2,148 research outputs found
Atreipus-like footprints and their co-occurrence with Evazoum from the upper Carnian (Tuvalian) of Trentino-Alto Adige
No full textAvanzini A. & Petti F.M. (eds), Proceedings of the Ichnology session of Geoitalia 2007, VI Forum Italiano di Scienze della Terra Rimini - September 12-14, 2007
Theropod and sauropod footprints in the Early Cretaceous (Aptian) Apenninic Carbonate Platform (Esperia, Lazio, Central Italy): a further constraint on the palaeogeography of the Central-Mediterranean area.
No full textAvanzini A. & Petti F.M. (eds), Proceedings of the Ichnology session of Geoitalia 2007, VI Forum Italiano di Scienze della Terra Rimini - September 12-14, 2007
A numerical model of the wave that overtopped the vajont dam in 1963
No full textThe Vajont landslide took place in northern Italy on October 9th 1963 and caused a huge impulse wave to travel in the artificial reservoir and overtop the dam, flooding and devastating a considerable area along the Piave riverbed. In this event, about 1900 people died, 1700 of them in the Piave Valley alone.
The water depth of the wave in some points exceeded 50 m. Although the phenomenon is clearly tridimensional, the application of a pure 3D hydraulic numerical model to this wide and natural territory is very difficult. Recently, the authors have presented a numerical model of the impulse wave that wasted the Vajont basin as a consequence of the landslide (Bosa and Petti, 2011). In this paper, a 2DH numerical model is applied to study the effects of the overtopping wave in the Piave Valley, in order to verify if the simplifications assumed by a 2DH model still make it possible to describe the evolution of the wave in the proper manner
Hydrodynamics in the swash zone
No full textThis paper describes a study of the hydrodynamics in the swash
zone using an impermeable concrete beach in a laboratory flume.
Analysis was made of the measurements achieved using level wave gauges and a laser Doppler velocimeter. From these measurements we could derive the mean motion and turbulence characteristics along the main flow direction in three vertical sections of the swash zone. Fluid velocity seems almost uniform along the vertical, especially during the up-rush; the behaviour of turbulence dynamics is a mixture of free turbulence generated during wave breaking and convected by the mean motion, and wall turbulence.
This work covers analysis in the time and frequency domain and
the turbulent properties of the flow field derived from our
measurements are discussed
Laboratory tests on the interaction between non-linear long waves and submerged breakwaters
No full textThis paper deals with the use of submerged detached breakwaters as beach protection, a use that today has become quite popular. This type of structure has been largely studied both theoretically and through experimental analysis in recent years, however its behavior has not been completely understood, specially if related to the real irregular wave attacks. In particular some laboratory studies carried out by the authors have pointed out some interesting phenomena associated with the interaction between the nonlinearities of wave transformations in shallow water and submerged breakwaters. Aiming at discerning between the phenomena related to the structure (beach and breakwater) and flume geometry, a new series of laboratory tests have been carried out in a 50 m long wave flume; these tests and the results obtained are described in this work. Besides the study of the behavior of submerged structures related to the bounded-long-waves, some current velocities have also been measured during this research through directional micro-propeller fluid meters
SWASH ZONE MEASUREMENTS IN A WAVE FLUME
No full textWave set-up has been measured on impermeable fiXed plane beaches by a number of researchers, from Bowen et a1 (1968) to Stive (1985). All the results refer to beach slopes ranging between 0.022 and 0.1. Starting from the outcomes resulting from research up to now, we have carried out new experiments on a impermeable beach with constant slope and with different values· of the surf similarity parameter. The main aim of these experiments is to take detailed measurements in the swash zone, where strongly non-linear processes occur, and to compare the results with some existing models. The experiments took place in the wave tank (0.8 m x 0.8 m x 50 m) of Florence Department, equipped with second order generation. The measurements refer to free surface profiles, to run-up and run-down limits and to fluid velocities. The specific equipment used were twin wire water level meters, pressure transducers, image analysis, LDA and micro propeller. All the tested waves are monochromatic, with possible future extension to irregular waves
Alcohol is not a risk factor for oral cancer in nonsmoking, betel quid non-chewing individuals. A meta-analysis update.
No full textAlcohol drinking is associated with high oral cancer (OC) risk. This association is particularly evident in tobacco smoking/betel quid (BQ) chewing subjects. In a previous stratified meta-analysis (Petti S et al., Cancer Epidemiol 2012) we reported that drinking was inversely associated with OC in non-smoking BQ non-chewing individuals, while this association was reversed in smoking individuals. However, the previous study could be excessively influenced by a large primary study, which yielded more than 50% of the weight of all the primary studies. Therefore, we updated this analysis using only recent studies. Case-control studies published between 2010 and 2012 were searched. In each study, non-smoking/ BQ non-chewing exposed (ever routine drinkers) and unexposed (never drinkers) subjects with (cases)/without (controls) OC were extracted and odds ratio (OR) calculated. Between-study heterogeneity was assessed with Cochran's Q. Publication bias was formally assessed with trim and fill method. Sensitivity analysis to inclusion criteria was made. The pooled OR was assessed with the fixed- and random-effect methods and corrected for publication bias. Seven of these studies met the inclusion criteria: they were not heterogeneous enough. Correction for publication bias was not necessary and provided only one missing study. The OR estimates were 0.70 (95% confidence interval -95CI, 0.51-0.98), 0.70 (95CI, 0.51-0.96), 0.75 (95CI, 0.54-1.03) with the three methods. Sensitivity analysis did not change the OR estimates considerably. This analysis corroborated the results of the previous analysis, confirming that drinking was inversely associated with OC in non-smoking, BQ non-chewing subjects
Centralità altre: il ruolo attuale e potenziale della conurbazione Baianese in Campania
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