102,019 research outputs found
Scritti in onore di Pietro Ciarlo
No full textScritti in onore del professore Pietro Ciarlo. Si tratta di tre tomi contenenti oltre duemila pagine e decine di contributi sui principali temi di ricerca del professore Ciarlo
La Costituzione e l'identità degli italiani
No full textIl recente dibattito politico e istituzionale, ipotizzando ampie revisioni costituzionali, pone l'esigenza di sapere come nascono le costituzioni, in particolare come è nata la nostra Costituzione. Il saggio analizza la nascita della Costituzione italiana, con particolare riferimento alle relazioni nelle Sottocomissioni, al fine di mettere a fuoco le modalità secondo cui le diverse forze politiche si avvicinavano alle tematiche e ne percepivano gli esiti. Il risultato dell'analisi è la dimostrazione di come il legame tra Costituzione e Nazione sia un legame necessario, nel senso che una Costituzione capace di radicarsi effettivamente non può fare a meno di "interpretare" la Nazione
La potestà legislativa regionale
No full textIl saggio mette in discussione l'impianto del titolo V della Costituzione per quanto attiene gli assetti competenziali della funzione legislativa e si ipotizza la necessità di una ulteriore revisione costituzionale
Giudici e giurisdizioni nella giurisprudenza della Corte costituzionale : atti del Convegno di Cagliari, 24-25 maggio 1996
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A model-system of Fickian yet non-Gaussian diffusion: Light patterns in place of complex matter
No full textFickian yet non-Gaussian Diffusion (FnGD), widely observed for colloidal particles in a variety of complex and biological fluids, emerges as a most intriguing open issue in Soft Matter. To fully monitor FnGD and advance its understanding, recording many trajectories over a large time range is crucial, which makes experiments challenging. Here we exploit a recently introduced experimental model of finely tunable FnGD: a quasi-2d system of Brownian beads in water moving in a heterogeneous energy landscape generated by a static and spatially random optical force field (speckle pattern). By performing experiments at different optical power, we succeed in monitoring the evolution as well as the precursors of FnGD. Fickian scaling of the mean square displacement is always attained after a subdiffusive regime while the displacement distributions keep on being non-Gaussian, which allows for measuring a characteristic length- and time-scale for the onset of FnGD, ξf and tf. We find that ξf stays constant, whereas tf grows as the inverse of the long-time diffusion coefficient tf ∝ D-1 for increasing the optical power. Deviations from the standard Gaussian shape of the displacement distribution are neatly characterized on a broad range of times, focusing on the excess probability at small displacements and on the decay-length of the distinctive exponential tails. Such deviations are fully built in the subdiffusive regime and, at the FnGD onset, grow with the optical power. As time goes on, the small-displacement probability narrows and the exponential tails progressively break up, with a tendency to recover the Gaussian behaviour. Overall, both subdiffusion and FnGD become more marked and persistent on increasing the optical power, suggesting a strict relation between these two regimes. As clearly demonstrated by our results, the adopted model-system represents a privileged stage for in-depth study of FnGD and opens the way to unveil the nature of this phenomenon through finely tuned and well-controlled experiments
Rapid Fickian Yet Non-Gaussian Diffusion after Subdiffusion
No full textThe recently discovered Fickian yet non-Gaussian diffusion (FnGD) is here finely tuned and investigated over a wide range of probabilities and timescales using a quasi-2D suspension of colloidal beads under the action of a static and spatially random optical force field. This experimental model allows one to demonstrate that a "rapid"FnGD regime with a diffusivity close to that of free suspension can originate from earlier subdiffusion. We show that these two regimes are strictly tangled: As subdiffusion deepens upon increasing the optical force, deviations from Gaussianity in the FnGD regime become larger and more persistent in time. In addition, the distinctive exponential tails of FnGD are quickly built up in the subdiffusive regime. Our results shed new light on previous experimental observations and suggest that FnGD may generally be a memory effect of earlier subdiffusive processes
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