chosen indicators actually support the aims of this policy is, however, not yet in place. Such frameworks are needed to ensure that the limited resources available to this assessment optimize the likelihood of achieving GEnS within collaborating states. Here, we developed a hypothesis-based protocol to evaluate whether candidate indicators meet quality criteria explicit to the MSFD, which the assessment community aspires to. Eight quality criteria are distilled from existing initiatives, and a testing and scoring protocol for each of them is presented. We exemplify its application in three worked examples, covering indicators for three GEnS descriptors (1, 5, and 6), various habitat components (seaweeds, seagrasses, benthic macrofauna, and plankton), and assessment regions (Danish, Lithuanian, and UK waters). We argue that this framework provides a necessary, transparent and standardized structure to support the comparison of candidate indicators, and the decision-making process leading to indicator selection. Its application could help identify potential limitations in currently available candidate metrics and, in such cases, help focus the development of more adequate indicators. Use of such standardized approaches will facilitate the sharing of knowledge gained across the MSFD parties despite context-specificity across assessment regions, and support the evidence-based management of European seas.European Union: 7th Framework ProgrammeNatural Environment Research Council (NERC)UK Department for Environment, Food and Rural Affair

The suitability of the marine biotic index (AMBI) to new impact sources along European coasts

In recent years, several benthic biotic indices have been proposed to be used as ecological indicators in estuarine and coastal waters. One such indicator, the AZTI Marine Biotic Index (AMBI), was designed to establish the ecological quality of European coasts. The index examined the response of soft-bottom benthic communities to natural and man-induced disturbances in coastal and estuarine environments. It has been successfully applied to different geographical areas and under different impact sources, with increasing user numbers in European marine waters (Baltic, North Sea, Atlantic and Mediterranean). The AMBI has been used also for the determination of the ecological quality status (EcoQ) within the context of the European Water Framework Directive (WFD).In this contribution, 38 different applications including six new case studies (hypoxia processes, sand extraction, oil platform impacts, engineering works, dredging and fish aquaculture) are presented. The results show the response of the benthic communities to different disturbance sources in a simple way. Those communities act as ecological indicators of the ‘health’ of the system, indicating clearly the gradient associated with the disturbance

Assessing proposed modifications to the AZTI marine biotic index (AMBI), using biomass and production

Initially described in 2000, AZTI's Marine Biotic Index (AMBI) aims to assess alterations in communities of soft-bottom marine benthic macroinvertebrates caused by anthropogenic impacts. Although it was designed to be used in European estuaries and coasts this index, based on Pearson and Rosenberg's model of responses to organic enrichment, is being used successfully worldwide. Taking into account statistical difficulties associated with the use of raw abundance data, modifications to the index were recently proposed. These included transforming abundances prior to its calculation, or to use data other than abundances which might be more functionally relevant (such as biomass or production data). Using data from the Basque coast and estuaries (northern Spain), collected between 1995 and 2009, where the evolution of human pressures and restoration actions in the area may be taken into account, the performance of AMBI is compared to that of the proposed modifications in order to assess their usefulness. Despite large variations in the form and nature of the input data, all variations of AMBI index are shown to be highly correlated, even when presence/absence data are used. New boundaries between disturbance categories were calculated, reflecting inter-relationships between different forms of the index. The disturbance classification obtained from all variations using the recalculated boundaries agreed closely with that derived from AMBI. The finding that AMBI values calculated with presence/absence data are potentially useful opens up many possibilities, such as determining the status of assemblages retrospectively using historical data