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Active Control of the Acoustic Field in a Vehicle Cabin
Get PDFIn this thesis, a thorough investigation on acoustic noise control systems for realistic automotive scenarios is presented. The thesis is organized in two parts dealing with the main topics treated: Active Noise Control (ANC) systems and Virtual Microphone Technique (VMT), respectively.
The technology of ANC allows to increase the driver's/passenger's comfort and safety exploiting the principle of mitigating the disturbing acoustic noise by the superposition of a secondary sound wave of equal amplitude but opposite phase. Performance analyses of both FeedForwrd (FF) and FeedBack (FB) ANC systems, in experimental scenarios, are presented. Since, environmental vibration noises within a car cabin are time-varying, most of the ANC solutions are adaptive. However, in this work, an effective fixed FB ANC system is proposed. Various ANC schemes are considered and compared with each other. In order to find the best possible ANC configuration which optimizes the performance in terms of disturbing noise attenuation, a thorough research of \gls{KPI}, system parameters and experimental setups design, is carried out.
In the second part of this thesis, VMT, based on the estimation of specific acoustic channels, is investigated with the aim of generating a quiet acoustic zone around a confined area, e.g., the driver's ears. Performance analysis and comparison of various estimation approaches is presented. Several measurement campaigns were performed in order to acquire a sufficient duration and number of microphone signals in a significant variety of driving scenarios and employed cars. To do this, different experimental setups were designed and their performance compared. Design guidelines are given to obtain good trade-off between accuracy performance and equipment costs. Finally, a preliminary analysis with an innovative approach based on Neural Networks (NNs) to improve the current state of the art in microphone virtualization is proposed
3D bioprinted organ models for drug screening
Get PDFIn recent years, 3D bioprinting has emerged as an innovative and versatile technology able to produce in vitro models that resemble the native spatial organization of organ tissues, by employing or more bioinks composed of various types of cells suspended in hydrogels. Natural and semi-synthetic hydrogels are extensively used for 3D bioprinting models since they can mimic the natural composition of the tissues, they are biocompatible and bioactive with customizable mechanical properties, allowing to support cell growth. The possibility to tailor hydrogels mechanical properties by modifying the chemical structures to obtain photo-crosslinkable materials, while maintaining their biocompatibility and biomimicry, make their use versatile and suitable to simulate a broad spectrum of physiological features. In this PhD Thesis, 3D bioprinted in vitro models with tailored mechanical properties and physiologically-like features were fabricated. AlgMa-based bioinks were employed to produce a living platform with gradient stiffness, with the aim to create an easy to handle and accessible biological tool to evaluate mechanobiology. In addition, GelMa, collagen and IPN of GelMa and collagen were used as bioinks to fabricate a proof-of-concept of 3D intestinal barrier, which include multiple cell components and multi-layered structure. A useful rheological guide to drive users to the selection of the suitable bioinks for 3D bioprinting and to correlate the model’s mechanical stability after crosslinking is proposed. In conclusion, a platform capable to reproduce models with physiological gradient stiffness was developed and the fabrication of 3D bioprinted intestinal models displaying a good hierarchical structure and cells composition was fully reported and successfully achieved. The good biological results obtained demonstrated that 3D bioprinting can be used for the fabrications of 3D models and that the mechanical properties of the external environment plays a key role on the cell pathways, viability and morphology
Eating together, a political art. The banquets of Emperor Taizong of the Tang.
Get PDFLa ricerca di dottorato riguarda i banchetti tenuti dall'imperatore Taizong di Tang durante i suoi 23 anni di regno (dal 626 al 649 d.C.) e a partire da essi ho esaminato la costruzione delle istituzioni politiche e dell'ordine sociale dello Stato cinese dell'epoca, per scoprire come queste attività contribuissero, in una certa misura, alla legittimazione e all'affermazione del potere dell'imperatore stesso.
Da questa premessa, sorgono una serie di domande che riguardano vari aspetti: ad esempio, cosa spinse Taizong a puntare su questi banchetti per la costruzione del suo ordine politico? Quando furono organizzati? In quali luoghi? Chi vi partecipava? E come venivano organizzati? Studiando questo tipo di attività ricreative a cui partecipavano Taizong e la sua corte, esplorerò l'evoluzione e i cambiamenti della cultura politica nella dinastia Tang (618-907 d.C.). Analizzerò come il sovrano utilizzasse i banchetti per promuovere lo sviluppo della politica statale e i rituali di corte al fine di mantenere la stabilità sociale all'interno della governance della macchina statale. Esaminerò e metterò a fuoco la relazione dinamica e simbiotica tra cibo e politica nell'antica Cina, anche facendo riferimento a semplici frammenti di cronaca relativi ai resoconti dei banchetti stessi, oltre che a concetti storiografici più generali.The PhD research concerns about the banquets held by Emperor Taizong of Tang during his 23-year reign (from 626 to 649 A.D.) and starting from them I examined the construction of political institutions and the social order of the Chinese state of the time, in order to discover how these activities contributed, to a certain extent, to the legitimization and affirmation of the power of the emperor himself.
From such a premise, a number of questions arise concerning various aspects: for example, what led Taizong to focus on such banquets for the construction of his political order? When were these organized? In what locations? Who took part in them? And how were they organized? By studying this type of recreational activity that Taizong and his court took part in, I will explore the evolution and changes of political culture in the Tang Dynasty (618-907 AD). I will analyze how the ruler used banquets to promote the development of state policy and court rituals in order to maintain social stability within the governance of the state machine. I will examine and focus on the dynamic and symbiotic relationship between food and politics in ancient China, including by referring to simple fragments of chronicles relating to accounts of the banquets themselves, as well as more general historiographical concepts
Novel hydroxystearoyl-, heterocyclic and carbocyclic derivatives: synthesis and applications in biological field
Get PDFThis PhD project has been mainly focused on the synthesis of novel organic compounds containing heterocyclic and/or carbocyclic scaffold and on the study of stearic acid derivatives and their applications in biological field. The synthesis of novel derivatives of 9-hydroxystearic acid (9-HSA) evidenced how the presence of substituents on C9, able to make hydrogen bonds is of crucial importance for the biological activity. Also the position of the hydroxy group along the chain of hydroxystearic acids was investigated: regioisomers with the hydroxy group bound to odd carbons resulted more active than those bearing the hydroxy group on even carbons. Further, the insertion of (R)-9-HSA in magnetic nanoparticles gave a novel material which characterization remarked its suitability for drug delivery. Structural hybrids between amino aza-heterocycles and azelaic acid have been synthesized and some of them showed a selective activity towards osteosarcoma cell line U2OS. Several Apcin analogues bearing indole, benzothiazole, benzofurazan moieties connected to tryptaminyl-, amino pyridinyl-, pyrimidinyl- and pyrazinyl ring through a 1,1,1-trichloroethyl group were synthesized. Biological tests showed the importance of both the tryptaminyl and the pyrimidinyl moieties, confirming the effectiveness against acute leukemia models. The SNAr between 2-aminothiazole derivatives and 7-chlorodinitrobenzofuroxan revealed different behaviour depending from amino substituent of the thiazole. The reaction with 2-N-piperidinyl-, 2-N-morpholinyl-, or 2-N-pyrrolidinyl thiazole gave two isomeric species derived from the attack on C-5 of thiazole ring. Thiazoles substituted with primary- or not-cyclic secondary amines reacted with the exocyclic amino nitrogen atom giving a series of compounds whose biological activity have highlighted as they might be promising candidates for further development of antitumor agents. A series of 9-fluorenylidene derivatives, of interest in medical and optoelectronic field as organic scintillators, was synthesized through Wittig or Suzuky reaction and will be analyzed to test their potential scintillatory properties
Numerical invariants for measurable cocycles
Get PDFThe theory of numerical invariants for representations can be generalized to measurable cocycles. This provides a natural notion of maximality for cocycles associated to complex hyperbolic lattices with values in groups of Hermitian type. Among maximal cocycles, the class of Zariski dense ones turns out to have a rigid behavior.
An alternative implementation of numerical invariants can be given by using equivariant maps at the level of boundaries and by exploiting the Burger-Monod approach to bounded cohomology.
Due to their crucial role in this theory, we prove existence results in two different contexts.
Precisely, we construct boundary maps for non-elementary cocycles into the isometry group of CAT(0)-spaces of finite telescopic dimension and for Zariski dense cocycles into simple Lie groups.
Then we approach numerical invariants.
Our first goal is to study cocycles from complex hyperbolic lattices into the Hermitian group SU(p,q).
Following the theory recently developed by Moraschini and Savini, we define the Toledo invariant by using the pullback along cocycles, also by involving boundary maps.
For cocycles Γ × X → SU(p,q) with 1<p<q<+∞,
we prove that maximality and Zariski density imply superrigidity in the sense of Zimmer, namely such cocycles come from representations PU(1,n) → SU(p,q) of the ambient group.
As a consequence, there is no Zariski dense such cocycle when 1<p<q.
Then we move to cocycles Γ × X → PU(p,∞) where PU(p,∞) is the infinite dimensional version of PU(p,q). We show that maximal cocycles are reducible, namely that, modulo cohomology, their image is contained in a finite dimensional algebraic subgroup of PU(p,∞).
Finally, we classify Zariski dense measurable cocycles Γ × X → G from finitely generated groups into Hermitian groups not of tube-type.
Precisely, we show that the pullback of the Kahler class completely determines the cohomology class of such cocycles
Fabrication and characterization of hybrid ferromagnetic-organic heterostructures for spintronics application
Get PDFRecent research in the field of organic spintronics highlighted the peculiar spin-dependent properties of the interface formed by an organic semiconductor (OSC) chemisorbed over a 3d ferromagnetic metal, also known as spinterface. The hybridization between the molecular and metallic orbitals, typically π orbitals of the molecule and the d orbitals of the ferromagnet, give rise to spin dependent properties that were not expected by considering the single components of interfaces, as for example the appearance of a magnetic moment on non-magnetic molecules or changes in the magnetic behavior of the ferromagnet. From a technological viewpoint these aspects provide novel engineering schemes for spin memory and for spintronics devices, featuring unexpected interfacial magnetoresistance, spin-filtering effects and even modulated magnetic anisotropy. Applications of these concepts to devices require nevertheless to transfer the spinterface effects from an ideal interface to room temperature operating thin films.
In this view, my work presents for the first time how spinterface effects can be obtained even at room temperature on polycrystalline ferromagnetic Co thin films interfaced with organic molecules. The considered molecules were commercial and widely used in the field of organic electronics: Fullerene (C60), Gallium Quinoline (Gaq3) and Sexithiophene (T6).
An increase of coercivity, up to 100% at room temperature, has been obtained on the Co ultra-thin films by the deposition of an organic molecule. This effect is accompanied by a change of in-plane anisotropy that is molecule-dependent. Moreover the Spinterface effect is not limited to the interfacial layer, but it extends throughout the whole thickness of the ferromagnetic layer, posing new questions on the nature of the 3d metal-molecule interaction
To make move, to let die. Analysis of the politics of confinement and mobility of the Syrian refugees in Lebanon.
Get PDFL’obiettivo di questa analisi è di coniugare la ricostruzione dei processi di assoggettamento che producono i copioni entro cui prende forma la soggettività dei profughi siriani, con la ricostruzione delle problematizzazioni alla base dei sistemi di controllo e gestione della circolazione regolare. Secondo l’UNHCR, tra il 2012 e il 2016 quasi un milione e mezzo di profughi siriani si è stabilita in Libano nel tentativo di sottrarsi all’intensificarsi del conflitto tra il regime di Assad e il fronte variegato di milizie ribelli. Questa popolazione in esilio si è confrontata con le politiche di amministrazione e controllo della loro presenza dispiegate dall’assemblaggio tra istituzioni locali e internazionali: in particolare, i governi libanesi che si sono avvicendati dal 2013 hanno progressivamente implementato interventi di inclusione differenziale della popolazione di profughi, relegandone la maggioranza in uno stato di marginalità e precarietà esistenziale. Di conseguenza, per molti di loro provare ad accedere a forme di mobilità regolare si impone come uno dei pochi percorsi possibili per ottenere il riconoscimento di un livello minimo di esistenza legittima. L’analisi sviluppata in questo elaborato si basa su una ricerca etnografica condotta in Libano nella regione dell’Akkar tra il 2019 e il 2020, a cui è stata associato uno studio dell’infrastruttura tecnico-politica dei Corridoi Umanitari, un programma per la mobilità dei profughi avviato nel biennio 2016-2017, grazie alla collaborazione tra autorità italiane e una serie di associazioni religiose attive in Italia.The aim of this analysis is to combine the reconstruction of the subjugation processes that produce the scripts within which the subjectivity of Syrian refugees takes shape, with the reconstruction of the problems underlying the control and management systems of regular circulation. According to the UNHCR, between 2012 and 2016 nearly 1.5 million Syrian refugees settled in Lebanon to escape the escalating conflict between the Assad regime and the varied front of rebel militias. This population in exile has been confronted with the policies of administration and control of their presence deployed by the assemblage of local and international institutions: in particular, since 2013 the Lebanese governments have progressively implemented interventions for the differential inclusion of the refugee population, relegating the majority to a state of marginality and existential precariousness. Consequently, for many of them, trying to access regular forms of mobility is one of the few possible paths to obtain recognition of a minimum level of legitimate existence. The analysis is based on ethnographic research conducted in Lebanon in the Akkar region between 2019 and 2020, associated with a study of the technical-political infrastructure of the Humanitarian Corridors, a program for refugee mobility launched in 2016-2017, by the collaboration of Italian authorities and a series of religious associations active in Italy
Solutions for the conservation and restoration of cement-based materials in XX Century architectural heritage
Get PDFAmong the most representative materials of XX Century architectural heritage, this dissertation focuses on the cement-based ones, investigating some different fields where they were exploited.
Primarily, concerning the surface preservation of cement-based materials used with aesthetic intent, new self-cleaning treatments based on titania nanoparticles embedded in inorganic matrices were tested. In order to consider the role of porosity, the treatments were applied to different kinds of materials (cement-based mortar, marble and concrete) and several analyses were conducted to investigate the morphology of the coatings, their photocatalytic effectiveness, their durability and the interaction between the coating and the substrate material. The outcomes showed that several parameters influence the treatment’s performances, in particular, the presence and nature of the matrix, the concentration and dispersion of nanoparticles and, in some cases, the amount of substrate material which interacts with the coatings.
Secondly, this dissertation deals with the historic “Terranova” render, a colored dry-mix mortar largely widespread in Europe in the first half of XX Century, whose formulation is still basically unknown. Some original samples of supposedly Terranova renders were subjected to several characterization analyses and the results were compared to those of the original “Terranova” render of the Engineering Faculty in Bologna. Despite the recurrence of some features, defining a common formulation seemed to be challenging.
Finally, the repair and conservation of structural reinforced concrete in heritage buildings were investigated, adopting the former “Casa del Fascio” in Predappio (FC, Italy) as case study. Three different materials and solutions were tested on a slab of the building, making its repair only from the intrados. Then several analyses were conducted both on site and in laboratory. Aside from the specific features characterizing every product, the results highlighted that the application method played a fundamental role in the effectiveness of the retrofit strategies
The public visual identity. New communication paradigms
Get PDFLa ricerca proposta affronta il tema dell’identità visiva — uno dei più caratterizzanti e complessi del progetto di comunicazione — applicato alla dimensione pubblica, partendo dalla comprensione e dalla misurazione del profondo mutamento che ha portato alla sua trasformazione da stemma a marchio e poi a logo, da immagine coordinata a brand a progetto di service e experience.
La ricognizione dell’evoluzione della comunicazione pubblica e l’analisi del contesto dell’eredità culturale della “grafica di pubblica utilità” forniscono il primo framework di indagine
nel quale si prospetta una lettura della complessità della trasformazione del progetto di identità visiva come occasione per un suo ripensamento.
Un secondo framework è individuato nel contesto della comunicazione pubblica italiana in cui l’organizzazione e la progettazione di un sistema “istituzione-design-cittadino” è ancora in transizione. L’analisi dell’evoluzione normativa, dei touchpoint, delle pratiche progettuali, degli strumenti e dei ruoli permette di inquadrare gli attuali spazi e paradigmi di interazione che vedono nel servizio digitale la forma prevalente di relazione tra cittadini e dimensione pubblica
Attraverso l'esperienza diretta, l’analisi dei casi studio come strumento di indagine e la sistematizzazione di cinque cluster, la tesi propone una rinnovata definizione di identità visiva pubblica che, distaccandosi da una predominante connotazione marketing-oriented, sia funzionale alla costruzione di esperienze utili, e percezioni di queste, rafforzando e stimolando nuovi paradigmi di relazione tra cittadini e dimensione pubblica.
Si propone inoltre una prospettiva progettuale che evolve dalla necessità di individuare nuovi percorsi e modalità di rapportarsi con il progetto di pubblica utilità e per la cittadinanza che rifuggono la manifestazione dell’equivoco - piuttosto comune nel contesto pubblico italiano - del confrontarsi con i cosiddetti «wicked problems» (Buchanan, 1992) ricercando, in termini di comunicazione pubblica soluzioni chiuse ed esclusivamente formali, ritenendo che queste possano avere una reale efficacia nel plasmare i rapporti tra cittadini e dimensione pubblica.The research faces the visual identity - one of the most characterizing of the communication project - applied to the public dimension, starting from the understanding and measurement of the profound change that led to its transformation from emblem to trademark and then to logo, from corporate image to brand, service and then to an experience project.
The recognition of the evolution of public communication and the analysis of the context of the cultural heritage of the "grafica di pubblica utilità" provide the first framework in which a reading of the complexity of the transformation of the visual identity is envisaged as an opportunity for its rethinking.
A second framework is the context of Italian public communication in which the organization of an "institution-design-citizen" system is still in transition. The analysis of regulatory evolution, touchpoints, practices, tools and roles allows us to frame the current spaces and paradigms of interaction that see digital service as the prevailing form of relationship between citizens and the public dimension.
Through direct experience, the analysis of case studies as an investigation tool and the systematization of five clusters, the thesis proposes a renewed definition of public visual identity which, detaching from a predominant marketing-oriented connotation, is functional to the construction of useful experiences, and perceptions of these, strengthening and stimulating new paradigms of relationship between citizens and the public dimension.
It also proposes a design perspective that evolves from the need to identify new paths and ways of relating to the public utility project and for citizenship that avoid the misunderstanding - quite common in the Italian public context - of dealing with the so-called "wicked problems"(Buchanan, 1992) seeking, in terms of public communication, closed and formal solutions believing that these can be effective in shaping the relationships between citizens and the public dimension
Plutarch's chemistry of stones and metals: conceptions and explanations. With an appendix on the TheSu XML annotation scheme
Get PDFThis dissertation presents a systematic and analytic overview of most of the information related to
stones, minerals, and stone masonry which is found in the corpus of Plutarch of Chaeronea, combined
with most of the information on metals and metalworking which is connected to the former. This
survey is intended as a first step in the reconstruction of the full landscape of ‘chemical’ ideas
occurring in Plutarch’s writings; accordingly, the exposition of the relevant passages, the assessment
of their possible interpretations, the discussion on their implications, and their contextualization in the
ancient traditions have been conducted with a special interest in the ‘mineralogical’ and ‘metallurgic’
themes developed in the frame of natural philosophy and meteorology. Although in this perspective
physical etiology could have come to acquire central prominence, non-etiological information on
Plutarch’s ideas on the nature and behaviour of stones and metals has been treated as equally relevant
to reach a fuller understanding of how Plutarch conceptualized and visualized them in general, in- and
outside the frame of philosophical explanation. Such extensive outline of Plutarch’s ideas on stones
and metals is a prerequisite for an accurate inquiry into his use of the two in analogies, metaphors, and
symbols: to predispose this kind of research was another aim of the present survey, and this aim has
contributed to shape it; moreover, a special attention has been paid to the analysis of analogical and
figurative speaking due to the nature itself of a large part of Plutarch’s references to stones and metals,
which are either metaphorical, presented in close association with metaphors, or framed in analogies.
Much of the information used for the present overview has been extracted —always with supporting
argumentation— from the implications of such metaphors and analogies