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Elementi gnostici nel pensiero di Guido Ceronetti
No full textQuesto lavoro intende approfondire la filosofia di Guido Ceronetti ancorandola alla variegata e multiforme costellazione gnostica. L'obiettivo verte anzitutto sulla definizione di una "tradizione" gnostica che attraversi trasversalmente la storia del pensiero filosofico fondando e formando la base teoretica su cui proiettare l'opera saggistica dell'autore
Transport coefficients and early time dynamics of the Quark-Gluon Plasma created in ultra-relativistic heavy ion collisions
No full textThe phase diagram of QCD is actually under exploration both theoretically and experimentally searching for the phase transition from ordinary matter to a deconfined phase of quarks and gluons, namely the Quark-Gluon Plasma. Being a very complex theory, such a task is very difficult however there are several indications that the phase transition occurs as indicated by Lattice QCD calculations, in the low baryon density region, at a critical temperature of Tc 155 MeV. The only way to access the QGP in a laboratory is to collide heavy ion collision at ultra-relativistic (uRHIC) energies as actually carry out at LHC at CERN and at RHIC at BNL.
One of the most amazing discovery was that the system created in these collisions behaves like a perfect fluid. Indeed hydrodynamics calculations show that the large anisotropic flows measured are in agreement with a shear viscosity to entropy density ration eta/s close to the minimum value predicted by AdS/CFT eta/s = 1/4pi.
In this thesis we discuss about two main subjects of QGP produced in uRHIC: transport coefficients, in particular shear viscosity and electric conductivity, and a modeling of initial fields
and their early time dynamics of the system produced in uRHIC.
Our challenge is to develop a very precise transport based approach with a fixed value of eta/s, being the physical quantity that describes a fluid in strong coupling. We compute the shear viscosity solving the Relativistic Boltzmann Transport (RBT) equation and using the Green-Kubo relation that, being not affected by any kind of approximation, gives us the possibility to find the correct formula among the analytical derivations in Relaxation Time Approximation and in Chapman-Enskog scheme.
Using our numerical solution to the RTB equation we also compute the electric conductivity sigma-el of the QGP. This transport coefficient represents the response of the system to an applied external electric field and only very recently has captured the attention in the field of QGP due to the strong electric and magnetic fields present in the early stage of the collision. Our focus was to characterize the relation between the sigmael and the relaxation time tau . Moreover we study the relationship between eta and sigmael investigating the ratio between eta/s and sigma-el/T, taking into account the QCD thermodynamics, and predicting that the ratio supplies a measure of the quark to gluon scattering rates.
Once we have developed a transport based approach describing a fluid with a given eta/s, our interest moved into describing, using a single consistent approach, the fireball created in uRHIC starting from the initial time. We modeled the early time dynamics considering only a color electric field which decays to pair particles thanks to the Schwinger mechanism.
Our studies focused on the isotropization and thermalization of the system in the early stage in order to quantify the isotropization time, which is assumed to be tau-iso = 0.6 ÷ 0.8 f m/c in hydrodynamics calculations. We investigate in a sistematic way different systems: the static box, the longitudinal expanding system and the 3+1D expanding case. We compute the ratio PL/PT , with PL (PT ) the longitudinal (transverse) pressure, finding that for the relevant cases of 1+1D and 3+1D the system reaches PL/PT about 1, which characterizes the isotropization of the system, in about 1fm/c for eta/s = 1/4pi while for higher value of shear viscosity the ratio PL/PT is quite smaller than 1, meaning that the system does not isotropize.
Moreover we study also the effects of eta/s on the elliptic flow v2. The first studies show that the final v2 developed by the system is not significantly affected by the strong early non-equilibrium dynamics. Hence, such a result provides a justification of the assumptions exploited in hydrodynamical approach
Salute e giustizia sociale. Verso una teoria politica normativa
No full textQuesto lavoro si concentra sul rapporto tra salute e giustizia sociale all'interno della cornice argomentativa e metodologica della filosofia politica. Si esplora tale nesso alla luce di un preciso fattore politico e sociale della salute: la distribuzione di risorse per l'assistenza sanitaria. Da quast'ultima dipende anche il diritto alla salute e il principio dell'eguale accesso alle cure. Le teorie della giustizia non hanno dato risalto alla salute, ma questo vuoto va riempito, cercando di elaborare una teoria politica normativa in grado di trattare in modo autonomo le questioni riguardanti la salute, considerandole tematiche proprie della giustizia distributiva
The European convention on human rights as a tool of protection of individual labour rights
No full textThe thesis explores how individual labour rights have been referred to in the human rights jurisprudence of the European Court of Human Rights (ECtHR). The research in this paper is based on the analysis of 334 cases, considered by the Strasburg bodies in the last 43 years (from 1963 until September 2015). In particular the paper investigates the contributions of the ECtHR to the antidiscrimination protection in employment relations, employee s privacy protection, protection from unfair dismissal and to the occupational safety matters. The author traces the historical development of the legal positions of the ECtHR in respect of protection of employee s freedom of religion, expression and association.
The thesis provides evidence of the applicability of the ECHR to the protection of both private and public employees and points out the positive obligations of the states, elaborated by the ECtHR in relevant case law.
The research of the possible implications of the living character of the European Convention on Human rights for the protection of individual labour rights demonstrates its theoretical applicability for the protection of the right to fair wage and for the protection of employees from psychosocial risks at work.
A specific consideration is paid to the analysis of the impact of the ECtHR s legal positions upon Russia and some other ex-soviet states
Targeting dopamine D3 receptor: new insights into the pathophysiology of alcohol addiction and anxiety
No full textThe dopaminergic neurotransmission in the central nervous system (CNS) is mediated by two different classes of G protein-coupled receptors, the D1R-like receptors (D1R and D5R) and the D2R-like receptors (D2R, D3R and D4R) (Seeman et al., 1994). Since its discovery in the early 90 s, the dopamine D3 receptor (D3R) has aroused great interest in the scientific community. Indeed, its limited distribution in the limbic brain areas involved in the control of cognitive and emotional functions has made this receptor a promising target for the treatment of several neuropsychiatric disorders such as drug addiction, depression and schizophrenia (Leggio et al., 2016). Several data suggest that D3R, likely acting as autoreceptor, modulates the activity of dopaminergic neurons throughout the mesolimbic, mesocortical and nigrostriatal dopaminergic pathways (Gobert et al., 1995; Tepper et al., 1997; Diaz et al., 2000). Yet, D3R-deficient mice (D3R-/-) ehibit extracellular levels of
dopamine (DA) twice as high as their wild-type (WT) littermates suggesting that D3R could play a inhibitory role in the control of basal extracellular DA levels (Koeltzow et al., 1998; Joseph et al., 2002). The central hypothesis of my PhD research project has been that D3R
exerting a pivotal role in the control of the mesolimbic dopamine pathway, is involved in the pathophysiological mechanisms subserving neuropsychiatric disorders linked to dysfunctionality of this dopaminergic pathway. In particular, the present thesis aimed to: 1) investigate the role of D3R in the mesolimbic DA control of ethanol reward; 2) assess the involvement of a GABAA/D3R interaction in the mesolimbic DA modulation of anxiety-like behavior by using both genetic and pharmacological approaches
Assembly of Functional Nanostructures for Optical, Electrical or Catalytic Systems
No full textThe aim of this PhD thesis is the fabrication and study of nanostructures showing optical, electrical or catalytic properties in the perspective of applications in different fields of the nanotechnology. An important aspect is represented by the method we used to manufacture these nanostructures. In fact, all synthesized systems are based on the covalent assembly of discrete molecules (organic molecules or inorganic complexes) on inorganic surfaces. The present molecules (building blocks) show interesting properties e.g. optical or catalytic activity, while the substrate materials are appropriate for applications of the final structures in the optoelectronic, microelectronic or catalytic industries.
Often, by changing just the inorganic substrate the same covalently assembled building blocks exhibit different properties and this is an evidence of the fact that single-molecules properties can be affected by the substrate nature upon anchoring. For example, anchoring of optically active molecules such as porphyrins to Si(100) substrates allows to exploit optoelectronic properties while the same porphyrin molecules on SnO2 and TiO2 nanocrystals provide electron injection on the semiconducting surfaces useful for photovoltaics.
Moreover, we also investigated optical active surfaces upon the self-assembly of porphyrin molecules functionalised with luminescent Eu(III) complexes in order to exploit the mutual interaction of systems whose luminescence is based on different mechanisms. In the same context, we functionalised a covalent polystirene film on a quartz substrates with an Eu(III) complex to examine the possibility to obtain tunable light emitting properties useful to transfer optical information.
The covalent assembly of porphyrins and Eu(III) complexes can be applied also to electroactive substrates as CdO, ITO, ZnO, etc. in the perspective of microelectronic applications. For this reason we optimized the deposition of high conducting CdO thin films by a metallorganic chemical vapour deposition route.
Finally, we studied the activity of some (salen)Mn(III) molecules covalently assembled on glass beads in the epoxidation of unfunctionalised prochiral olefins with the aim of increasing the catalytic behaviour upon heterogeneization thus obtaining huge turnover numbers.
In summary the most important achievement of this thesis is to have demonstrated that the covalent assembly of suitable molecules on appropriate inorganic surfaces allows the synthesis of molecular architectures showing unique properties appealing for future technologies
Complex Pore Geometries in Natural Building Stones: an experimental and theoretical approach for the modeling of porosity changes in natural, degraded and treated calcarenites
No full textCalcarenites are the most widely used natural stones in Sicily as building materials. The comprehension of the degradation style of these natural building stone is of great interest in order to preserve the ancient masonry, especially in the case of relevant Cultural Heritages. A large number of Sicilian monuments are included in UNESCO Heritage List as their special cultural or physical significance. Considering the cultural importance of these ones, smart solutions are required in the perspective of their conservation.
In the framework of restoration actions, the complete knowledge of the internal structure of building stones is fundamental in order to estimate durability and prevent degradation processes. Salt growth is a significant cause of damage for natural stones. The effects of the salt weathering are, in addition to the properties of the salt itself and the climatic conditions, strongly related to the structural and textural features of materials. For this reason, an integrate study on petrographic, physical, mechanical and porosimetric proprieties changes due to salts crystallization could be useful to highlight correlation among textural, structural and engineering parameters. Moreover, one of the main problems in conservation field is the use of suitable consolidant and protective treatments able to preserve the masonry, being compatible with the stone substrate and not affecting its aesthetical proprieties. There are numerous tests able to verify the efficiency of consolidant or protective products, mainly devoted to verify their ability to not modify the appearance of stone and its physical proprieties, especially against water; however, particularly in the case of consolidant, one of the most important feature is related to its penetration depth, often difficult to evaluate by using the standard test routines.
For aforementioned, this research work is devoted to apply a multi-methodological approach for characterizing and modeling pore structure modifications due to weathering processes in a coarse grained Sicilian calcarenite used as building and replace stones in Sicilian Cultural Heritages (Sabucina Stone), also through fractal models and innovative and non invasive methods. The obtained data on Sabucina stone have been employed for planning conservative treatments devoted to coarse grained calcarenite substrates. Therefore, innovative nanostructured and hybrid consolidant and protective products have been experimented and the results of efficiency tests along with the determination of surface and sub-surface changes due to the treatments are proposed.
In conclusion, the applied theoretical and empirical approach has allowed to: highlight the potential of classical and innovative complementary methods in quantifying the structural changes in porous materials due to degradation processes and conservative treatments, explain how they help to facilitate the understanding of stone weathering and validate the use of geometrical models in describing complex pore systems
Sviluppo sostenibile di Reti e Servizi di Telecomunicazioni
No full textSustainable development of telecommunication network is related to the provisioning of new architectures and services aware of current and future needs of people. This reaserch work wants to analyze aspects related to the sustainable development in general and their relation with the telecommunication networks and services in order to help designing the Internet of the future. The first step has been related to a deep analysis on the sustainable development and the work carried on by the United Nations in the last few years. This concept has been enriched thanks to the work done by the Internet Society which identified gaps to be bridged from different perspectives. The main goal of this work is to explore technological aspects that could help out the future Internet and the telecommunication world to meet requirements supporting the sustainable development. The gaps identified during this analysis were the followings: High costs, High environmental impact, Low flexibility and scalability, Low reliability and relisilience.
The main results of the research activity here discussed is the proposal of a new high level architecture that integrates new kind of devices and embraces the network as a whole. To properly support the sustainable development, four technological drivers have been individuated and they are briefly listed below: Energy efficiency of network devices, Software Defined Networking (SDN), Network Function Virtualization (NFV), Cloud and Fog computin
Efficient light emission from bismuth-doped rare earths compounds for Si microphotonics
No full textFor almost 50 years, silicon microelectronics has been the engine of the modern information revolution, owing to the advent of the nanotechnology era that has produced always faster, cheaper, smaller and more performing devices inside the same silicon chip. However its fortune might be coming to an end. Indeed, as a consequence of the continuous reduction in size, much longer electrical interconnects are required, thus leading to an increase of signal delays and to electromagnetic interferences that cause power dissipation and limit the total performances of a chip. A possible solution to this problem can be obtained by replacing the electrical interconnections with the optical ones by the realization of a totally integrated photonic circuit on a silicon platform. For this reason, recently strong efforts have been devoted to the development of the main constituents of a photonic circuit, such as waveguides, splitters or multiplexers, detectors, etc. However there is still a lack of integrated infrared light sources that are required to generate logic value 1-0 and to compensate the optical losses in waveguides. In addition recently also the demand for efficient integrated visible light sources for LEDs, displays and lab-on-chip applications is increasing. Different strategies have been proposed to satisfy these requirements and will be reviewed in the following chapter, by evidencing their strengths and their limits. In order to further increase the efficiency of these light sources and to realize integrated photonic circuits, their coupling with passive devices, such as SOI or plasmonic waveguides and photonic crystals, has been recently proposed owing to the existence of several interesting effects. Two completely different approaches will be pursued in this thesis work: (i) the synthesis of silicon compatible REs compounds in which the REs amount can be varied in a continuous way increasing the efficiency of the light source without suffering from detrimental effects and (ii) the contemporary introduction of post-transition metals as either strong emitting elements in the visible range or as sensitizers for the infrared emission, thus suggesting these materials as good candidates for an integrated light source on silicon. In particular in Chapter 2, the needs of new light sources in the visible range will be faced. Bismuth is proposed as an emitter for Si-based transparent materials in place of the most common used REs, as Eu and Tb: this element indeed can improve much more the optical efficiency of the systems thanks to its peculiar electronic configuration and to its high absorption and emission cross sections. Its introduction in two different Si-compatible yttrium based hosts, the yttrium disilicate and the yttrium oxide, will be discussed. These matrices are indeed suitable for the introduction of dopant elements in the Y3+ substitutional position. In particular, the influence of different annealing atmospheres on the structural and optical properties will be presented for both the hosts, thus proposing them as efficient, Si compatible optical materials for applications on Si platforms as down-converters for the solar spectrum and as broad and tunable emitters in the visible range. In Chapter 3, the possibility to exploit also infrared emission by involving erbium-yttrium mixed compounds will be addressed. This approach permits to increase the Er content up to the constituent level without optically inactive clusters formation. The additional introduction of Bi as a sensitizer for Er will be proposed. Therefore by the optimization of the structural and optical properties, the coupling Bi-Er will be demonstrated in order to enhance Er optical emission at 1.54 micron up to 2000 times. This result makes Bi-Er-Y mixed compounds good candidates for light emission and amplification in the telecommunication windows, thus achieving an interesting goal for Si-microphotonics
Progetto degli edifici a quasi zero energia.
No full textA seguito della direttiva europea 31/2010/ce e della Legge 90/2013 i nuovi edifici dovranno essere a quasi zero energia a partire dal 2021. Il lavoro esamina le problematiche sia di involucro che impiantistiche di questi edifici e propone un metodo dinamico per il calcolo dei consumi energetici mensili, stagionali ed annuali