Ricerche sul lessico della provvidenza in Agostino

Questa ricerca è un’indagine semasiologica del lessico agostiniano della provvidenza divina, costituito dalle parole-chiave prouidentia, prouideo, prouidens, prouidus, prouisio, prouisor, prouisus, e dai lessemi in relazione logico-sintattica diretta con esse. La prospettiva è sia sincronica (si considerano tutte le attestazioni delle parole-chiave presenti nel corpus agostiniano), sia diacronica: si soppesano di volta in volta analogie e differenze agostiniane rispetto agli antecedenti, nell’intento di arricchire il panorama dei possibili modelli lessicali latini (pagani, biblici, patristici) di Agostino. I dati lessicali sono stati raccolti in una banca dati appositamente costituita, selezionati secondo i criteri di frequenza e pregnanza semantica, e analizzati per nuclei tematici, coincidenti in parte con i capitoli della tesi. Si studiano dapprima i lessemi che esprimono il governo della provvidenza (le famiglie lessicali di administro, guberno e rego, e altri lessemi che designano l’azione della provvidenza); sono poi analizzati lessemi e iuncturae in cui prevale l’idea del mistero della provvidenza. Gli ultimi due capitoli sono dedicati al tema della cura divina, e a quello della cosiddetta “pedagogia divina”: attraverso i segni esteriori, la provvidenza ‘richiama’ l’uomo a rientrare in se stesso. Un’appendice approfondisce infine l’uso agostiniano di Sap 6,16 e Sap 8,1. L’apporto di Agostino al lessico filosofico latino va individuato a livello semantico più che nell’innovazione lessicale. Accanto a suffissazione, composizione, calco, la metafora svolge un ruolo essenziale nella formazione del lessico dell’Ipponate, e proviene spesso da altre lingue tecniche oppure è radicata nel patrimonio di immagini tradizionali della religione pagana. Il debito di Agostino è indubbiamente verso Cicerone, ma anche verso Seneca, per l’uso in ambito esistenziale-biografico di alcuni lessemi. Agostino li trasferisce però dal piano umano a quello divino, come nel caso del concetto di admonitio: parte integrante del programma filosofico senecano; ‘richiamo’ della provvidenza per Agostino, concetto che risente anche dell’apporto di retorica ed esegesi.

La paradoja de Maastricht. Los distintos modelos económicos y políticos para el futuro integrador de la UE

La crisis existencial del proyecto de integración europea constituye el principal reto al que debe enfrentarse la Comunidad en su futuro más inmediato puesto que se alza como toda una amenaza para la continuidad del sistema establecido desde el Tratado fundacional de Roma (1957). Las tres crisis acontecidas durante los primeros años del siglo XXI, véase la gran crisis económica del año 2008, la pandemia global de la Covid-19 y la actual intervención de la Federación Rusa en Ucrania, están poniendo constantemente a prueba la firmeza de los cimientos y valores sobre los cuales se ha construido la Comunidad durante todos estos años. Esta tesis doctoral pretende ser una contribución académica al debate abierto en las sociedades comunitarias acerca de por donde debe de transitar la evolución del proyecto de integración europea en los próximos años. Para conseguir alcanzar este objetivo, la investigación se retrotrae hasta los orígenes del proceso de integración y avanza en la línea temporal hasta nuestros días, analizando con ello las posibles causas que pudieran encontrarse detrás de la crisis existencial actual. A su vez, , la investigación estudia con detenimiento los múltiples efectos que está generando la problemática existencial en los Estados miembros en los últimos años, tales como el aumento del apoyo social a favor de actores considerados populistas o el fenómeno de la creciente desafección ciudadana. Esta investigación analiza los distintos escenarios propuestos por la Comisión Europea en su Libro Blanco sobre el futuro de Europa para determinar cuál podría ser el mejor escenario que concordara con la nueva realidad económica y sociopolítica que actualmente impera en los Estados miembro. Lo que se persigue es formular una propuesta que pueda dar por terminada la crisis existencial de la Comunidad abriendo con ello una nueva etapa en la historia de la integración europea.

Modeling the cosmological co-evolution of supermassive black holes and galaxies

In this Thesis, we investigate the cosmological co-evolution of supermassive black holes (BHs), Active Galactic Nuclei (AGN) and their hosting dark matter (DM) halos and galaxies, within the standard CDM scenario. We analyze both analytic, semi-analytic and hybrid techniques and use the most recent observational data available to constrain the assumptions underlying our models. First, we focus on very simple analytic models where the assembly of BHs is directly related to the merger history of DM haloes. For this purpose, we implement the two original analytic models of Wyithe & Loeb 2002 and Wyithe & Loeb 2003, compare their predictions to the AGN luminosity function and clustering data, and discuss possible modifications to the models that improve the match to the observation. Then we study more sophisticated semi-analytic models in which however the baryonic physics is neglected as well. Finally we improve the hybrid simulation of De Lucia & Blaizot 2007, adding new semi-analytical prescriptions to describe the BH mass accretion rate during each merger event and its conversion into radiation, and compare the derived BH scaling relations, fundamental plane and mass function, and the AGN luminosity function with observations. All our results support the following scenario: • The cosmological co-evolution of BHs, AGN and galaxies can be well described within the CDM model. • At redshifts z & 1, the evolution history of DM halo fully determines the overall properties of the BH and AGN populations. The AGN emission is triggered mainly by DM halo major mergers and, on average, AGN shine at their Eddington luminosity. • At redshifts z . 1, BH growth decouples from halo growth. Galaxy major mergers cannot constitute the only trigger to accretion episodes in this phase. • When a static hot halo has formed around a galaxy, a fraction of the hot gas continuously accretes onto the central BH, causing a low-energy “radio” activity at the galactic centre, which prevents significant gas cooling and thus limiting the mass of the central galaxies and quenching the star formation at late time. • The cold gas fraction accreted by BHs at high redshifts seems to be larger than at low redshifts.

"Narrativa di frontiera". Fenomenologia di una forma aperta.

«Fiction of frontier». Phenomenology of an open form/voice. Francesco Giustini’s PhD dissertation fits into a genre of research usually neglected by the literary criticism which nevertheless is arousing much interest in recent years: the relationship between Literature and Space. In this context, the specific issue of his work consists in the category of the Frontier including its several implications for the XX century fiction. The preliminary step, at the beginning of the first section of the dissertation, is a semantic analysis: with precision, Giustini describes the meaning of the word “frontier” here declined in a multiplicity of cultural, political and geographical contexts, starting from the American frontier of the pioneers who headed for the West, to the exotic frontiers of the world, with whose the imperialistic colonization has come into contact; from the semi-uninhabited areas like deserts, highlands and virgin forests, to the ethnic frontiers between Indian and white people in South America, since the internal frontiers of the Countries like those ones between the District and the Capital City, the Centre and the Outskirts. In the next step, Giustini wants to focus on a real “ myth of the frontier”, able to nourish cultural and literary imagination. Indeed, the literature has told and chosen the frontier as the scenery for many stories; especially in the 20th Century it made the frontier a problematic space in the light of events and changes that have transformed the perception of space and our relationship with it. Therefore, the dissertation proposes a critical category, it traces the hallmarks of a specific literary phenomenon defined “ Fiction of the frontier” ,present in many literary traditions during the 20th Century. The term “Fiction” (not “Literature” or “Poetics”) does not define a genre but rather a “procedure”, focusing on a constant issue pointed out from the texts examined in this work : the strong call to the act of narration and to its oral traditions. The “Fiction of the Frontier” is perceived as an approach to the world, a way of watching and feeling the objects, an emotion that is lived and told through the story- a story where the narrator ,through his body and his voice, takes the rule of the witness. The following parts, that have an analytic style, are constructed on the basis of this theoretical and methodological reflection. The second section gives a wide range of examples into we can find the figure and the myth of the frontier through the textual analysis which range over several literary traditions. Starting from monographic chapters (Garcia Marquez, Callado, McCarthy), to the comparative reading of couples of texts (Calvino and Verga Llosa, Buzzati and Coetzee, Arguedas and Rulfo). The selection of texts is introduced so as to underline a particular aspect or a form of the frontier at every reading. This section is articulated into thematic voices which recall some actions that can be taken into the ambiguous and liminal space of the frontier (to communicate, to wait, to “trans-culturate”, to imagine, to live in, to not-live in). In this phenomenology, the frontier comes to the light as a physical and concrete element or as a cultural, imaginary, linguistic, ethnic and existential category. In the end, the third section is centered on a more defined and elaborated analysis of two authors, considered as fundamental for the comprehension of the “Fiction of the frontier”: Joseph Conrad and João Guimarães Rosa. Even if they are very different, being part of unlike literary traditions, these two authors show many connections which are pointed by the comparative analysis. Maybe Conrad is the first author that understand the feeling of the frontier , freeing himself from the adventure romance and from the exotic nineteenthcentury tradition. João Guimarães Rosa, in his turn, is the great narrator of Brazilian and South American frontier, he is the man of sertão and of endless spaces of the Centre of Brazil. His production is strongly linked to that one belonged to the author of Heart of Darkness.

Mixed Mode Fracture Behaviour of Piezoelectric Materials

Piezoelectrics present an interactive electromechanical behaviour that, especially in recent years, has generated much interest since it renders these materials adapt for use in a variety of electronic and industrial applications like sensors, actuators, transducers, smart structures. Both mechanical and electric loads are generally applied on these devices and can cause high concentrations of stress, particularly in proximity of defects or inhomogeneities, such as flaws, cavities or included particles. A thorough understanding of their fracture behaviour is crucial in order to improve their performances and avoid unexpected failures. Therefore, a considerable number of research works have addressed this topic in the last decades. Most of the theoretical studies on this subject find their analytical background in the complex variable formulation of plane anisotropic elasticity. This theoretical approach bases its main origins in the pioneering works of Muskelishvili and Lekhnitskii who obtained the solution of the elastic problem in terms of independent analytic functions of complex variables. In the present work, the expressions of stresses and elastic and electric displacements are obtained as functions of complex potentials through an analytical formulation which is the application to the piezoelectric static case of an approach introduced for orthotropic materials to solve elastodynamics problems. This method can be considered an alternative to other formalisms currently used, like the Stroh’s formalism. The equilibrium equations are reduced to a first order system involving a six-dimensional vector field. After that, a similarity transformation is induced to reach three independent Cauchy-Riemann systems, so justifying the introduction of the complex variable notation. Closed form expressions of near tip stress and displacement fields are therefore obtained. In the theoretical study of cracked piezoelectric bodies, the issue of assigning consistent electric boundary conditions on the crack faces is of central importance and has been addressed by many researchers. Three different boundary conditions are commonly accepted in literature: the permeable, the impermeable and the semipermeable (“exact”) crack model. This thesis takes into considerations all the three models, comparing the results obtained and analysing the effects of the boundary condition choice on the solution. The influence of load biaxiality and of the application of a remote electric field has been studied, pointing out that both can affect to a various extent the stress fields and the angle of initial crack extension, especially when non-singular terms are retained in the expressions of the electro-elastic solution. Furthermore, two different fracture criteria are applied to the piezoelectric case, and their outcomes are compared and discussed. The work is organized as follows: Chapter 1 briefly introduces the fundamental concepts of Fracture Mechanics. Chapter 2 describes plane elasticity formalisms for an anisotropic continuum (Eshelby-Read-Shockley and Stroh) and introduces for the simplified orthotropic case the alternative formalism we want to propose. Chapter 3 outlines the Linear Theory of Piezoelectricity, its basic relations and electro-elastic equations. Chapter 4 introduces the proposed method for obtaining the expressions of stresses and elastic and electric displacements, given as functions of complex potentials. The solution is obtained in close form and non-singular terms are retained as well. Chapter 5 presents several numerical applications aimed at estimating the effect of load biaxiality, electric field, considered permittivity of the crack. Through the application of fracture criteria the influence of the above listed conditions on the response of the system and in particular on the direction of crack branching is thoroughly discussed.

Determinants of the Economic Use of Patented Inventions: An Analysis of European Patents

The purpose of this research is to provide empirical evidence on determinants of the economic use of patented inventions in order to contribute to the literature on technology and innovation management. The current work consists of three main parts, each of which constitutes a self-consistent research paper. The first paper uses a meta-analytic approach to review and synthesize the existing body of empirical research on the determinants of technology licensing. The second paper investigates the factors affecting the choice between the following alternative economic uses of patented inventions: pure internal use, pure licensing, and mixed use. Finally, the third paper explores the least studied option of the economic use of patented inventions, namely, the sale of patent rights. The data to empirically test the hypotheses come from a large-scale survey of European Patent inventors resident in 21 European countries, Japan, and US. The findings provided in this dissertation contribute to a better understanding of the economic use of patented inventions by expanding the limits of previous research in several different dimensions.

Dynamics and control issues of multi-rotor platforms

This thesis deals with the analytic study of dynamics of Multi--Rotor Unmanned Aerial Vehicles. It is conceived to give a set of mathematical instruments apt to the theoretical study and design of these flying machines. The entire work is organized in analogy with classical academic texts about airplane flight dynamics. First, the non--linear equations of motion are defined and all the external actions are modeled, with particular attention to rotors aerodynamics. All the equations are provided in a form, and with personal expedients, to be directly exploitable in a simulation environment. This has requited an answer to questions like the trim of such mathematical systems. All the treatment is developed aiming at the description of different multi--rotor configurations. Then, the linearized equations of motion are derived. The computation of the stability and control derivatives of the linear model is carried out. The study of static and dynamic stability characteristics is, thus, addressed, showing the influence of the various geometric and aerodynamic parameters of the machine and in particular of the rotors. All the theoretic results are finally utilized in two interesting cases. One concerns the design of control systems for attitude stabilization. The linear model permits the tuning of linear controllers gains and the non--linear model allows the numerical testing. The other case is the study of the performances of an innovative configuration of quad--rotor aircraft. With the non--linear model the feasibility of maneuvers impossible for a traditional quad--rotor is assessed. The linear model is applied to the controllability analysis of such an aircraft in case of actuator block.