18 results on '"Legnaioli, Stefano"'
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2. Determination of excitation temperature in laser-induced plasmas using columnar density Saha-Boltzmann plot.
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Safi, Ali, Tavassoli, S. Hassan, Cristoforetti, Gabriele, Legnaioli, Stefano, Palleschi, Vincenzo, Rezaei, Fatemeh, and Tognoni, Elisabetta
- Abstract
• Characterization of LIP by the Columnar Density Saha-Boltzmann (CD-SB) plot. • Use of strongly self-absorbed lines to calculate the plasma temperature. • Temporal evolution of the plasma temperature by CD-SB plot. • CD-SB plot as a promising method to obtain plasma temperature at later times. • CD-SB plot does not require the calibration of the detection system. In exploiting the analytical capabilities of plasma-based spectroscopy method, the evaluation of plasma parameters, particularly the plasma temperature, is a crucial step. In this work, a modified Saha-Boltzmann plot, which uses the columnar densities of atomic and ionic ground levels, is utilized to calculate the plasma temperature in a laser-induced plasma from an aluminum alloy target. The columnar densities are here calculated by quantifying the self-absorption of resonance lines. It is demonstrated that this is a promising method for accurate determination of plasma temperature. To validate the capability of this technique, plasma emission is measured at different gate delay times. For each delay, excitation temperature is calculated both by the conventional Saha-Boltzmann plot (by using the excited states) and by exploiting the new Columnar Density Saha–Boltzmann (CD-SB) plot. The results suggest that at later times of the plasma evolution, the CD-SB plot can be more suitable for the determination of plasma temperature than conventional Saha-Boltzmann plot. These findings provide a new approach for physical characterization of plasmas and give access to a wealth of information about the state of plasma. [ABSTRACT FROM AUTHOR]
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- 2019
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3. Analytical and mathematical methods for revealing hidden details in ancient manuscripts and paintings: A review.
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Tonazzini, Anna, Salerno, Emanuele, Abdel-Salam, Zienab A., Harith, Mohamed Abdel, Marras, Luciano, Botto, Asia, Campanella, Beatrice, Legnaioli, Stefano, Pagnotta, Stefano, Poggialini, Francesco, and Palleschi, Vincenzo
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• Methods for revealing hidden details in ancient manuscripts and paintings are presented. • Different experimental approaches are described. • The most effective techniques of image analysis are introduced. • Special attention is given to multi-spectral imaging and blind separation methods. • Several case studies are presented. In this work, a critical review of the current nondestructive probing and image analysis approaches is presented, to revealing otherwise invisible or hardly discernible details in manuscripts and paintings relevant to cultural heritage and archaeology. Multispectral imaging, X-ray fluorescence, Laser-Induced Breakdown Spectroscopy, Raman spectroscopy and Thermography are considered, as techniques for acquiring images and spectral image sets; statistical methods for the analysis of these images are then discussed, including blind separation and false colour techniques. Several case studies are presented, with particular attention dedicated to the approaches that appear most promising for future applications. Some of the techniques described herein are likely to replace, in the near future, classical digital photography in the study of ancient manuscripts and paintings. [ABSTRACT FROM AUTHOR]
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- 2019
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4. MICRO-CHEMICAL EVALUATION OF ANCIENT POTSHERDS BY μ-LIBS SCANNING ON THIN SECTION NEGATIVES.
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Pagnotta, Stefano, Legnaioli, Stefano, Campanella, Beatrice, Grifoni, Emanuela, Lezzerini, Marco, Lorenzetti, Giulia, Palleschi, Vincenzo, Poggialini, Francesco, and Raneri, Simona
- Subjects
POTSHERDS ,POTTERY ,SPECTRUM analysis ,CERAMIC industries ,PETROLOGY - Abstract
In the study of ancient pottery, thin section analysis represents the basic approach to study mineralogical and petrografic features in order to obtain preliminary information about the production technology and origin of archaeological ceramics. However, even if thin section analysis allows investigating the textural and structural characteristics of potteries, peculiar features related to clay paste and temper composition, as well as provenance issues, can be detailed addressed only by quantitative mineralogical and chemical studies. In the realization of thin sections, a negative face is always produced, similar to the thin section itself; these remains can be used for additional analyses, such as high spatial resolution micro-chemical studies using, for example, a micro-laser induced breakdown spectroscopy (LIBS) scanner. LIBS is a spectroscopic technique that, exploiting the laser radiation, is able to bring into the plasma state micrometric portions of the sample, and to analyse its content through the study of the optical emission of the plasma itself. Unlike other techniques, LIBS can detect and quantify also light elements such as aluminium and magnesium. Images produced by the micro-LIBS instrument show the spatial distribution of the chemical elements within a portion of the sample, which may have dimensions from a few hundred microns up to several centimeters. The combination of these images with algorithms derived from image processing techniques may return interesting information and supporting data to in-depth investigate pottery components detected by optical microscopy observations. In this work, we present the results of an experimental study performed on thin-section negatives with different grain size, surface treatments and aggregates, coming from some Neolithic Italian sites, exploring the potential of the LIBS method in microchemical studies of ancient potsherds. [ABSTRACT FROM AUTHOR]
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- 2018
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5. PETROGRAPHIC AND MINERALOGICAL CHARACTERIZATION OF VOLCANIC ROCKS AND SURFACE-DEPOSITIONS ON ROMANESQUE MONUMENTS.
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Columbu, Stefano, Piras, Giovanni, Sitzia, Fabio, Pagnotta, Stefano, Raneri, Simona, Legnaioli, Stefano, Palleschi, Vincenzo, Lezzerini, Marco, and Giamello, Marco
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VOLCANIC ash, tuff, etc. ,METAMORPHIC rocks ,MINERALOGY ,GRANITE ,PETROLOGY - Abstract
The stone used on the monuments, especially if they come from ancient times (e.g. medieval period), when exposed to the atmosphere, they are frequently affected by weathering and bio-deterioration processes. Thus, these latter produce various chemical and mineralogical transformations of substrate at the interface with the atmospheric agents as function of intrinsic compositional and physical characteristics of the material. Moreover, if there also are ancient treatments on the surface of geomaterials, the investigation field is further complicated. This research aims to analyse the surfaces of different volcanic lithology (basalts, andesite, pyroclastic rocks) used in the medieval Romanesque churches of Sardinia (XI-XIV cent.) having high historical- architectural and cultural relevance. By mineralogical and petrographic analysis (OM) and other different analytical methods (XRPD, colorimetry) the investigations addressed to define: i) petrographic features of volcanic rocks substrate; ii) chemical and mineralogical composition of coatings/crusts and any salt fanoand cryptoefflorescence; iii) compositional and microstratigraphic characterization of ancient treatments (i.e., Ca-oxalate films) on the surface of facades; iv) chromatic modifications of surface with respect to the substrate due to the alteration processes. The results show the incidence of several factors in the alteration process, as function of the occurred time, petrophysical features and composition of geomaterials, their position in the monument structure, exposition to the weathering processes, microclimatic characteristics, environmental conditions. [ABSTRACT FROM AUTHOR]
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- 2018
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6. Polymer-Based Black Phosphorus (bP) Hybrid Materials by in Situ Radical Polymerization: An Effective Tool To Exfoliate bP and Stabilize bP Nanoflakes.
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Passaglia, Elisa, Cicogna, Francesca, Costantino, Federica, Coiai, Serena, Legnaioli, Stefano, Lorenzetti, Giulia, Borsacchi, Silvia, Geppi, Marco, Telesio, Francesca, Heun, Stefan, Ienco, Andrea, Serrano-Ruiz, Manuel, and Peruzzini, Maurizio
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- 2018
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7. Exploiting Self-Absorption for Plasma Characterization in Laser-Induced Breakdown Spectroscopy Experiments: A Comparison of Two Recent Approaches
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Safi, Ali, Tavassoli, S.Hassan, Cristoforetti, Gabriele, Tognoni, Elisabetta, Campanella, Beatrice, Legnaioli, Stefano, Pagnotta, Stefano, Poggialini, Francesco, and Palleschi, Vincenzo
- Abstract
In this article, we compare two analytical methods that have been recently proposed: the columnar density Saha–Boltzmann plot method of Cristoforetti and Tognoni (Cristoforetti, G.; Tognoni, E. Spectrochim. Acta, Part B, 2013, 79–80, 63–71) and the C-sigma model of Aragon and Aguilera (Aragon, C.; Aguilera, J. A. J. Quant. Spectrosc. Radiat. Trans.2014, 149, 90–102). Both methods are based on the exploitation of self-absorbed lines for the characterization of plasmas in laser-induced breakdown spectroscopy experiments. However, although the two methods can be safely applied in many cases, their usefulness is limited in many practical cases of interest because of the intrinsic constraints of the used plasma model or because of the complexity of the numerical treatment. The two methods are presented here and critically discussed. Finally, an extended C-sigma approach is proposed to merge the advantages of the two methods, overcoming their intrinsic limitations and simplifying the numerical treatment.
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- 2019
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8. A New Infrared True-Color Approach for Visible-Infrared Multispectral Image Analysis
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Grifoni, Emanuela, Campanella, Beatrice, Legnaioli, Stefano, Lorenzetti, Giulia, Marras, Luciano, Pagnotta, Stefano, Palleschi, Vincenzo, Poggialini, Francesco, Salerno, Emanuele, and Tonazzini, Anna
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- 2019
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9. Portrait of an artist at work: exploring Max Ernst’s surrealist techniques
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Zuena, Martina, Pensabene Buemi, Luciano, Nodari, Luca, Subelytė, Grazina, Stringari, Lena, Campanella, Beatrice, Lorenzetti, Giulia, Palleschi, Vincenzo, Tomasin, Patrizia, and Legnaioli, Stefano
- Abstract
Max Ernst was one of the most influential artists associated with both the Dada and Surrealist movements. However, until now, only few scientific studies have been devoted to his works. This paper presents the results of a multi-analytical investigation on six oil paintings, made between 1927 and 1942, belonging to the Peggy Guggenheim Collection in Venice (Solomon R. Guggenheim Foundation, New York). Through a combined art historical and scientific approach, this study aims at understanding Ernst’s painting techniques, including frottage, grattage, dripping, and decalcomania, the used materials, and the state of conservation of the artworks. Non-invasive in situ investigations were performed by means of Vis–NIR multi-spectral imaging, X-ray fluorescence, external reflection FTIR and Raman spectroscopy. Imaging analysis revealed important information about Ernst’s painting methods while the other techniques provided useful information about the ground layer, the painting materials and the presence of alteration products. Ernst’s palette discloses great freedom in his use of materials and evolution during the time. This investigation demonstrates that an integrated, non-invasive, diagnostic approach provides a thorough analysis of materials and execution techniques of Ernst’ masterworks allowing an in-depth knowledge of his highly skilled work.
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- 2022
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10. PROTEUS: an immersive tool for exploring the world of cultural heritage across space and time scales
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Albertini, Niccolò, Baldini, Jacopo, Dal Pino, Andrea, Lazzari, Federico, Legnaioli, Stefano, and Barone, Vincenzo
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Graphical Abstract:
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- 2022
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11. The northern-Italy Renaissance in a panel by Defendente Ferrari: A complete study with a multi-analytical investigation
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Cavaleri, Tiziana, Pelosi, Claudia, Giustetto, Roberto, Andreotti, Alessia, Bonaduce, Ilaria, Calabrò, Giuseppe, Caliri, Claudia, Colantonio, Claudia, Manchinu, Paola, Legnaioli, Stefano, Piccirillo, Anna, Paolo Romano, Francesco, Ventura, Bernadette, Ferraris di Celle, Gianna, and Gargano, Marco
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•Defendente Ferrari was one of the most important painters of the Piedmontese Renaissance.•Interesting traits of his painting technique were discovered.•IR reflectography at 1000-1700 nm highlighted a very rich underdrawing.•The study of the Virgin's blue garment shed light on possible causes of blackening.•GC–MS analyses showed that the artist mastered the use of different binders.
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- 2022
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12. A multidisciplinary approach to the investigation of “La Caverna dell’Antimateria” (1958–1959) by Pinot Gallizio
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Bartolozzi, Giovanni, Cucci, Costanza, Marchiafava, Veronica, Masi, Susanna, Picollo, Marcello, Grifoni, Emanuela, Legnaioli, Stefano, Lorenzetti, Giulia, Pagnotta, Stefano, Palleschi, Vincenzo, Di Girolamo, Francesca, La Nasa, Jacopo, Modugno, Francesca, and Colombini, Maria
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This study concerns the application of non-invasive and micro-invasive analyses for the study of a contemporary artwork entitled La Caverna dell’Antimateria(“The Cave of Antimatter”) which was created by Pinot Gallizio in 1958–1959. The work represents one of the most significant examples of industrial painting. It consists of a total of 145 meters of painted canvas, designed in order to cover the entire floor plan of the René Drouin gallery in Paris, where it was displayed for the first time. Gallizio wanted to create an environment in which visitors could find themselves immersed in painting, in what he termed as a “work-environment”. Non-invasive (Fibre Optic Reflectance Spectroscopy) and micro-invasive analyses (Fourier Transform Infrared and micro-Raman Spectroscopies, Pyrolysis-Gas Chromatography and Gas Chromatography/Mass Spectrometry) were performed on three of the canvases which constitute this work of art in order to obtain information regarding the artistic materials used by Gallizio. Pigments and unconventional materials (such as metal wires, sand) are present in the canvases that form the ceiling. The colours are unevenly distributed on the surface, thus revealing large areas of the white preparation below. In the canvas of the wall, instead, the paint is applied more uniformly and gives a dark colour cast. The analytical results led to the identification of many of the materials used by Gallizio. The pictorial palette consists of both inorganic and organic pigments, while polyvinylacetate, pure or mixed with a siccative oil, was identified as a binder thus confirming what was reported by the artist in his notes. The results of this research provide information concerning the artistic technique used by Pinot Gallizio. The analyses were successfully performed both in situand on micro-samples in order to characterise the pigments of the coloured area, the ground layer and the organic binders.
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- 2014
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13. Recovery of archaeological wall paintings using novel multispectral imaging approaches
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Legnaioli, Stefano, Lorenzetti, Giulia, Cavalcanti, Gildo, Grifoni, Emanuela, Marras, Luciano, Tonazzini, Anna, Salerno, Emanuele, Pallecchi, Pasquino, Giachi, Gianna, and Palleschi, Vincenzo
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New approaches in the application of multispectral imaging to the recovery of archeological wall paintings are presented, based on statistical techniques and on a novel method of image treatment (Chromatic Derivative Imaging – ChromaDI) which offers a way of embedding information coming from four spectral bands into a standard RGB image. The methods are applied to some wall paintings from the Tomb of the Monkey, an Etruscan tomb in the necropolis of Poggio Renzo, near the city of Chiusi (Siena), Italy, dated around 480-470 BC. It is shown that the techniques described are able to highlight and enhance a number of details that cannot be perceived in either any of the original channel images or any single processed output channel.
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- 2013
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14. Quantitative analysis of aluminium alloys by low-energy, high-repetition rate laser-induced breakdown spectroscopy
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Cristoforetti, Gabriele, Legnaioli, Stefano, Palleschi, Vincenzo, Salvetti, Azenio, Tognoni, Elisabetta, Alberto Benedetti, Pier, Brioschi, Franco, and Ferrario, Fabio
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With the aim of reducing the dimensions of a laser-induced breakdown spectroscopy (LIBS) apparatus for building a portable instrument, a diode-pumped Nd:YAG mini-laser at high repetition rate was tested as an excitation source for the quantitative analysis of aluminium alloy samples. Moreover, LIBS spectra acquired by using an ICCD-echelle spectrometer detection system were compared with those obtained by a traditional spectrometer coupled to a non-intensified linear array detector. Calibration curves were built and limits of detections were calculated using both detection systems for magnesium, silicon, copper, titanium, manganese, nickel and iron. The results were compared with those obtained by recently proposed LIBS systems based on the use of microchip lasers.
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- 2006
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15. Effect of Laser-Induced Crater Depth in Laser-Induced Breakdown Spectroscopy Emission Features
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Corsi, Michela, Cristoforetti, Gabriele, Hidalgo, Montserrat, Iriarte, Daniela, Legnaioli, Stefano, Palleschi, Vincenzo, Salvetti, Azenio, and Tognoni, Elisabetta
- Abstract
The influence of crater depth on plasma properties and laser-induced breakdown spectroscopy (LIBS) emission has been evaluated. Laser-induced plasmas were generated at the surface and at the bottom of different craters in a copper sample. Plasmas produced at the sample surface and at the bottom of the craters were spatially and temporally resolved. LIBS emission, temperature, and electronic number density of the plasmas were evaluated. It is shown that the confinement effect produced by the craters enhances the LIBS signal from the laser-induced plasmas.
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- 2005
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16. Application of laser-induced breakdown spectroscopy technique to hair tissue mineral analysis
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Corsi, Michela, Cristoforetti, Gabriele, Hidalgo, Montserrat, Legnaioli, Stefano, Palleschi, Vincenzo, Salvetti, Azenio, Tognoni, Elisabetta, and Vallebona, Chiara
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The concentration of the main minerals present in human hair is measured on several subjects by Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) and compared with the results obtained through a commercial analytical laboratory. The possibility of using CF-LIBS for mineral analysis in hair is discussed, as well as its feasibility for the fast and inexpensive determination of the occurrence of heavy-metal poisoning in hair.
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- 2003
17. Incorporation of 2D black phosphorus (2D-bP) in P3HT/PMMA mixtures for novel materials with tuned spectroscopic, morphological and electric features
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Coiai, Serena, Cicogna, Francesca, Scittarelli, Doriana, Legnaioli, Stefano, Borsacchi, Silvia, Ienco, Andrea, Serrano-Ruiz, Manuel, Caporali, Maria, Peruzzini, Maurizio, Dinelli, Franco, Ishak, Randa, Signori, Francesca, Toffanin, Stefano, Bolognesi, Margherita, Prescimone, Federico, and Passaglia, Elisa
- Abstract
•P3HT/PMMA based composites containing 2D-bP layers were prepared for the first time by bP liquid phase exfoliation and polymerization in situ techniques.•The 2D-bP layers were partially exfoliated/intercalated with a good preservation of their physiochemical features.•The 2D-bP layers resulted preferentially allocated in the P3HT polymer phase and its dispersion changes the morphology of the blend P3HT/PMMA.•When a continuous P3HT phase with dispersed 2D-bP nanoflakes was achieved, the charge mobility of P3HT/PMMA polymer matrix was significant despite the presence of 50% wt of a dielectric PMMA.
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- 2021
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18. X-Ray Fluorescence Analysis of XII–XIV Century Italian Gold Coins
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Baldassarri, Monica, de Holanda Cavalcanti, Gildo, Ferretti, Marco, Gorghinian, Astrik, Grifoni, Emanuela, Legnaioli, Stefano, Lorenzetti, Giulia, Pagnotta, Stefano, Marras, Luciano, Violano, Eleonora, Lezzerini, Marco, and Palleschi, Vincenzo
- Abstract
An extensive analytical study has been performed on a large number of gold coins (Norman-Swabian Augustale and Tarì, Grosso of Lucca, Florin of Florence) minted in Italy from the end of XII century to XIV century. The X-ray fluorescence (XRF) technique was used for verifying the composition of the coins. XRF is a nondestructive technique particularly suited for in situ quantitative analysis of gold and minor elements in the precious alloy. The Florins turned out to have a gold content very close to 24 carats (pure gold) although in a couple of cases we observed relatively high concentrations of iron (around 2%) or lead (around 1%). The Grosso of Lucca has a similar composition, with a measured gold content around 97% due to a higher silver percentage (about 2%), with respect to the average Florin. The Augustali analyzed showed, on average, a gold content around 89%. The average gold content of the Tarì analysed is around 72%, with a relatively large variability. The analysis revealed the use of native gold for the coinage of the Florins, excluding the possibility of recycling gold coming from other sources. On the other hand, the variability observed in the compositions of the Tarì and Augustali could suggest the reuse of Islamic and North African gold. The study could shed some light on the sudden diffusion of gold coins in Italy around the first half of XIII century, allowing hypotheses on the provenience of the gold used for a coinage that dominated the economic trades from then on.
- Published
- 2014
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