Multimetric Supergravities

Making use of integral forms and superfield techniques we propose supersymmetric extensions of the multimetric gravity Lagrangians in dimensions one, two, three and four. The supersymmetric interaction potential covariantly deforms the bosonic one, producing in particular suitable super-symmetric polynomials generated by the Berezinian. As an additional application of our formalism we construct supersymmetric multi-Maxwell theories in dimensions three and four.Comment: 37 pages, Latex2e, no figure

Underpricing and Firm’s Distance from Financial Centre: Evidence from three European Countries

We provide international evidence on the relationship between the extent of underpricing related to initial public offerings (IPOs) and the distance of the issuing firm from the financial centre of a country: for France, Germany and Italy, the higher the distance, the higher the level of underpricing. Under the maintained assumption that headquarters of institutional investors and underwriters are part of a financial centre, our evidence is consistent with the hypothesis that ex ante uncertainty regarding the value per share of an issuing firm increases with the firm’s physical distance from the underwriter. As financial centres are usually located in the richest areas of the countries concerned, spatial difference in the cost of equity financing may contribute to the persistence or the widening of local disparities.Asymmetric information, Distance, IPO, Underpricing

Multitemporal dendrogeomorphological analysis of slope instability in Upper Orcia Valley (Southern Tuscany, Italy)

The Upper Orcia Valley (Southern Tuscany, Italy) is a key site for the comprehension of denudation processes typically acting in Mediterranean badlands (calanchi) areas, thanks to the availability of long-lasting erosion monitoring datasets and the rapidity of erosion processes development. These features make the area suitable as an open air laboratory for the study of badlands dynamic and changes in geoheritage due to erosion (i.e. active geomorphosites). Decadal multitemporal investigations on the erosion rates and the geomorphological dynamics of the study area allowed to highlight a decrease in the average water erosion rates during the last 60 years. More in detail, a reduction of bare land and, consequently, of erosion processes effectiveness and a contemporary increasing frequency of mass wasting events were recorded. These trends can be partly related to the land cover changes occurred in the study area from the 1950s onwards, which consist of the significant increase of reforestation practices and important other forms of human impacts on slopes, mainly land levelling for agricultural exploitation. In order to better identify the most significant phases of geomorphological instability occurred in this area during the last decades, an integrated approach based on multitemporal geomorphological mapping and dendrogeomorphology analysis on specimen of Pinus nigra Arn. was used. In detail, trees colonizing a denudation slope located in the surrounding of the Radicofani town (Tuscany, Italy) and characterized by calanchi and shallow mass movements deposits, were analyzed for the 1985-2012 time period. The analysis of the growth anomaly indexes and of compression wood allowed to determine a spatio-temporal differentiation along the slope and respect to an undisturbed reference site. The negative anomaly index results to be more pronounced in the trees located on the investigated slope with respect to the ones sampled in a non-disturbed area. Compression wood characterizes trees on slope sectors mainly affected by runoff and/or mass movements with a different persistence. Erosion rates were finally calculated through dendrogeomorphological analysis on tree roots exposure (0.31-3 cm/y runoff prevailing; 5.86-27.5 cm/y, mass movements prevailing). Dendrogeomorphological results are in accordance with those obtained in the investigated areas with multitemporal photogrammetric and geomorphologic analyses

Crisis económica en España y sus factores determinantes

El trabajo trata de analizar las causas o factores determinantes de la crisis en España desde el punto de vista de la teoría Keynesiana, analizando la evolución de factores como la inversión, el consumo y el trabajo, desembocando en medidas que se pueden tomar para la salida de la crisis.Grado en Administración y Dirección de Empresa

Progettazione di un sistema di interfaccia per bio-sensore basato su piattaforma "ISIF"

Questa tesi tratta la progettazione e realizzazione di un sistema di interfaccia e condizionamento per un bio-sensore basato su piattaforma "ISIF". La piattaforma ISIF é un sistema dotato di una sezione di acquisizione analogica, una di processamento digitale e una CPU in grado di eseguire routine firmware. L'obiettivo del presente lavoro é stato trovare la configurazione piú adeguata per la sezione analogica, nonché realizzare il firmware; inoltre é sato sviluppato un software per l'acquisizione dei dati

Fluvial dynamics and watermills location in Basilicata (Southern Italy)

Watermills (grain mills, waulk mills, olive mills, sawmills and threshing machines) operated in the Basilicata Region from the Roman Period until the early decades of the twentieth century, representing an important feature of waterways that is today almost totally forgotten. Using documentary sources, ancient maps and field survey it is possible to catalogue and identify the location of these ancient hydraulic structures. Watermills were usually placed far enough away from the river to avoid inundation during floods, and near natural knickpoints or artificial steps in the river long profile that were created by mill engineers. Mill construction often had significant impacts on a rivers morphology, because it was necessary to divert the river discharge towards the mill wheel, to drive the grain-grinding mechanism. Watermill typological variations have been examined in relation to variations in river pattern to assess the ways in which the hydrographic and hydrological settings of the Basilicata Region have affected mill siting and operation. Most Basilicata watermills were built with a horizontal water-wheel and a tower. The characteristics of the tower and the associated hydraulic structures varied according to the environmental setting. Finally, mill positions define also the locations on the river system that have already been used to exploit hydraulic power and thus could be useful for future use in the micro-hydroelectric secto

The radiation environment in a Low Earth Orbit: the case of BeppoSAX

Low-inclination, low altitude Earth orbits (LEO) are of increasing importance for astrophysical satellites, due to their low background environment. Here, the South Atlantic Anomaly (SAA) is the region with the highest amount of radiation. We study the radiation environment in a LEO (500-600 km altitude, 4 degrees inclination) through the particle background measured by the Particle Monitor (PM) experiment onboard the BeppoSAX satellite, between 1996 and 2002. Using time series of particle count rates measured by PM we construct intensity maps and derive SAA passage times and fluences. The low-latitude SAA regions are found to have an intensity strongly decreasing with altitude and dependent on the magnetic rigidity. The SAA extent, westward drift and strength vs altitude is shown.Comment: 16 pages, 12 figures. Accepted for publication in Experimental Astronom

The development of Digital Broadcasting in Italy

The paper has two aims.The first is to show how the current features of Italian TV industry are the consequences of past regulatory intervention.The second purpose is to analyse how the current structure of Italian industry affects the policies to promote the switch from analogue to digital TV,and to consider whether these policies will be able to bring competitiion to the Italian TV market