Diagnostic investigation to support the restoration of the polychrome terracotta relief "Madonna and Child" in Piove di Sacco (Padova, Italy)

Restoration procedures of the polychrome terracotta relief “Madonna and Child” with papier-mâché inserts from a shrine in Piove di Sacco (Padova, orthern Italy) were assisted by analytical investigations, contributing to identify the chemical composition of the pigments, fractures and internal damages, additions and retouchings, which strongly modified the original manufact. In particular, energy dispersive X-ray fluorescence, Raman spectroscopy and FT-IR spectroscopy were employed to determine the chemical composition of pigments on the original layer and on the overpaintings and to understand the artistic techniques. Moreover, X-ray planar radiography and computed tomography were used to understand the structure and its conservative state. Finally, the relief, stylistically dated to the 17th century, turned out to be a Renaissance terracotta artefact. The polychrome blue traces of lapis lazuli highlighted a valuable artwork and the resemblance with the style of Donatello and his apprentices have recently led to further studies, as an initial part of a larger research on polychrome terracotta in Veneto

The restoration of the Colosso di Barletta: EDXRF analysis

The Colosso di Barletta is an imposing outdoor bronze statue, dating back the V century, located near the Basilica of “Santo Sepolcro” in Barletta (Apulia, Southern Italy). The monument underwent a structural restoration in 1981, during which the Central Institute of Restoration in Rome performed cleaning treatments and consolidation of the patinas. Currently, the Laboratory of Archaeometry of the University of Salento is carrying on a campaign of non-destructive and in situ measurements by using energy dispersion X-ray fluorescence (EDXRF) in order to assess the chemical composition of the alloy and to study its patinas

Plasmonic Light Trapping in Titania–Silver Dots Thin Films

Metal nanoparticles (NPs) in a transparent dielectric matrix represent a very intriguing system due to the plasmonic absorption tunable in the range of visible wavelengths. Herein, the preparation and physical characterization of plasmonic titania–silver dots thin films are reported. The synthesis parameter that leads to making a TiO2 matrix in which the Ag NPs are actually incorporated is carefully analyzed and controlled. Morphological (scanning electron microscopy, transmission electron microscopy, high resolution electron microscopy), structural (selected area diffraction, X-ray diffraction), and spectroscopic (Raman spectroscopy) characterization techniques attest that the Ag NPs are spherical and homogeneously distributed into the TiO2 dielectric matrix in the structural modification of anatase. The study of the optical properties of films concludes the work. Plasmonic resonance is analyzed according to the light scattering theory

Use of mixed study techniques in the evaluation of coastline dynamics - the “Porto Cesareo” MPA case of study

In recent decades, the much-discussed climate changes with the consequent variations in sea and weather conditions and the rise of the mean sea level are causing an indisputable set of negative actions on the entire coastal system mainly due to the increase of the erosive phenomenon along the shorelines. These critical scenarios have a major impact even on a local scale, and because of that, we decided to study a well knows tract of rocky/sandy mixed coast, in a highly anthropized area, even if located inside the “Porto Cesareo” Marine Protected Area (MPA) (Ionian Sea, Gulf of Taranto, Puglia Region, Italy). The high naturalistic and archaeological value of this area calls for a greater institutional effort in the study of erosional phenomena. Several historical documents from other studies point out that this coastal area is an ideal place for this kind of research. The effects of coastal erosion and anthropic pressures along this tract of coast require adequate efforts for a consistent and rapid evaluation of the coastal dynamics. The methodologies proposed in this work are based on mixed techniques from different fields of study, integrating recent aero photogrammetry surveys with drones, aerial images acquired by the Italian Military Geographic Institute (IGM), elaboration of paleoshorelines related by underwater archaeological markers and their dating, and finally on the elaboration of satellite products useful for the study of vast areas. The monitoring of coastal areas and the evaluation of shoreline dynamics are core topics in the implementation of managing actions of decision makers on a local, regional, national, and international scale, above all in places like the chosen one, inside an MPA. Remote sensing through the use of RPAS (Remotely Piloted Aircraft Systems or Drones) has proved to be very useful for identifying phenomena that act on a small spatial scale and in supporting and implementing protective measures according to the adaptive management approach, through multi-year surveys on habitats of conservation interest [18]. For the implementation of fine-scale monitoring actions, we have chosen products from the Sentinel satellite of the Copernicus constellation (European Space Agency - ESA). In this context, the use of satellite products provides a recurrent view of the ground, useful in the short and long-term monitoring of changes in wide coastal areas, and in particular, offers a coastline positioning evaluation in near real-time. Local monitoring actions performed in recent years have already shown an erosive trend in the past decades, and even, negative forecasts for the next decade, so further surveys with mixed methodologies could be crucial in the evaluation of the evolution of this particular coastal area by local authorities

Characterization of the Airborne Microbiome in Different Indoor and Outdoor Locations of a University Building Using an Innovative Compositional Data Analysis Approach

In this work, we investigated the structure of the airborne bacterial community obtained by 16S rRNA gene sequencing performed on aerosol samples from different indoor and outdoor locations. The 48-h aerosol samples were collected in two laboratories, in the corridors, and on the roof of the Mathematics and Physics Department of the University of Salento (Italy). The investigation was carried out through the application of an innovative compositional data analysis approach, mainly based on a centered log-ratio transformation as a standardization procedure, the Aitchison distance for data ordination, and the principal component analysis via singular value decomposition for data clustering. This methodology allowed us to explore the main relationships among samples, identifying different results between indoor and outdoor samples both at the genus level and at the species level. Bacillus and Pseudomonas represented the most abundant genera identified in the analyzed samples. Out of the 21 identified bacterial species with the highest abundances in the collected aerosol samples, Acinetobacter lwoffii, Propionibacterium acnes, Diplorickettsia massiliensis, and Corynebacterium tuberculostearicum were the only four commonly classified as human opportunistic pathogens. Among the genera mostly associated with indoor environments, Hymenobacter and Arthrobacter could be noted as including many species that are unique in being radiation resistant

Misure di radioattività naturale nel sito preistorico di Grotta dei Cervi in Porto Badisco (LE)

Nel presente lavoro sono riportati I risultati di una campagna di misure finalizzata alle determinazione della concentrazione di radon all’interno di Grotta dei Cervi di Porto Badisco (LE). Grotta dei Cervi è una cavità carsica caratterizzata da un complesso pittorico neolitico imponente

Study of Faraday cups for fast ion beams provided by a LIS source

Faraday cups are widely utilized to characterize ion and electrons beams. Owing to the secondary electron emission (SEE) induced by the collision of beams with collectors, wrong measurements could emerge from these detectors. To overcome this problem a polarized grid is utilized in front the cup collector at a negative voltage with respect to the collector. Unfortunately, the high voltage connection of the Faraday cups is hard to obtain. Then, in this work we want to study the secondary emission on different Al ion collector designs having tilted surfaces with respect to beam axis. Tests were performed using ion beams accelerated by a power supply up to 40 kV. The results by the modified collector surfaces were compared to the ones performed with a simple flat collector. The results we obtained point out that the secondary electron emission enhanced on incident beam energy and on the angle with respect to the normal direction of the surface. The ratio of the SEE to angle value results constant for the accelerating voltage and the possibility to design an ion collector able to reset the SEE seems not to be reached

Nanostructures for SERS in living cell

Surface-enhanced Raman spectroscopy (SERS) has received renewed interest in recent years in fields such as trace analysis, biorelated diagnosis, and living cell study. However, the interference of impurities left on the surface from the preparation process of substrates limits to some extent the application of SERS. In the present paper, we propose a method to prepare clean SERS substrates by a combined method of hydrothermal green synthesis and thermal treatment to obtain a clean and impurity-free surface for SERS measurements, suitable for cells growth. The goal of such activity was the study of the membrane proteome, with special attention to prion protein (PrPC), in its physiological ambient. SERS has been used to evidence the PrPC-Cu(II) interaction in a rat neuroblastoma cell line (B104), known to overexpress the cellular prion protein PrPC

High ordered biomineralization induced by carbon nanoparticles in the sea urchin Paracentrotus lividus

A surprising and unexpected biomineralization process was observed during toxicological assessment of carbon nanoparticles on Paracentrotus lividus (sea urchin) pluteus larvae. The larvae activate a process of defense against external material, by incorporating the nanoparticles into microstructures of aragonite similarly to pearl oysters. Aiming at a better understanding of this phenomenon, the larvae were exposed to increasing concentrations of carbon nanoparticles and the biomineralization products were analyzed by electron microscopy, x-ray diffraction and Raman spectroscopy. In order to evaluate the possible influence of Sp-CyP-1 expression on this biomineralization process by larvae, analyses of gene expression (Sp-CyP-1) and calcein labeling were performed. Overall, we report experimental evidence about the capability of carbon nanoparticles to induce an increment of Sp-CyP-1 expression with the consequent activation of a biomineralization process leading to the production of a new pearl-like biomaterial never previously observed in sea urchins