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I sedimenti superficiali della piattaforma interna del golfo di Cagliari. Relazioni tra moto ondoso, correnti indotte e processi di sedimentazione su sistemi di spiaggia campione
Get PDFLa presente tesi di dottorato ha come fine principale l’approfondimento delle conoscenze sedimentologiche sui fondali marini dell’area compresa tra Capo Spartivento e Capo Carbonara e dei meccanismi di apporto, ridistribuzione e sedimentazione attuale nella piattaforma interna. Particolare attenzione è stata posta sui processi di interazione tra moto ondoso e fondali marini di acqua bassa (shallow water) che generano correnti costiere (long-shore, offshore-inshore, upwelling, sinking e rip current) e controllano i processi di erosione, trasporto e sedimentazione sui sistemi di spiaggia oggetto di studio. Primo obiettivo della tesi è contribuire a migliorare le conoscenze finalizzate a realizzare una cartografia dei sedimenti superficiali in scala 1:50.000 del Golfo di Cagliari, base indispensabile per raggiungere il secondo obiettivo che è quello di entrare nei dettagli relativi ai meccanismi delle dinamiche sedimentarie che si attivano sui sistemi di spiaggia per effetto dei diversi eventi meteomarini e comprendere quantitativamente assetto e scenari evolutivi. Contestualmente si è sperimentata per la prima volta sui litorali del Golfo di Cagliari la modellizzazione basata su misure topografiche di alta precisione di spiaggia emersa e batimetriche di spiaggia sommersa e relativi assetti sedimentari nelle diverse stagioni. Inoltre utilizzando come modello le due spiagge campione di Santa Margherita di Pula e Solanas (Sinnai) sono state studiate le differenti risposte idrodinamiche e morfo-batimetriche della surf-zone (zona più dinamica della spiaggia sottomarina) per le quattro principali direzioni di vento comprese nel settore di traversia e per gli eventi con intensità di 5, 10, 15, 25 m/s
Organic Thin-Film Transistors: an Investigation of Device Properties, Applications and Market Perspectives
Get PDFThe possibility for printing circuits completely made of plastics and polymers is paving the way for exploiting both innovative and challenging applications that one could never have thought about only a few years ago. In addition, the low fabrication costs of the devices make them appealing for the market place. Thus, both scientific community and investors focus on the synthesis of new materials able to achieve better and better performances so that they can be marketable very soon. Unfortunately, organic materials are still too sensitive to ambient conditions such as oxygen, moisture and light that degrade and consequently change their pristine properties. Though many steps forward have been done, still a better control on the performances is needed for aiming to realistic applications of organic electronics. However, this marked environmental sensitivity can be exploited in those applications where it can represent a plus rather than a minus such as gas, humidity or temperature sensing or in low speed switching circuits. The first part of this thesis deals with organic thin-film transistors (OTFTs) and successively proposes their application as chemical sensors. It finally ends with an overview of the real market perspectives for organic-based sensors. In particular, •Chapter 1 mainly deals with organic materials properties and the related transport mechanisms. Then the OTFT equation and working principles as well as the threshold voltage and the parasitic resistances role are discussed. Finally, the main device fabrication techniques used throughout this work are presented. •Chapter 2 describes several techniques used to characterize both device and interfaces. •Chapter 3 is focused on the non-idealities in OTFTs such as bias stress, aging and finally short-channel effects. •Chapter 4 examines non-planar geometry OTFTs, more specifically the cylindrical as well as the double-gate case. •First in Chapter 5 an overview of the main organic dielectrics employed as the gate insulator in OTFTs fabrication will be presented; then the dielectrics we have been testing throughout this thesis work as well as the role of the interfaces will be discussed together with the trapping mechanisms occurring when dealing with organic materials, and finally how semiconductor morphology and chemical-physical nature of the interface can influence the OTFTs electrical performances. •In Chapter 6, a brief overview of what is in literature on organic-based chemical sensors will be given. Starting from a deep insight into the Ion-Sensitive FET (ISFET) and its organic version, namely the Ion-Sensitive Organic FET (ISOFET). We will then examine the Charge-Modulated FET working principles useful to understand the Charge-Modulated Organic FETs which have been part of this thesis work and whose experimental results will be eventually shown and discussed. •Finally, Chapter 7 is dedicated to the analysis of the real organic electronics market perspectives focusing then on OTFTs used as sensors. This study was possible thanks to a J. W. Fulbright I was awarded in 2007. In fact the American Embassy in Italy created a pilot program called BEST (Business Exchange for Student Training) that is intended to foster entrepreneurship skills in young researchers having a smart scientific-based entrepreneurial idea to bring to the market place
Studio dell'effetto dell'attivazione del recettore GABAB sul consumo di alcol e sulle proprietà motivazionali dell'alcol nel ratto
Get PDFGABA is a major inhibitory neurotransmitter in the brain. Recent preclinical evidence suggests that pharmacological activation of the GABAB receptor (one of the two receptorstypes to which GABA may bind) reduced alcohol intake and ameliorated alcohol in take and ameliorated alcohol withdrawal syndrome. The recent discovery of a modulatory binding site within the GABAB receptor, together with the synthesis of in vivo effective drugs with positive allosteric modulatory activity, provide novel tools for investigations on the role of the GABAB receptor in the mediation of alcohol-related behaviors. The aim of the present study was twofold: (a) investigating the effect of GABAB receptor direct agonists on alcohol�s reinforcing and motivational properties, and (b) extending the investigation to some GABAB receptor positive allosteric modulators (PAMs). Selectively bred, Sardinian alcohol preferring (sP) rats (an animal model of alcoholism) were initially trained to press a lever to gain access to alcohol (index of the reinforcing and motivational properties of alcohol) under standard procedure of oral alcohol self-administration. Injection of non-sedative doses of both baclofen (direct agonist) and GS39383 (PAM) resulted in statistically, dose-dependent reduction of the rats' responding on the, alcohol-associated lever. These data suggest that activation of the GABAB receptor-either by mean of direct agonists or PAMs - may suppress alcohol reinforcement and motivation to consume alcohol
Adaptive and power-aware mechanism in wireless sensor networks
Get PDFIn a very short time, the interest about Wireless Sensors Networks(WSN) and their applications has grown both within the academic community and in the industry. At the same time, the complexity of the envisaged WSN-based systems has grown from a handful of homogeneous sensors to hundreds or thousands of devices, possibly differing in terms of capability, architecture, and operating system. Recently, some deployments of WSNs have been suggested in the literature both addressing the energy-aware and the adaptability to environmental changes issues; in both cases limitations arise which either prevent a long lifetime or/and the Quality of Service(QoS) of the envisaged applications.Energy is one of the scarcest resources in WSNs; energy harvesting technologies are thus required to design credible autonomous sensor networks. In addition to energy harvesting technologies, energy saving mechanisms play an important role to reduce energy consumption in sensor nodes. Moreover, in wireless sensor networks, the network topology may change over time due to permanent or transient node and communication faults, energy availability for the nodes (despite thepossible presence of energy harvesting mechanisms) and environmental changes (e.g., a landslide phenomenon, solar powerdensity made available to the nodes, presence of vegetation subject to seasonal dynamics). Development of smart routing algorithms is hence a must for granting effective communications in large scale wireless networks with adaptation ability combined with energy-aware aspects
La pianificazione urbanistica partecipativa per il governo dei processi di recupero urbano
No full textThe research aims to look at advances in disciplinary practice through the testing of new frontiers in the participative approach to planning. By using Information Communication Technology (ICT), which is able to integrate and improve planning now and in the future, it is possible to test an operating model, which through the interaction and interoperability of the different people involved, is able to manage the territorial use and transformation in urban renewal and redevelopment. The innovative aspect of the research can be seen in an experimental participative approach procedure, applied to a local case study (the historic centre of Cagliari). By sharing knowledge put together through WebGis, this directly involves the local community in the plan of action (Carta M., 2003), assuming a significant role. The knowledge and understanding of strategic choices made in the planning process allows the construction of “a shared image of the city” (Venti D., 2002), developing local pride and rediscovering “the territory as a patrimony to reuse, protect, complete and contextualise” (Venti D., 1996). The online platform, dedicated to and managed by WebGis technology, differentiates between general users and administrators, providing access to cartography, territorial data, and projects in progress, through exact decoding and associations between spatial entities of the single blocks and an alfanumerical database which have been used to examine the historic centre in general (by analysing the blocks) and in detail (by analysing architectural elements of the buildings). In this way the concept of sharing knowledge and participation is associated with proposals for sustainable policies and compatibility assessments in interventions aimed at renewal and reuse of historic buildings. By setting out protocol and technology for a participative approach procedure, it has been possible to test operating methods which, in the future, could be applied to real participative approach projects involving both public administrators and citizens. The results of the experimental application have shown that the availability of a ”window” and the use of WebGis are significant in the sharing of policies and planning choices. Its role in the construction of urban planning effectively creates a democratic planning process allowing everyone involved to have their say. The simple “knowledge” of rights to a higher quality is no longer sufficient to guarantee a sustainable vision of the future of the city and satisfy individual interests
Metodi e strumenti dell'analisi ambientale nelle nuove forme di piano
Get PDFEnvironmental planning, oriented towards recognising “natural, historic and cultural values” throughout the territory, tests innovative techniques and methods based on the convergence of expert and local knowledge which creates an overall context used to evaluate the compatibility of the transformation carried out. To this, criteria is applied which is long-term in the sustainable use of resources and effective in the developmental planning of the territory. The environmental approach to planning is therefore able to interface scientific, technical and other knowledge, facilitating an ethical decision making process in order to reach an agreement.
The conflict between the fragmentation of expert knowledge, unequivocal position of the environment and the plurality of the developmental proposals for use or transformation of the territory, requires reflection and a concise vision based on recognising local values. Experience of park planning and historic cultural resources has helped in developing this theme, above all in the light of innovations introduced by law 394/1991 which have required a critical re-evaluation of the “planning view” regarding environmental problems. In particular, the nature of substitution which the law has impressed on park planning as opposed to other types of planning (urban, territorial, environmental, and landscape planning) seems to imply the need to create, for every protected area, an instrument to manage the territory. As far as possible this should be able, on the one hand to systematise an interdisciplinary summary of knowledge and on the other to coherently effect the multiple norms afferent to the various disciplinary and environmental components.
The experience of park planning repeatedly highlighted the need to codify new paradigms o recognition, interpretation of values and consequent issues in the use of the environment. The inadequacy of traditional methodological apparatus – urban planning instruments, manifests itself, in these cases, in the problem of using the zoning paradigm to assess the complexity of environmental phenomenon. Problems present themselves following the environmental system networks in order to pinpoint boundaries of areas where action needs to be taken to conserve and protect the landscape, acts to guarantee the variety and abundance of fauna and flora present and at the same time to guaranteeing economical development. In the case of historic centres, by recognising characteristics, places, architecture and identifying signs in social and productive spaces incentives should be provided for coherent policies of urban protection and redevelopment which encourage transformation and use, compatible with the conservation of present historical and cultural values.
Based on these considerations, the thesis tests an innovative approach which uses an informative
geographic system with an interdisciplinary analytical basis. This reveals the systemic interaction between the natural components and signs of man in the construction of environments and highlights how to conserve them. For this purpose a SIT was carried out in order to highlight environmental, historical and cultural sensitivity and anthropological activity allowing the construction and sharing of contextual knowledge in order to plan and monitor the interventions considered admissible in sensitive areas of the territory
L'Unione Sovietica alla Mostra internazionale d'arte cinematografica di Venezia (1932-1953)
Get PDFAttraverso la lente del cinema e nella peculiare prospettiva offerta dal “microcosmo” della mostra di Venezia, è stato possibile vedere uno spaccato dell’evoluzione dei rapporti politici e culturali fra l’URSS e la comunità internazionale dagli anni trenta ai primi anni cinquanta, con un’attenzione specifica alle relazioni italo-sovietiche. Il coinvolgimento diretto dei principali organi statali e di partito dell’URSS in merito all’opportunità di prendere parte al festival ha rivelato il grande significato attribuito dal Cremlino alla manifestazione lagunare. La partecipazione alla mostra fu figlia di un ben preciso calcolo politico dell’Unione Sovietica, che intese l’evento veneziano come un’autentica competizione in cui avrebbe potuto dimostrare la sua preminenza a livello ideologico-culturale, in sintonia con la dichiarata supremazia dei propri sistemi socio-economico e politico. L’esame della stampa sull’accoglienza riservata ai film ed alle delegazioni giunte da Mosca ha poi palesato le forti aspettative e il grande interesse espressi dall’opinione pubblica italiana verso il cinema dell’URSS. Si sono inoltre messe in luce le trasformazioni organizzative ed estetiche subite dalla cinematografia sovietica nel periodo considerato e la sua collocazione all’interno del complesso rapporto fra arte, cultura e potere negli anni dello stalinismo e all’alba del disgelo post-staliniano
A panel data analysis of electric consumptions in the residential sector
Get PDFThe present work analyses a dataset on electricity consumption in an Italian region for a period of 11 years, using aggregated data on municipalities. Our aim is to estimate the value of the price elasticity, of the income elasticity and cross-price elasticity of other fuels and to analyse the influence of socio-economic, demographic, structural and climate variables on consumption levels and trends. The FEVD procedure, recently proposed by Plumper and Troeger (2007), is adopted to estimate panel data characterised by the presence of time invariant variables, or variables which vary rarely in time
Gender Wage Differentials in Italy: a Structural Estimation Approach
Get PDFThis paper studies gender wage differentials in Italy by providing a structural estimation of the frictional parameters of two different theoretical specifications of an equilibrium search model. I alternatively allow for firm heterogeneity and discrimination empirically using maximum likelihood and matching .first moments in the data. Results indicate substantial differences in transition parameters with higher level of search frictions for women. The mapping from productivity to wages for men is highly non linear, with high productivity firms offering proportionally higher wages; for women, the relationships is almost linear. Including discrimination, I find that productivity accounts for 61% of the wage offer differential, search for 28% and 11% is the part of discrimination
Near-Infrared Luminescent Lanthanide Complexes of Quinolinol Ligands: Structure/Properties Relationship
Get PDFThe synthesis and the characterisation of lanthanide complexes with quinolinolato ligands, a class of complexes proposed as near-infrared emitters for several optical applications, with a full investigation of the structure/property relationship, valuable for a reliable interpretation of their photo-physical properties, are described in this thesis.
This work has been addressed to a detailed investigation of the proper synthetic procedures useful to prepare pure products suitable for structural, spectroscopic and photo-physical studies. Several types of lanthanide quinolinolates have been identified and characterised depending on reaction’ conditions and on the nature of the ligand. The spectroscopic properties are discussed with the view to provide suitable tools to identify and characterise univocally the structural features of this class of complexes. The excited-state dynamics and light emission properties of Er-complexes have been investigated applying a reliable quantitative description of the non-radiative decay processes induced by the dipolar coupling between quencher groups and the lanthanide ion. It has been also demonstrated that the ligand emission is significantly affected by the supramolecular interactions in the crystal packing. The study of the magnetic properties of erbium quinolinolates evidences small magnetic interactions, due to the supramolecular arrangement, relevant in the optical behaviour of optically active ErIII derivatives. The lanthanide quinolinolates have also been incorporated into sol-gel glasses as promising low-cost materials for optical applications, with the aim to investigate the processing potential of this class of emitting molecules