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The aim of the present research is to validate the combined use, through data fusion, of a Laser Induced Fluorescence (LIF) scanning system and a radar scanner (RGB-ITR, Red Green Blue Imaging Topological Radar system), as a unique tool to address the need for non-invasive, rapid, and low-cost techniques for both diagnostic and operational needs. The integrated system has been applied to the House of Diana complex in Ostia Antica. The main diagnostic objective of this research was to trace the materials used in different phases of restoration, from antiquity to modernity, on both masonry and pictorial surfaces, to reconstruct the history of the building. Due to the significant interest in this insula, other studies have been recently carried out on the House of Diana, but they once again highlighted the necessity of multiple approaches and non-invasive methods capable of providing quasi-real-time answers, delivering point-by-point information on very large surfaces to overcome the limits related to representativeness of sampling. The data acquired by the RGB-ITR system are quantitative, allowing for morphological and 3-colour analysis of the investigated artwork. In this work, the sensor has been used to create coloured 3D models useful for structural assessments and for locating different classes of materials. In fact, the LIF maps, which integrate knowledge about the original constituent materials and previous conservation interventions, have been used as additional layers of the tridimensional models. Therefore, the method can direct possible new investigations and restoration actions, piecing together the history of the House of Diana to build for it a safer future.

In this work, nanomaterials were used as consolidants and protective layers for artistic stones. Synthetized nanocomposites were applied on marble and their performances as protective and water repellent coating were characterized. For the preparation of the novel nanocomposites, SiO2 and TiO2 nanoparticles were synthesized by laser pyrolysis and were dispersed in acrylic polymer and silicon-based resin. To evaluate the retreatability of water repellent treatments, the capability of laser to remove protective layers was explored. Laser cleaning tests with different working parameters have been carried out to optimize the effectiveness of the process. The effects of laser treatments on stone surfaces and on the applied nanocomposites were estimated by using confocal optical microscopy and Laser-Induced Fluorescence (LIF).

In nature, calcium carbonate (CaCO 3 ) in the form of calcite and aragonite nucleates through different pathways including geogenic and biogenic processes. It may also occur as pyrogenic lime plaster and laboratory-precipitated crystals. All of these formation processes are conducive to different degrees of local structural order in CaCO 3 crystals, with the pyrogenic and precipitated forms being the least ordered. These variations affect the manner in which crystals interact with electromagnetic radiation, and thus formation processes may be tracked using methods such as X-ray diffraction and infrared spectroscopy. Here we show that defects in the crystal structure of CaCO 3 may be detected by looking at the luminescence of crystals. Using cathodoluminescence by scanning electron microscopy (SEM-CL) and laser-induced fluorescence (LIF), it is possible to discern different polymorphs and their mechanism of formation. We were thus able to determine that pyrogenic calcite and aragonite exhibit blue luminescence due to the incorporation of distortions in the crystal lattice caused by heat and rapid precipitation, in agreement with infrared spectroscopy assessments of local structural order. These results provide the first detailed reference database of SEM-CL and LIF spectra of CaCO 3 standards, and find application in the characterization of optical, archaeological and construction materials.

No information exists on phototrophs growing on the stone surfaces of the Catacombs of SS. Marcellino and Pietro (the site was only recently opened to the public in 2014). Therefore, it was decided to characterise the microbial communities and to compare them with those of the other previously studied catacombs. Moreover, a new non-invasive strategy to reduce the phototrophic growth was tested. Phototrophic microorganisms were investigated under light and confocal laser scanning microscopes from samples collected non-invasively in situ. Tests were carried out to determine the effect of the application of two essential oils (from L. angustifolia and T. vulgaris ) on biofilm photosynthetic activity. Laser-induced fluorescence (LIF) and reflectance measurements in the visible range have been used to evaluate respectively, any chemical modification and discolouration on a frescoed stone that may occur after the application of the essential oils. At all the concentrations of essential oils, there was a quasi-immediate, large reduction in photosynthetic activity of the biofilms. At 10% essential oil concentration, there was no detectable photosynthetic activity after 15 min. At 1%, there was a need for two applications and after 5-day activity was undetectable. No effect of the essential oils on the substrate surface properties or colour modification of the fresco has been observed with the LIF prototype. Cyanobacterial typical of Roman catacombs were present in the sites investigated. Innovative and non-destructive strategies, involving the application of a combination of two essential oils, have been successfully tested and developed to prevent biodeterioration of these sites.

Accurate radiocarbon (14C) dating of lime mortars requires a thorough mineralogical characterization of binders in order to verify the presence of carbon-bearing contaminants. In the last 20 years, cathodoluminescence (CL) has been widely used for the identification of geologic calcium carbonate (CaCO3) aggregates and unreacted lime lumps within the particle size fraction selected for carbon recovery. These components are major sources of older and younger carbon, respectively, and should be removed to obtain accurate age determinations. More recently, laser-induced fluorescence (LIF) has provided another means of investigating the preservation state and composition of CaCO3 binders. Considered the growing interest of the mortar dating community in the latest advancements of these analytical methods, here we review the principles of CL and LIF of CaCO3, their instrument setup, and their application to the characterization of ancient lime mortars used for 14C dating. In addition, we provide examples of SEM-CL and LIF analyses using high-resolution instrumentation, we discuss current issues and propose future lines of research.

Quartz from La Sassa (Tuscany, Italy) presents a unique luminescence related to intrinsic and extrinsic defects in the crystal lattice due to the growth mechanisms in hydrothermal conditions. The bright fluorescence under the UV lamp was apparent to collectors since the early 1970s, and it entered the literature as a reference case of yellow-luminescent quartz. Early reports present the history of the discovery, the geological context, and preliminary luminescence measurements of the quartz nodules, suggesting various activators as potentially responsible of the peculiar luminescence effects: uranyl groups (UO22+), rare earths (Tb3+, Eu3+, Dy3+, Sm3+, Ce3+) and polycyclic aromatic compounds (PAH). Here, we report a full investigation of the La Sassa material, by a multi-analytical approach encompassing cathodoluminescence optical microscopy (OM-CL), laser-induced fluorescence (LIF), wavelength resolved thermally stimulated luminescence (WR-TSL), trace elements analysis by mass spectrometry (ICP-MS) and Raman spectroscopy (RS). The results provide a significant step forward in the interpretation of the luminescence mechanisms: the main luminescent centres are identified as alkali-compensated (mainly Li+ and Na+, K+ and H+) aluminum [AlO4/M+]0 centres substituting for Si, where the recombination of a self-trapped exciton (STE) or an electron at a nonbridging oxygen hole centre (NBOHC) are active.

Laser-induced fluorescence (LIF) has found, in the recent years, widespread application to the field of material study and characterization. In particular, LIF has been applied to the assessment of damage, biological growth, and the analysis of specific materials on various surfaces in cultural heritages. Only a few papers deal with the application of LIF to the study of modern synthetic materials (mostly plastics) and pigments, and the analysis of contemporary works of art. Preliminary laboratory measurements on a wide range of plastic and cellulose-based materials, solvents, resins, and varnishes have been performed for rapid material characterization during in situ measurement campaigns in cultural heritage, security, and forensic contexts. Four paintings by Gastone Novelli, in the National Gallery of Modern and Contemporary Art, Rome, have been investigated by a compact LIDAR fluorosensor scanning system developed at the Laboratory of Diagnostic and Metrology in the ENEA Centre of Frascati (UTAPRAD-DIM Laboratory) for LIF measurements. Results and the relative data processing have provided fluorescence images, false color images, and punctual spectral information. The comparison with data and spectra from purpose-built reference databases has enabled recognition of materials on the paintings, and provided information on their production.

Laser induced fluorescence (LIF) is a powerful remote and non-invasive analysis technique that has been successfully applied to the real-time diagnosis of historical artworks. Hyperspectral images collection on fresco' s and their false colours processing allowed to reveal features invisible to the naked eye and to obtain specific information on pigments composition and consolidants utilization, the latter also related to former restorations. This report presents the results obtained by ENEA LIF scanning system during a field campaign conducted in June 2010 on fresco's by Giusto de' Menabuoi in the Padua Baptistery. The data collected by LidArt allowed the detection of Paraloid B72 and Movilith/Primal AC33, guiding the restorers in their conservation actions.