The unusual Ca’ Bonettini landslide (Province of Modena, Italy)

In September 2003, in concomitance with a weak seismic shock, a landslide took place in the River Panaro valley, in the municipality of Marano (Province of Modena, northern Italy). The singularity of this slope movement consisted in the fact that, although the mobilised soils were mainly argillaceous, the activation occurred at the end of a long drought period, whereas such landslides are usually recorded in the wet season, when the soil is saturated with water. After examining the geological and physical-mechanical characteristics of the formations making up the slope, the causes of this landslide are discussed in relation to man’s activities and the seismic tremor recorded. Finally, suitable remedial measures for slope stabilisation are suggested

Geomorphological assets of central Australia

The semiarid plains of central Australia host some spectacular geomorphological assets: Ayers Rock, The Olgas and Mt. Conner. The origin of these impressive landforms is due to the complex depositional, tectonic and climatic events taking place over several hundred million years, starting from the primordial formation of Australia itself. The peculiarities of this region are described; in particular the geomorphological processes which have shaped the physical environment of the vast Australian outback, creating these monuments of Nature, are discussed

Analisi delle caratteristiche fisico-ambientali dell’oasi naturalistica “La Francesa” (Comune di Carpi, pianura modenese)

E' stata recentemente istituita un’oasi naturalistica presso il sito denominato “La Francesa”, in località Fossoli di Carpi. Il lavoro si propone di analizzare le caratteristiche pedologiche, litologiche e idrografiche dell’area di studio, che comprende uno stagno e un percorso didattico in un bosco planiziale di recente impianto. L’oasi, sorta principalmente per scopi protezionistici ed educativi, ospita una ricca avifauna e un giardino di piante rare e officinali tipiche della bassa pianura modenese. Lo studio intrapreso ha evidenziato la prevalenza di litotipi argillosi soggetti a forte indurimento e ritiro volumetrico nei periodi siccitosi. Tale caratteristica negativa per la vegetazione può tuttavia essere attenuata tramite irrigazioni dalla rete idrografica presente sul territorio

Lessons learnt from the Sgorigrad and Stava disasters

The catastrophic failures of tailings dams at Sgorigrad (Bulgaria) and Stava (Italy) are analyzed, pinpointing the many similarities of the two cases. A description is given about the shortcomings in the construction of these geotechnical structures and the causes of their collapse. Further information is provided about the lessons learnt from these disasters and the activities carried out to keep memory alive and qualify young engineers and geologists on the proper and safe management of tailings dams

Il disastro di Molare del 1935 in Valle Orba (AL): un Vajont dimenticato

Nel 1926 nella Valle Orba (Piemonte) fu ultimata la realizzazione di un grande bacino idroelettrico ottenuto dallo sbarramento del Torrente Orba per mezzo di due differenti dighe: la Diga Principale e la Diga Secondaria. Il 13 agosto 1935, a seguito di una fortissima precipitazione, la Diga Secondaria collassò insieme ad una porzione di terreno sul quale era fondata. L’ondata che si riversò violentemente verso valle determinò la morte di 110-115 persone e causò gravissimi danni ai sottostanti centri abitati. L'articolo esamina le cause geologico-strutturali, idrologico-idrauliche e progettuali che portarono al crollo dell'opera e alla devastazione della valle

Strongly correlated metal interfaces in the Gutzwiller approximation

We study the effect of spatial inhomogeneity on the physics of a strongly correlated electron system exhibiting a metallic phase and a Mott insulating phase, represented by the simple Hubbard model. In three dimensions, we consider various geometries, including vacuum-metal-vacuum, a junction between a weakly and a strongly correlated metal, and finally the double junctions metal-Mott insulator-metal and metal-strongly correlated metal- metal. We applied to these problems the self-consistent Gutzwiller technique recently developed in our group, whose approximate nature is compensated by an extreme flexibility,ability to treat very large systems, and physical transparency. The main general result is a clear characterization of the position dependent metallic quasiparticle spectral weight. Its behavior at interfaces reveals the ubiquitous presence of exponential decays and crossovers, with decay lengths of clear physical significance. The decay length of metallic strength in a weakly-strongly correlated metal interface is due to poor screening in the strongly correlated side. The decay length of metallic strength from a metal into a Mott insulator (or into vacuum) is due to tunneling. In both cases, the decay length is a bulk property, and diverges with a critical exponent ($\sim 1/2$ in the present approximation, mean field in character) as the (continuous, paramagnetic) Mott transition is approached.Comment: 19 pages, 19 figure