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Study of the response of a large volume TPC prototype for the CYGNO experiment at LNGS
No full textAstrophysical and cosmological observations have provided strong evidence that a significant portion of the Universe is composed of non-luminous matter, known as Dark Matter (DM). The Standard Model (SM) of particle physics successfully describes the fundamental particles and their interactions but does not account for any Dark Matter particle candidate. One of the most supported hypotheses suggests that DM is composed of particles different from those in the SM. Among the most promising candidates are Weakly Interactive Massive Particles (WIMPs), which are non-relativistic particles that interact weakly with SM particles. A stable, weakly interacting particle in thermal equilibrium in the early Universe would be capable of explaining the observed relic DM density. The motion of the Sun and the Earth with respect to the rest frame of the Galaxy produces an apparent "wind" of WIMPs coming from the direction of the Cygnus constellation. Assuming DM can interact with SM particles, it is possible to exploit the weak interaction with regular matter measuring the recoils induced by DM interactions. This is known as direct detection. The fundamental strategy is to expose a large amount of instrumented mass and wait for DM to produce recoils in it. Direct detection experiments look for nuclear recoils of low energy, 1-100 keV, with an expected rate below 1 event/kg/year. The low expected event rate implies detectors with extremely challenging requirements on the background reduction techniques, such as operating detectors underground to suppress cosmic rays, using radiopure materials, and implementing active or passive shielding. The CYGNO project aims to build a large O(30m 3 ) directional detector for rare event searches, including Dark Matter. The detector uses a gaseous Time Projection Chamber (TPC), which is sensitive to recoil topology and allows direction measurement. The TPC is filled with a gas mixture rich in helium and fluorine at atmospheric pressure, making it sensitive to both Spin-Independent and Spin-Dependent interactions. A triple Gas Electron Multiplier (GEM) stack provides ionization signal amplification, and the signals are optically read out using photomultiplier tubes (PMTs) and scientific CMOS cameras, enabling 3D track reconstruction. Several CYGNO prototypes have been built and tested in both overground and underground environments to assess their performance. Currently, the CYGNO project is at the end of the R&D phase with the Long Imaging ModulE (LIME), the largest prototype built, comprising a 50 liters active volume. After commissioning overground at Laboratori Nazionali di Frascati (LNF), LIME was installed underground at Laboratori Nazionali del Gran Sasso (LNGS) in February 2022. This underground operation marks a significant milestone in the CYGNO roadmap towards constructing a large-scale TPC for directional Dark Matter searches
LC Parameters Identification for a 3-Phase AC-DC Converter through Digital Twin Modeling Technique and Optimization Algorithms
No full textThe Digital Twin (DT) technology is transforming the energy conversion industry by replicating in real-time the behavior of physical systems by means of high-fidelity digital models (DMs). Specifically, close monitoring of parameters influencing the health status of components prone to failure is essential for the application of predictive maintenance strategies. This capability is made achievable through the use of the DT concept and the advanced optimization algorithms introduced in this work. This paper presents the parameters' estimation approach based on the DT method applied to 3-phase AC-DC switching converters. First, a Particle Swarm Optimization (PSO) algorithm is employed to estimate the characteristics of the L-type AC filter and the DC capacitance. The same approach has been repeated using the Genetic Algorithm (GA) and the Simulated Annealing (SA) as optimization algorithms. Balanced and unbalanced situations have been tested to demonstrate the robustness and feasibility of the proposal and the comparison between the three proposed optimization algorithms has been carried out. The results show the potential of the procedure for application in system identification and condition monitoring
Le poesie del canzoniere e i loro destinatari (con una nota su «Spirto gentil»)
No full textIl saggio analizza il ruolo dei destinatari nel Canzoniere di Petrarca, evidenziando come oltre un terzo dei componimenti sia rivolto a interlocutori reali o astratti, con particolare attenzione alla famiglia Colonna e a Sennuccio del Bene. Lo studio mostra come Petrarca abbia progressivamente decontestualizzato questi riferimenti, rendendo meno evidente il legame con la realtà storica. Infine, l’articolo propone una nuova ipotesi sul destinatario della canzone Spirto gentil (53), identificandolo in Bosone da Gubbio, poeta e politico del tempo.The paper analyzes the role of recipients in Petrarch’s Canzoniere, highlighting how more than a third of the poems are addressed to real or abstract interlocutors, with particular focus on the Colonna family and Sennuccio del Bene. The study explores how Petrarch progressively decontextualized these references, making their historical connections less evident. Finally, the article proposes a new hypothesis regarding the recipient of the poem Spirto gentil (53), identifying him as Bosone da Gubbio, a poet and politician of the time
Experimental investigation and numerical modeling of FDM-3D printed material mechanical behavior
No full textWith the increasing use of 3D printed materials, the production technology needs to be thoroughly investigated from both experimental and numerical perspectives. Experimental analysis of 3D printed materials helps to elucidate the impact of numerous printing parameters on material behavior, thereby guiding the design of 3D printed components for specific applications. On the other hand, numerical modeling allows researchers to identify the most effective approaches to simulate the materials’ behavior, taking into account the various factors involved, such as anisotropy and the influence of printing parameters. While the literature offers extensive experimental studies on the mechanical behavior of 3D printed materials, numerical modeling remains less explored. Although recent contributions have emerged, there is still a need for comprehensive studies addressing the numerical simulation of these materials’ behavior. This study has two main objectives. The first objective is to conduct an in-depth investigation into the mechanical behavior of 3D printed PLA through a series of experimental tests on two different types of PLA. These tests focus on understanding damage mechanisms and propagation patterns. Specifically, standard tensile and flexural tests, as well as fracture tests such as compact tension (C/T) and single-edge notched bending (SENB), are performed. These tests allow to characterize the mechanical behavior of these materials, estimating their elasto-plastic parameters and identifying the various damage mechanisms that occur. The second objective is to develop a plasticity and damage model to simulate the experimentally observed mechanical behavior, including the overall stress-strain behavior, the detection of the different damage mechanisms, and their propagation timelines. Using experimental results, the model’s elasto-plastic and damage parameters are calibrated to accurately replicate the experimentally obtained behavior. The numerical study is both challenging and stimulating due to the material’s anisotropy and the simultaneous presence of multiple damage mechanisms. Numerous parameters must be considered to effectively simulate these materials’ behavior. The model’s underlying assumptions are derived from and validated through experimental tests. Comparisons between experimental and numerical results highlight the model’s effectiveness and identify areas for potential improvement, ensuring a robust framework for simulating the complex behavior of 3D printed materials
LA SOSTENIBILITÀ D’IMPRESA - Un fragile equilibrio tra obblighi, opportunità e controversie normative
No full textAd oggi, la sostenibilità di impresa, specialmente nel contesto europeo, costituisce un tema largamente dibattuto sia in letteratura che in ambito professionale. In un contesto di continuo cambiamento, sia formale e sia sostanziale, la rendicontazione della sostenibilità rischia di costituire uno “tsunami informativo” troppo oneroso per le aziende, soprattutto per le PMI tradizionalmente dotate di mezzi economici e organizzativi ridotti rispetto alle grandi società quotate.
Il presente studio, in accezione teorica, ripercorre le fasi salienti del discorso internazionale inerente alla sostenibilità, partito con slancio negli Anni ’80, per capire come questo tema pian piano si sia avvicinato alla dimensione economica legata all’accounting e alla finanza. Parallelamente, l’elaborato approfondisce in maniera dettagliata le principali normative e regolamenti europei, che configurano l’attuale quadro prescrittivo comunitario, come la Non-Financial Reporting Directive (NFRD), il Sustainable Finance Disclosure Regulation (SFDR), il Regolamento sulla Tassonomia, la recente Corporate Sustainability Reporting Directive (CSRD) e, in ultima, l’attuale proposta costituita dal “Pacchetto Omnibus”. Questo elaborato presenta anche un valore pratico. In particolare, sono analizzati gli standard di rendicontazione sviluppati da EFRAG, sia per le PMI quotate (ESRS-LSME) sia per quelle non quotate (VSME), attraverso un’analisi incentrata sui requisiti formali e sostanziali, che mette in evidenza le principali differenze non solo tra i due modelli, ma anche rispetto agli standard ESRS attualmente applicabili alle grandi società quotate
Roma città aperta. Ottanta anni dopo.
No full textBreve intervento sul film di Roberto Rossellini, Roma Città Aperta del 1945, del quale ricorre l'ottantesimo anniversario