Search the repository

A+ | A- | | SLO | ENG

Abstract: Introduction: Herbaceous plant species constitute an essential element of the flora of European beech (Fagus sylvatica) forests. There is increasing evidence that rapidly changing climate is likely to modify the spatial distribution of plant species. However, we lack understanding of the impact that climate change might have on beech forest herbs across the European continent. We investigated the possible effects of predicted increasing rates of global warming and altered precipitation regimes on 71 forest herbs closely associated with beech forests, but with varying biogeographic and climatic niche attributes. Methods: By using a total of 394,502 occurrence records and an ensemble of species distribution models (SDMs), we quantified the potential current distribution and future (2061-2080) range shifts in climatic suitability (expressed as occurrence probability, OP) according to two climate change scenarios (moderate SSP2-4.5 and severe SSP5-8.5). Results: Overall, precipitation of the warmest quarter and temperature seasonality were the most influential predictors in shaping current distribution patterns. For SSP5-8.5 scenario, all studied species experienced significant reductions (52.9% on average) in the total size of highly suitable areas (OP >0.75). However, the magnitude and directions of changes in the climatic suitability were highly species-specific; few species might even increase OP in the future, particularly in case of SSP2-4.5 scenario. The SDMs revealed the most substantial decline of climatic suitability at the trailing edges in southern Europe. We found that climatic suitability is predicted to show unidirectional northward shift and to move toward higher elevations. The gain/loss ratio was generally higher for narrow-ranged species compared to widespread taxa. Discussion: Our findings are contextualized with regards to potential confounding factors (dispersal limitation, microclimatic buffering) that may mitigate or accelerate climate change impacts. Given the low long-distance migration ability, many beech forest herbs are unlikely to track the velocity with which macroclimatic isotherms are moving toward higher latitudes, making this species group particularly vulnerable to climate change.
Keywords: species distribution modelling, global warming, range shift, climatic niche, biogeography, Europe
Published in DiRROS: 29.11.2023; Views: 253; Downloads: 131
Full text (8,49 MB)
This document has many files! More...

Abstract: Numerical simulations and parametric studies of glued-in rods in cross-laminated timber have been performed. The simulations were based on 3D finite element analysis, using a cohesive surface model for the bond-lines between the laminations and the bond-line along the rod. The parametric studies investigated the influence of the glued-in length, the rod diameter, and the rod-to-grain angle on the load-bearing capacity and stiffness of the connection. The analyses showed that the load-bearing capacity generally increases with the glued-in length and the rod diameter, which agrees well with experiments. For different rod-to-grain angles, different mechanical behaviour was observed, especially considering the failure modes.
Keywords: glued-in rods, cross laminated timber (CLT), parametric study, nonlinear numerical modelling, glued-in length, rod diameter, rod orientation
Published in DiRROS: 13.09.2023; Views: 235; Downloads: 144
Full text (2,66 MB)
This document has many files! More...

Abstract: The responses of the current and the coupled potential to rapid depassivation have been studied on a three-electrode system under open-circuit conditions. Passivated AISI 304 stainless steel in low- and high-conductivity solutions of NaSO has been depassivated with a single, rapid scratch over the small fraction of surface of the working electrode (WE). Single- and dual-WE configurations have been implemented. Once the surface is scratched, the current and potential transients exhibit a delayed maximum and minimum, respectively, in contrast to the outcome of more common potentiostatic scratching experiments. A simple model based on the equivalent circuit has been developed to predict the observed transients and provides clear relations between the features of the transient and the parameters of the electrolyte and the electrodes. The interfacial capacitance of the electrodes’ passive surfaces proves crucial for the shapes of the observed potential and current transients. It is shown that this capacitance temporarily provides the majority of the charge for repassivation under open-circuit conditions. Possible sources of specific discrepancies between the model and the measured transients are indicated.
Keywords: repassivation, open circuit conditions, transient, modelling, interfacial capacitance
Published in DiRROS: 21.06.2023; Views: 319; Downloads: 149
Full text (1,75 MB)
This document has many files! More...

Abstract: Old metallurgical dumps across Europe represent a loss of valuable land and a potential threat to the environment, especially to groundwater (GW). The Javornik electric arc furnace (EAF) and ladle slag heap, situated in Slovenia, was investigated in this study. The environmental impact of the slag heap was evaluated by combining leaching characterization tests of landfill samples and geochemical modelling. It was shown that throughout the landfill the same minerals and sorptive phases control the leaching of elements of potential concern, despite variations in chemical composi- tion. Although carbonation of the disposed steel slags occurred (molar ratio CO3/(Ca+Mg) = 0.53) relative to fresh slag, it had a limited effect on the leaching behaviour of elements of potential concern. The leaching from the slag heaps had also a limited effect on the quality of the GW. A site-specific case, however, was that leachates from the slag heap were strongly diluted, since a rapid flow of GW fed from the nearby Sava River was observed in the landfill area. The sampling and testing approach applied provides a basis for assessing the long-term impact of release and is a good starting point for evaluating future management options, including beneficial uses for this type of slag.
Keywords: EAF slag, field verification, geochemical modelling, ladle slag, leaching, release prediction, steel slag heap
Published in DiRROS: 28.04.2023; Views: 367; Downloads: 195
Full text (4,37 MB)
This document has many files! More...

Abstract: With increasing exploitation of groundwater resources and implementation of various activities in their recharge areas, it is vital to conduct a comprehensive assessment of aquifers to ensure their conservation and sustainable management. In the present study, we used a comprehensive approach to conceptualise and identify the functioning of two connected aquifer systems in north-eastern Slovenia: the Quaternary porous aquifers Dravsko polje and Ptujsko polje. The study presents the conceptual models of both aquifers and their interconnectedness using separate mathematical-numerical models with the aim of ensuring an integrated management of these alluvial aquifer systems. It also highlights the importance of understanding connections between such systems for simulating groundwater flow and transport of different contaminants.
Keywords: hydrogeological model, Modflow model, aquifer geometry, aquifer recharge, modelling
Published in DiRROS: 27.03.2023; Views: 460; Downloads: 160
Full text (5,58 MB)