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Experimenting urban living lab methodology on circular economy co-design activities in some Italian urban territories
No full textThe Urban Living Lab (ULL) is both a methodology and a place where different actors of a territory can collaborate with the aim of urban transformation and sustainable development. This paper briefly introduces a methodological framework, that combines stakeholder engagement and co-design process on Circular Economy (CE) ideas and projects. The structure of the methodological framework foresees four main phases: scouting and analysis of the territorial context, listening and exploration, participation and execution. The main objective of this paper focuses on the application and experimentation of the same ULL methodology framework in four different Italian urban territories (Anguillara Sabazia in the metropolitan area of Rome, Bologna, Taranto and Venosa, a small town in southern Italy), to highlight how the ULL is an effective approach for stakeholder engagement and co-design processes aiming to the transition toward CE. The discussion section of the four ULL cases highlights the main results of the co-design process: the ideation of project proposals of CE activities suitable for implementation in the reference urban territories. The four ULL cases have shown how the same methodological steps can be applied in urban areas with different geographical, territorial and socio-economic characteristics, with comparable results in terms of activating processes of engagement and co-design within the communities living there. In conclusion, experimenting the proposed methodological framework in each of the four urban areas, despite their differing characteristics, it has stimulated the growth of cultural capital and community ties. This was achieved through the exchange of different skills and the collaborative contributions of multidisciplinary teams, resulting in increased collective awareness
Frequency Chirping of Electromagnetic Ion Cyclotron Waves in Earth's Magnetosphere
Full text linkElectromagnetic ion cyclotron (EMIC) waves are known to exhibit frequency chirping occasionally, contributing to the rapid acceleration and precipitation of energetic particles in the magnetosphere. However, the chirping mechanism of EMIC waves remains elusive. In this work, a phenomenological model of whistler mode chorus waves named the Trap-Release-Amplify (TaRA) model is applied to EMIC waves. Based on the proposed model, we explain how the chirping of EMIC waves occurs, and give predictions on their frequency chirping rates. For the first time, we relate the frequency chirping rate of EMIC waves to both the wave amplitude and the background magnetic field inhomogeneity. Direct observational evidence is provided to validate the model using previously published events of chirping EMIC waves. Our results not only provide a new model for EMIC wave frequency chirping, but more importantly, they indicate the potential wide applicability of the underlying principles of TaRA model
DEMO toroidal field coil fast discharge unit integration studies
Full text linkThe Fast Discharge Units (FDUs) of the Superconducting (SC) Toroidal Field (TF) coils in the European demonstration fusion power plant DEMO warrant the machine integrity over its full lifetime against severe failure events, such as SC coil quenches or any other plant events requiring the safe TF magnet system discharge. A low (75 kA) and a high current (105 kA) configuration are under study for the TF coils for DEMO. The FDUs must be extremely reliable for the purpose of commutating in short time (∼1 s) the currents and to discharge the TF magnets safely into resistors outside of the tokamak building. Malfunctions of the FDUs must be avoided. The FDUs are considered as Safety Important Class (SIC) components that need to discharge high amounts of energy of about 161 GJ (@75 kA) resp. 118 GJ (@105 kA) stored in the DEMO TF coils. The TF FDUs Circuit Breakers (CBs) shall be installed in the lower level of the tokamak to minimize the length of the connecting busbars. The FDUs integration is challenging because of the high neutron and gamma radiation and stray magnetic fields of the tokamak. Since in DEMO the neutron fluence over lifetime is much higher than in ITER, the problems of using FDUs with electronic subsystems was expected to be more severe, so that their integration has been considered from the beginning of the DEMO project. Sufficient shielding or possible re-positioning of the whole FDUs or sensitive FDU components compared to ITER are being investigated, to reduce the neutron fluxes and neutron and gamma ray fluences. Alternative concepts, e.g., fully mechanical CBs are studied in the EUROfusion Work Package Plant Electrical System (WPPES) in parallel. This paper presents the CAD integration work on the DEMO TF FDUs supported by neutronics assessments. It is assumed the same FDU technology as in ITER. The magnet feeder ́s integration is commenced at the same time
Regeneration and Long-Term Stability of a Low-Power Eco-Friendly Temperature Sensor Based on a Hydrogel Nanocomposite
No full textA water-processable and low-cost nanocomposite material, based on gelatin and graphene, has been used to fabricate an environmentally friendly temperature sensor. Demonstrating a temperature-dependent open-circuit voltage between 260 and 310 K, the sensor effectively detects subzero ice formation. Notably, it maintains a constant temperature sensitivity of approximately −19 mV/K over two years, showcasing long-term stability. Experimental evidence demonstrates the efficient regeneration of aged sensors by injecting a few drops of water at a temperature higher than the gelation point of the hydrogel nanocomposite. The real-time monitoring of the electrical characteristics during the hydration reveals the initiation of the regeneration process at the gelation point (~306 K), resulting in a more conductive nanocomposite. These findings, together with a fast response and low power consumption in the range of microwatts, underscore the potential of the eco-friendly sensor for diverse practical applications in temperature monitoring and environmental sensing. Furthermore, the successful regeneration process significantly enhances its sustainability and reusability, making a valuable contribution to environmentally conscious technologies
Mapping Resilience of Distribution Networks Against Heatwaves
No full textThis paper proposes a method of assessing some aspects of the resilience of distribution networks with particular reference to the heatwave phenomena using a probabilistic approach. Combining the characteristics of the network with the probability of failure of the electrical grid components most affected by the heatwaves (e.g., the medium voltage cable joints) and the weather forecasts in a given territory, maps of risk of failure, or dually of the resilience of the network, can be developed by means of a Geographic Information System (GIS) environment. The approach exploits knowledge graph technology, linking different kinds of data, information, and models to an ontology to support the integrated processing and visualization of relevant information for decision-making. This contribution is part of the activities of the project 'Network 4 Energy Sustainable Transition - NEST,' funded under the National Recovery and Resilience Plan (NRRP)
A comparison of Italian and UK methods for establishing the need for structural assessment of bridges
No full textThis paper compares the risk-based methodologies on the structural assessment of highway bridges underlying two national guidance documents, namely the well-established UK Design Manual for Roads and Bridges and the recent Italian Ministry of Infrastructure and Transport's Guidelines. Both documents present risk-based methods for evaluating the need for a structural assessment, while exhibiting fundamental differences. For instance, the Italian methodology uses a qualitative approach combining hazard, vulnerability and exposure classes in order to determine whether a structural assessment is required, whereas the UK methodology uses a quantitative risk appraisal based on reliability and risk scores. Both methodologies are applied to the case study of two bridges, highlighting similarities and differences between the two methodologies. The comparison of these two risk-based approaches may allow for a better understanding of the governing factors and for potential improvement of guidelines
Woodchips from Forest Residues as a Sustainable and Circular Biofuel for Electricity Production: Evidence from an Environmental Life Cycle Assessment
Full text linkEnergy production from biomass represents a strategic solution for the achievement of global sustainability goals. In addition, the use of biofuels offers both significant environmental advantages and several socio-economic benefits. In this study, the environmental life cycle impacts associated with the use of woodchips from forest residues for combined heat and power generation in Italy were analyzed. Moreover, the use of woodchips was compared to the use of conventional fossil fuels in similar applications, and different biomass supply scenarios were evaluated to understand their effect on the overall impact related to 1 kWh of electricity. The impacts on “Climate Change” (2.94 × 10−2 kgCO2eq/kWh) and “Resources” (4.28 × 10−1 MJ primary) were revealed to be minimal compared to fossil fuels (reduction of about 95–97%) and forest woodchips emerged as a sustainable alternative for electricity generation. Moreover, impacts regarding “Human health” (3.04 × 10−7 DALY) and “Ecosystem quality” (3.58 × 10−1 PDF·m2·yr) were revealed to be relevant and identified as a research area to be further explored. The findings of this study also highlighted the key role played by the supply mode/distance of the woodchips on the overall life cycle impacts, with the use of “local” biomass representing the best reduction option. Lastly, another aspect to be further investigated is the optimization of the biomass supply
Phase-matching in high-energy photon sources by relativistic laser–plasma interactions
No full textIn this article we briefly review three generation mechanisms of high-energy photons related, directly or otherwise, to high-intensity laser–matter interactions. The three mechanisms are the “Betatron Radiation” (BR), the “Parametric X-ray Radiation” (PXR) from Laser-WakeField Accelerated Electrons (LWFA), and the all-optical “Compton BackScattering” (CBS). The aim is to highlight similarities and differences, in particular regarding the phase-matching conditions for the high-energy photons to be emitted
Modeling complete and shortcut simultaneous nitrification and denitrification coupled to phosphorus removal in moving bed biofilm reactors
Full text linkThis study aimed to model simultaneous nitrification and denitrification (SND) and shortcut (partial) SND processes coupled to phosphorus removal in lab-scale moving bed biofilm reactors based on data collected during two different experimental campaigns. Modeling was performed using BioWin 6.0 to accurately predict the experimental results. A sensitivity analysis conducted for the first experimental campaign identified the most influential process parameters. The absolute variance, Thiel's inequality coefficient, and normal objective function were used to evaluate the consistency of the experimental and modeled data. The calibrated and validated models satisfactorily reproduced the experimental data for all experimental campaigns and within the acceptance criteria, resulting in a suitable tool for predicting the process efficiency. Moreover, calibrated and validated data were used to test different dissolved oxygen (DO) ranges (0.6–0.8 mg O2·L−1), pH (6.5–9.0), and hydraulic retention time (HRT) (0.5–1.0 d) to improve shortcut SND. Based on the different simulated scenarios, the intermittent DO conditions can induce and maintain the inhibition of the nitrite-oxidizing bacteria with an average N-NO3− concentration of 0.05 mg N·L−1, while an HRT of 0.9 d resulted in average effluent N-NH4+, N-NO3− and N-NO2− concentrations of 4.0, 0.02 and 0.07 mg·L−1, respectively, indicating an efficient shortcut SND process
Optimized Water Distillation Layout for Detritiation Purpose
Full text linkTritium permeation constitutes a key issue for the future EU-DEMO, especially in the Breeding Blanket (BB) where fusion energy must be delivered to the Primary Heat Transport System (PHTS) and where tritium must be bred. Currently, the mitigation strategy of the tritium permeation from BB into primary coolant is based on the adoption of anti-permeation barriers and on the operation of the Coolant Purification System (CPS). This system must ensure a tritium removal rate from the primary coolant equal to the BB permeation rate at a target tritium-specific activity inside the PHTS. In the case of the Water-Cooled Lithium Lead (WCLL) BB, water distillation was selected as the most promising technology for the primary coolant detritiation due to its intrinsic simplicity and safety. Nevertheless, power consumption was recognized as a relevant concern. For this reason, the present work aims at investigating possibilities to reduce power consumption of the water CPS implementing Heat Pump-Assisted Distillation (HPAD) concepts. To do this, a review of the HPADs developed in the chemical industry was carried out, and the best options for the water CPS were identified based on qualitative considerations. Then, a quantitatively assessment of the best solution in terms of power consumption and tritium inventory was performed with the commercial numerical tool Aspen Plus. Finally, the Mechanical Vapor Recompression (MVR) concept was recognized as the most promising solution, ensuring a power saving of around 80% while keeping a limited tritium inventory