Papers by Vincenzo Palleschi
Materials
A macroscopic lithological study and physical (hardness, size, weight) investigations, coupled wi... more A macroscopic lithological study and physical (hardness, size, weight) investigations, coupled with laser-induced breakdown spectroscopy (LIBS) and X-ray fluorescence (XRF) chemical analyses of three egg- and one pear-shaped polished black stones, exposed in the library of the child home of the famous poet Giacomo Leopardi, at Recanati (Italy), were carried out. They are characterized by different sizes: two with the same weight of 16.9 kg and the two smaller ones of 5.6 kg each, corresponding to multiples of standard roman weights (drachma and scrupulum). These features and the presence of some grooves on the rock artefacts, probably for grappling hooks, suggest an original use as counterweight for the four black stones herein classified as amphibole-bearing serpentinites whose lithologies are far away from Recanati (probably coming from geological outcrops in Tuscany). The four serpentinite stones closely match with the so-called Lapis Aequipondus used in antiquity by the Romans a...
Heritage
Several samples coming from the recently discovered (February 2019) Late Bronze Age/Early Iron Ag... more Several samples coming from the recently discovered (February 2019) Late Bronze Age/Early Iron Age Chovdar necropolis in Azerbaijan were analysed using the X-ray fluorescence (XRF) technique. The analysis allowed a preliminary classification of the samples in eight groups based on their composition, obtained from the XRF spectra using the fundamental parameter method. A more detailed classification was then obtained using the graph clustering method.
Laser Induced Plasma Spectroscopy and Applications, 2002
Several samples of oriental colored pottery have been analyzed with micro-LIBS and micro-Raman te... more Several samples of oriental colored pottery have been analyzed with micro-LIBS and micro-Raman technique in order to get information about the elemental composition and molecular structure of the pigments used.
Journal de Physique Lettres, 1984
2014 Nous étudions par réflectométrie optique les propriétés de l'interface nématique-isotrope du... more 2014 Nous étudions par réflectométrie optique les propriétés de l'interface nématique-isotrope du cristal liquide 7CB. Nous mesurons l'épaisseur de l'interface, l'angle polaire du directeur à l'interface et son énergie d'ancrage. Abstract 2014 The properties of the nematic-isotropic interface of the nematic liquid crystal 7CB are studied by optical reflectometry. It is found that at the interface the director is tilted with respect to the vertical axis. Measurements are reported of the tilt angle 03B8t, of the thickness of the interface, and of the anchoring energy.
Journal of Cultural Heritage, 2015
In this paper, we report a multidisciplinary approach for the analytic study and the reconstructi... more In this paper, we report a multidisciplinary approach for the analytic study and the reconstruction of the ancient colour used for Roman sarcophagi. For this purpose, we adopted the three-dimensional (3D) digital technology and found it to be a valuable tool for the identification, documentation and reconstruction of the ancient colour. This technology proved to be an excellent link between archaeological knowledge and scientific analyses. Therefore, 3D digital technologies would effectively facilitate the exchange of information and collaboration between experts in various disciplines. This is extremely important in order to obtain demonstrable results in a new area of study, such as polychrome Roman sarcophagi (and the ancient polychromy and gilding on the marble). In this study, the digital 3D model of Ulpia Domnina's sarcophagus (National Roman Museum in Rome, inv. no. 125891) has been used to identify both the pigments and the techniques of application used, and to explore the potential of emerging technologies in the reconstruction and visualization of the ancient colour.
Construction and Building Materials, 2014
Abstract The aim of this research is to characterize the binder and aggregate fractions of sixtee... more Abstract The aim of this research is to characterize the binder and aggregate fractions of sixteen mortar samples from the bell tower of the St. Nicholas church at Pisa, using X-ray fluorescence (XRF), X-ray powder diffraction (XRPD), simultaneous thermogravimetric/differential scanning calorimetry analysis (TG/DSC), optical microscopy (OM) and electron microscopy equipped with a microanalysis system (SEM/EDS). The analytical procedure used for studying the mortars is based on TG/DSC analyses performed on the binder fractions, obtained by disaggregation of the mortar samples, and on micro-analytical data directly collected on the mortar binders combined with chemical, mineralogical (qualitative composition) and petrographic (modal composition) data measured on the bulk mortar samples. The collected data indicate that the examined samples are hydraulic lime mortars with natural river sands (average binder/aggregate ratio 1:1), except for two of them which are artificial pozzolanic mortars with cocciopesto . The most probable raw materials used to produce the mortars are the binding materials obtained by firing carbonate rocks locally available, cherty limestone and subordinately Mt. Pisano marble, and the Arno River sands or, more likely, natural admixtures of Arno and Serchio River sandy sediments.
NATO Science Series II: Mathematics, Physics and Chemistry, 2006
In recent years, several groups have proposed the use of Laser Induced Breakdown Spectroscopy as ... more In recent years, several groups have proposed the use of Laser Induced Breakdown Spectroscopy as a technique capable of giving information on the pigment compositions with minimal damage of the artwork. However, until the development of quantitative ...
Journal of Fusion Energy, 1994
In the spherical pinch scheme, the temperature of central D-T plasma must reach the value T = 2.5... more In the spherical pinch scheme, the temperature of central D-T plasma must reach the value T = 2.58 kev and the density of central D-T plasma is also not very high. The radiation energy and pressure cannot be neglected. Taking into account the influence of the radiation, the present study reveals the new scaling laws under the conditions of high temperature radiation hydrodynamics.
Clean Air, 2002
The Calibration-Free LIBS technique is a new standardless procedure for quantitative determinatio... more The Calibration-Free LIBS technique is a new standardless procedure for quantitative determination of metals in industrial smoke emissions, based on the Laser Induced Plasma Spectroscopy technique, which has been recently developed and patented by the Laser Spectroscopy Group at IFAM/CNR (Pisa). This procedure allows for fast and reliable quantitative analysis of industrial emissions, with typical sensitivities of one part per million (ppm) or better and precision of order 1% for all the elements in the sample. Major constituents, trace elements and impurities are all measured in the same run. These features make CF-LIBS an eligible method for on line continuous quantitative measurements. In fact, CF-LIBS is the only existing technique which gives precise quantitative results, comparable with laboratory chemical analysis, in real time and in situ.
Spectrochimica Acta Part B: Atomic Spectroscopy, 2009
The problem of finding new methods for the analysis of precious alloys has stimulated, in recent ... more The problem of finding new methods for the analysis of precious alloys has stimulated, in recent years, a 22 number of different proposals for improving the analytical procedures introducing more robust calibration 23 (or calibration-free) methods. In the paper "Accurate quantitative analysis of gold alloys using multi-pulse 24 laser-induced breakdown spectroscopy and a correlation-based calibration method" by G. Galbács, N.
Spectrochimica Acta Part B: Atomic Spectroscopy, 2005
Spectrochimica Acta Part B: Atomic Spectroscopy, 2010
In this work we compare the analytical results obtained by traditional calibration curves (CC) an... more In this work we compare the analytical results obtained by traditional calibration curves (CC) and multivariate Partial Least Squares (PLS) algorithm when applied to the LIBS spectra obtained from ten brass samples (nine standards of known composition and one 'unknown'). Both major (Cu and Zn) and trace (Sn, Pb, Fe) elements in the sample matrix were analyzed. After the analysis, the composition of the 'unknown' sample, measured by X-ray Fluorescence (XRF) technique, was revealed. The predicted concentrations of major elements obtained by rapid PLS algorithms are in very good agreement with the nominal concentrations, as well as with those obtained by the more time-consuming CC approach. A discussion about the possible effects leading to discrepancies of the results is reported. The results of this study open encouraging perspectives towards the development of cheap LIBS instrumentation which would be capable, despite the limitations of the experimental apparatus, to perform fast and precise quantitative analysis on complex samples.
Spectrochimica Acta Part B: Atomic Spectroscopy, 2008
The Stark broadening of hydrogen Balmer α line is often measured in Laser-Induced Breakdown Spect... more The Stark broadening of hydrogen Balmer α line is often measured in Laser-Induced Breakdown Spectroscopy (LIBS) to evaluate the electron number density of the plasma. When measurements are carried out in air, hydrogen atoms are supposedly supplied by the atmosphere. This hypothesis casts some doubts on the validity of hydrogen as an indicator of the conditions in the inner part of the plasma. In this experiment, we acquired spectrally resolved images of a Laser-Induced Breakdown Spectroscopy plasma generated in air on an aluminum target by irradiation with the Nd:YAG fundamental emission. The evolution of the plasma was studied by acquiring images at several delay times. In particular, we imaged the spatial distribution of plasma emitters along the direction orthogonal to the target surface. The spatial distribution of hydrogen emission was compared to the one of the species ablated from the sample. Moreover, electron density and temperature were evaluated in the time-and space-resolved spectra extracted from the images, obtaining thus a picture of the propagation and internal structure of the plasma. The fluid dynamics implications of the plasma expansion were discussed. The z-resolved characterization was compared with the picture of the plasma obtained by processing space-integrated spectra.
Physics Letters A, 1988
The effect of changing noise statistics on first passage times (FPT) distribution 1s studied by m... more The effect of changing noise statistics on first passage times (FPT) distribution 1s studied by means of d&al simulation m a simple dynamical system. The first experimental determination of the FPT distribution is given in three different situations. involving "shot", dichotomic and gaussian noise statistics. In the first two cases, the experimental results are compared with an exact theory recently developed by Lindenberg et al., whilst the results obtained with gaussian noise statistics are compared with the theoretical prevision of Doering et al. A remarkably good agreement between theory and experiment is found. Important effects on the FPT distribution are found by increasing the correlation time 5,. of the noise.
Physical Review Letters, 1985
The anchoring energy at the interface between the nematic liquid crystal 4-n-pentyl-4'cyanobiphen... more The anchoring energy at the interface between the nematic liquid crystal 4-n-pentyl-4'cyanobiphenyl (5CB) and a glass plate treated by oblique evaporation of SiO is studied by measurement of the torque exerted on the surface by the nematic subject to an orienting magnetic field.
Physical Review A, 1992
In the process of shock-wave reflection at a surface, a transition from regular to Mach reflectio... more In the process of shock-wave reflection at a surface, a transition from regular to Mach reflection occurs when the angle of incidence exceeds a certain critical value. This critical angle, which depends on the Mach number of the propagating shock wave and y, the adiabatic exponent of the medium, is well approximated in many experimental situations by its value in the limit of infinite Mach number. Unfortunately, the often-cited critical angle for infinitely strong shock waves is incorrect. We present a short analysis of the process of shock-wave reflection and discuss the condition for infinitely strong shock waves. The exact and approximate solutions for the dependence of the critical angle on the adiabatic exponent of the medium are also compared with the above-mentioned formula.
Microchimica Acta, 2005
Twelve archaeological copper objects from the burial site of ''Fontino'' cave, near Grosseto, (ar... more Twelve archaeological copper objects from the burial site of ''Fontino'' cave, near Grosseto, (around 2500-2000 B.C.) were analysed using laserinduced breakdown spectroscopy. Qualitative results and a preliminary study of the samples' composition are reported and used to make a quantitative estimate; based on these results, the samples were classified using principal components statistical analysis. The perspectives of using laser-induced breakdown spectroscopy for archaeometric analysis are also discussed.
Liquid Crystals, 1987
Abstract The twist elastic constant of the nematic liquid crystal 4-n-octyl-4′-cyano-biphenyl (8C... more Abstract The twist elastic constant of the nematic liquid crystal 4-n-octyl-4′-cyano-biphenyl (8CB) and the azimuthal anchoring energy at the SiO-nematic interface have been measured by using the torsion pendulum technique. The twist elastic constant of 8CB is found to be systematically larger than that measured by the Freedericksz transition technique. The azimuthal anchoring energy is found to decrease rapidly as the nematic-isotropic transition temperature is approached. This behaviour is analogous to that already reported by us for the nematogen 5CB and can be interpreted by extending the Berreman model of the anchoring energy at a grooved interface.
Laser and Particle Beams, 1990
The Spherical Pinch (SP) is a particular variation of the inertial confinement scheme, in that th... more The Spherical Pinch (SP) is a particular variation of the inertial confinement scheme, in that the two criteria required for plasma fusion breakeven condition, namely the attainment of a sufficiently high plasma temperature and of a product nτ in excess of 1014 cm-3. sec, are satisfied through two separate mechanisms. The advantage of this approach is that the scaling laws for breakeven are easier to satisfy than in the classical inertial confinement scheme. The first derivation of the scaling laws for spherical pinch experiments (Panarella & Savic 1983; Panarella 1987) was obtained under the simplifying assumption of an infinitely small central plasma in a sphere reaching the required high temperature for fusion, and of an undefined time delay Δt between the creation of such central plasma and the launching of the peripheral shock waves used to contain the central plasma. The analysis reported in this paper removes these assumptions and derives scaling laws which are generalized in...
Journal of Statistical Physics, 1988
Two models for the Freedericksz transition in a fluctuating magnetic field are considered: one is... more Two models for the Freedericksz transition in a fluctuating magnetic field are considered: one is based on a dichotomic and the other on a nonlinear Gaussian noise. Both noises are characterized by a finite correlation time ~. It is shown that the linear response assumption leading to the "best Fokker-Planck approximation" in the dichotomic and nonlinear Gaussian cases can be trusted only up to the order z ~ and t ~ respectively. The role of the corrections to the linear response approximation is discussed and it is shown how to replace the non-Fokker-Planck terms stemming from these corrections with equivalent terms of standard type. This technique is shown to produce perfect agreement with the exact analytical results (dichotomic noise) and to satisfactorily fit the results of analog simulation (nonlinear Gaussian noise).
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Papers by Vincenzo Palleschi
Tali indagini hanno consentito di contestualizzare e definire le vicende e le caratteristiche di questo insediamento tra il medioevo e la prima età moderna. Ciò ha permesso non solo di sfatare alcune ipotesi sulle origini gote della fortificazione - basate su una lettura semplicistica dei toponimi - ma di caratterizzare meglio la storia e la cultura materiale del castello e del suo territorio, ubicati in una zona di confine tra poteri e istituzioni diverse (Comuni di Genova e di Pontremoli, signori Malaspina e Fieschi).
Non ultimo lo scavo ha portato in luce i primi resti di una zecca clandestina, cui si deve probabilmente anche la distruzione della rocca del castello nel 1524, fatto prima non noto da altre fonti. Nel contributo sono presentati anche i primi dati dello studio archeologico e archeometrico (X-ray Fluorescence Spectroscopy e Laser-Induced Breakdown Spectroscopy) dei materiali relativi a tale attività produttiva, in base al quale è stato possibile caratterizzare le tecniche impiegate nell’officina monetaria non autorizzata e determinare il tipo di monete false ivi probabilmente realizzate.
From 2010 to 2016 a series of historical and archaeological research focused on the castle of Godano and its territory, located on the mountains in the heart of the Val di Vara, in the hinterland of La Spezia.
These investigations have made it to contextualize and define the events and characteristics of this settlement between the Middle Ages and the Early Modern Age. This allowed not only to dispel some hypotheses about the Gothic origins of the fortification - based on a simplistic reading of the place names - but to better characterize the history and material culture of the castle and its territory, located in a border area between different powers and institutions (Municipalities of Genoa and Pontremoli, Lords Malaspina and Fieschi).
Last but not least, the excavation brought to light the first remains of a clandestine mint, which probably was also the cause of the castle destruction in 1524, a fact not previously known from other sources.
The paper also presents the first data of the archaeological and archeometric study (X-ray Fluorescence Spectroscopy and Laser-Induced Breakdown Spectroscopy) of the materials related to this production activity, on the basis of which it was possible to characterize the techniques used in the unauthorized monetary workshop and determine the type of counterfeit coins probably made there.