Negli ultimi decenni si è vista la nascita di un grande interesse verso l'utilizzo dell'idrogeno come vettore energetico. Le ragioni sono da ricercarsi nelle problematiche sorte in tempi recenti in relazione alle emissioni inquinanti ed al rapido esaurimento delle fonti energetiche. Per poter concepire un'economia basata sull'idrogeno è tuttavia necessario risolvere una serie di problematiche connesse alla sua produzione, immagazzinamento e filtraggio. Il presente lavoro di tesi ha riguardato gli ultimi due punti. In relazione allo stoccaggio del gas, uno dei sistemi più promettenti risulta quello dell'utilizzo d'idruri metallici. Tali materiali presentano ancora una serie di problematiche che ne limitano l'utilizzo pratico, sia in ambito stazionario, che per applicazioni al settore della mobilità. Per superare questi ostacoli è necessaria la comprensione dei meccanismi microscopici con cui avviene la formazione e la dissociazione della fase idruro. Il presente lavoro è stato quindi incentrato sull'approfondimento di tale aspetto, concentrandosi in particolare sul ruolo giocato dai difetti di tipo vacanza in sistemi a base magnesio. Per quanto concerne l'aspetto del filtraggio, le tecniche positroniche sono state impiegate, in concomitanza con altre ad esse complementari, per ottenere una caratterizzazione della porosità, in termini di dimensioni, distribuzione ed interconnettività dei pori, in film di silice da utilizzare per la realizzazione di membrane selettive.

The problem of the relationship between brain function, characterized by functional magnetic resonance imaging, and physiological fluctuations by means of cardiac / respiratory oscillations is one of the most debated topics in the last decade. In recent literature, a great number of studies are found that focus on both practical and conceptual aspects about this topic. In this work, we start with reviewing two distinct approaches in considering physiology - related sequences with respect to functional magnetic resonance imaging: one treating physiology - related fluctuations as generators of noise, the other considering them as carriers of cognitively relevant information. In chapter 2 – “Physiology – related effects in the BOLD signal at rest at 4T”, we consider physiological quantities as generators of noise, and discuss conceptual flaws researchers have to face when dealing with data de-noising procedures. We point out that it can be difficult to show that the procedure has achieved its stated aim, i.e. to remove only physiology - related components from the data. As a practical solution, we present a benchmark for assessing whether correction for physiological noise has achieved its stated aim, based on the principle of permutation testing. In chapter 3 – “Directional relationships between BOLD activity and autonomic nervous system fluctuations revealed by fast fMRI acquisition”, on the other hand, we will consider autonomic indicants derived from physiological time - series as meaningful components of the BOLD signal. There, we describe a FMRI experiment building on this, where the goal was to localize brain areas whose activity is directionally related to autonomic one, in a top - down modulation fashion. In chapter 4 we recap the conclusions we found from the two approaches and we summarize the general contributions of our findings. We point out that bringing together the distinct approaches we reviewed lead us to mainly two contributions. On one hand we thought back the validity of almost established procedures in FMRI resting - state pre-processing pipelines. On the other we were able to say something new about general relationship between BOLD and autonomic activity, resting state fluctuations and deactivation theory.

The goal of this thesis is the discovery of a bioinformatics solution for network-based predictive analysis of NGS data, in which network structures can substitute gene lists as a more rich and complex signature of disease. I have focused on methods for network stability, network inference and network comparison, as additional components of the pipeline and as methods to detects outliers in high-throughput datasets. Besides a first work on GEO datasets, the main application of my pipeline has been on original data from the FDA SEQC (Sequencing Quality Control)project. Here I will report some initial findings to which I have contributed with methods and analysis: as the corresponding papers are being submitted. My goal is to provide a comprehensive tool for network reconstruction and network comparison as an R package and user-friendly web service interface available on-line at https://renette.fbk.eu The goal of this thesis is the discovery of a bioinformatics solution for network-based predictive analysis of NGS data, in which network structures can substitute gene lists as a more rich and complex signature of disease. I have focused on methods for network stability, network inference and network comparison, as additional components of the pipeline and as methods to detects outliers in high-throughput datasets. Besides a first work on GEO datasets, the main application of my pipeline has been on original data from the FDA SEQC (Sequencing Quality Control)project. Here I will report some initial findings to which I have contributed with methods and analysis: as the corresponding papers are being submitted. My goal is to provide a comprehensive tool for network reconstruction and network comparison as an R package and user-friendly web service interface available on-line at https://renette.fbk.eu.

The scarcity of freshwater is becoming a global challenge worldwide due to limited resources availability and increasing demand both for manufacturing and household use. For this reason, there is an important need to develop efficient, economic and sustainable desalination technologies able to take advantage of unconventional sources of water (seawater, brackish groundwater and wastewater) in order to produce freshwater. Sun is considered as the most promising abundant renewable (and free) energy source that can be employed in steam and vapor generation processes, which has a great importance in many applications such as: water desalination, domestic water heating, and power generation. This doctoral dissertation presents a study on the efficiency of different carbon based systems - nanofluids and hybrid natural composites - for the improvement of direct-solar evaporation systems, for the production of freshwater. The two main goals of this work consist of: (i) the synthesis and characterization of stable carbon-based nanofluids in water and of re-usable, economical and ecological hybrid composite materials, and (ii) the comparison of such carbon-based systems applied to water evaporation, understanding mechanisms, advantages and limitations. Carbon based materials (carbon black, graphene and multi-walled carbon nanotubes) were chosen because of their high sunlight absorption ability, unique thermal properties, as well as low cost and abundant availability. However, the hydrophobic character of such materials makes necessary to find efficient strategies to overcome this problem when dealing with water. In this work, the suspension stability of graphene-based nanofluids in water - a key parameter for the application of nanofluids in any field - was effectively improved by combining physical (by RF Sputtering coating) or chemical (by NaClO-NaBr solution) graphene surface modification treatments, and the use of common additives (Triton X-114, SDBS and gum arabic) showing different stabilization mechanisms. The best strategy to obtain long-time graphene suspension stability in water (both deionized water and saline solution with 3.5 wt% NaCl) turned out to be the combination of the easy chemical treatment with the electro-steric stabilization effect of gum arabic. In addition to nanofluids, a re-usable devices based on gum arabic cross-linked gelatin hydrogel were synthesized and characterized. Hydrophobic carbon-based materials were easily and uniformly embedded into the porous hydrogel matrix, thanks to the amphiphilic character of both gelatin and gum arabic. The effect of carbon-nanoparticles nature, morphology and concentration on the measured effective thermal conductivity of the composite material was studied and the thermal conductivity of the nanoparticles was evaluated applying several models based on the effective medium approach. The values obtained for the nanoparticles were far from the tabulated thermal conductivity values because of the combination of the composite features (such as nanoparticles concentration, Kapitza resistance) and the particles characteristics (such as aspect ratio, crystalline structure). The performance of carbon-based nanofluids and hybrid hydrogels on direct-solar evaporation of water was tested and compared to that of carbon-wood bilayer composite (which presents both hydrophilic character and natural channels for water transportation) under solar simulator. The effect of surface temperature, light-to-heat conversion efficiency of carbon-based materials, heat losses, water transport through a porous medium and suspension stability (in the case of nanofluids) were investigated in order to understand the advantages and limitations of such systems. All the tested systems were able to improve water evaporation rate and evaporation efficiency up to 70% and 82% under 1 sun and 2 suns respectively using a small amount of nanoparticles: the same amount of particles dispersed in nanofluid (0.01 wt%) was embedded into hydrogels or deposited onto wood. The high sunlight absorption ability of carbon-based nanoparticles appeared as a dominant parameter for the improvement of water evaporation rate. In fact, enhanced light absorption was directly related to a high photothermal conversion efficiency, which caused an improvement in the surface temperature, leading to a consequent enhancement in evaporation rate. It has been found that an adequate supply of water to the evaporation surface represents a fundamental parameter as well considering floating systems.

The present work regards the development of a methodology for the study of atmospheric particulate matter (PM) which is alternative to instrumental measurements. The methodology developed exploits the surfaces already present in the field as samplers of PM. In particular, conifer needles and building facades are employed to investigate different temporal ranges: conifer needles potentially retain particles circulating in the atmosphere from the recent past up to now, while building facades could retain particles from an older period up to know. The field of application of the approach developed are the situations in which a wide territory must be monitored, eventually including remote locations, or information on past pollution scenario must be reconstructed in the absence of monitoring stations. For instance, the evaluation of the improved efficiency of off-gas abatement systems of industrial plants is a typical case of application. These pollution sources affect large areas and might have been active before regulation on air quality required constant monitoring of their emissions. Typically in such a case the methodology could assist in evaluating how large was in the past and it is nowadays the area of impact of the plant. In general, such an approach could be valuable whenever relying on instrumental measurements is cost and time consuming in terms of installing a large network of monitoring stations to study the dispersion of pollutants from a single or few sources. To have a detailed description of the spatial distribution of pollutant particles, they are studied individually with subsequent higher magnification. Where no traces of a source are detected by scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (SEM-EDXS), the samples are analyzed with the higher resolution of transmission electron microscopy coupled with energy dispersive x-ray spectroscopy (TEM-EDXS) and selected area electron diffraction (SAED) in order to make sure that no smaller particles, able to travel farther from their source, are present at a certain site. All data provided by electron microscopy analysis of particles collected by conifer needles are placed in the context of elemental concentrations measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), which is a bulk analytical technique. The same is not possible for the data on single particles present on building facades given the inorganic matrix of the substrate, especially in the case of metal oxide paints, which does not allow the bulk measurement. Both the preparation of the samples for bulk analytical techniques and single particle analysis by electron microscopy were optimized. For method development and evaluation, the analytical protocol was applied to estimate spatial and temporal trends of accumulation of inorganic pollutants that can be related with changes in the emissions of atmospheric pollutants by an electric arc furnace (EAF) steelmaking plant located in a test site. The benefits of combining the single particle and bulk analytical techniques emerged especially for the discrimination of the emissions from different sources.

La tesi indaga il ruolo specifico agito dalle organizzazioni di terzo settore in reti associative multilivello, dal punto di vista della capacità di generare e valorizzare le relazioni con gli altri membri e con l'ambiente esterno. Per reti multilivello si intendono quegli organismi, a diversi gradi di formalizzazione, che riuniscono al loro interno entità locali, di secondo livello, ed eventualmente di livelli coordinativi superiori, con lo scopo di fornire supporto all'attività dei gruppi affiliati o di coordinarne le risorse materiali e immateriali per il benessere sociale della comunità. Le indagini condotte hanno incluso nel campo di osservazione sia le reti che comprendono esclusivamente organizzazioni di terzo settore le organizzazioni multilivello di terzo settore sia i network di partnership miste con enti pubblici. La dimensione della produttività sociale delle reti è stata letta attraverso la lente del concetto di capitale sociale, inteso come la dotazione, da parte di una rete, di relazioni caratterizzate da codici normativi e prassi di fiducia, reciprocità e collaborazione. I risultati delle tre indagini presentate, di carattere sia quantitativo che qualitativo, mostrano che: a) esiste uno specifico capitale sociale prodotto da organizzazioni multilivello di terzo settore che è in grado di connetterle sia all'interno del network (funzione bonding) che all'esterno (funzione bridging); b) che tale capitale sociale di terzo settore possiede delle sue proprie qualità che lo distinguono dalla relazionalità agita in reti di servizio pubbliche; c) che la relazionalità delle organizzazioni di terzo settore è in grado, in certe condizioni, di svilupparsi verso l'esterno in reti di partnership miste con soggetti del settore pubblico, determinando nuove dinamiche relazionali ed esiti societari peculiari. / The dissertation deals with the specific role played by third sector organizations in multilevel associative networks in terms of capacity to generate and foster relationships with other members and with the outer context. Multilevel associative networks are defined as those entities that gather local agencies, second level and higher coordination level entities with the aim of providing support for the affiliated groups and/or coordinating material and immaterial resources for the benefit of the community. The research field included networks comprising third sector organizations only so-called third sector multilevel organizations as well as plural partnership networks with other public agencies. The social productivity dimension was studied through the lenses of the social capital concept, defined as that specific set of resources possessed by those networks endowed with relationships of trust, reciprocity and collaboration. The results of the three research projects presented, carried out with quantitative and qualitative techniques, show that: a) there is a specific social capital produced by third sector multilevel organizations which connects actors both within the network (bonding function) and with the outer world (bridging function); b) the third sector's social capital presents some distinctive characteristics compared with the relational properties of public service networks; c) third sector organizations are able, under certain circumstances, to develop social capital networks also with public agencies, setting new dynamics and peculiar social outcomes.

I nodi concettuali analizzati nel presente lavoro sono stati fondamentalmente due: 1) le politiche dello sviluppo in area mediterranea; 2) l'importanza che assumono in questo quadro i temi legati all'appartenenza e all'identità. In questo senso il concetto di sviluppo sostenibile è un altro punto chiave di questa parte. Al percorso teorico ha fatto seguito uno studio di caso presso l'arcipelago maltese. / This thesis is focused on two aspects: 1) the politics of development in the Mediterranean area, 2) the crucial role played by identity. The theoretical part is followed by a case study in the Malta archipelago, where we studied the development processes along with the identity dynamics through a multimethod approach.

Obiettivo di questa tesi è una lettura del coolhunting, attività professionale ancora relativamente poco diffusa, come luogo emblematico di meccanismi simbolici cruciali per spiegare non solo il sistema della moda ma anche molti degli andamenti della produzione e del consumo di beni materiali ricchi di contenuti immateriali. Non a caso, il debito teorico di questo lavoro non riguarda solo i fashion studies a partire dal classico saggio di Simmel, ma soprattutto un autore come Pierre Bourdieu, che poche pagine ha dedicato alla moda ma ha coniato concetti, come quelli di campo, capitale culturale e simbolico, habitus e distinzione, che sono diventati imprescindibili in ogni studio di tipo culturale. La base empirica della ricerca è costituita da 42 interviste del tipo racconti di vita, che hanno coinvolto una variegata popolazione di coolhunters inseriti in agenzie o nelle imprese della moda, ricercatori e consulenti free-lance, le cui esperienze lavorative sono analiticamente descritte nei capitoli centrali della tesi. La ricostruzione del mondo del coolhunting si avvale anche di una accurata ricerca effettuata su siti web dedicati. Nel capitolo finale la prospettiva teorica e il corpus di informazioni raccolte trovano una sintesi in (a) una definizione articolata ma precisa di cool-hunter; (b) una tipologia idealtipica; (c) nel concetto bourdieusiano di distinzione, che sembra essere la posta in gioco intorno alla quale ruota tutto il mondo del coolhunting. I coolhunters emergono come intermediari culturali riconosciuti per la loro capacità di cogliere gli stili di consumo emergenti e le macrotendenze culturali per offrirli come spunto alla creatività dei produttori di oggetti di moda mainstream. / The aim of this thesis is a reading of coolhunting, an emergent professional activity, as an emblematic place of symbolic mechanisms that are crucial in order to explain not only the fashion system but also many cultural processes of the production and the consumption of material goods rich of immaterial contents. The theoretical debt does not regard only the fashion studies, beginning from the classic work of Simmel, but above all an author like Pierre Bourdieu, that has dedicated few pages to the fashion, but has coined concepts - as those of field, cultural and symbolic capital, habitus, distinction - that are nowadays essential in every cultural study. The empiric base of the research is a set of 42 in-depht interviews that have involved a heterogeneous population of coolhunters working in trend agencies or fashion companies, researchers and free-lance consultants, whose working experiences are analytically described in the central chapters of the thesis. The reconstruction of the world of the coolhunting is carried out also with a search based on dedicated websites. In the final chapter the theoretical perspective and the empirical evidences are summarized in (a) an articulate definition of coolhunter; b) an idealtypical classification of coolhunting workers; (c) in Pierre Bourdiue’s concept of distinction, that seems to be the stake that moves the field of coolhunting. The coolhunters emerge as cultural intermediaries recognized for their ability to identify the emergent styles of consumption and macro-cultural trends in order to offer them as useful ideas to the creativity of the producers of fashionable mainstream objects.

Nella società odierna il termine “salute” assume una valenza sempre più omnicomprensiva e legata al concetto di benessere. L’individuo vive la questione della salute come un problema cogente e quotidiano e si dimostra attivo, ha però bisogno di informazioni e uno degli strumenti più importanti attraverso cui riesce a ottenerle sono proprio i media. A questa domanda così insistente corrisponde effettivamente una elevata offerta relativa ai temi della salute, ma l’abbondanza di contenuti, anche molto specifici, rende i cittadini disorientati e rischia di divenire un indistinto rumore di fondo in cui risulta difficile trovare ciò che interessa e comprendere cosa sia effettivamente utile, affidabile e corretto. In questo contesto si inserisce la comunicazione sul farmaco: le aziende farmaceutiche non utilizzano più solo strumenti diretti per comunicare (la pubblicità per i prodotti e verso chi è concesso dalla legge o l’informazione scientifica sul farmaco), ma anche mezzi “indiretti” come i mass media, che contemplano la presenza di intermediari, soprattutto giornalisti. La ricerca si occupa quindi da un lato di individuare gli strumenti utilizzati dall’industria farmaceutica per comunicare e dall’altro di analizzare le modalità di rappresentazione del tema della salute e del farmaco nei media. / In today's society the term “health” becomes increasingly comprehensive and linked to the concept of wellness. People live the issue of health as a cogent and daily problem and become active, therefore they need information and one of the most important instruments through which they manage to get them is the media system. This persistent question coincides with abundance of health issues, but the richness of themes, even very specific, makes people confused and could become a blurred background noise in which it is difficult to find what you are looking for and to understand what it is actually useful, reliable and correct. The communication about drugs stands in this context: pharmaceutical companies are not only using direct instruments to communicate (advertising for products when is permitted by law or scientific information), but also "indirect tools” as mass media, which include the presence of intermediaries, especially journalists. The research seeks to identify the instruments used by pharmaceutical industry to communicate and secondly to analyze the representation of the theme of health and medicine in media.

Questa dissertazione si propone di contribuire alla riflessione teorica sulle trasformazioni della città contemporanea, che discipline come la sociologia urbana e, nell’ultimo decennio, la sociologia della cultura, stanno portando avanti; vorrebbe, in particolare, costruire dei ponti tra queste e la produzione artistica per lo spazio pubblico che va sotto il nome di Public Art. Il mutato rapporto fra forma fisica della città, modelli produttivi e modalità di uso degli spazi pubblici ha contribuito a stimolare la formazione di nuovi ambiti di elaborazione dell’identità collettiva. Attraverso uno studio qualitativo realizzato in Italia e negli Stati Uniti, mostra come l'Arte Pubblica obblighi l’arte e gli artisti ad una ridefinizione del loro ruolo “pubblico”: la sperimentazione di nuove strategie di comunicazione simbolica nello spazio pubblico e la ricerca di un confronto con la dimensione locale del territorio fanno della Public Art un’innovativa formula di rappresentazione e rappresentatività del territorio. / This dissertation contributes to the ongoing debates about the transformations of contemporary cities, which has long invested urban sociology and, more recently, has become a concern in the sociology of culture. It also explores the possibility to build bridges between these disciplines and the production of art in public space known as Public Art. The transformed relationship between the city’s physical form, its production systems and the different ways in which public space is used nowadays creates new areas for the elaboration of social identities. Through a qualitative study carried out in Italy and the United States, it also shows how contemporary Public Art requires a redefinition of the “public” role of art and artists: as it tests new strategies of symbolic communication in public space and it tries to get in contact with the local dimension, Public Art becomes an innovative formula of representation of the territory.