A semi-empirical index for estimating soil moisture from MIVIS data to identify subsurface archaeological sites

The possibilities offered by studying the tonal variations of the bare soil (damp-mark) are well known in archaeology: their existence in fact can be an indication of the presence in the subsoil of archaeological structures or ditches that inhibit or facilitate the absorption of rainwater and of the rising of humidity. The studying of the different degrees of water absorption of a soil becomes therefore particularly useful for the identification of buried archaeological sites in extra-urban context. In this work will be presented a Soil Index for hyperspectral MIVIS data that aims to constitute a support for the identification of traces over not-vegetated soil, emphasizing the wetness or the dryness of a portion of the ground

MIVIS Hyperspectral Sensors for the Detection and GIS Supported Interpretation of Subsoil Archaeological Sites

In recent years, Italian researchers have paid particular attention to the use of airborne hyperspectral sensors applied to archaeology, where the MIVIS sensor has found large application proving to be a very important complementary source of information for archaeological goals. In this paper, the results of research based in Aquileia (northeast Italy) are presented. The spectral content of the MIVIS images has been used to give prominence to the archaeological traces on the base of the different spectral characteristics of the terrain and the vegetation, allowing the detection of an elevated number of surface features. The paper will describe the various processes that have been applied to the images according to the different environmental situations: Vegetation Indices have allowed detection of traces over several types of vegetated surfaces; Soil Index has supported discoveries over bare soil; and Principal Component Analysis provided help in terms of better discrimination of contiguous surfaces

Archaeological usability of Hyperspectral images: successes and failures of image processing techniques

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High-speed and high-resolution 2D and 3D elemental imaging of corroded ancient glass by laser ablation-ICP-MS

In this work, laser ablation-inductively coupled plasma-mass spectrometry was used to investigate for the first time glass weathering mechanisms using high-resolution 2D and 3D elemental maps of altered layers of ancient glass. Roman archaeological glass shards, displaying several corrosion indicators, were studied using multiple raster-scanning ablation with high depth and lateral resolution. The concentration gradients of different elements were captured (in their variations from the surface to the bulk of pristine glass) by multiple ablations on degraded regions of interest to observe the dissolution of the glass network due to the hydration and leaching processes that occur during its alteration. The results indicated an enrichment of silicon and a depletion of alkaline/alkaline earth element concentration in the first few microns of depth under the surface area suggesting that a de-alkalinisation phenomenon occurs on the glass surface when ancient items have been buried under soil for extended timeframes. The layer-by-layer elemental distribution revealed also how the composition of the archaeological glass changes from the bulk to the surface, shedding light on the leaching behaviour of glass constituents during the alteration process

Consolidation and coating treatments for glass in the cultural heritage field: A review

Consolidation and coating treatments are two types of interventions that form part of the active con- servation actions developed for historical and archaeological glass over the years. While thermoplastic and thermosetting resins are widely adopted by conservators worldwide, issues related to the toxicity and the material compatibility of these products remains unsolved. To address these issues, effort s have been made to develop new formulations that can functionally replace or exhibit performance advantages with respect to these canonical polymeric materials. In this review, we discuss the main classes of ma- terials applied thus far for protection and consolidation aims in the cultural heritage glass field, starting from the beginning of the 19th century and continuing until present days. We also assess the potential of hybrid organic-inorganic materials and full inorganic materials as alternative solutions to the limita- tions of organic materials in application. Finally, we provide our perspectives on future directions for the development of consolidation products that meet the specific requirements of the cultural heritage field

Compositional changes by SIMS and XPS analyses on fresh and aged Roman-like glass

This study reports important analytical evidence of an unusual non-uniform element distribution in the superficial layers of glass matrices (from few nm up to 1 µm). The unforeseen observation was made on silica-soda-lime glass mock-ups before and after their artificial ageing, using secondary ion mass spectrometry (SIMS) and X-ray photoelectron spectroscopy (XPS) surface analysis techniques. The analyses showed a marked non-homogeneous element distribution at the glass surface. The results indicated a very low concentration of Na at the surface up to a depth of around 500 nm below the surface, where its concentration increases reaching a plateau. In addition, the profile distribution of H in the first 200 nm of the pristine glass surface indicated a diffusion of hydrogen from the surrounding environment to the glass network. Additional modifications during the glass ageing process related to external factors (such as temperature and humidity) were also identified in relation to sodium atoms, with atoms on the glass surface showing a different chemical state from those in the bulk. This study confirms that glass composition as well as glass alteration are non-homogeneous locally supporting the importance of studying glass surface as region of interaction with surrounding environment

Machine Learning for Cultural Heritage: A Survey

The application of Machine Learning (ML) to Cultural Heritage (CH) has evolved since basic statistical approaches such as Linear Regression to complex Deep Learning models. The question remains how much of this actively improves on the underlying algorithm versus using it within a ‘black box’ setting. We survey across ML and CH literature to identify the theoretical changes which contribute to the algorithm and in turn them suitable for CH applications. Alternatively, and most commonly, when there are no changes, we review the CH applications, features and pre/post-processing which make the algorithm suitable for its use. We analyse the dominant divides within ML, Supervised, Semi-supervised and Unsupervised, and reflect on a variety of algorithms that have been extensively used. From such an analysis, we give a critical look at the use of ML in CH and consider why CH has only limited adoption of ML

A New Green Coating for the Protection of Frescoes: From the Synthesis to the Performances Evaluation

This work presents the formulation and characterization of a new product for the protection of outdoor frescoes from aggressive environmental agents. The formulation is designed as an innovative green coating, prepared through a zero-waste one-pot-synthetic method to form silver nanoparticles (AgNPs) directly in a chitosan-based medium. The AgNPs are seeded and grown in a mixed hydrogel of chitosan, azelaic, and lactic acid, by the reduction of silver nitrate, and using calcium hydroxide as precipitating agent. The rheological properties of this coating base are optimized by the addition of a solvent mixture of glycerol and ethanol with a 1:1 volume ratio. The new formulation and two commercial products (Paraloid® B72 and Proconsol®) are then applied by brush to ad hoc mock-ups to be evaluated for chemical stability, color and gloss variations, morphological variation, hydrophobicity, and water vapor permeability via Fourier-transform infrared spectroscopy (FT-IR) in attenuated total reflection (ATR) mode, spectrophotometer analysis, stereomicroscope observations, UNI EN 15802, and UNI EN 15803, respectively. The results show that the application of the hybrid chitosan-AgNPs coating is promising for the protection of outdoor frescoes and that it can underpin the development of new products that address the lack of conservation strategies specifically designed for wall painting

The changing landscape of Constanciacus: a lost settlement in the Lagoon of Venice

« Costanziaco Project » is an interdisciplinary, multi-period archaeological project focused on the study of an ancient settlement in the Northern Lagoon of Venice, known in Medieval and later documentary sources as Costanciacus (Cottica et al., 2008). The project has been promoted by the Department of Antiquity and the Near East of the University of Venice and by the Superintendence for the Archaeological Heritage in the Veneto region. In Antiquity Costanciacus comprised two islands, S. Aria..

The changing landscape of Constanciacus: a lost settlement in the Lagoon of Venice

« Costanziaco Project » is an interdisciplinary, multi-period archaeological project focused on the study of an ancient settlement in the Northern Lagoon of Venice, known in Medieval and later documentary sources as Costanciacus (Cottica et al., 2008). The project has been promoted by the Department of Antiquity and the Near East of the University of Venice and by the Superintendence for the Archaeological Heritage in the Veneto region. In Antiquity Costanciacus comprised two islands, S. Aria..