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Diaspore mercantili e regia Azienda nella Sardegna Sabauda: commercio e imprese dal passaggio dell'isola ai Savoia (1720) alle riforme degli anni Venti dell'Ottocento
Get PDFThis thesis investigates the economic, trade and state concessions in 1700 Sardinia. In the first part of the thesis, the establishment of commercial networks in the territory was studied. It was observed how mainland traders created commercial networks in the early eighteenth century, by establishing themselves in key locations in the territory to link mainland markets to those in coastal and inland Sardinia. Over time this commercial diaspora promoted the emergence of local entrepreneurs managing small businesses. These local entrepreneurs managed the distribution of commercial products from the mainland traders as well as the provision of local products to the traders who maintained contact with mainland trade networks. In the second part of the thesis, the dynamics of state concessions were studied. It was observed how the system moved from concessions to foreign businessmen that controlled key segments of the Sardinian economy, such as salt and mining, to a centralized system accompanied by the development of a state bureaucracy that progressively took over direct management of key industries
Materiali molecolari basati su complessi inorganici
Get PDFSynthesis and characterization of molecular materials based on inorganic complexes. Recent news and perspectives about molecular materials. Syntheses of croconate (croc) and dithiocroconate (dtcr) ligands. New complexes based on croconate and dithiocroconate ligands, spectroscopic and structural properties of (TBA)2[Cu(dtcr)2], (TBA)[Au(dtcr)2], (TBA)3[Ga(croc)3]. New charge transfer salts based on dithiocroconate ligand, structural properties and electrical conductivity behavior of ET2[Ni(dtcr)2], TTF2[Ni(dtcr)2] e ET[Au(dtcr)2], initial spectroscopic characterization of ET/[Cu(dtcr)2] e TTF/[Cu(dtcr)2]. New complexes of Cr(III) with croconate ligand, spectroscopic and structural properties of [Cr(µ-C5O5)(µ-OH)(OH2)2]2[K5(C5O5)2.5]•7H2O e [Cr(µ-C5O5)(µ-OH)(OH2)2]2•6H2O, preliminary studies of magnetic properties and DFT calculations to clarify the bridge structure of the dimer [Cr(µ-C5O5)(µ-OH)(OH2)2]2•6H2O. Future perspectives on the use of these new complexes in the field of molecular materials
Assessing visitor satisfaction with tourism rejuvenation policies: the case of Rimini, Italy
Get PDFIn this paper we assess the appeal of potential interventions on the tourism offer of Rimini, a popular Italian seaside holiday destination, by means of a choice modelling analysis. Tourism can be viewed as a composite good, its overall utility depending on the arrangement of the component characteristics. Our discrete choice experiments incorporate as attributes a number of possible changes to current tourist activities (the subject of public debate), including them in hypothetical alternative holiday packages. The conditional logit analysis indicates that tourists show lesser preference for interventions aimed at protecting the environmental integrity of the beach and greater preference for those, such as the creation of a pedestrianised seafront with late-night opening of amenities and facilities, that are likely to diminish the role of the traditional sea, sun and sand component of the overall holiday experience
Correlation between interface-dependent properties and electrical performances in OFETs
Get PDFOne of the fundamental points in determining the electrical performances in organic devices is that, even though they are usually thought as macroscopic devices, their behaviour is strongly driven by interfacial phenomena taking place in the nano scale. The focus of this thesis is the realization and characterization of Organic Field effect Transistors (OFETs) with a particular interest for investigating the influence of the interfaces on the electrical performances of the devices. Indeed, the parameters which mostly influence the electrical behaviour can be divided into to groups:
1) Intrinsic parameters of the material, as molecular packing and island nucleation, where the interfacial phenomena are taking place in the inter-molecular and inter-island scale.
2) Structural properties of the device, where the role of the triple interface metal electrode/organic semiconductor/gate dielectric can, in fact, significantly dictate the electrical behaviour of the device.
In conclusion, in this thesis we demonstrated that the electrical and optoelectronic performances of organic semiconductor based devices are strongly influenced on one side by the geometry and architecture of the device itself, on the other hand, by the structural and morphological properties of the employed materials, and that the nanosized interfacial volume between the different materials layers in the device often play a key-role for determining the final properties of the device. In other words, device behaviour is more affected by material boundaries than by intrinsic properties of materials
Mediterranean vegetation monitoring by remotely sensed data: LAI retrieval and vegetation trend analysis within two forested areas in southern italy
Get PDFThe object of the research was twofold: 1) The production of LAI (Leaf Area Index) distribution maps of two Mediterranean forested areas by means of satellite data, to this aim, high resolution IKONOS-2 and medium resolution LANDSAT-TM data were used, and their results compared, the choice to focus on LAI derives from the paramount role this vegetation biophysical, parameter plays in many climate and ecological models, since it is a control variable of important processes such as canopy radiation interception, evapotranspiration and net photosynthesis; 2) A trend analysis, within the same study areas, aimed at improving our understanding of Mediterranean forests response to changing climatic conditions. A yearly series of landsat satellite data and local climatic measurements over a time span of twenty years (1984-2005) were processed and compared in order to evaluate possible relationships between inter-annual variations of vegetation (as expressed by landsat-derived spectral vegetation indices) and related meteorological parameters
Optical and structural characterization of crystalline oxides for laser applications
Get PDFThe development of new solid-state lasers, especially those operating between 0.9 and 3.0 µm, has renewed general interest in the optical properties of rare-earth ions (Re3+) in crystalline oxides with garnet structure. At this purpose, the aim of this study concerns the optical and structural characterization of crystalline oxides for laser application, with the prospective of enhancing efficiency and tunability of solid state lasers, and the experimentation of new materials able to meet specific technological purposes. The development of new laser materials, with mixed structure, for example, is devoted to the remote sensing of the atmosphere. Light detection and ranging (LIDAR) or differential absorption lidar (DIAL) techniques can be applied to determine molecular constituent concentrations present in the atmosphere, such as water vapor. The possibility of tuning the laser emission to investigate the desired molecule easily explains the growing interest in the optical characterization of mixed garnet materials. In this scenery mixed garnet host materials, like Y3Al5O12 (YAG), Y3Sc2Ga3O12 (YSGG), Gd3Sc2Ga3O12 (GSGG) and Y3Sc2Al3O12 (YSAG), doped with lanthanides allow the so-called compositional tuning. In this work we studied the optical and structural properties of two different materials with garnet structure: yttrium aluminum garnet (Y3Al5O12 - YAG) doped with Fe3+ ions, and the mixed structure Y3Sc2Ga3O12 (YSGG) - Y3Al5O12 (YAG) doped with Neodymium
Stimolazione da etanolo del sistema dopaminergico mesolimbico: ruolo dell'acetaldeide
Get PDFEvidence shows that acetaldehyde (ACD), the main metabolite of alcohol previously considered only a toxic substance, may actually mediates the reinforcing effects of ethanol (EtOH) (1). Accordingly, in rodents ACD is self-administred and stimulates the firing of Ventral Tegmental Area (VTA) mesolimbic dopaminergic neurones (2,3). Moreover, recent data show that ACD blockade by sequestration with D-penicillamine or by alcohol dehydrogenase competitive inhibition with 4-methylpyrazolean prevent various electrophysiological and behavioral effects of EtOH (3,4). In this study, we used in vivo microdialysis to measure dopamine (DA) output in the Nucleus Accumbens shell (Nacbs) of male albino Wistar rats in response to a challenge with ACD and EtOH. Both EtOH (0.5, 1.0, 2.0 g/kg) and ACD (10,20 40 mg/kg) were administered by gavage (i.g.) in order to mimic the route of administration used by humans. To further research the effect of ACD on the mesolimbic DAergic system, ACD (50, 75, 100 µM) was administered via reverse dialysis within the VTA while measuring DA output in the NAcbs. Intragastric EtOH and ACD administration dose-dependently increased DA extracellular levels in (i.g. administration) was more potent than EtOH, eliciting similar effects on DA outflow in the NAcbs at doses 50-fold lower. These findings support the hypothesis that ACD has central nervous system effects in its own right and show that ACD stimulates mesolimbic DAergic neurons by an NAcbs. Our results, togheter with the data in the literature, allows to conclude that ACD plays a key role in the EtOH-induced stimulation of mesolimbic pathway and possibly in its rewarding and motivational properties.
1) Quartemont et Al., TIPS 25(3): 130-4, 2004
2) Rodd-Henricks et Al., PBB 72:55-64, 2002
3) Foddai et Al., Neuropsych. 29(3): 530-6, 2004
4) Font et Al., Neuropsych. 184(1): 56-64, 200
Optimization of traffic flows in multiservice telecomunications networks
Get PDFThis dissertation investigates routing optimization in IP telecommunication networks, under normal working conditions as well as under failure conditions.
The main objectives of the present optimization procedure are the minimization of the maximum link utilization in the network and to provide a configuration that guarantees a 100% survivability degree.
Traditionally two different steps are used to achieve this goal. The first one aims to solve the well known “General Routing Problem (GRP)” in order to find the optimal routing network configuration and, successively, a set of “optimal” backup paths is found in order to guarantee network survivability. Furthermore, traditional survivable techniques assume that the planning tasks are performed in a network control center while restoration schemes are implemented distributively in network nodes.
In this dissertation innovative linear programming models are presented that, making use of the Multi Protocol Label Switching – Traffic Engineering (MPLS-TE) techniques and IS-IS/OSPF IP routing protocol, melt routing and survivability requirements. The models are extremely flexible, thus it is possible to improve the objective function in order to fit itself to newer applications and/or traffic typologies.
The models presented in this dissertation help Internet Service Providers to optimize their network resources and to guarantee connectivity in case of failure, while still be able to offer a good quality of service
Oil spill detection by means of synthetic aperture radar
No full textIn this thesis work a new approach to observe sea oil spills by means of remotely sensed SAR data and physical scattering modeling has been developed. First the mahematical problem of the oil spill detection has looked for the objective definition of the feature space and of the nature of the classification problem. The oil spill classification problem is formulated as a one-class classification problem and an approach to perform a qualitatively analysis and to objectively select among the classical features, used in SAR oil spill classification procedures, is proposed. Successively, a new a speckle model for marine Single-Look Complex SAR images has been proposed. This model allowed showing that full-resolution speckled SAR images can be effectively employed to detect dark areas and strong scatterers. The new approach is based on the generalized K model (GK) which is able to embody very different scattering cases. Finally, two studies on sea oil spills observation by means of polarimetric SAR data are accomplished. In the first approach, a CFAR filter tailored for full-polarimetric SAR data has been first applied over marine images. The polarimetric CFAR filter is able to effectively identify the dark patches which may be due to oil spills. Further, it has been studied the relevance of the polarimetric features H, α and A to assist oil spill classification. Experiments results showed that the main polarimetric feature is H. In the second approach, a filtering technique based on the standard deviation of the co-polar phase difference (σφc) has been developed and tested. Experimental results showed the usefulness of using σφc to assist oil spill detection and, in particular, for distinguishing among oil spills and biogenic look-alikes
Stime sul bordo per soluzioni di equazioni ellittiche singolari
Get PDFNella prima parte di questa tesi viene studiata l’equazione Δu + f(u) = 0 in un dominio regolare (che soddisfa la proprietà della sfera interna e della sfera esterna) e limitato di RN, dove f(t) è una funzione regolare positiva, decrescente, e che tende a infinito per t che
tende a zero.
Nella seconda parte della tesi si studia invece l’equazione Δu = f(u)in un dominio regolare e limitato Ω di RN, dove f(t) è una funzione regolare, crescente per t > 0 e che soddisfa la condizione di Keller-Osserman. Se si considera la condizione sul bordo u(x) ->(infinito) per x -> @Ω, la soluzione di quest’altro problema di Dirichlet è chiamata
soluzione blow-up (o esplosiva).
In entrambi i casi si parla di equazione singolare