Search results for " Fisica"

Holocene sea level change in Malta

2013

A multidisciplinary approach has been applied to study sea level changes along the coast of Malta using data collected from underwater archaeological remains. The elevation of archaeological markers have been compared with predicted sea level curves providing new bodies of evidence that outline the vertical tectonic behaviour of this region, allowing estimation of the relative sea level changes that occurred in this area of the Mediterranean since the Bronze Age. During the Roman Age, sea level was at −1.36 ± 0.1 m, while in the Midde Age it was at −0.56 ± 0.2 m, in agreement with previous estimations for the Mediterranean region. Data indicate that Malta was tectonically stable during the …

High-Reynolds-number turbulent cavity flow using the lattice Boltzmann method

2018

We present a boundary condition scheme for the lattice Boltzmann method that has significantly improved stability for modeling turbulent flows while maintaining excellent parallel scalability. Simulations of a three-dimensional lid-driven cavity flow are found to be stable up to the unprecedented Reynolds number $\mathrm{Re}=5\ifmmode\times\else\texttimes\fi{}{10}^{4}$ for this setup. Excellent agreement with energy balance equations, computational and experimental results are shown. We quantify rises in the production of turbulence and turbulent drag, and determine peak locations of turbulent production.

Talete di Mileto

2020

Alan Mathison Turing

2020

Electrochemical sensor for phosphate ions based on laser scriber reduced graphene oxide

2022

This preliminary work shows a new and innovative way to produce laser scribed reduced graphene oxide (LSGO) electrodes using different porous substrates (ranging from paper to plastic and fabric). The obtained electrodes were also tested as electrochemical sensors towards the detection of phosphate ions in water. To obtain the electrodes, a water suspension of GO was filtered on top of substrate (such as Whatman® filter paper) and a complete sensor was obtained from its reduction using a CO2 laser. The electrode is composed of working and counter electrodes made of LSGO and a reference electrode of a Ag/AgCl obtained by using a commercial AgCl conductive paste. Phosphate ions were detected …

Consolidation tests on the graffiti of the Steri’s prison with nanotechnological Ca(OH)2 dispersed in iso-propanol

2009

The combination of weathering and human activities often induce pyhisicochemical alteration on the surface of wall paintings. One of the most still largely used restoration techniques for these works of art, is based on the application of organic polymers. Due to their ability to stick detached and powdered pigments,these products provide an immediate consolidating effects. Unfortunately, both their aging and their pyhisicochemical incompatibility with the inorganic support can have serious consequences also causing further damage to the work of art. In this paper a new technological approach is presented based on the use of Ca(OH)2 nanoparticles dispersed in isopropanol. Some applicative t…

Gli affreschi provenienti dalle terme romane di Reggio Calabria. Dalla conoscenza al restauro

2023

The frescoes at marine thermae discovered in 1886 during the excavation of the small thermal complex dating between the 1th and 3rd century AD, and located on the seafront of Reggio Calabria, have been collected already collapsed. They are currently part of the permanent exhibition of the National Archaeological Museum of Reggio Calabria. This paper illustrates the results of the restoration intervention, carried out in the form of an educational activity in the context of an agreement signed between the MarRC and the University of Calabria, and the results of the diagnostic investigations carried out by the IPCF-CNR of Messina and the STEBICEF department of the University of Palermo.

Monitoring of erosion on two calanchi fronts – Northern Sicily (Italy)

2011

In the present research, two neighbouring calanchi fronts have been monitored by means of repeated readings on erosion pins, that were carried out between November 2006 and October 2008. During the monitoring period, a gauge station has been recording rainfalls, allowing us to compute the Rainfall-Runoff Erosivity Factor of the USLE model. The research highlighted: i) a general correspondence between rainfalls temporal trends and surface variation rhythms; ii) alternating erosion and deposition phases result in a retreat of the “calanchi” fronts.

Non-Hermiticity in Quantum Physics

2022

The field of non-Hermitian Physics has attracted great attention over the last 23years, both from the in the physical and mathematical communities. From the physical point of view, non-Hermiticity was regarded as a phenomenological tool to describe open quantum systems. Besides this, the rising interest in this field comes especially from the possible exploitation of exceptional points for quantum technologies, and from the exotic topology arising in periodic non-Hermitian systems, connected to the so called non-Hermitian skin effect. From the mathematical point of view, the range of possible topics to investigate has been wide open, as dropping an hypothesis of a theory makes the mathemati…

Oscillatory periodic pattern dynamics in hyperbolic reaction-advection-diffusion models

2022

In this work we consider a quite general class of two-species hyperbolic reaction-advection-diffusion system with the main aim of elucidating the role played by inertial effects in the dynamics of oscillatory periodic patterns. To this aim, first, we use linear stability analysis techniques to deduce the conditions under which wave (or oscillatory Turing) instability takes place. Then, we apply multiple-scale weakly nonlinear analysis to determine the equation which rules the spatiotemporal evolution of pattern amplitude close to criticality. This investigation leads to a cubic complex Ginzburg-Landau (CCGL) equation which, owing to the functional dependence of the coefficients here involve…