Energy communities (ECs) are gaining strong interest to support the energy transition with increasing number of practical implementations in Europe. Encouraged by favorable regulations—such as reduced grid tariffs for internal energy exchanges— ECs enable consumers and prosumers to share locally generated electricity and reduce their energy costs. However, in practice, these exchanges rely on the public distribution network, which may lead to cost distortions if grid usage is not adequately reflected in tariff structures. This paper investigates the economic and grid impacts of ECs through a large-scale analysis of more than 500 configurations with varying sizes, installed capacities, and shares of prosumers. Each configuration is simulated under both individual and collective management schemes, with different levels of grid tariffs applied to internal exchanges. Results show that collective management systematically reduces users' electricity bills. At the same time, internal energy exchanges can grow significantly if they are not charged by any grid tariffs, leading to higher overall grid usage while reducing the revenue collected by the distribution system operator (DSO). A 10% increase in ECs self-sufficiency results in an average 8% decrease in DSO revenue, alongside a 3% increase in total grid energy usage ad 2% increase in terms of peak power. Applying standard grid tariffs to community exchanges, identical to the purchase form retailer, reverses this trend, increasing DSO revenues and reducing grid usage. These findings highlight the need for carefully designed grid tariffs that balance incentives for EC development with fair cost recovery for network operators.
Tunnel stability in tectonically disturbed rock masses remains particularly challenging near rock–soil interfaces, where abrupt stiffness contrasts and heterogeneous geological structures can trigger collapse mechanisms that conventional rock mass classification systems do not adequately capture. This study identifies and quantifies a geometry-controlled instability mechanism governing tunnels excavated near rock–soil interfaces under low-to-medium overburden conditions.The analysis combines 26 roof-collapse incidents recorded in three railway tunnels and one adit in Northern Thailand with geological mapping, RMR–GSI characterization, construction records, convergence monitoring, and two-dimensional finite element analyses. Results from the Phayao Tunnel demonstrate that the occurrence of collapse is governed not only by rock mass quality but also by the effective thickness of competent material available above the excavation. A normalized interface-depth parameter V/H is introduced to quantify this confinement condition.Field observations and numerical simulations show that when V/H decreases below approximately 2.5, the compressive arch above the tunnel crown becomes progressively truncated, leading to reduced confinement, increased deformation, and increased collapse susceptibility. A collapse-risk framework integrating rock mass quality, effective confinement, and interface geometry is proposed. Although additional validation is required in other geological environments, the proposed approach provides a mechanics-based framework for identifying interface-controlled instability and supporting adaptive excavation and reinforcement strategies.
This paper addresses a key blind spot in industrial robot fault detection and dynamic modeling: the modeling of temperature effects. Although often neglected, ambient temperature and joint temperature significantly influence robot dynamics and vary widely in practice. To address this challenge, a one-class anomaly detection approach is proposed based on an adaptation of a previously introduced hybrid inverse dynamic model combining physics-based and data-driven components, which constructs tight envelopes of normality. The resulting anomaly detector is capable of detecting very slight torque deviations in a real TX2-90 Stäubli 6-axis robot, while remaining robust across a wide trajectory space and continuous joint temperature ranges. The behavior of the envelopes is further analyzed, their effectiveness for anomaly detection on the considered robot is illustrated through preliminary experiments, and the importance of accounting for temperature for mechanical fault detection and localization is highlighted.
The reduction of tetravalent manganese (Mn-(IV)) to trivalent manganese (Mn-(III)) by HEPES Good's buffer is often used to modify the reactivity of δ-MnO2 and to distinguish between the Mn-(III) and Mn-(IV) oxidants in redox reactions. However, the structure of HEPES-reacted δ-MnO2 has remained elusive, hindering a detailed understanding of interfacial electron transfer between adsorbed species and structural Mn. Here, we characterized the structure of δ-MnO2 reacted with HEPES at pH 6 and 8 under low and high NaCl ionic strength, using chemical analysis, high-energy X-ray diffraction, pair distribution function (PDF), extended X-ray absorption fine structure (EXAFS) spectroscopy, and high-resolution transmission electron microscopy (HRTEM) coupled with selected area electron diffraction (SAED). The average Mn oxidation state (AMOS) decreases from 3.92-3.87 to 3.71-3.59 after HEPES addition, depending on pH and ionic strength. HEPES-reacted δ-MnO2 has a distinctly different structure at low and high ionic strength. At low ionic strength, the δ-MnO2 HE crystallites are 3-6 nm across, and the MnO2 layers have approximately 23% vacant sites capped with mainly Mn-(III) and some Mn-(II). At high ionic strength and pH 8, δ-MnO2 HE contains large crystals, several hundred nanometers across, made up of crystallographically oriented nanodomains. Most SAED patterns show streaks along the [100]* direction, indicating a high degree of disorder in the close packing of the anionic sheets, in the Na position within the interlayer, and in the Mn-(IV)-Mn-(III) distribution within the layer. Some nanodiffraction patterns show distinct superstructure reflections along the streaks with A* = 3a*, as seen in well-crystallized triclinic birnessite, and A* = 6a*. High-ionic-strength δ-MnO2 HE has no interlayer Mn-(III), and the Na-(I) ions, along with the layer Mn-(III) and Mn-(IV) cations, are semiordered at the short- to medium-range scales and essentially disordered over longer distances. Identifying the two distinct structures of HEPES-reacted δ-MnO2 clarifies structural ambiguities reported in the literature and provides a solid foundation for exploring its redox reactivity and electrochemical performance.
Construction on soft, highly compressible soils increasingly requires reliable ground improvement solutions. Among these, Rigid Inclusions (RIs) have emerged as one of the most efficient soil-reinforcement techniques. This paper synthesizes evidence from over 180 studies to provide a comprehensive state-of-the-art review of RI technology encompassing its governing mechanisms, design methodologies, and field performance. While the static behavior of RI systems has now been extensively studied and is supported by international design guidelines, the response under cyclic and seismic loading, particularly in liquefiable soils, remains less documented and subject to significant uncertainty. This review critically analyzes the degradation of key load-transfer mechanisms including soil arching, membrane tension, and interface shear transfer under repeated loading conditions. It further emphasizes the distinct role of RIs in liquefiable soils, where mitigation relies primarily on reinforcement and confinement rather than on drainage-driven mechanisms typical of granular columns. The evolution of design practice is traced from analytical formulations validated under static conditions toward advanced numerical and physical modeling frameworks suitable for dynamic loading. The lack of validated seismic design guidelines is high-lighted, and critical knowledge gaps are identified, underscoring the need for advanced numerical simulations and large-scale physical testing to support the future development of performance-based seismic design (PBSD) approaches for RI-improved ground.
