Tesi di Dottorato

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Author: search.filters.author.Pantano, PietroEnd date: 2016

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    <> costruzione di possibili profili di sostenibilità applicati a scala di quartiere.
    (2013-11-29) Manfredi, Emilia; Pantano, Pietro; Rossi, Francesco
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    Modellazione di linguaggi naturali e artificiali attraverso la scienza delle reti
    (2012-12-17) Bertacchini, Francesca; Bilotta, Eleonora; Pantano, Pietro
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    <> comunicazione scientifica nell'arte tra realtà e realtà aumentata
    (2014-06-05) Rinaudo, Daniela; Pantano, Pietro
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    Study of the electronic and structural properties of tin dioxide and armchair graphene nanoribbons
    (2016-02-02) Villamagua Conza, Luis Miguel; Pantano, Pietro; Carini, Manuela; Stashans, Arvids
    This dissertation is focused on the study of the electrical and structural properties of two emerging materials, the tin dioxide (SnO2) and graphene, which have attracted the interest of the semiconductor-device community due to their extraordinary characteristics. The SnO2 has been studied by means of ab initio simulations (Vienna ab initio Simulation Package, VASP). Both n-type and p-type conductivities were investigated. The intrinsic n-type conductivity has been achieved through two schemes: the first one through the combination of oxygen deficiencies and interstitial atoms inside the SnO2 lattice, whereas in the second one, through the combination of interstitial and/or substitutional hydrogen atoms inside the SnO2 lattice. On the other hand, the p-type conductivity was achieved by codoping n-type SnO2 (from earlier configurations) with low concentrations of nitrogen and aluminum impurities. The performed theoretical studies, to a good extent, agree with the experimental results provided by our collaboration group at the National Central University, Jhong-Li (Taiwan). In prospective, these results confirmed that SnO2 is a promising candidate to replace indium in transparent conductive oxides (TCOs) used in photovoltaic, thin-film transistor, and transparent electronic applications. The theoretical study of graphene has been conducted by means of a tight-binding approach (Atomistic ToolKit simulation package, ATK): the electrical and structural properties of edge-defected armchair graphene nanoribbons (AGNRs) were studied. It was found that Stone-Wales defect (very common in carbon allotropes) placed at the edges of the AGNRs can spark an extra opening of the energy gap in graphene, in addition to that obtained through the quantum confinement of electrons. Moreover, an experimental study on the electrical properties of graphene was carried out at the Tyndall National Institute (Ireland) to understand the influence of multiple cleaning treatments on graphene field-effect transistor (GFET) devices. Debris from residual polymers that appeared during device fabrication was swept off the graphene surface without significantly degrading the electronic properties of the graphene flake. The results suggest that the unusual but extraordinary properties of these graphene allotropes can be considered as a very innovative booster for semiconductor devices, allowing the improvement of the scaling trend beyond that obtained with conventional materials.
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    Urban magnetism:understanding cities through the lens of geo-tagged photography
    (2016-02-02) Paldino, Silvia; Pantano, Pietro; Sobolevsky, Stanislav
    This research work presents a method for a new mapping process, based on social networks (especially geo-referred pictures downloaded from the websites of photosharing) to work alongside the maps commonly used in spatial planning. In the vast world of social, I choose to consider in particular the photographs, because people choose to photograph specific places or times that they consider important for some reasons. This would allow a truly innovative reading of the territory, making the concept of smart city in its dual aspects: the technological (because they take into account the social networks by creating dynamic maps of the territories) and human (because it takes into account the actual participation and objective citizens and more generally of land users, without the burden of being directly involved, but only through the daily activities that each of us carries on social networks). In this way it is possible to monitor urban areas that should be protected, managed, potentiated, discovered, making liveble and lived all the city and the territory to have smarter and safer city.
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    Permittivity characterization of a dielectric material using radar techniques
    (2016-02-02) Moreno Aviles, Paul David; Crupo, Felice; Pantano, Pietro; Di Massa, Giuseppe; Costanzo, Sandra
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    <> Defect-Centric analysis of the channel hot carrier degradation
    (2016-02-02) Pròcel-Moya, Luis-Miguel; Pantano, Pietro; Crupi, Felice
    Durante l'ultimo decennio, il channel hot carrier (CHC) e stato considerato uno dei pi u importanti meccanismi di degrado della moderna tecnologia CMOS. La degradazione CHC si veri- ca quando un voltaggio superiore a quello di saturazione viene applicato sul terminale di drain e, contemporaneamente, un voltaggio superiore alla tensione di soglia (VTH) viene applicato sul terminale di gate. Nel presente lavoro, abbiamo utilizzato la cosiddetta defect-centric distribution (DCD) per spiegare e descrivere il meccanismo di degradazione CHC. Il DCD si basa su due presupposti: il VTH prodotto da una singola carica segue una distribuzione esponenziale (valore medio ) e il numero to- tale di difetti segue la distribuzione di Poisson (valore medio Nt). La combinazione di questi due presupposti da come risultato la DCD. Negli ultimi anni, la distribuzione DCD e stata usata per descrivere e spiegare la bias temperature instability (BTI) ed e in grado di predirre le code estreme della distribuzione VTH no a 4 . Il vantaggio di usare il DCD e che i suoi primi e secondi momenti sono direttamente correlati ai parametri sici e Nt. Nel presente lavoro, e stato dimostrato che il DCD e anche in grado di descrivere e spiegare il degrado della distribuzione VTH no a 3 . E stata studiata la dipendenza dei parametri de ect-centric, e Nt, in relazione alla geometria del dispos- itivo. E stato dimostrato che e inversamente proporzionale all'area del dispositivo come in la degradazione BTI. Inoltre, il valore previsto della distribuzione VTH (< VTH >) si incre- menta fortemente quando la lunghezza di canale (L) diminuisce e si incrementa debolmente con il decremento della larghezza del dispositivo (W). In la degradazione BTI, si riporta che non vi e alcuna dipendenza tra < VTH > ed L. Pertanto, la forte dipendenza trovata e da atribuire alla degradazione CHC. Si e anche studiata la dipendenza della temperatura (T) dei parametri defect-centric e abbiamo trovato che non dipende da T, al contrario degli esperimenti BTI, dove invece Nt aumenta con T, fatto che si spiega con l'attivazione del meccanismo di dispersione elettrone-elettrone. Inoltre, abbiamo estratto una energia di attivazione di 56meV per Nt. Finalmente, abbi- amo usato dispositivi matching-pair con la nalit a di studiare la variabilit a tempo zero e la variabilit a dipendente dal tempo. E stato dimostrato che il tempo di stress e la tensione di stress applicati sul terminale di drain non in uenzano la variabilit a.
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    Valutazione della scuscettibilità e degli scenari di pericolosità e di rischio da frana in aree di interesse socio-economico (Calabria Settentrionale)
    (2016-02-02) Rago, Valeria; Pantano, Pietro; Gagliardo, Pietro; Muto, Francesco
    Landslides are natural geologic processes that play a key role in landscape evolution, but represent also one of the most widespread natural hazard in Italian territory. In particular, many areas of the Calabria region (southern Italy) have been affected historically by mass movements, due to the combination of its peculiar geological, morphological, seismic and climatic features and frequently to regionally unsustainable land management. Landslides are responsible for direct and indirect damages, may cause loss of life and property, damages to natural resources and hamper infrastructure projects, by generating strong social and economic impacts. This resulting in millions of Euro per year in damages and restoration as well. Therefore, spatial identification of potentially unstable slopes and landslide risk evaluation are very important in order to get mitigation measures and for land planning. The aim of this study is landslide susceptibility and risk assessment in areas of socio-economic interest in Northern Calabria. Study areas were a section of the A3 highway and a part of Amendolara town. The identification and selection of study areas took into account topography, geology and urban development conditions for which the landsliding is potentially a problem. Landslide risk assessment in the section of A3 highway was performed in a qualitative way by overlapping the highway on the landslide susceptibility map; this had lead to the zonation of spatial risk which allowed an evaluation of the involvement of the highway in the different susceptibility areas. In the Amendolara territory risk assessment was carried out in a quantitative way according to the formula: Risk = Hazard × Vulnerability × Economic value of elements at risk (buildings and roads). Hazard was computed in a probabilistic way by means the product between spatial probability (probability that any given region will be affected by landslides), temporal probability (probability of occurrence of landslide events during time t) and probability of landslide size (probability that a landslide will have a certain size). Physical vulnerability was evaluated considering elements at risk features and landslide size. Finally, landslide risk was computed on the basis of economic value of elements at risk, pointing to the probability of money that can be lost at the occurrence of a landslide in a given area, in a certain interval of time and with a certain area. This study provides two case example for the qualitative and quantitative risk assessment which can be useful to planners and decision makers to identify areas where more damages are expected and that should receive priority in the use of limited resources directed to preventive plans to reduce the impact of the landslides.
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    Circuit and architecture solutions for the low-voltage, low-power domain
    (2016-02-02) Albano, Domenico; Pantano, Pietro; Crupi, Felice