University of Cyprus

About: University of Cyprus is a education organization based out in Nicosia, Cyprus. It is known for research contribution in the topics: Large Hadron Collider & Context (language use). The organization has 3624 authors who have published 15157 publications receiving 412135 citations.

Coordination and Control of Distributed Energy Resources for Provision of Ancillary Services

Abstract: This paper discusses the utilization of distributed energy resources on the distribution side of the power grid to provide a number of ancillary services. While the individual capability of these resources to provide grid support might be very small, their presence in large numbers in many distribution networks implies that, under proper control, they can collectively become an asset for providing ancillary services. An example is the power electronics interface of a photovoltaic array mounted in a residential building roof. While its primary function is to control active power flow, when properly controlled, it can also be used to provide reactive power. This paper develops and analyzes distributed control strategies to enable the utilization of these distributed resources for provision of grid support services. We provide a careful analysis of the applicability capabilities and limitations of each of these strategies. Several simulation examples are provided to illustrate the proposed approaches.

The rise of low-cost sensing for managing air pollution in cities

Abstract: Ever growing populations in cities are associated with a major increase in road vehicles and air pollution. The overall high levels of urban air pollution have been shown to be of a significant risk to city dwellers. However, the impacts of very high but temporally and spatially restricted pollution, and thus exposure, are still poorly understood. Conventional approaches to air quality monitoring are based on networks of static and sparse measurement stations. However, these are prohibitively expensive to capture tempo-spatial heterogeneity and identify pollution hotspots, which is required for the development of robust real-time strategies for exposure control. Current progress in developing low-cost micro-scale sensing technology is radically changing the conventional approach to allow real-time information in a capillary form. But the question remains whether there is value in the less accurate data they generate. This article illustrates the drivers behind current rises in the use of low-cost sensors for air pollution management in cities, whilst addressing the major challenges for their effective implementation.

Acute heart failure congestion and perfusion status - impact of the clinical classification on in-hospital and long-term outcomes; insights from the ESC-EORP-HFA Heart Failure Long-Term Registry.

Abstract: Aims Classification of acute heart failure (AHF) patients into four clinical profiles defined by evidence of congestion and perfusion is advocated by the 2016 European Society of Cardiology (ESC)guidelines. Based on the ESC-EORP-HFA Heart Failure Long-Term Registry, we compared differences in baseline characteristics, in-hospital management and outcomes among congestion/perfusion profiles using this classification. Methods and results We included 7865 AHF patients classified at admission as: 'dry-warm' (9.9%), 'wet-warm' (69.9%), 'wet-cold' (19.8%) and 'dry-cold' (0.4%). These groups differed significantly in terms of baseline characteristics, in-hospital management and outcomes. In-hospital mortality was 2.0% in 'dry-warm', 3.8% in 'wet-warm', 9.1% in 'dry-cold' and 12.1% in 'wet-cold' patients. Based on clinical classification at admission, the adjusted hazard ratios (95% confidence interval) for 1-year mortality were: 'wet-warm' vs. 'dry-warm' 1.78 (1.43-2.21) and 'wet-cold' vs. 'wet-warm' 1.33 (1.19-1.48). For profiles resulting from discharge classification, the adjusted hazard ratios (95% confidence interval) for 1-year mortality were: 'wet-warm' vs. 'dry-warm' 1.46 (1.31-1.63) and 'wet-cold' vs. 'wet-warm' 2.20 (1.89-2.56). Among patients discharged alive, 30.9% had residual congestion, and these patients had higher 1-year mortality compared to patients discharged without congestion (28.0 vs. 18.5%). Tricuspid regurgitation, diabetes, anaemia and high New York Heart Association class were independently associated with higher risk of congestion at discharge, while beta-blockers at admission, de novo heart failure, or any cardiovascular procedure during hospitalization were associated with lower risk of residual congestion. Conclusion Classification based on congestion/perfusion status provides clinically relevant information at hospital admission and discharge. A better understanding of the clinical course of the two entities could play an important role towards the implementation of targeted strategies that may improve outcomes.