Tesi di Dottorato
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Item Studenti universitari con disturbo specifico dell'apprendimento: implicazioni cliniche e pratica educativa(Università della Calabria, 2023-06-04) Montesano, Lorena; Perrelli, Raffaele; Valenti, AntonellaIntroduction In recent years, with the approval of Law No.170/2010, the number of the university students with Specific Learning Disorders in Italy has considerably increased. Despite this, the percentage of these students in the university population (around 1%) is still significantly lower than expected, especially when compared to the percentage of pupils with SLD in schools of all types and grades (around 5%). Moreover, as the most recent scientific literature show, still a significant number of young adults with SLD drop out at university. Additionally, there is another critical issue: the lack of knowledge about the characteristics of these disorders in adulthood. While a vast scientific literature is available regarding the difficulties of pupils with SLD during primary school, we are still far from an in-depth knowledge of the difficulties that an adult with SLD encounters during his university studies. Objectives On this basis, the present research project focused on the following objectives: to investigate the characteristics of SLD in adulthood, to analyse the difficulties reported by the students with SLD and to identify the barriers and the facilitators, which characterize their university experience. Results The results obtained have highlighted the presence of difficulties in reading, writing and calculating abilities even in adulthood. In this age group, university students with SLD continue to be slower and less accurate in reading and writing compared to adults without SLD and show weak calculation abilities. Additionally, the results demonstrate deficits in the working memory and the processing speed. These deficits are associated with difficulties in the tasks of rapid automatized naming and phonological awareness. Concerning the emotional and motivational aspects, our SLD group did not present high levels of anxiety, low self-esteem or poor resilience compared to controls. We then identified the main barriers and facilitators encountered by students with SLD in the university environment and during distance learning (initiated in the Covid-19 health emergency period), by means of qualitative surveys conducted according to the Student Voice approach. Finally, we included the results of the research period performed at the University of Burgos, Spain, under the supervision of Prof. Sonia Rodríguez Cano, consisting in the standardization of the Vinegrad questionnaire for the Spanish context.Item Nanofillers doped buckypaper membranes for highly enhanced recovery of pollutants from wastewater(Università della Calabria, 2023-03-29) Baratta, Mariafrancesca; Cipparrone, Gabriella; De Filpo, GiovanniL’acqua è un bene prezioso, fonte di vita sulla Terra. Sin dalla notte dei tempi, questa minuscola molecola fatta di soli due elementi e tre atomi, ha assistito all’alternarsi di ere geologiche, ha conosciuto epoche e visto lo sviluppo e il declino di civiltà che attorno all’acqua hanno costruito la loro ricchezza e il loro sostentamento. Dall’acqua dipende la vita e attorno all’acqua si è costruita la vita. L’idea che questa risorsa naturale sia sempre stata presente sulla Terra ha fatto credere per molto tempo che essa sia una fonte inesauribile, a cui tutti possono accedere illimitatamente per soddisfare i propri bisogni. Tuttavia, se fino al secolo scorso, il rapporto tra la domanda e l’offerta si è mantenuto pressoché unitario, con l’avvento della civiltà moderna e, dunque, con lo sviluppo economico che ciò ha comportato, si è assistito a un progressivo aumento della disuguaglianza tra questi due termini, con il primo, quello della domanda, che è letteralmente schizzato alle stelle. La richiesta d’acqua da parte della popolazione mondiale, che attualmente ammonta a 8 miliardi, per il soddisfacimento dei propri bisogni quotidiani ha portato, nel corso degli anni, a un enorme consumo di questa risorsa, senza però che la Terra ricevesse nel frattempo un efficiente ricambio di acqua pulita. Non solo, infatti, il consumo d’acqua è notevolmente aumentato, e le risorse del pianeta nel frattempo sono rimaste pressoché uguali, ma gran parte di questa grossa quantità di acqua è stata sprecata e costantemente inquinata. Inquinata da quella stessa popolazione che ne fa domanda, attraverso il rilascio improprio di rifiuti provenienti dagli impianti di scarico di attività connesse con il sostentamento della vita umana, in primis quelle industriali. Stando a quanto riportato dall’ONU all’Assemblea Generale delle Nazioni Unite del luglio 2010, l’acqua è un diritto umano universale e a tutti deve essere garantito l'accesso all'acqua potabile, al fine di prevenire l’insorgere di malattie infettive. Pratiche di igiene e sanificazione sono dunque necessarie e obbligatorie per rimuovere gli inquinanti presenti nelle acque, prima che queste vengano nuovamente introdotte sulla superficie terrestre e giungano poi sulla nostra tavola. A seguito della notevole diversificazione delle attività antropogeniche, gli inquinanti comunemente rinvenuti nelle acque sono molteplici. Si annoverano coloranti, pesticidi, metalli pesanti, farmaci e organismi patogeni come batteri e virus. Accanto a queste “molecole”, una grossa fonte di inquinamento è poi rappresentata dalla presenza di plastiche, il cui consumo negli ultimi decenni è cresciuto in maniera esponenziale. Il seguente lavoro di tesi si propone di sviluppare delle nuove membrane a base di nanotubi di carbonio (CNTs) da impiegare nella rimozione di inquinanti dalle acque mediante processi di fotocatalisi o di assorbimento. Le membrane a base di CNTs, anche note come buckypapers, si presentano come dei fogli sottili, perfettamente autosostenuti, in cui i CNTs sono assemblati formando una vera e propria rete. Le prestazioni di tali membrane dipendono molto dal tipo di CNTs utilizzati (SWNTs o MWNTs); in generale, però, a differenza delle membrane polimeriche attualmente in commercio, esse sono stabili anche ad alte temperature, sono inoltre flessibili, presentano una buona stabilità chimico-fisica e una buona conduttività elettrica. Al fine di migliorare le loro performances, tali membrane sono state dopate con opportune nanoparticelle, introdotte allo scopo di incrementare selettivamente il recupero dei seguenti inquinanti: piombo e cerio, per quanto concerne la categoria dei metalli pesanti, e, per la categoria dei farmaci, le molecole di diclofenac, ketoprofene e naprossene, tutte comunemente impiegate come antinfiammatori. Nell’ottica della degradazione di inquinanti mediante processi fotocatalitici, sono state inoltre sviluppate nuove membrane composite della forma semiconduttore/buckypapers, in cui questi ultimi espletano la funzione di supporto a uno strato fine di semiconduttore depositato sulla loro superficie. In tal caso, una nuova applicazione nella degradazione di coloranti e antinfiammatori è stata rinvenuta per tali membrane, le quali hanno mostrato delle ottime efficienze di rimozione per gli inquinanti investigati.Item Optical metasurfaces: from reconfigurable polymer-based platforms to sensing applications(Università della Calabria, 2024-04-11) Nicoletta, Giuseppe; Cipparrone, Gabriella; Strangi, GiuseppeResearch is of paramount importance for the well-being and improvement of life, and this is often supported by material research. It is enough to remember that in the past man could greatly improve his own existence by the discovery of stone, and later he could do so by the discovery of bronze and still later iron. Technology today leads us to have increasingly compact devices that are capable of transmitting data as quickly as possible. Among the greatest challenges for scientists is research into materials for microprocessors, optical fibers, and the optimal use of renewable energy sources. The study of light-matter interaction is of fundamental importance since most electromagnetic devices and phenomena originate from it. In this case, the creation of different structures and geometries makes it possible to modify electromagnetic radiation for the intended scientific purposes. Metamaterials offer the possibility to overcome the limits of the physical and chemical properties of materials. With technical processes, it is possible to create structures that show a unique response thanks to their dimensions, which are smaller than the characteristic incident wavelength. One of the most important challenges in the biomedical, environmental, and chemical fields is the biorecognition of analytes in the surrounding environment with high sensitivity and specificity. One possible solution to achieve this goal is to study the change in refractive index that correlates with the specific molecule or biomolecule that needs to be detected in a fluid. The aim of this thesis is to develop an optical approach for various metasurfaces with high sensitivity, which can be used for biosensors and thus for the detection of biological material such as cells, proteins, bacteria etc. Another important aspect is the study of metasurfaces capable of opti-cal reconfiguration by external stimuli, useful to tune the focus of metalenses. This thesis is divided into four chapters, one appendix, and conclusion and perspective. In the first chapter, the concept of chirality is introduced, the interaction between chiral light and chiral matter. The focus is on extrinsic chiral metasurfaces, the study of 3D out-of-plane helices. A modeling study of various helix parameters and an analysis of the modes and their sensitivity have been performed. The second chapter presents Fano Resonance Optical Coating (FROC). After a brief introduction, relevant theoretical references are given. After accurate simulations on the FROCs, several samples were fabricated and analyzed by spectrophotometry and ellipsometry to provide a few applications for these samples. In the third chapter, metalenses supplied by the Capasso group are presented, infiltrated with various liquid crystals according to Cassie-Baxter theory. The purpose is to tune the metasurface to allow in-depth optical investigation. The goal is to tune the metalenses using photonics to excite the gold nanoparticles inside the liquid crystal. In the fourth chapter, a technique is presented for the low-cost reproduction of metalenses, which focus visible light and can be thermally tuned. The goal is to provide materials that do not degrade over time and that retain their properties for focusing. It has been experimentally demonstrated that due to the thermal effect, it is possible to tune the focus of the lens with a shift of 150 μm. In the appendix, we present a metasurface consisting of a polymer matrix containing gold nanoparticles. These substrates are analyzed from a thermoplasmonic point of view, obtaining excellent results useful, for example, for the purification of materials from bacteria. In addition, these membranes are analyzed from the point of view of sensing by stretching. In the second appendix metasurfaces based on the MIMI nanocavities used as a platform for refractive index sensing are presented.Item Nonlinear processes in general relativity: from vacuum spacetimes to turbulent plasmas near compact objects(Università della Calabria, 2023-07-14) Meringolo, Claudio; Cipparrone, Gabriella; Servidio, SergioStrong gravitational fields are well-described by Einstein’s theory of gravity. In the last decades, observational breakthroughs have supported the milestones of general relativity, stimulating increasing scientific activity. Together with observations, numerical relativity became a very important instrument to validate and extend the comprehension of such observations. In the first part of this thesis, we present new results through the full threedimensional (3D) evolution of black holes, in binary- and multiple-body systems. After a brief review of Einstein’s theory and of the "3+1" formalism adopted, we describe the Spectral FIltered Numerical Gravity CodE (SFINGE). This is a numerical code based on the Fourier decomposition, accompanied by different filtering techniques. The accuracy of the model has been validated through standard testbeds, revealing that the filtered pseudo-spectral technique is highly accurate. We evolve black hole dynamics in vacuum conditions and small domains. The gravitational wave signals have been inspected by employing both Fourier and wavelet analyses, showing net differences among the global configurations. We observe strong nonlinear emission in the case of three-black holes, which can be a template for future observational campaigns. Finally, we introduced also the presence of matter in spacetime, presenting some preliminary results of general relativistic hydrodynamics. In the second part of the thesis, we focus on the plasma in the neighboring regions of black holes, by using numerical models for plasmas in trans-relativistic regimes. We present a very comprehensive campaign of two-dimensional (2D) kinetic Particle-In-Cell (PIC) simulations of special-relativistic turbulence by using the Zeltron code. Imposing a realistic mass ratio between electrons and protons, we analyze the energization of electrons, by varying several plasma parameters. The simulations have been designed to cover several regimes of turbulence in the vicinity of compact objects. These results can find application in a wide range of astrophysical scenarios, including the accretion and the jet emission onto supermassive black holes, such as M87* and Sgr A*.Item Probing the high-energy dynamics of QCD: selected theoretical and phenomenological studies(Università della Calabria, 2023-05-04) Fucilla, Michael; Cipparrone, Gabriella; Papa, AlessandroThe center-of-mass energies available at modern accelerators, such as the Large Hadron Collider (LHC), and at future generation accelerators, such as the Electron-Ion Collider (EIC) and Future Circular Collider (FCC), offer us a unique opportunity to investigate hadronic matter under the most extreme conditions ever reached. In particular, we can access the Regge-Gribov (or semi-hard) limit of QCD, characterized by the scale hierarchy s ≫ {Q2} ≫ Λ2 QCD, where √s is the center-of-mass energy, {Q} a set of hard scales characterizing the process and ΛQCD is the QCD mass scale. In this limit, large logarithmic corrections can affect both parton densities and hard scattering cross sections. The Balitsky-Fadin-Kuraev-Lipatov (BFKL) approach represents the established tool to resum to all orders, both in the leading (LLA) and the next-to-leading (NLA) approximation, these large-energy logarithmic contributions. However, it is well known that at very low values of the Bjorken-x, the density of partons, per unit transverse area, in hadronic wavefunctions becomes very large leading to the so-called saturation effects. The evolution of densities is then described by non-linear generalizations of the BFKL equation. Among these, the most general is represented by the Balitsky-JIMWLK hierarchy of equations, which is needed to describe the scattering of a dilute projectile on a dense target, or also the scattering of two dense systems. The dense system condition can be achieved by a very small-x proton, but is more easily achieved for large nuclei. It is clear that a detailed comparison with experimental data requires precision predictions that can only be achieved in the next-to-leading logarithmic approximation or beyond. We face this task from two different perspectives. On the one hand developing analytical calculations that allow to increase the theoretical accuracy that can be reached in predictions, and on the other, by proposing phenomenological analyzes that can be directly tested experimentally. In particular, within the BFKL approach we calculate the full NLO impact factor for the Higgs production. This is the necessary ingredient to study the inclusive forward emissions of a Higgs boson in association with a backward identified jet. We claim that this result should necessarily supplement pure fixed-order calculations entering in the collinear factorization framework, which cannot be able to describe the entire kinematic spectrum in the Higgs-plus-jet channel. The result can be as well used to describe the inclusive hadroproduction of a forward Higgs in the limit of small Bjorken x. Moreover, using the knowledge of already known impact factors we propose a series of new semi-hard reactions that can be used to investigate BFKL dynamics at the LHC. We investigate all observables used so far to study BFKL, including: total cross sections, azimuthal coefficients, azimuthal distributions and pT -differential distributions. In the context of linear evolution, we consider also the problem of extending BFKL beyond the NLLA. To this aim, we compute the Lipatov vertex in QCD with higher ϵ- accuracy, where ϵ = (D − 4)/2. This ingredient enters the BFKL kernel at next-to-NLA (NNLLA) accuracy. In fact, the NNLLA formulation of BFKL requires not only two and three-loop calculations, but also higher ϵ-accuracy of the one-loop results, for instance, in the part of the kernel containing the product of two one-loop Lipatov vertices. Finally, in the saturation framework, and more specifically in the Shockwave approach, we calculate the diffractive double hadron photo- or electroproduction cross sections with full NLL accuracy. These results are usable to detect saturation effects, at both the future EIC or already at LHC, using Ultra Peripheral Collisions.Item Identification of selective chelators towards metals responsible for neurodegenerative diseases(Università della Calabria, 2021-03-21) Malacaria, Luana; Catalano, Stefania; Furia, EmiliaItem Big Data Analysis: Methodologies, Frameworks and Real-World Applications(Università della Calabria, 2023-06-28) Branda, Francesco; Fortino, Giancarlo; Talia, DomenicoInthelastyears,thecapacitytoproduceandcollectdatahasincreasedexpo- nentially.Thehugeamountofdatagenerated,commonlyreferredtoasBigData, thespeedatwhichitisproduced,anditsheterogeneityintermsofformatrepresent a challengetocurrentstorage,processing,andanalysiscapabilities.Thisscenario requiresthedesignandimplementationofnewarchitecturesandanalyticalplatform solutionsthatmustprocessBigDatatoextractcomplexpredictiveanddescriptive models.Today,high-performancecomputing(HPC)infrastructuressuchashighly parallelclusters,supercomputers,andcloudscanbeusedforprocessingandanalyz- ingmassivesourcesofreal-worlddatainvariousfields,includinggenomicsequencing andmedicalresearch,frauddetection,andweatherforecasting.Followingthesepre- liminaryobservations,thegoalofthisthesisistwofold.First,themainchallengesto besolvedforimplementinginnovativedataanalysisapplicationsonHPCsystemsare investigated.Inparticular,themainkeyresearchtopicsaddressedinclude:(i)stud- iesofsoftwaresystemsforBigDatastoring,processing,andanalysis;(ii)methods, techniques,andprototypesdesignedandusedtoimplementBigDatasolutionson massivedatasourcesrequiringtheuseofhigh-performancecomputingsystems;and (iii)designandprogrammingissuesforBigDataanalysisinExascalesystems,which willrepresentthenextcomputingstep.Second,severalinnovativeapplicationsand usecasesofBigDataanalyticsthatcanbeimplementedinlarge-scaleparallelsys- temsareproposed.Theseresearchcontributionsprovidenewinsightsandsolutions forextractingusefulknowledgefromlargevolumesofdata,describingmethodsand mechanismstosupportusers,practitioners,andscientistsworkingintheareaofBig Datainthedesignandexecutionofdataanalysistechniquesindifferentapplication domains.Item Analisi, previsione e metodologia innovativa per la gestione del rischio costiero da mare – Il caso studio di Belvedere Marittimo (CS)(Università della Calabria, 2023-05-23) Sinopoli, Salvatore; Maiolo, Mario; Alvise Mel, RiccardoI numerosi episodi di allagamenti ed i continui fenomeni di arretramento delle spiagge espongono ad elevato rischio abitanti e beni presenti sulle coste. Le mareggiate influenzano l'evoluzione e la vita delle comunità costiere, e in aggiunta i cambiamenti climatici introducono elementi di aggravio, evidenziando una sfida amministrativa per la protezione e la gestione di questi territori. L’esempio fornito da opere di difesa costiera già presenti sul territorio calabrese e l’analisi dell’efficacia e degli effetti da esse prodotti ha permesso di individuare nel ripascimento protetto di Calabaia a Belvedere Marittmo (CS) un caso studio significativo, che da venti anni protegge la spiaggia e il vicino centro abitato. Per comprendere meglio le caratteristiche dell’opera e la sua applicabilità sono state quindi condotte delle campagne di indagine ed acquisizione dati, che hanno permesso di ricostruire digitalmente l’opera e di analizzarla attraverso il modello numerico MIKE-21FM. Le analisi hanno permesso di evidenziare i limiti ed i pregi di questa tipologia di opera, quantificandone il campo di applicabilità. Inoltre i dati acquisiti durante le campagne di indagine hanno permesso di estendere l’analisi a tutto il paraggio dell’area Diamante-Bonifati sotto l’aspetto sia morfologico che climatico, ricostruendo eventi estremi che nel tempo si sono abbattuti sulla costa, modellandone di futuri in relazione ai possibili cambiamenti climatici, e fornendo quindi una metodologia di simulazione e di analisi per le strategie di mitigazione dei rischi costieri.Item Numerical modeling of fracture phenomena by means of moving mesh method(Università della Calabria, 2023-07-15) Ammendolea, Domenico; Critelli, Salvatore; Lonetto ,PaoloIn recent years, the impact of crack evolution on the bearing capac-ity of a structure has become one of the most important features in mod-ern design processes to choose the best structural intervention, which must be as “sustainable” as possible both in terms of the materials used and from an economic point of view. The important advances in computational fields have led to several numerical methods that can accurately reproduce crack propagation phenomena. Most of them have been developed in the framework of the Finite Element (FE) method because of its simplicity and flexibility in analyzing complex structures. Commonly, FE methods are classified into (i) smeared crack models and (ii) discrete crack approaches. Dis-crete crack approaches reproduce internal defects, including strain or discontinuity fields, into finite element formulations. In contrast, smeared crack models account for the presence of cracks at the consti-tutive level by using proper damage laws that degrade the mechanical properties of the material once crack conditions occur. Each method presents negative and positive features, thus denoting that it is some-what challenging to find the best one. Developing advanced approaches ensuring a suitable compromise between low computational costs and reliable predictions is attracting considerable attention from national and international research communities. The present thesis aims to develop a numerical model for reproduc-ing crack propagation mechanisms in different structural components under generalized loading conditions. The proposed methodology com-bines the Moving Mesh (MM) technique and the Interaction integral method (M-integral) in an FE framework. In particular, based on the Arbitrary Lagrangian-Eulerian (ALE) formulation, the MM approach is used for tracing the variation in the geometry of the computational do-main due to the crack advance. More precisely, the mesh node associ-ated with the crack tip is moved consistently with the conditions dic-tated by classic fracture criteria developed in the context of Fracture Mechanics. To ensure the consistency of the mesh point's motion, the proposed strategy uses mesh regularization techniques based on proper rezoning equations. This feature drastically reduces the overall amount of re-meshing events, which typically affect the computational effi-ciency of standard crack propagation procedures, thereby saving rele-vant computational resources meanwhile avoiding convergence issues. Useful solutions to overcome the major issues of traditional FEM pro-cedure for studying crack propagation mechanisms are much sought. Another key aspect of the present thesis is a novel strategy for ex-tracting fracture variables at the crack front, which are necessary for defining crack onset conditions, the direction of propagation, and the crack tip velocity. Specifically, the proposed model uses the M-integral method to extract Stress Intensity Factors (SIFs) at the crack front. In particular, in the framework of the MM strategy adopted, this work in-troduces the ALE formulation of the M-integral. Comparisons with predictions of other numerical methodologies, analytical formulations, and, especially, experimental results are devel-oped to check the reliability and efficacy of the proposed method. In this context, parametric analyses regarding mesh discretization and pa-rameters involved in the numerical model serve to assess the computa-tional efficiency and accuracy in predicting fracture variables and crack trajectories. The results show that the proposed approach is an efficient and robust and numerical tool for reproducing complex crack propaga-tion phenomena. The thesis is organized as follows: chapter 1 contains the introduc-tion, which reports a brief literature review on the fracture phenomena and modeling approaches, the aims and scope. Chapters 2 and 3 present the developed method in a static framework. In particular, chapter 2 depicts the theoretical formulation, the numerical implementation, and the computational procedure, while chapter 3 shows numerical results to assess the proposed strategy's reliability and efficacy. Chapter 4 gen-eralizes the proposed modeling approach to the context of dynamic Fracture Mechanics. Finally, chapter 5 outlines the conclusions and fu-ture perspectives of this work.Item Geologia ed evoluzione tettono-stratigrafica del acino di Cirò fra S. Morello (CS) e strongoli (KR): implicazioni paleogeografiche durante i Serravalliano-Tortoniano(Università della Calabria, 2023-06-28) Arcuri, Nicodemo; Critelli, Salvatore; Muto, Francesco