A deep learning experiment for semantic segmentation of overlapping characters in palimpsests

Palimpsests refer to historical manuscripts where erased writings have been partially covered by the superimposition of a second writing. By employing imaging techniques, e.g., multispectral imaging, it becomes possible to identify features that are imperceptible to the naked eye, including faded and erased inks. When dealing with overlapping inks, Artificial Intelligence techniques can be utilized to disentangle complex nodes of overlapping letters. In this work, we propose deep learning-based semantic segmentation as a method for identifying and segmenting individual letters in overlapping characters. The experiment was conceived as a proof of concept, focusing on the palimpsests of the Ars Grammatica by Prisciano as a case study. Furthermore, caveats and prospects of our approach combined with multispectral imaging are also discussed

Estakhr Project - Third preliminary report of the joint Mission of the Iranian center for archaeological research, the Parsa-Pasargadae research foundation and the Sapienza University of Rome, Italy

This report presents the preliminary results of the study of the pottery collected during the excavation campaign carried out in 2012 in the framework of the joint Iranian-Italian Archaeological Mission in Estakhr. The ceramic finds relate to a time span ranging from the 9th to the 12th century, corresponding to the occupation phases identified within the stratigraphy. Moreover, the use of archaeometry made it possible to identify both imported and locally manufactured wares

Antibacterial effect of zinc oxide-based nanomaterials on environmental biodeteriogens affecting historical buildings

The colonization of microorganisms and their subsequent interaction with stone substrates under different environmental conditions encourage deterioration of materials by multiple mechanisms resulting in changes in the original color, appearance and durability. One of the emerging alternatives to remedy biodeterioration is nanotechnology, thanks to nanoparticle properties such as small size, no-toxicity, high photo-reactivity, and low impact on the environment. This study highlighted the effects of ZnO-based nanomaterials of two bacteria genera isolated from the Temple of Concordia (Agrigento’s Valley of the Temples in Sicily, Italy) that are involved in biodeterioration processes. The antimicrobial activities of ZnO-nanorods (Zn-NRs) and graphene nanoplatelets decorated with Zn-NRs (ZNGs) were evaluated against the Gram positive Arthrobacter aurescens and two isolates of the Gram negative Achromobacter spanius. ZNGs demonstrated high antibacterial and antibiofilm activities on several substrates such as stones with different porosity. In the case of ZNGs, a marked time- and dose-dependent bactericidal effect was highlighted against all bacterial species. Therefore, these nanomaterials represent a promising tool for developing biocompatible materials that can be exploited for the conservation of cultural heritage. These nanostructures can be successfully applied without releasing toxic compounds, thus spreading their usability

SPETTROSCOPIE DEI BENI CULTURALI CON STRUMENTAZIONE PORTATILE

In questo lavoro vengono presentati i principi fisici della fluorescenza dei raggi X e della riflettografia infrarossa, due delle tecniche più utilizzate per rispondere ad alcuni quesiti posti dagli Umanisti nello studio e nella conservazione dei Beni Cultural

DETERMINATION OF THE COMPLEX DIELECTRIC FUNCTION OF CDTE(110)1X1 SURFACE BY POLARIZED SURFACE DIFFERENTIAL REFLECTIVITY

We present a determination of the complex surface dielectric function (SDF) of the CdTe(110)1 x 1 surface obtained by using polarized surface differential reflectivity data (Delta R/R) obtained for the light electric vector along the [1 $($) over bar$$ 10] and [001] directions, i.e. ''parallel'' and ''perpendicular'' to the natural chains of the unreconstructed (110) surface. In the energy range below 3.3 eV the imaginary part of the SDF (epsilon'') and Delta R/R are very similar while above 3.3 eV they differ markedly because of the effect of bulk contribution. Three mainly isotropic structures are clearly visible in the epsilon'' spectra at the following photon energies: 2.7, 3.3 and 3.65 eV. The interpretation of such structures in terms of optical transitions between surface state bands as derived from direct and inverse photoemission is shown. Moreover, the effective number of electrons per atom participating in the optical transitions is calculated for energies up to 4.0 eV

SURFACE DIELECTRIC FUNCTION OF CDTE(110) OBTAINED BY POLARIZED SURFACE DIFFERENTIAL REFLECTIVITY DATA

We present a determination of the complex surface dielectric function (SDF) of CdTe(110) obtained by using polarized surface differential reflectivity (SDR) data. The analysis of SDR data is done in the framework of a macroscopic three-layer model in which the media involved (vacuum, surface, and substrate) are assumed to have definite anisotropic functions. A relation between SDR data and the complex SDF is obtained under the assumption that the oxide layer is nonabsorbing in the range explored. From the experimental data SDF has been computed for light electric vector along [1(1) over bar0$] and [001] directions, i.e., parallel and perpendicular to the natural chains of the unreconstructed (110) surface. In the energy range below 3.3 eV the imaginary part of SDF (epsilon(s)'') and SDR data are very similar while above 3.3 eV they differ markedly because of the effect of bulk contribution. Three mainly isotropic structures are clearly visible in the deconvolved epsilon'' spectra at the following photon energies: 2.7, 3.3, and 3.7 eV. Such structures are interpreted in terms of optical transitions between surface state bands as derived from direct and inverse photoemission. The transition at 2.7 eV is assigned at the Gamma point in the surface Brillouin zone, the one at 3.3 eV at the Gamma and X while the one at 3.7 eV at the X and X'. The effective number of electrons per atom participating in the optical transitions is calculated for energies up to 4.0 eV resulting in slightly more than 0.5. (C) 1995 American Vacuum Society