Wind-wave characteristics and extremes along the Emilia-Romagna coast

This study examines the wind-wave characteristics along the Emilia-Romagna coasts (northern Adriatic Sea, Italy) with a 10-year wave simulation for the period 2010-2019 performed with the high-resolution unstructured-grid WAVEWATCH III (WW3) coastal wave model. The wave parameters (significant wave height, mean and peak wave period, and wave direction) were validated with the in situ measurements at a coastal station, Cesenatico. In the coastal belt, the annual mean wave heights varied from 0.2-0.4 m, and the seasonal mean was highest for the winter period (> 0.4 m). The Emilia-Romagna coastal belt was characterized by wave and spectra seasonal signals with two dominant frequencies of the order of 10 and 5-6 s for autumn and winter and 7-9 and 4 s for spring and summer. The wavelet power spectra of significant wave height for 10 years show considerable variability, having monthly and seasonal periods. This validated and calibrated data set enabled us to study the probability distributions of the significant wave height along the coasts and define a hazard index based on a fitted Weibull probability distribution function

Ground states for a class of deterministic spin models with glassy behaviour

We consider the deterministic model with glassy behaviour, recently introduced by Marinari, Parisi and Ritort, with \ha\ $H=\sum_{i,j=1}^N J_{i,j}\sigma_i\sigma_j$, where $J$ is the discrete sine Fourier transform. The ground state found by these authors for $N$ odd and $2N+1$ prime is shown to become asymptotically dege\-ne\-ra\-te when $2N+1$ is a product of odd primes, and to disappear for $N$ even. This last result is based on the explicit construction of a set of eigenvectors for $J$, obtained through its formal identity with the imaginary part of the propagator of the quantized unit symplectic matrix over the $2$-torus.Comment: 15 pages, plain LaTe

Deterministic spin models with a glassy phase transition

We consider the infinite-range deterministic spin models with Hamiltonian $H=\sum_{i,j=1}^N J_{i,j}\sigma_i\sigma_j$, where $J$ is the quantization of a chaotic map of the torus. The mean field (TAP) equations are derived by summing the high temperature expansion. They predict a glassy phase transition at the critical temperature $T\sim 0.8$.Comment: 8 pages, no figures, RevTex forma

Reports on Geodesy

The Calabria region has been characterised for a lot of geodynamic phenomena and a complex Geoid. This zone is a very interesting zone for geophysical and geodetic studies. In 1993 has been effectuated a GPS survey. This work shows the quality of the results and a comparison between GPS Geoid and the Italian Gravimetric Geoid performed by Politecnico di Milano.Published1-3753.3. Geodinamica e struttura dell'interno della Terraope

Resonant harmonic oscillators and eigenvalue multiplicity

Explicit formulas are worked out for the eigenvalue multiplicity of a systemof $n$ independent quantum harmonic oscillators in the general case of 1\leq s\leqn-1 resonance relations among the frequencies\om_1,\ldots,\om_n. As a particular case we prove that, even though the quantumnumbers are always less than the degrees of freedom, the \ev s are in generalintrinsically degenerate only in the completely resonant case$s=n-1$

Absence of glassy behaviour in the deterministic spherical and XY models.

We consider the infinite-range spin models with Hamiltonian H = ni,j=1 Ji,j i j , where J is the quantization of a map of the torus. Although deterministic, these models are known to exhibit glassy behaviour. We show, through explicit computation of the Gibbs free energy, that unlike the random case this behaviour disappears in the corresponding spherical and continuous XY models. The only minimum of the Gibbs free energy is indeed the trivial one, even though the ground state is highly degenerate

Le conoscenze attuali dei movimenti del suolo nell'area italiana. Proposte per un coordinamento delle ricerche in atto in considerazione delle nuove strumentazioni e tecniche operative.

The significance of monitoring crustal deformations related to variousgeophysical phenomena is pointed out; both classical geodetic methodsand modern spatial techniques are reviewed. The analysis of thestate of the art in Italy is carried out with particular concern to surveysin seismic and volcanic areas

Ground States for a Class of Deterministic Spin Models With Glassy Behaviour

We consider the deterministic model with glassy behaviour, recently introduced by Marinari, Parisi and Ritort, with Hamiltonian H = P N i;j=1 J i;j oe i oe j , where J is the discrete sine Fourier transform. The ground state found by these authors for N odd and 2N + 1 prime is shown to become asymptotically degenerate when 2N + 1 is a product of odd primes, and to disappear for N even. This last result is based on the explicit construction of a set of eigenvectors for J , obtained through its formal identity with the imaginary part of the propagator of the quantized unit symplectic matrix over the 2-torus. 1 Introduction It has been recently established [1],[2],[3] that a wide class of deterministic, infiniterange deterministic Ising spin models does actually exhibit the glassy behaviour of the random coupling case, with the important difference, however, that the mean field equations of the model, derived by Parisi and Potters[4](hereafter the PP equations), are not the standard TAP..

Il nuovo quaderno di Arpae sull’erosione costiera

Il volume “Stato del litorale emiliano-romagnolo al 2012. Erosione e interventi di difesa”, in uscita per la collana “I quaderni di Arpae”, presenta i risultati del quinto studio sull’evoluzione del fenomeno e dei processi che ne influenzano l’andamento. L’esito del monitoraggio conferma l’efficacia del ripascimento

Utilizzo del modello XBeach come strumento di analisi dell’erosione costiera in seguito a eventi di mareggiata

Il presente studio analizza il fenomeno dell’erosione costiera mediante l’utilizzo della modellazione numerica. In particolare viene presentata un’analisi dell’evoluzione del profilo di spiaggia in caso di mareggiate intense, con quantificazione del fenomeno di erosione della spiaggia. Sull’area di indagine, un tratto di costa emiliano-romagnola compreso tra Cesenatico e Cervia, sono stati condotti rilievi topo-batimetrici e sedimentologici, prima e dopo un evento di mareggiata intenso. Mediante l’utilizzo del software di modellazione XBeach (Roelvink et al., 2009), è stato simulato il comportamento della spiaggia soggetta a tale evento. Contestualmente, è stata effettuata l’analisi di sensitività del modello in relazione alla variazione dei suoi parametri di input. Tale analisi ha reso possibile una successiva calibrazione del modello in riferimento all’area di studio. I risultati evidenziano l’importanza di una buona calibrazione dei parametri facua, facAs e facSk, legati alla forma dell’onda e del parametro fw legato all’attrito al fondo