µ-LIBS-SCAN FOR CULTURAL HERITAGE GEOMATERIALS

This article reports the experimental results obtained with the Micro-Laser-Induced-Breakdown Spectroscopy Scanning (µ-LIBS-Scan) technique and the optimization parameters obtained in the analysis of geological materials of interest for cultural heritage. The main improvements regard the use of a microscope with at least a 10X objective and a software-operated sample holder. In particular, the control software and a specific routine for the data processing were developed. An optimized routine using MATLAB® was developed for the LIBS technique applied to Cultural Heritage geomaterials. In particular, the work focused on the analysis of highly inhomogeneous materials, such as mortars and archaeological pottery with the aim of overcoming the measurement uncertainties. The followed strategy aimed to realize the elementary maps of representative portions of materials. Moreover, the use of different statistical methods for the data processing allowed overcoming the intrinsic drawbacks. The main results of this work were the capability to obtain virtual elemental cross-section of the analyzed samples and the possibility to carry out in a fast way quantitative information with proper precision and accuracy. There are still several aspects to be improved and carried out. For instance, a possible improvement could be the realization of a more compact and lightweight instrument, with a tunable laser and a 20X objective. Finally, the analysis code in a multiplatform software able to work on IOs, Android and Windows devices would be compiled

Studi di Archeologia Preistorica e Archeometria sulle ceramiche del sito Neolitico di Settefonti, Prata d'Ansidonia (AQ)

Riassunto: Il sito neolitico di Settefonti, prata d'Ansidonia (AQ), risulta inquadrabile negli aspetti avanzati della cultura abruzzese di Ripoli. Le ceramche precedentemente indagate con metodi classici sono state sottoposte sperimentalmente ad indagine LIBS (laser Breakdown spectroscopy) e Raman e indagate microscopicamente. I risultati ottenuti sono stati inseriti in un database e trattati con metodi di KDD (Knowledge Discovery in Database), Data mining e di statistica multivariata, per l'estrazione di nuovi dati significativi. Infine, le informazioni ottenute sono state messe insieme a quelle bibliograficamente disponibili per poter generare nuove conoscenze e confermare alcune di quelle già acquisite. Abstract: The Neolithic site of Settefonti, prata of Ansidonia (AQ), is framed in the advanced aspects of Abruzzese culture of Ripoli. Pottery previously investigated with classical methods have been subjected to experimental investigation with LIBS (Laser Breakdown Spectroscopy) and Raman spectroscopy and investigated microscopically. The results were compiled into a database and treated with methods of KDD (Knowledge Discovery in Databases), Data mining and multivariate statistical analysis for the extraction of significant new data. Finally, the information obtained were put together with those Bibliographically available in order to generate new knowledge and to confirm some of those already acquired

The best and brightest. Positive selection and brain drain in Italian internal migrations

During the last decade, the internal migration flows from Southern Italy to the central and northern regions of the country have become more significant. Unlike the past, these flows are characterised by a strong incidence of qualified workers with secondary or tertiary education. Also, even in this restricted set of workers, the most talented (the best and brightest) individuals are the ones showing the highest propensity to migrate. This paper applies a binary segmentation technique to a database of 10701 individuals graduated at Palermo and Naples universities between 2004 and 2007 in order to get groups with mostly differentiated attitudes to migrate. The evidence shows that variables driving segmentation (i.e. the most relevant variables in explaining the propensity to migrate) are the subject of study (who graduates in engineering and scientific disciplines is more mobile), the graduation mark (who gets higher marks is more likely to migrate) and the family social and cultural background. This strong positive self selection of migrants enhances the ability of internal migration to trigger considerable harmful effects on origin regions and jeopardises Southern Italy to suffer from heavy losses of human capital.internal migration; positive self selection of migrants

Archaeometric study of mortars from the Pisa's Cathedral Square (Italy)

The present work is focused on the study of forty-two mortars used in the construction of both Roman buildings, old Pisa’s Cathedral and Modern structures in the Miracles Square (Italy). This area, included since 1987 in the World Heritage List of the UNESCO, is famous for the presence of an important historical complex built in the Middle Ages (the Cathedral, the Baptistery, the Leaning Tower and the Monumental Cemetery). The archaeologists discovered some structures related to more ancient periods: the Roman domus (1st–5th centuries) and the older cathedral with its foundations and crypt (10th century). Based on OM, XRF, XRPD, TG-DSC and SEM-EDS analyses, the main characteristics of binder and aggregate of the mortars have been determined, and some raw materials used for the production of the analysed binding materials have been identified

The Source Materials for Lime Production in the Monte Pisano Area (NW Tuscany, Italy)

In the Monte Pisano area (north-western Tuscany, Italy) several limestones outcrop and some of them are carbonate-rich rocks that were used for air-hardening lime or hydraulic lime production. Since Roman times, carbonate rocks outcropping in the Monte Pisano area have been used for that purpose. Monte Pisano is a mountainous system of modest size that is part of the Tuscan Apennine, located in the north-western part of Tuscany, and it separates the two cities of Pisa and Lucca. As an obvious consequence of the presence of good source rocks useful for the production of lime, in the surroundings of Monte Pisano there was a great use of carbonate rocks for the production of aerial lime and hydraulic lime. In fact, the monumental buildings in the Middle Ages were built making extensive use of binding materials obtained by firing rocks belonging to formations of the Tuscan metamorphic sequence: the Monte Pisano marble and the Selciferous Limestone. Several famous monuments in Pisa’s Miracle Square and in Lucca’s historical centre were built by using air-hardening lime and hydraulic lime obtained by firing these rocks. The aim of this work is to characterize samples from the Monte Pisano quarries, where the aforementioned carbonate-rich stones were quarried to produce airhardening lime and hydraulic lime, by mean of chemical, mineralogical and petrographic studies and by determining their physical and mechanical properties. These same properties will also be determined on handmade mortar samples made up of self-produced binders and normalised sand to evaluate the best uses, and the optimum time and temperature of stone firing

Finding recurrent copy number alterations preserving within-sample homogeneity

Abstract Motivation: Copy number alterations (CNAs) represent an important component of genetic variation and play a significant role in many human diseases. Development of array comparative genomic hybridization (aCGH) technology has made it possible to identify CNAs. Identification of recurrent CNAs represents the first fundamental step to provide a list of genomic regions which form the basis for further biological investigations. The main problem in recurrent CNAs discovery is related to the need to distinguish between functional changes and random events without pathological relevance. Within-sample homogeneity represents a common feature of copy number profile in cancer, so it can be used as additional source of information to increase the accuracy of the results. Although several algorithms aimed at the identification of recurrent CNAs have been proposed, no attempt of a comprehensive comparison of different approaches has yet been published. Results: We propose a new approach, called Genomic Analysis of Important Alterations (GAIA), to find recurrent CNAs where a statistical hypothesis framework is extended to take into account within-sample homogeneity. Statistical significance and within-sample homogeneity are combined into an iterative procedure to extract the regions that likely are involved in functional changes. Results show that GAIA represents a valid alternative to other proposed approaches. In addition, we perform an accurate comparison by using two real aCGH datasets and a carefully planned simulation study. Availability: GAIA has been implemented as R/Bioconductor package. It can be downloaded from the following page http://bioinformatics.biogem.it/download/gaia Contact: [email protected]; [email protected] Supplementary Information: Supplementary data are available at Bioinformatics online

A fast and user-friendly software for quantitative chemical analysis through XRF

X-ray fluorescence (XRF) spectroscopy is a technique widely used for the study and conservation of cultural heritage materials. A Microsoft Excel spreadsheet to determine major (Na, Mg, Al, Si, K, Ca, Fe) and minor (P, Ti, Mn) elements in rocks and other materials by XRF is presented. The code is based on the analytical method proposed a few decades ago by Franzini et al., which is based on the algorithm: Ci = Ii ⋅ ΣKi,j Cj, where Ci is the concentration (expressed as wt%) of the chemical element “i”, Ii is the intensity of the characteristic line, Cj is the concentration of interfering elements, and Ki,j are experimental coefficients that account for the matrix effects (absorption and enhancement). Ki,j have the dimension of mass absorption coefficients and they may be calculated from a set of N reference samples using multivariate regression methods. The algorithm proposed by these authors is particularly suitable for processing samples prepared in the form of pressed powders. The Microsoft Excel spreadsheet allows you to: a) choose a set of reference samples (international or interlaboratory standards); b) evaluate the expected matrix effects on the basis of the XRF total mass absorption coefficients; c) calculate the correction coefficients Ki,j through multivariable regression; d) calculate the analytical accuracy and graphically represent the results; e) choose five samples (monitors) for the correction of instrumental drift. Based on these steps, the software allows you to: i) enter the analytical intensities of major and minor elements measured on the monitors and on unknown samples (the loss on ignition must be determined separately); ii) calculate the correction of the instrumental drift; iii) determine the concentration of elements and express them as wt%

LIBS analysis to define the alteration processes on the surface of ancient stones: the case study of Romanesque medieval monuments (Italy)

Weathering and bio-deterioration processes frequently affect the chromatic aspect of the stones used in the monuments. The surface alteration involves both physical modifications (e.g., increase of porosity) and chemical-mineralogical transformations of the rock, with formation of new secondary phases and deposition of the organic substances and inorganic solid phases (amorphous or crystalline particles). This research aims to study the surface films of stones (i.e., basalts, pyroclastic rocks, limestone, marbles) used in some historical-cultural relevant Sardinian Romanesque churches (XI-XIV sec.) using LIBS and XRD analysis. These latter, together with petrographic analysis by polarized light microscopy in thin section, are useful to reconstruct the micro-stratigraphic aspects of different film levels. The results highlight three different cases: i) chromatic alteration of the stone surface, ii) chemical-mineralogical alteration of stone with formation of coatings similar to the stone substrate, iii) chemical-mineralogical processes with the formation on the surface of secondary phases not related to the substrate, with the presence of Ca-oxalate (i.e. weddelite, whevellite). The presence of the Ca-oxalates, as noted in literature, is a testimony of application of organic substances on the surfaces themselves, with aesthetic purposes, to standardize or improve the color of the stone, or conservative, to limit the negative effects of weathering

Panchina Calcarenite: A Building Material from Tuscany Coast

The “Panchina” calcarenite widely outcrops along the Tuscan coastline from Livorno to Baratti (western Tuscany). It is a stone, highly porous with medium sized grains rich in organogenic carbonate fragments, mainly consisting in shells of bivalves, gastropods, and echinoderms visible to the naked eye or by using a lens. In the framework of the ongoing research on the building stones and mortars used throughout the Middle Ages in and surrounding the Pisa’s city (western Tuscany), this study focuses on the determination of the main physical and mechanical properties of “Panchina” stone samples from Livorno coast (Tuscany, Italy). The “Panchina” stone is no longer quarried and data is collected from unweathered rocks sampled from currently accessible outcrops. The data collected on twenty-eightsamples from six outcrops of the Tuscan coast showed that the analysed specimens are made up of abundant calcite, subordinate quartz and feldspars, and traces of phyllosilicates. The analysed samples are characterized by medium-high porosity, highly variable water absorption by both capillarity and total immersion at atmospheric pressure, low uniaxial compressive resistance. Thanks to the good physical and mechanical properties that characterize the stone, the “Panchina” calcarenite is easy to work and extensively used in the necropolis of the Gulf of Baratti since Etruscan times and, in medieval times, in various public and religious buildings in the city of Pisa