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Effetto ormesi nei kiwi (Actinidia spp.) stimolato da radiazione ultravioletta-C
Full text linkStudi scientifici hanno dimostrato che l'irradiazione con raggi ultravioletti UV-C può aumentare la resistenza naturale delle piante ai patogeni e alle malattie, sia prima che dopo la raccolta. Una dose appropriata di raggi UV-C induce la produzione di metaboliti che rafforzano le difese naturali delle piante, effetto noto come "ormesi". L’ormesi è un'alternativa promettente ai fitofarmaci sintetici, che sono dannosi per l'ambiente e la salute umana. Questo Rapporto nasce dalla collaborazione tra ENEA (Centri di Frascati e Casaccia) e CREA (Centro di Ricerca per l’Olivicoltura, la Frutticoltura e l’Agrumicoltura di Roma); esso descrive gli effetti dei raggi UV-C emessi da matrici di Light Emitting Diodes (LED), atti a generare una risposta ormetica in piante di kiwi (Actinidia spp.) esposte al patogeno Pseudomonas syringae pv. actinidiae prima o dopo irraggiamento.Scientific studies have shown that irradiation with UV-C ultraviolet rays can increase plant resistance to pathogens and diseases, either before or after harvest. An adequate dose of UV-C radiation induces the production of metabolites that strengthen plants' natural defenses, an effect known as "hormesis." Hormesis is a promising alternative to synthetic pesticides that are harmful to the environment and human health. This report, the result of the joint work of ENEA (Frascati and Casaccia Research Centers) and CREA (Research Center for Olive, Fruit and Citrus Cultivation, Rome) describes the effects of UV-C radiation emitted by Light Emitting Diodes (LED) arrays, which can generate a hormesis response in kiwifruit (Actinidia spp.) plants exposed to Pseudomonas syringae pv. actinidiae pathogens before or after irradiation
Experimental investigation of PDI bifurcation of lower hybrid waves during electron density ramp-up in EAST
No full textThe effect of parametric decay instability (PDI) on the current drive efficiency of 4.6 GHz lower hybrid (LH) waves in EAST is investigated experimentally, showing the PDI channel bifurcation of LH waves for the first time in EAST. First, experiments with three platforms of LH power were performed, achieving the LH power required for the PDI occurrence. Second, PDI bifurcation experiments were further carried out by ramping up the plasma electron density. The loop voltage increases with an increase in density, implying a decrease in the current driven by the LH wave. PDI bifurcation during electron density ramp-up was studied by analyzing the parallel refractive index ( n ∥ ) and the frequency spectrum broadening, which is measured with a radio frequency magnetic probe array recently installed close to the LH antenna. It is observed for the first time that they both first increase with density, then there is not much variation and a clear sideband in the frequency spectrum is also observed when the density is up to 4 × 10 19 m − 3 , suggesting a change in the PDI channel. Calculation of the mode growth rate driven by PDI shows that when the edge electron density is up to 1.9 × 10 18 m − 3 , the growth rate of the ion cyclotron quasi-mode (ICQM) will exceed that of the ion sound quasi-mode (ISQM), quantitively explaining that with an increase in density, the PDI channel partly transits from the ISQM to the ICQM channel. Studies provide a possible way to reduce the power deposition in the edge region and improve drive capability by means of mitigating PDI behavior
EUROfusion contributions to ITER nuclear operation
Full text linkITER is of key importance in the European fusion roadmap as it aims to prove the scientific and technological feasibility of fusion as a future energy source. The EUROfusion consortium of labs within Europe is contributing to the preparation of ITER scientific exploitation and operation and aspires to exploit ITER outcomes in view of DEMO. The paper provides an overview of the major progress obtained recently, carried out in the frame of the new (initiated in 2021) EUROfusion work-package called ‘Preparation of ITER Operation’ (PrIO). The overview paper is directly supported by the eleven EUROfusion PrIO contributions given at the 29th Fusion Energy Conference (16–21 October 2023) London, UK [www.iaea.org/events/ fec2023]. The paper covers the following topics: (i) development and validation of tools in support to ITER operation (plasma breakdown/burn-through with evolving plasma volume, new infra-red synthetic diagnostic for off-line analysis and wall monitoring using Artificial Intelligence techniques, synthetic diagnostics development, development and exploitation of multi-machine databases); (ii) R&D for the radio-frequency ITER neutral beam sources leading to long duration of negative deuterium/hydrogen ions current extraction at ELISE and participation in the neutral beam test facility with progress on the ITER source SPIDER, and, the commissioning of the 1 MV high voltage accelerator (MITICA) with lessons learned for ITER; (iii) validation of neutronic tools for ITER nuclear operation following the second JET deuterium–tritium experimental campaigns carried out in 2021 and in 2023 (neutron streaming and shutdown dose rate calculation, water activation and activated corrosion products with advanced fluid dynamic simulation; irradiation of several materials under 14.1 MeV neutron flux etc)
Thermal neutron detection based on resistive gaseous devices
No full textIn the uRANIA-V project, new gaseous detector technologies for neutron detection were explored. The first is the micro-Resistive WELL (μ-RWELL), a compact resistive MPGD with a single amplification stage. The second is the surface-Resistive Plate Counter (sRPC), a new generation RPC based on surface resistivity. Both detectors used 10B4C converters to detect thermal neutrons, achieving efficiencies of 5–10%
Vanadium Recovery from Bayer Process Liquor Residue
No full textThe objective of this work is to develop a vanadium recovery process from a liquor residue of Bayer process. Vanadium finds application in strategic industrial sectors such as steel production and energy storage. The recognized importance of vanadium has pushed academic and industrial research towards the development of technologies for its recovery from different types of secondary sources. The developed process refers to a sodium fluorovanadate sludge from a spent Bayer liquor. The resulting filter cake was characterized to determine its composition and a vanadium recovery process was studied and optimized. This starts with a solubilization of the filter cake by water, followed by a precipitation step of aluminum through pH adjustment with sulfuric acid till 9.2. Vanadium is then recovered as ammonium metavanadate by precipitation with ammonium sulfate using a ratio (NH4)2SO4/salt cake = 2.25 w/w; the precipitate was calcined at T = 500°C to obtain vanadium as V2O5. The results showed an overall vanadium recovery of about 95%, with a purity > 99.6%. The innovative contribution here addressed is represented by the feasibility of producing high-purity V2O5 from the Bayer liquor through a relatively simple precipitation route
Customized shading solutions for complex building façades: the potential of an innovative cement-textile composite material through a performance-based generative design
No full textPurpose: The paper aims to investigate the comfort-related performances of an innovative solar shading solution based on a new composite patented material that consists of a cement-based matrix coupled with a stretchable three-dimensional textile. The paper’s aim is, through a performance-based generative design approach, to develop a high-performance static shading system able to guarantee adequate daylit spaces, a connection with the outdoors and a glare-free environment in the view of a holistic and occupant-centric daylight assessment. Design/methodology/approach: The paper describes the design and simulation process of a complex static shading system for digital manufacturing purposes. Initially, the optical material properties were characterized to calibrate radiance-based simulations. The developed models were then implemented in a multi-objective genetic optimization algorithm to improve the shading geometries, and their performance was assessed and compared with traditional external louvres and overhangs. Findings: The system developed demonstrates, for a reference office space located in Milan (Italy), the potential of increasing useful daylight illuminance by 35% with a reduced glare of up to 70%–80% while providing better uniformity and connection with the outdoors as a result of a topological optimization of the shape and position of the openings. Originality/value: The paper presents the innovative nature of a new composite material that, coupled with the proposed performance-based optimization process, enables the fabrication of optimized shading/cladding surfaces with complex geometries whose formability does not require ad hoc formworks, making the process fast and economic
High-Frequency Irreversible Electroporation: Optimum Parameter Prediction via Machine-Learning
No full textThe adoption of high-frequency irreversible electroporation in various medical treatments is becoming increasingly prevalent. There is currently a special focus on its applications in oncology, offering new perspectives in terms of treatable tumor types and treatment effectiveness. A multitude of parameters can influence the efficiency and effectiveness of high-frequency irreversible electroporation procedures, with the selection of suitable electrodes and possible prediction of ablated area as interesting examples. In this paper, we demonstrate that machine-learning strategies, specifically neural networks, provide an appropriate approach for optimizing the choice of some electrode characteristics, and predicting the ablation area, this being quite useful in high-frequency electroporation applications in oncology. This possibility, in turn, may lead to superior results in high-frequency irreversible electroporation, and to a significant reduction of the time required for achieving them
Influence of Friction in the Seismic Behaviour of HDRB+SD Isolation Systems
No full textThe response of an isolation system made of HDRBs and SDs under low energy earthquakes, classified on the basis of the energy at the basement, is analyzed. The study pointed out that for very low values of the energy, measured by means of the Arias intensity, the isolation system was not put in action, and the superstucture behaved like a fixed base one. The behaviour has been correlated to the ratio between the inertial force resultant and the maximum friction forces of the slider devices. For higher values of the energy, instead, the isolation system was activated and a value of the Arias intensity was individualized, which separates the two behaviours. The variability of the first resonance frequencies with the input energy has been particularly analyzed, as well as the structural response in terms of maximum accelerations, maximum displacements and relative horizontal displacements in the building
Relation Between Composition and Crystalline Structure in Substituted CaKFe4As4
No full text1144 is a family of Iron Based Superconducting Compounds that attracts interest due to its regular structure, composed by an alternance of alkaline and alkaline-earth planes that intercalate Fe-As layers. This rigidity grants to 1144 compounds a stoichiometric nature, and thus a robust critical temperature not affected by chemical inhomogeneities, and a peculiar pinning landscape enhancing critical currents at high fields. Critical currents can be however further enhanced by introducing further defects by means of irradiation and chemical doping on the Fe site. In our works, as a different approach, we evaluate the effect of the alkaline and alkaline-earth aliovalent substitutions. For this scope, CaKFe4As4 polycrystalline powders have been successfully doped by partially replacing Ca with Na and K with Ba by means of a mechanochemically assisted thermal synthesis. Such substituted compounds crystallize in the P4/mmm structure typical of 1144 compounds. X-ray diffraction analysis revealed that depending on the level of substitution the reflections characteristic of the P4/mmm tend to vanish. In particular, peaks analysis has shown that doping introduces increasing disorder in selected crystalline planes. Barium and sodium, as dopant, do not act the same way, the latter being less invasive, so that 1144 structure is preserved up to 40% substitution. The contemporary replacement of potassium and calcium with barium and sodium exhibits an intermediate behavior. Analysis of X-ray diffraction profiles collected as a function of temperature down to 100 K allowed to calculate the thermal expansion coefficients for the synthesized compounds, with CTE values similar for pristine and substituted compounds close to 1 × 10−6K−1 and 3 × 10−5K−1 respectively along the a-axis and c-axis
Bioproducts Extraction from Agro-Industrial By-Products and Their Valorisation. Development of Process Layouts
No full textThe agro-food industry generates important quantities of by-products, often considered waste, which represent for the companies huge costs of handling and disposal. On the other hand, they contain copious amounts and varieties of compounds that, appropriately extracted, purified, and processed, can be valued in several industrial sectors. Their exploitation generates an improvement of the sustainability performance of the supply chains, since it generates economic advantages, making available new commercial products and reducing disposal costs, improves the environmental performance of the agro-industrial productions, and allows new employment opportunities, thanks to the development of new industrial sectors. The Percival project aims to valorize the byproducts of agro-industrial supply chains of South of Italy, converting them into high-added value products, through innovative, efficient, and low environmental impact processes, going for the development of technologies that could represent new business opportunities for this territory. Particularly, the project deals with the development of processes for pretreatment, extraction, separation, and chemical/biotechnological transformation, using a biorefinery cascade approach. Indeed, the study of processes having the purpose of converting the residues from the above-mentioned transformations into advanced biofuels (biomethane) and agricultural products (e.g. soil improver and bio-stimulants) are also included in the project’s scope. The present paper provides an overview of the Percival project, along with the evaluation of the availability of residual biomasses from the supply chains of typical Southern agricultural products, and the valuable bioproducts achievable from these feedstocks, through a biorefinery processing scheme