169,100 research outputs found
L'approccio etnografico per documentare storie di emigrazione
No full textA partire dall'esperienza di AMMER- Archivio Regionale multimediale per la memoria dell'emigrazione regionale, l'articolo analizza potenzialità e rischi metodologici della videointervista come strumento di ricerca e di documentazione delle migrazioni
A Modified Fokker-Planck Approach for a Complete Description of Vibrational Kinetics in a N2Plasma Chemistry Model
No full textThe Fokker-Planck (FP) approach for the description of vibrational kinetics is extended in order to include multiquanta transitions and time dependent solutions. Due to the importance of vibrational ladder climbing for the optimization of plasma-assisted nitrogen fixation, nitrogen is used as a test case with a comprehensive set of elementary processes affecting the vibrational distribution function (VDF). The inclusion of the vibrational energy equation is shown to be the best way to model transient conditions in a plasma reactor using the FP approach. Results are benchmarked against results from the widely employed state-to-state (STS) approach for a wide parameters range. STS and FP solutions agree within 10% for the lowest vibrational levels, while time dependent VDFs are in agreement with the STS solution within a ∼5% error. Using the FP approach offers the possibility to parametrize drift and diffusion coefficients in energy space as a function of vibrational and gas temperature, providing intuitive and immediate insights into energy transport within the vibrational manifold
Virtual Private Network Design Under Traffic Uncertainty
No full textWe propose different formulations as well as efficient solution approaches for the VPN design problem under traffic uncertainty with symmetric bandwidths. © 2004 Elsevier B.V. All rights reserved
Exopolis reloaded : fragmented landscapes and no man’s lands in a North-Eastern Italian border region
No full textThis paper examines a ‘landscape of power’ in the marginal northeastern corner of Italy, near the Italian-Slovenian border. The landscape is centred around the small town of Gradisca and its highly contested centres for asylum seekers and marked by the concomitant presence of a giant shopping mall, the largest Italian war memorial, and an aestheticised wine district. The result of participant observation, visual and textual analysis, and selected interviews, this study reflects on the transformation of a former cold war border area into a mix of carceral, hospitality, commercial, residential, rural spatialities that seem to be entirely disconnected with each other and linked instead to broader regional, national and international geographies. This fragmented landscape, dominated by massive ‘fortified’ enclosures and with gradually deterritorialised in-between spaces, described here as no man’s land, may be provocatively analysed as an Italian exopolis.</p
An investigation on microstructure and milling performance of arc-evaporated TiSin/AlTiN film
No full textIn this work, TiSiN/AlTiN multilayer film was deposited on cemented-carbide solid end mill tools by cathodic arc evaporation. The multilayer consisted of CrN buffer layer, Al(0.6)7Ti(0.33)N adhesion layer, Ti0.9Si0.1N/Al(0.6)7Ti(0.33)N alternate layer, and Ti0.9Si0.1N outlayer. An investigation on microstructure, mechanical properties, high-temperature wear rate, and milling performance of TiSiN/AlTiN multilayer film was conducted. The results indicate that the as-deposited TiSiN/AlTiN film exhibits a mixture phase of fcc-TiN and fcc-(Ti, Al)N. The hardness and elastic modulus of the TiSiN/AlTiN film are 41.7 +/- 1.6 GPa and 340 +/- 17 GPa, respectively. The wear rate of TiSiN/AlTiN film changes slightly when the experiment temperature is below 400 degrees C, and then increases with the temperature increases to 600 degrees C. Indentation hardness of TiSiN/AlTiN changes can be maintained above 40 GPa upon annealing to 800 degrees C. However, the hardness of the film decreases from above 40 GPa to similar to 30.6 GPa when the annealing temperature increases to 1000 degrees C. During dry milling, the TiSiN/AlTiN film reduces the adhesion between the coated tool and machined material SKD 11, leading to a low cutting force and cutting temperature.</p
Nuovi scenari digitali per la sociologia visuale
No full textIl passaggio dai supporti analogici a quelli digitali è da considerarsi come qualcosà di più di un semplice up-grade tecnologico. La trasformazione riguarda non solo il modo di fotografare della gente comune, ma anche il modo di utilizzare l'immagine come strumento di ricerca per il sociologo. La digitalizzazione dell'immagine obbliga quindi la sociologia visuale a rivedere e riconsiderare i suoi presupposti epistemologici
Provisioning virtual private networks under traffic uncertainty
No full textWe investigate a network design problem under traffic uncertainty that arises when provisioning Virtual Private Networks (VPNs): given a set of terminals that must communicate with one another, and a set of possible traffic matrices, sufficient capacity has to be reserved on the links of the large underlying public network to support all possible traffic matrices while minimizing the total reservation cost. The problem admits several versions depending on the desired topology of the reserved links, and the nature of the traffic data uncertainty. We present compact linear mixed-integer programming formulations for the problem with the classical hose traffic model and for a less conservative robust variant relying on the traffic statistics that are often available. These flow-based formulations allow us to solve optimally medium-to-large instances with commercial MIP solvers. We also propose a combined branch-and-price and cutting-plane algorithm to tackle larger instances. Computational results obtained for several classes of instances are reported and discussed
Competenze informatiche, apprendimento linguistico e comunicazione interculturale: le risorse digitali
No full textLe risorse digitali per favorire la comunicazione in contesti intercultural
Attuazione di strategie IPM per controllare le malattie batteriche di drupacee e noci causate da pseudomonadi e xantomonadi resistenti/tolleranti al rame
No full textIl cancro batterico delle drupacee causato da Pseudomonas syringae pv. syringae e Pseudomonas syringae pv. morsprunorum e il mal secco del noce causato da Xanthomonas arboricola pv. juglandis, sono stati studiati per oltre un secolo e hanno portato a significativi progressi nella nostra comprensione dell'epidemiologia delle malattie batteriche fogliari e del ciclo di vita epifita di questi agenti patogeni. Recenti studi sull'ecologia, la caratterizzazione e l'identificazione dei patogeni sono stati stimolati dall'importanza economica delle malattie e dalla mancanza di misure di controllo efficaci. Una collezione di 54 isolati di P. syringae spp. da albicocco e 47 isolati di X. a. pv. juglandis da noce sono stati studiati utilizzando il fingerprinting genomico mediante reazione a catena della polimerasi ripetitiva (PCR), utilizzando i set di primer ERIC, BOX e REP e l'analisi della sequenza multi-locus (MLSA). La tolleranza al rame di tutti i ceppi è stata valutata osservando la crescita batterica su terreni con aggiunta di solfato di rame e i risultati sono stati confrontati con quelli di uno studio di cinque anni nella stessa area. Questa tesi ha mostrato che la frequenza dei batteri resistenti al rame aumenta dopo ripetuti trattamenti con composti a base di rame. Questi risultati suggeriscono che la selezione di ceppi resistenti al rame può essere una delle principali cause di fallimento nel controllo dopo il trattamento con composti rameici. I batteriofagi, in quanto elementi naturalmente presenti nell’ambiente, potrebbero essere un'opzione praticabile per il controllo di queste malattie batteriche. In questa tesi, dieci nuovi fagi che lisano P. s. pv. syringae e dieci nuovi fagi che lisano X. a. pv. juglandis sono stati isolati da frutti, foglie, suolo e acqua di irrigazione di albicocche e noci nel nord Italia. La digestione con endonucleasi di restrizione dei fagi ha rivelato che esistono tre gruppi fagici distinti, designati come gruppi 1, 2 e 3. Nonostante il fatto che tutti i fagi isolati fossero specifici per X. a. pv. juglandis, un'analisi della gamma ospite di fagi che coinvolge 25 diversi X. a. pv. juglandis ha rivelato che i fagi possono essere suddivisi in quattro classi in base alla loro capacità di lisare i 25 ceppi considerati. Nei test di laboratorio, tutti i fagi hanno avuto un promettente effetto litico su P. s. pv. syringae e X. a. pv. juglandis.Bacterial canker of stone fruits caused by Pseudomonas syringae pv. syringae and Pseudomonas syringae pv. morsprunorum, and bacterial blight of walnut caused by Xanthomonas arboricola pv. juglandis, have been studied for over a century and have resulted in significant advances in our understanding of the epidemiology of foliar bacterial diseases and epiphytic life cycle of these pathogens. Recent studies on the ecology, characterization, and identification of pathogens have been prompted by the economic importance of the diseases and the lack of effective control measures. A collection of 54 P. syringae spp. on apricot and 47 X. a.pv. juglandis strains on walnut were studied using repetitive polymerase chain reaction (PCR) genomic fingerprinting using ERIC, BOX, and REP primer sets, and Multi-Locus Sequence Analysis (MLSA). Copper tolerance of all strains were assessed by observing bacterial growth on copper sulphate-added media, and the results were compared to those of a five-year-old study in the same area. This thesis showed that the frequency of copper resistant bacteria increased after repeated treatments with copper-based compounds. These findings suggest that the selection of copper-resistant strains may be a major cause of control failures after copper bactericide treatment. Bacteriophages, as realistic and environmentally friendly microorganisms, could be a viable option for controlling these bacterial diseases. In this thesis, ten novel phages that lyse P. s. pv. syringae and ten novel phages that lyse X. a. pv. juglandis were isolated from apricot and walnut fruits, leaves, soil, and irrigation water in Northern Italy. The restriction endonuclease digestion of phages revealed that there are three distinct phage groups, designated as groups 1, 2, and 3. Despite the fact that all isolated phages were specific to X. a. pv. juglandis, an analysis of the host range of phages involving 25 different X. a. pv. juglandis strains revealed that the phages can be divided into four classes based on their ability to lyse the 25 strains considered. In laboratory tests, all phages had a promising lytic effect on P. s. pv. syringae and X. a. pv. juglandis. P. s. pv. syringae and X. a. pv. juglandis showed promising lytic effect in laboratory trials
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