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A thorough experimental assessment of THz-TDS plasma diagnostic techniques for nuclear fusion applications
No full textIn this paper, the study of a plasma diagnostic system based on the THz time domain spectroscopy technique is presented. Such a system could potentially probe a large part of the electromagnetic spectrum currently covered by several other diagnostics in a single measurement. This feature, keeping in mind the basic requirements for plasma diagnostics in nuclear fusion experiments, such as robustness and hard environment applicability, as well as durability and low maintenance, makes the diagnostic of great interest. A conceptual design of the THz-TDS diagnostic has been developed, starting from the well-established classical microwave and far infrared plasma diagnostics landscape. The physical constraints and required instrumental characteristics have been studied and are described in detail here, together with the solutions available for each type of plasma measurement. Specific experimental laboratory tests of the different experimental configurations have been carried out, evaluating the capacity and potential of the novel diagnostic, together with the instrumental constraint, within the diagnostic parameter space
On farm conservation, analysis of antimicrobial and antifungal activity and biothecnological use of the essential oil of the endemic and endangered species Santolina etrusca
No full textMicro-analysis as a Tool for the Characterization of Historical Masonry Buildings: The Decorative Elements of the Basilica Della Beata Vergine Maria Del Rosario (Polesella, Rovigo)
No full textThe Basilica of the Beata Vergine Maria del Rosario of Polesella, the subject of this study, was built in the mid-eighteenth century in the village of Polesella (in the province of Rovigo, Veneto Region, Italy). Some restoration work on the Basilica has been necessary for recent years; this has allowed sampling of interior plasters on which preliminary microanalyses have been performed to better characterize the building materials used, in support of subsequent repair work. Among the many planned restoration works, interventions on the interior walls were, in addition, also planned. For this, the interior plasters and interior painting of the church were studied through observations with SEM–EDS. The objective of this work is mainly to show how archeometric analyses can be a valuable tool to improve the knowledge and characterization of the materials used, in this case, on some decorative elements of the Basilica. In particular, regarding the frescoes, the research was also aimed at identifying the type of pigments used by the author Luigi Battisti, believed to be the author of some of the works on display
Drivers of persistent marine heatwaves in the Mediterranean in recent years
No full textThe Mediterranean basin has experienced several marine heatwaves (MHWs) over the last few decades. During MHWs anomalous warm ocean temperatures are present for several days at least and can influence atmospheric circulation and negatively affect ecosystems. There is increased interest in these events as they occurred more frequently and with larger severity, fuelled by global warming trends. Here we examine the strong Mediterranean MHW of 2022, which started in May and lasted for several months. This MHW event rapidly spread through western and central Mediterranean with peak intensity at par with the record-breaking 2003 event. In this communication we focus on the drivers of the prolonged 2022/2023 case which led to its exceptional duration. We find that persistent anticyclonic conditions, that continued through fall and winter, were responsible for the persistence of the 2022/23 MHW. We also discuss recent Mediterranean conditions by analyzing near real-time observational products, and discuss the possible impacts of global warming on MHW characteristics
Systems Engineering and Multi-criteria Decision Making Technique for Concept Design of DTT Divertor Fixation System
No full textThe conceptual design stage is one of the main challenging phases in System Engineering. Starting from the High-Level Requirements (provided by the project needs), defining the broad features and conditions that a product must ensure, different design solutions are often implemented. Several methodologies can aid whenever a decision-making process has to be performed. Among these, the Fuzzy Analytic Hierarchy Process (Fuzzy AHP) stands out, providing a rational framework for a needed decision by quantifying its criteria and alternative options, and for relating those elements to the overall goal. Fuzzy AHP centralizes the opinion of experts who, through objective and subjective opinions, can rank the conceptual alternatives. The paper deals with the assessment of components for thermonuclear reactors, in particular the design of the DTT Divertor In-Vessel Fixation System. The main requirements that the Fixation System must guarantee are strictly related to the geometric-dimensional constraints concerning the presence of the various in-vessel components. Furthermore, the Fixation System must withstand the strong loads acting on the Divertor due to the partial or full loss of plasma confinement (Disruption Events). The aim is, therefore, to identify, through Fuzzy AHP, among different alternatives, the solution which best matches the functional requirements, geometrical constraints and Remote Handling compatibility
Results on the 1 MW CW 170 GHz gyrotron TH1509UA for ITER and DTT at the FALCON test stand
No full textIn this contribution, the tests of the pre-series gyrotron TH1509UA for the Divertor Tokamak Test facility (DTT) at the FALCON test facility are presented. This versatile test bed proves useful for testing continuous wave (CW) high-power gyrotrons, but also serves as a platform for testing components for the transmission line or the Upper Launcher of ITER and DTT. The gyrotron has demonstrated a power level of 1.02 MW at the gyrotron output window, corresponding to 980 kW at the output of the Matching Optics Unit (MOU) with a power variation during the pulse of < 2% after a stabilisation period. Additionally, an efficiency of 40% has been demonstrated during five consecutive 100 s pulses. Compared to the previous version, TH1509U, this gyrotron demonstrates the successful prevention of parasitic mode excitation over a wide range of parameters around the design operating point. The potential for even higher power performance has been shown in short pulses but not explored in long pulses yet, which instead focused on demonstrating compliance with the required specifications for the DTT project
Assessment of Population Health Risks Due to Heat Islands Using Thermal Satellite Images (The Case of Valencia)
No full textHeatwaves, have been made more frequent and intense in the last decades due to climate change and have been severely impacting the population, especially vulnerable ones, causing illness, death and impact on productivity. Heatwaves and their consequences are worst in urban areas that become islands of higher temperatures, usually refereed to as urban heat islands, UHI. In the framework of the European Commission-funded research project ARCH: Advancing Resilience of historic areas against Climate-related and other Hazards this phenomenon has been analyzed with special focus on historic and cultural heritage areas. This paper proposes an easy to be implemented procedure to provide to local administrations and stakeholders readable and easy to be understood information on the location of UHI within the territory and the induced risks of impact on the population, enabling them to take informed decisions on possible and effective mitigation strategies. The proposed procedures use satellite thermal maps to quantify the thermal hazard within the analysed territory in the first instance; the exposure to UHI effect in terms of location and severity of possible urban islands within the city is evaluated by considering both the land cover and the population. A social vulnerability assessment is then performed based on age and economic indicators readily available from census data. Using a fuzzy overlay approach all the above-mentioned assessments are combined to estimate the risk for possible impacts to the population induced by heatwaves
RELAP5 simulations of the PASI experiment on Containment Wall Condensation
No full textDuring a Design Basis Accident (DBA) or Beyond Design Basis Accident (BDBA) scenario, concerning a Loss Of Coolant Accident (LOCA), the heat extraction from the containment is related to the steam condensation on the cold surfaces, thermosiphon cooling loop and through the connection to the water tank. For these reasons the presence of a Containment Wall Condenser (CWC) as passive system integrated in the plant design, increase the safety margin in accidental scenarios. Within the framework of the EU2020 PASTELS (Passive Systems: Simulating the Thermal-hydraulics with ExperimentaL Studies) project, a series of test comprising the natural circulation phenomena in a low pressure open loop CWC has been performed. The PASI facility, developed by LUT University, has been used in order to identify the physical phenomena and investigate upon the mechanisms to assure the preservation of the safety function of the entire system and further, to support the system codes validation. As partner of the project, ENEA developed the RELAP5/mod3.3 input deck and performed the whole PASI test matrix, to verify the capability of the code to simulate complex loop component, e.g. the sparger, and related thermohydraulic phenomena such as the water flashing and geysering inside the open loop. In the present paper will be shown the post-test calculations performed with RELAP5 of test 1 (quasi-static test) and test 5-10 (reproducing the drain and refill phase of the water storage tank)
Indirect Identification of the Bond-Slip Model at SRP-Concrete Interface
No full textSteel Reinforced Polymer (SRP) systems represent an appealing solution for the external strengthening and repairing of existing reinforced concrete structures. However, similarly to what known for composite materials employing other fibers, such as carbon or glass ones, to assure an adequate bond between the reinforcement and the concrete substrate is fundamental for the success of many strengthening applications. In this paper, an analytical procedure recently published by the authors is applied for an indirect identification of the concrete-SRP interface law by varying some parameters, such as the compressive strength and the surface finish of the concrete. To this purpose, results from a wide experimental campaign performed by the authors have been considered. The bond-slip laws found case by case, implemented in the analytical procedure, allow for accurately fitting the experimental load-slip curves obtained from the performed direct shear tests
Decentralised by-product valorisation in the dairy value chain: An opportunity for sustainable intensification
Get PDFIncreasing the sustainability of the livestock sector is a vital goal in lowering the environmental burden of food production globally. The dairy sector is of particular interest in this context since it is responsible for a significant share of this burden. In the past, research has focused on approaches to lower the impacts at the farming stage of production, while fewer efforts have been directed at the later stages of the value chain. By-product valorisation is a tool within the wider framework of Circular Economy that allows to increase the efficiency of resource use by increasing the product output at high quality, potentially leading to a sustainable intensification. The present study aims to test this hypothesis. For this purpose, data was collected from a cheese production case study and pilot-scale experiments on whey valorisation, to model several scenarios of by-product valorisation in the dairy value chain. This includes a decentralised valorisation scenario modelled for the purpose of supporting a local Circular Economy and three scenarios representing common valorisation approaches. The impacts of the entire value chain are then assessed based on an attributional LCA considering three different functional units in order to examine the potential for a relative reduction of impacts per unit of product output. The results suggest that while there is no clear favourite among the investigated valorisation scenarios, by-product valorisation in general can lower the relative impacts of the value chain significantly as compared to the base scenario without valorisation. Depending on the valorisation scenario and impact category, impact reductions of up to 14%, 20% and 32% can be achieved for the three functional units, respectively. Hence, by-product valorisation allows for a sustainable intensification. While centralised lower quality valorisation is favourable in terms of product mass and overall process efficiency, decentralised and high-quality valorisation performs better when the economic value of the products is taken into consideration. Thus, the choice for the most suitable approach for a production site will depend on the context of the production and the intentions of the stakeholders