1,721,059 research outputs found
Preliminary investigations of the action of nanostructured materials for the conservation of fresco paintings in high-humid environments
No full textA preliminary study on the protective effect of nanostructured materials developed for the conservation of fresco paintings sited in high humidity environments is here reported. The study has been performed on mock-up samples prepared on the base of a non-invasive investigation performed on the frescos of the complex St. Mary of the Cave in Marsala (Trapani, Italy). The mock-up samples simulate both the stone support and the mortar preparation as well as the fresco painted with the same kind of pigments found in two of fresco paintings. Some nanostructured materials such as nano-sized fluorosilanes in water, nanosilica in water, nanolime and their mixtures have been tested evaluating the effect on the colour appearance and on surface properties
Role of the thermal treatment on the microstructure of YAGG nanopowders prepared by urea glass route
Full text linkYttrium aluminium gallium garnet (YAGG, Y3Al2Ga3O12) doped with rare-earth ions has drawn large attention
owing to its optical properties with applications ranging from persistent luminescent phosphors to nanothermometers.
Herein, three different YAGG materials were synthesized via the urea glass route followed by
thermal treatment, relatively undoped; doped with Ce3+, Cr3+, and Nd3+; and doped with Ce3+, Cr3+, and Yb3+.
The garnet formation was studied in situ upon thermal treatment from 300 to 1000 ◦C using synchrotron powder
diffraction. Our results show that with this method, the onset of formation of the garnet is about 860 ◦C, with
comparable cell parameters for both undoped and doped YAGG. A possible growth mechanism of YAGG is
therefore discussed on the basis of observed microstructural parameters such as occupancy, microstrain, and
crystallite size
Amber resins provenance and datation by non invasive FTIR and chemometric analysis
No full textIn this study, 28 fossil resins of amber samples from various localities in Europe, Asia and America. Infrared spectroscopy was used to identify the molecular features that characterize these ambers. Through the development of a tailored chemometric approach, we reduced the impact of non-significant spectral contributions and highlighted the most relevant features for classifying amber samples. This was achieved by applying second-derivative processing to the spectra and segmenting them into specific wavenumber ranges. Our novel approach successfully groups ambers based on both age and geographical provenance using their FTIR spectral profiles. Additionally, it isolates the molecular vibrations that have the greatest influence on this classification, particularly the contributions from functional groups that differentiate these samples. This method offers a valuable tool for researchers engaged in amber provenance studies, especially for succinites originated from Eastern Europe, providing a new approach to identify and classify unknown resin samples based on their unique molecular signatures
Investigation of composition of archeological Helmets, type Montefortino
No full textIn this work, a preliminary non invasive and non destructive investigation, performed on two helmets, is presented
Geochemical and mineralogical characterization on an ochre residue adhering to a pebble found in the Oriente A Epigravettian burial, in the Grotta d’Oriente of Favignana (Egadi, Italy)
No full textThe Grotta d’Oriente, on the island of Favignana (Egadi, Sicily) has yielded a series of burials and human remains attributable to the final Epigravettian and Mesolithic. The Epigravettian burial, known as Oriente A, is characterised by funerary equipment consisting of perforated shells and a pebble with traces of red ochre. This site is one of the rare cases in which there is evidence of the use of ochre in a funerary context in Sicily and therefore the archaeological reconstruction requires the chemical-mineralogical characterization of this pigment using SEM, EDS, XRD, FORS and Raman spectroscopy. The comparative analysis of this pigment with a series of Terra Rossa from Favignana and other areas of Sicily has demonstrated that the Oriental A ochre does not derive from these sediments. This study shows the importance of applying different analysis methods for the characterization of ochres to try to define their origin
The colours of Segesta. Searching for the traces of the lost pigments
Full text linkMany monuments and objects of the ancient civilizations were painted, but unfortunately the pigments are not still present and sometimes only small traces are evident. The analysis of the traces requires a multianalytical approach through the use of non-invasive techniques and only if necessary of a microsampling. Here, the study of the traces of colours found in some architectural elements and findings belonging to the Archeological Park of Segesta (Trapani, Italy) is reported. The traces are identified and characterised via several techniques such as Optical Microscopy, UV-Fluorescence Imaging, Fiber Optical Reflectance Spectroscopy (FORS), X-ray Fluorescence (XRF) and FT-IR Spectroscopy. Various pigments were identified, some of which are no longer clearly visible to the naked eye: hematite, umber, vegetable black and bone black. Despite the small amount of detectable pigment, the performed investigations allowed us to define part of the pictorial palette to imagine and relive the past in one place
Sistemi nanostrutturati per la conservazione di affreschi in ambienti ad elevata umidità
No full textPreliminary studies about the effect of three nanostructured materials on the conservation of fresco located in a highhumidity environment is reported. Nanostructured materials were tested to assess their impact on the surface properties, such as wettability and color, of mock-up samples simulating the wall paintings saved at the S. Maria della Grotta Complex (Marsala, TP)
Appendice I. Indagini sulle tracce di pigmenti
No full textIn questa Appendice sono riportati i risultati delle indagini su tracce di pigmenti, individuate su quattro
frammenti di sima con gronde a protome leonina e
su un frammento di geison del tempio periptero, su
alcuni dei blocchi del muro di temenos del santuario
e su altri reperti provenienti da tale contesto, conservati presso il Parco Archeologico di Segesta (TP)
MULTI-APPROACH STUDY, DIGITIZATION AND DISSEMINATION OF A BRONZE-AGE ENGRAVED CUP FOUND IN FILO BRACCIO, FILICUDI (AEOLIAN ISLANDS, ITALY)
No full textThis paper presents a multidisciplinary study combining photogrammetry, near-infrared (NIR) imaging and archaeological analysis to analyse a 1900-1800 BC engraved cup, found at the Bronze Age site of Filo Braccio in Filicudi, Aeolian Islands, Italy. The artefact is unique within the contemporary 'Capo Graziano' culture, featuring a rare complex figural scene engraved along the exterior walls; the "scene" provides insights into the prehistoric culture of Filicudi and the Aeolian Islands. The study focused on generating an accurate three-dimensional (3D) model to i) support archaeological research on the artefact's engravings and ii) create engaging digital media for remote and on-site visitors. Photogrammetry used high-resolution photographs taken around the object and control points for metric accuracy assessment. This study also utilises NIR and visible light imaging to examine the engraved cup. The photogrammetric workflow provided a realistic 3D model textured with both visible and NIR data: the 3D model enabled to improve the reading of the engraved scene, revealing horizontal registers of figures, while NIR imaging highlighted material inhomogeneity. The resulting 3D model achieved a high level of detail, with 4381407 faces and a root mean square (RMS) reprojection error of approximately 3.9 mu m. The NIR imaging revealed additional surface details not visible in the standard photographs. For dissemination, the optimised 3D model was uploaded to Sketchfab with informative annotations, enabling remote study and cultural promotion of the artefact. This multi-approach methodology offers a valuable tool for comprehensive artefact documentation and analysis, providing new insights into the artefact's complex figural scene
Multimodal anti-counterfeiting inks: modern use of an ancient pigment in synergy with a persistent phosphor
No full textMulti-level luminescent, transparent and non-permanent inks for anti-counterfeiting systems and security were developed. The inks emit radiation at different wavelengths based on the type of radiation used to illuminate them, providing multiple layers of safety. The red persistent phosphor Y2O2S:Eu3+,Mg2+,Ti4+ (YOS) was mixed with Egyptian Blue (EB) and dispersed in an aqueous solution of arabic gum. Imaging techniques, excitation and emission spectra, the study of luminescence over time and the duration time were used to verify that the obtained systems showed the desired optical characteristic both in the infrared and in the visible spectral ranges. The two luminescent materials act synergistically: when illuminated with UV light, YOS emits red photons over time and EB, absorbing this energy, emits infrared photons. The resulting emission characteristics are non-obvious and can be designed at the ink developing stage. The tests performed on several substrates showed that the developed luminescent inks are well suited for use in the field of security and anti-counterfeiting
- …
