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Introduction: The ability of species to colonize newly suitable habitats under rapid climate change can be constrained by migration processes, resulting in a shift of the leading edge lagging behind the ameliorating climate, i.e. migration lag. The importance and extent of such migration lags during the forest expansion after the Last Glacial Maximum (LGM) are still debated. Similarly, the relative importance of the main drivers of post-glacial vegetation dynamics (temperature, dispersal limitation, and competition) is still discussed in the literature. Methods: We used the dynamic global vegetation model LPJ-GM 2.0 to reconstruct the range shifts of 16 competing major European tree species after the LGM (18.5 ka BP) until recent times (0 ka BP). We simulated two dispersal modes by allowing free establishment whenever the climatic conditions suited the species (free dispersal), or by accounting for migration processes in the simulated vegetation dynamics (dispersal limitation). We then calculated thermal and range shift velocities, competition at establishment, thermal and dispersal lags for each species and dispersal mode. Finally, we compared our simulated range shift velocities with pollen-derived migration rates. Results: The simulation assuming limited dispersal resulted in more accurate migration rates as compared to pollen-derived migration rates and spreading patterns. We found no marked migration lags in the post-glacial establishment of pioneer species (Pinus sylvestris and Betula pubescens). Under the free dispersal mode, the remaining temperate species expanded rapidly and almost synchronously across central Europe upon climate warming (Bolling-Allerod interstadial). Differently, the northward spread of temperate species simulated under dispersal limitation happened mainly during the Holocene and in successive waves, with late spreaders (e.g. Fraxinus excelsior) experiencing multi-millennial dispersal lags and higher competition. Discussion: Our simulation under dispersal constraints suggests that the postglacial tree expansion in Europe was mainly driven by species-specific thermal requirements and dispersal capacity, which in turn affected the order of taxa establishment and thus the degree of competition. Namely, taxa with less cold-tolerance and relatively low dispersal ability experienced the highest migration lags, whereas the establishment of pioneer species was mostly in equilibrium with the climate. [ABSTRACT FROM AUTHOR]

This paper presents a study on the relationship between transport properties and geometric free volume for a hard sphere (HS) system in a dense fluid region. First, a generic free volume distribution function is proposed based on recent simulation results on the HS geometric free volume by Maiti and Sastry [J. Chem. Phys. 141(4), 044510 (2014)] and Maiti et al. [Eur. Phys. J. E 36(1), 5 (2013)]. Combining the new distribution function with a local particle transportation model, we obtain a power law for the HS transport properties. Then, a relation between the geometric free volume and thermodynamic free volume is established, which makes it possible to use well-developed equations of state (EoS) for the expressions of the geometric free volume. The new power law models are tested with molecular dynamic simulation results for HS viscosity, diffusivity and thermal conductivity, respectively, and the results are very satisfactory. Moreover, using the power law, we are able to reproduce several equations obtained from different approaches, such as the entropy scaling laws [Bell et al., J. Phys. Chem. B 123(29), 6345–6363 (2019]), mode coupling theory [Barrat et al., J. Phys. Condens. Matter 1, 7163–7170 (1989)], or empirical correlations [Sigurgeirsson and Heyes, J. Mol. Phys. 101(3), 469–482 (2003)]. In particular, a long-standing controversy regarding the well-known Cohen–Turnbull–Doolittle free volume model [Cohen and Turnbull, J. Chem. Phys. 31(3), 1164–1169 (1959); Doolittle, J. Appl. Phys. 22(12), 1471–1475 (1951)] is resolved by using the power law combined with the Heyes and Woodcock EoS [Heyes and Woodcock, Mol. Phys. 59(6), 1369–1388 (1986)]. [ABSTRACT FROM AUTHOR]

The building sector greatly contributes to energy consumption and Greenhouse Gas emissions, relating to the whole building life cycle. Boasting a huge building heritage of historical and architectural value, Europe faces challenging retrofit perspectives, as the potential for high energy efficiency has to be exploited while preserving the buildings' original characteristics. The present work aims to feature the influence of a passive strategy on a heritage building in a mild climate. As historical its façade cannot be modified, its large glazing areas involve multiple issues, such as an increase in the heating ( Q H) and cooling ( Q C ) energy demands and the risk of thermal discomfort. Thus, window replacement was proposed for retrofitting. A dynamic simulation model in TRNSYS was validated with experimental data collected by the continuous monitoring of walls of different thicknesses and orientations. Solutions from replacement with Double Glazing Units (DGUs) with improved thermal insulation, to internal shading activation were applied. All configurations were compared in terms of Q H , Q C , thermal performance of the building and user comfort (Fanger). Low-e DGU enabled the saving of up to 14% of the annual energy demand, and shading also offered good results in summer, reducing Q C by 19%. In summer, DGU involved a maximum PPD reduction of 10 units. [ABSTRACT FROM AUTHOR]

The concept of segmented AC power systems interconnected by means of HVDC is becoming more and more significant for many cases worldwide. Such systems already exist and will become more complex with the increasing emergence of HVDC links and grids. The concept of a grid composed of multiple subgrids motivates the need to define the governing roles of Interconnecting Power Converters (IPC) which connect the different subgrids. Such IPC can have various operation modes which are presented and analyzed in this paper. In addition, the principles of operation needed for each individual subgrid and for the overall system are introduced and discussed. The resulting fundamental equations are outlined and combined in a power flow formulation of the overall system. A simple case study is presented to illustrate the power flow formulation in a grid of multiple subgrids, also introducing example dynamic simulations of transitions between different operating points. [ABSTRACT FROM AUTHOR]

Extreme sea levels (ESLs) in Europe could rise by as much as one metre or more by the end of this century due to climate change. This poses significant challenges to safeguard coastal communities. Here we present a comprehensive analysis of economically efficient protection scenarios along Europe's coastlines during the present century. We employ a probabilistic framework that integrates dynamic simulations of all ESL components and flood inundation, impact modelling and a cost-benefit analysis of raising dykes. We find that at least 83% of flood damages in Europe could be avoided by elevating dykes in an economically efficient way along 23.7%-32.1% of Europe's coastline, specifically where high value conurbations exist. The European mean benefit to cost ratio of the investments varies from 8.3 to 14.9 while at country level this ranges between 1.6 and 34.3, with higher efficiencies for a scenario with high-end greenhouse gas emissions and strong socio-economic growth. There lacks a European cost-benefit analysis of possible protective measures against rising seas. Here the authors used a probabilistic data and modeling framework to estimate costs and benefits of coastal protection measures and found that at least 83% of flood damages could be avoided by dyke improvements along a third of the European coastline. [ABSTRACT FROM AUTHOR]

• An innovative slim decentralised plug-and-play tank is proposed for DHW production. • Model calibration is performed by experimental data in charge/discharge process. • Retrofit solution cuts required annual energy in half of which 82% is RES quota. • Optimised charging scheme reduces the total annual electrical energy by 5.2 %. • A degree increment in draw-off temperature increases annual CO 2 emission by 103 kg. The present study deals with a multi-objective analysis of an innovative decentralised system to produce and store domestic hot water (DHW), emphasising on the combined effects of the technological aspect, control strategy and user's behaviour. The proposed system, by relying on thermal energy storage, decouples energy production and demand while shaves peaks in the energy demand and, at the same time, provides more autonomy to users through local storages. To identify subtle interactions in components of DHW system, dynamic simulations are carried out by establishing a coupled TRNSYS-MATLAB code, calibrated and validated by experimental measurements. The energy analysis implies that the proposed system cuts the required annual electrical energy in half, of which up to 82% of needed primary energy is supplied from renewable sources, compared to previous electrical-decentralised system. The optimisation of the results through applying control strategies indicates that adopting a three-time charging scheme is advantageous in terms of providing a more stable temperature profile as well as a higher hot water temperature. Compared to an available-by-demand operation, this scheme reduces the required total annual electricity by 5.2 % and enhances total thermal loss from components up to 4.0%. Furthermore, a sensitivity analysis on the results emphasises the striking role of the user behaviour in electrical energy consumption either via draw-off temperature or adjusting the pre-defined temperature for activation of the built-in auxiliary heater. [ABSTRACT FROM AUTHOR]

• European-scalable method to simulate rainfall erosivity from gridded rainfall data. • Monthly power-law models link rainfall depth to erosivity with European coverage. • EMO-5 shows the best potential to simulate rainfall erosivity events. • Gridded datasets perform better in Northern over Southern Europe. • Future upscaling and regional bias correction may overcome current limitations. Soil erosion is time compressed into a number of episodic erosive rainfall events with an associated potential to detach and transport soil particles (rainfall erosivity), each possessing unique spatial and temporal characteristics. Rainfall erosivity events in Europe follow extreme value distributions in which a limited number of rainstorms dominate the long-term budget of available erosive energy. To combat soil erosion in Europe in a targeted manor, timely erosion mitigation measures should derive from dynamic model simulations that incorporate spatially and temporally distributed estimations of rainfall erosivity. Rain gauge measurements from singular points are typically used to quantify rainfall erosivity, however the spatial uniqueness of rainfall presents a key limitation to dynamically model rainfall across broad spatial scales with a limited number of point measurements. Discretised gridded precipitation datasets with a widespread (e.g. continental) spatial coverage potentially offer an opportunity to adequately replicate the dynamics of rainfall erosivity events, however their performance remains poorly tested in the pan-European context. This study builds upon the comprehensive Rainfall Erosivity Database at European Scale (REDES) archive of over 300,000 events from 1181 gauge stations to develop a two-step modelling process: 1) firstly, optimal monthly models were fitted and evaluated between gauge-recorded rainfall depth and rainfall erosivity (EI 30) across European climatic regions to develop a European-scale parameter surface, 2) secondly, three datasets (EMO-5 (6-hr), E-OBS (24-hr), UERRA MESCAN-SURFEX (24hr)) were directly evaluated via a grid-to-point analysis based on their ability to simulate the station-specific event rainfall erosivity timeseries at a random selection of 32 locations. EMO-5 (Nash-Sutcliffe model efficiency mean = 0.24) outperformed other tested gridded datasets, showing the capability to adequately replicate the event number, timing, and their average magnitude. A higher model performance in Northern compared with Southern European climatic regions, in which characteristically higher and spatially-complex event rainfall erosivity magnitudes are found, was symptomatic of a poor ability of grid-based simulations to replicate the magnitudes of events in the outer extents of the frequency-magnitude spectrum. The absence of a clear global systematic predictive bias amongst simulated locations suggests the need for future upscaling of this analysis to the entire European REDES dataset to fully understand and correct for the method-derived bias in a climate region-specific way. [ABSTRACT FROM AUTHOR]

The safety rules for the construction and installation of lifts, currently in force in Europe, include several requirements concerning the behaviour of the shock absorbers when stopping an elevator. In this paper, a finite element model simulating the behaviour of a cellular polyurethane shock absorber has been developed. The material mechanical behaviour was simulated by means of an elastomeric foam theoretical model, previously calibrated in a former paper. Several in-service and extreme condition scenarios have been analysed with this numerical model, thus verifying the fulfilment of the requirements of the standard. [ABSTRACT FROM AUTHOR]

• Existing approaches to EPCs in Europe reviewed. • Limitations to current and future applications highlighted. • New forms of modelling for future EPCs documented. • A framework of criteria for evaluating new assessment approaches proposed. As our need for energy information of buildings evolves, and the tools and methods at our disposal increase in scale and complexity, it is perhaps reasonable to expect a similar level of change in the way energy in buildings is assessed within national energy compliance frameworks. By comparing the available opportunities for building energy modelling with the current methodologies underlying Energy Performance Certificates, this study proposes future directions for standardised energy assessment of residential buildings and the impact this could have on different facets of energy policy. In carrying out this exercise, a number of criteria are proposed that could be used to appraise methodologies that align with future requirements of energy assessment, with two potential candidates for future energy assessment considered as part of this appraisal. An argument is thus proposed for better aligning future forms of standardised energy assessment with directions and requirements of future low-carbon energy policy. [ABSTRACT FROM AUTHOR]