Search results for "Beni culturali"

NONEQUILIBRIUM PHENOMENA AND METASTABILITY IN MESOSCOPIC AND QUANTUM SYSTEMS

2020

Here we summarize some relevant results related to nonequilibrium phenomena in mesoscopic and quantum systems. A common phenomenon in the dynamics of out-of-equilibrium systems is the metastability, and the problem of the lifetime of metastable states involves fundamental aspects of nonequilibrium statistical mechanics. Metastability (see Fig. 1) is a signature of a first order phase transition, often characterized by a long-living metastable state. In particular, the stability of a metastable state can be enhanced by Gaussian and non-Gaussian noise sources. This counterintuitive effect has been found in different physical areas, ranging from spintronics, aggregation kinetics of Brownian pa…

Dielectric properties of myoglobin at 10 GHz by microwave cavity perturbation measurements

2010

We report on the temperature dependence, at microwave (mw) frequency, of the imaginary part of the dielectric constant (En) in myoglobin powder samples with different hydration levels (h). The measurements have been performed by the cavity perturbation technique, in the range of temperature 80-345 K. The sample is located inside a glass capillary along the axis of a cylindrical copper cavity, resonating in the TE011 mode at 9.6 GHz, where the mw electric field has a node. By measuring the variation of the quality factor of the resonant cavity, one can extract the imaginary part of the dielectric constant. At temperatures higher than 230 K we observe an evident increase of the dielectric los…

Characterisation of component pigments in a mixture

2011

This work is part of Raman spectra database constitution of pigments and materials of Cultural Heritage interest for polychrome artworks characterization. The colours of paintings are often obtained mixing pigments of palette artist’s. The attribution of a work of art to an author and the individuation of fakes are related to the identification of used pigments and also to the detection of mixture constituents. The main research objective is the extension of PH3DRA laboratory database with information useful to detect not only each single pigment but also quantitative data regarding its relative ratio in the examined mixture. The availability of spectra as revealed represents the primary li…

Archaeometric characterization and 3D survey: new perspectives for monitoring and valorization of Morgantina silver Treasure (Sicily)

2015

The Morgantina silver Treasure belonging to the collections of the Archaeological Museum of Aidone (Sicily) were involved in a 3D survey and diagnostics campaign for monitoring over time of the finds, in anticipation of their temporary transfer to the Metropolitan Museum of Art in New York, for a period of four years. According to a multidisciplinary approach, it has been developed a scientific and methodological protocol based on non-invasive techniques to achieve a complete and integrated knowledge of the precious items, of their conservation state and increasing their valorisation. All acquired data, i.e. 3D models, UV fluorescence and X-Ray images and chemical information, will be made …

Mosaici Artificiali

2005

La città e i musei. Indirizzi per la riqualificazione urbana a Palermo

2009

Multiphoton Absorption of Myoglobin Nitric-Oxide complex: Relaxation by D-NEMD of a Stationary State

2012

ABSTRACT: The photodissociation and geminate recombination of nitric oxide in myoglobin, under continuous illumination, is modeled computationally. The relaxation of the photon energy into the protein matrix is also considered in a single simulation scheme that mimics a complete experimental setup. The dynamic approach to non-equilibrium molecular dynamics is used, starting from a steady state, to compute its relaxation to equilibrium. Simulations are conducted for the native form of sperm whale myoglobin and for two other mutants, V68W and L29F, illustrating a fair diversity of spatial and temporal geminate recombination processes. Energy flow to the heme and immediate protein environment …

Proteins in Amorphous Saccharides: Structural and Dynamical Insights on Bioprotection

2011

We report on experimental and simulative insights on saccharide-based bioprotection, obtained through the study of proteins embedded in amorphous saccharide matrices. The data presented come from a complementary set of techniques (FTIR, MD simulations and SAXS), which provides a description of the bioprotection mechanism from the atomistic to the macroscopic level. The results concur to draw a picture in which bioprotection by saccharides can be explained in terms of a tight anchorage of the protein surface to a stiff matrix, via extended hydrogen-bond networks, whose properties are defined by all its components, and are strongly dependent on the water content. In particular, they show how …

A Classification of Palermo Historical Centre Heritage based on the local seismic response

2009

A very high density of monumental heritage falls within Palermo Historical Centre, an area characterized by high variability of near surface geology and soil physical-mechanical properties on a very short distance scale, even few meters. So, neighboring heritage elements can have a totally different hazard exposition. Within a project regarding Palermo area (Project 7T7, Cluster 29, funded by Ministero dell’Università e della Ricerca, Italy) a very reliable high density stratigraphic-geotechnical dataset has been assembled, by means of a careful data reviewing process. This dataset has been stored in a Geographic Information System (GIS) application, named City-GIS, having all GIS functions…

Setting the basis for the study of intermediate conformers of human neuroserpin by Double Electron Electron Resonance

2012

The Double Electron Electron Resonance (DEER) is an innovative technique that allows to measure the distance distribution between two spin labels within a range of 2-8 nm. This technique does not require crystalline samples, thus it is possible to determine the position of two different spin labelled domains of intrinsically flexible macromolecular systems. Our idea is to determinate the structural details of the intermediate conformers of human neuroserpin (hNS) by DEER. hNS is a protein that in the native state is folded in a metastable conformation. In particular conditions, hNS can either adopt a more stable conformation with the reactive centre loop (RCL) inserted into a β-sheet (laten…