19 research outputs found
A low-cost automatic acquisition system for photogrammetry
No full textPhotogrammetry is a non-destructive technique commonly employed in the cultural heritage field for reconstructing a 3D virtual replica of an artifact by simply taking several photos of the artifact itself from different points of view. The 3D model can be used either for documenting the artifact or for preserving its geometrical information and appearance. Moreover, by using a digital 3D model is extremely easy sharing information with the public and researchers without physically moving the artifact, and this represents a unique opportunity which cannot be achieved with traditional methods. Unfortunately most systems already present on the market are complex and costly both due to their hardware and software. This paper presents a novel acquisition system which is extremely cheap and can be easily arranged in any conservation laboratory. The solution is based on a simple acquisition system designed with the aim of providing researchers with a user-friendly and low-cost platform for the reconstruction of an artifact 3D model. The proposed system can be virtually interfaced to every commercial camera and can be integrated with several 3D reconstruction software. As an example, the authors employed a free open-source software referred to as Meshroom
A long-term corrosion investigation of bronze sculptures exposed outdoor
No full textSafeguarding our cultural heritage for the future generations is possible only by applying tailored conservation strategies. The safeguard is a complex task and often requires measurements to be performed on the artefacts. This paper describes an interesting case regarding the metallic artefacts belonging to the Gori Art Collection at Fattoria Celle (Pistoia, Italy). This collection of modern art, developed inside a project of environmental art, is facing different corrosion phenomena due to its permanent exposure to outdoor environmental conditions. A non-invasive and in-situ multi-analytical approach was recently started in order to assess the conservation state of the metal artefacts and to assure their long-lasting preservation trough the development of a conservation project. In this paper, the preliminary results of the monitoring campaign carried on the bronze sculpture "Cavaliere" by Marino Marini will be presented and discussed
Monitoraggio dello stato di conservazione delle opere d’arte della Collezione Gori = In situ monitoring of the conservation state of the Gori’s collection works of art
No full textIl monitoraggio dello stato di conservazione dei manufatti metallici è di grande rilevanza nel mondo dei beni culturali ed è essenziale per lo sviluppo di metodologie e buone pratiche per la conservazione preventiva di manufatti metallici d’interesse storico-artistico esposti all’aperto. In questo lavoro è presentato il monitoraggio di una scultura in bron- zo appartenente alla Collezione d’arte Gori, raccolta privata di un grande numero di opere d’arte moderna, realizzate all’interno di un programma di arte ambientale. In particolare è stato eseguito uno studio tramite l’impiego di tecniche non invasive, applicabili in situ, che permettessero di attestare la presenza dei fenomeni corrosivi in atto e la caratteriz- zazione delle patine di corrosione presenti. Le tecniche impiegate sono la spettroscopia di impedenza elettrochimica (EIS), la spettroscopia Raman e la fotogrammetria. Mediante lo sviluppo di un approccio d’indagine multi-analitico è stato possibile valutare nel complesso lo stato di conservazione dell’opera e la capacità protettiva delle patine
Micro-Raman investigation of dangerous corrosion products of archaeological bronzes from Tharros (Sardinia-Italy)
No full textA large number of bronze artefacts have been found during archaeological excavations carried out at Tharros (Sardinia, Italy). The composition of corrosion products have been determined by the combined use of optical microscopy (OM), micro-Raman spectroscopy (μ-Raman), scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS). In particular, we will use μ-Raman spectroscopy to identify the corrosion products of natural patinas. This technique is equivalent or sometimes more efficient than microscopic and diffraction techniques to identify archaeological corrosion products. It is able to discriminate between different polymorphs, has a high spatial resolution and assures a correlation between the colour and the mineralogical nature. Furthermore has the advantage of being a nondestructive technique, quality highly valued in the cultural heritage
Application of μ-Raman spectroscopy to the study of the corrosion products of archaeological coins
No full textIn this paper, a study of the corrosion products formed on archaeological bronze artefacts excavated in Tharros (Sardinia, Italy) is presented. The investigation was carried out by means of the combination of different analytical techniques, including optical microscopy, micro-Raman spectroscopy (μ-RS), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and X-ray diffraction. The artefacts under study are three bronze coins from the Phoenician-Punic period that are deeply corroded due to the chloride-rich soil of the Tharros excavation site. μ-Raman spectroscopy was chosen to investigate the corroded surfaces of the artefacts because it is a non-destructive technique, it has high spatial resolution, and it makes it possible to discriminate between polymorphs and correlate colour and chemical composition. Through μ-RS, it was possible to identify different mineralogical phases and different polymorphs, such as cuprite (Cu2O), copper trihydroxychloride [Cu2Cl(OH)3] polymorphs, hydroxy lead chloride laurionite [PbCl(OH)] and calcium carbonate polymorph aragonite. The experimental findings highlight that micro-Raman spectroscopy can be used to provide further knowledge regarding the environmental factors that may cause the degradation of archaeological bronzes in soil
SISTEMA DI MISURA PER LA VALUTAZIONE DELLO STATO DI CONSERVAZIONE DI MANUFATTI METALLICI ESPOSTI A CORROSIONE ATMOSFERICA
No full textLa memoria verte sulla presentazione di un caso di studio relativo all'impiego di misure in situ per la valutazione dello stato di conservazione di opere in bronzo esposte a corrosine atmosferic
In-situ multi-analytical study of ongoing corrosion processes on bronze artworks exposed outdoors
No full textThis paper presents a long-term in-situ campaign to monitor contemporary bronze statuary exposed outdoors. The case study relates to the characterisation of three sculptures belonging to the Gori Art Collection, located in the Fattoria di Celle: 'Cavaliere' and 'Miracolo - Composizione' by Marino Marini and 'Due forme o due ombre n°2' by Luciano Minguzzi. The overall conservation state of the sculptures was investigated by means of a multi-analytical and non-invasive approach, involving different techniques. Three-dimensional photogrammetry was performed to fully document the artworks. The chemical and microstructural features of the corrosion patinas were then characterised through X-ray fluorescence and Raman spectroscopy. In addition, the stability and the protective effectiveness of the corrosion products were assessed by electrochemical impedance spectroscopy. Thanks to the combined use of these specific techniques, the information extracted through the different analyses could be correlated with each other and with the exposure conditions. The different corrosion products were identified as being primarily copper sulphates and phosphates, and they were correlated with the different microclimate conditions related to their location on the statues. The information gathered from the presented multi-analytical approach represents the fundamental knowledge required to develop a tailored conservation project to assure the long-lasting preservation of these artworks
Non-invasive characterization of ancient Cu-based coins using Raman spectroscopy
No full textCharacterization of archaeological finds is a challenging case study for researchers, as the need of non-invasive measurements strongly affects the investigation strategies. Moreover, it is almost not possible to follow a fixed protocol, because the measurement conditions should be tailored to the samples under study. This paper presents a preliminary characterization of bronze coins coming from an archaeological site located in the south of Israel. The superficial corrosion layers have been analysed by means of Raman spectroscopy in order to investigate their composition and assess the conservation state of the finds. Reference samples of known composition have also been used to help peaks identification in the Raman spectra. Results coming from this study can help in defining the correct conservation strategies for the artefacts
Preventive conservation plan for a group of bronze sculptures from the Gori Art Collection
No full textThis paper deals with a multi-analytical and long-term in-situ monitoring campaign for evaluating the state of conservation of some outdoor contemporary bronze sculptures of the environmental Gori Collection, at the Fattoria di Celle, located in the municipality of Santomato, Pistoia, Italy. Digital 3D models of the Cavaliere and of one of the thirty-three figures of Katharsis have been made by means of photogrammetry in order to characterize the artworks. On the same sculptures, the chemical composition of the corrosion patinas has been determined by Raman spectroscopy. Moreover, the protective effectiveness of the corrosion products layer has been assessed by means of electrochemical impedance spectroscopy (EIS). The analytical data obtained in the monitoring campaign, still in progress, are discussed as a function of the exposure time and conditions to outdoor environment of the works of art
Raman investigation of corrosion products on Roman copper-based artefacts
No full textThis paper illustrates a case study related to the characterisation of corrosion products present on recently excavated artefacts. The archaeological findings, from the Rakafot 54 site (Beer-Sheva, Israel), consist of 23 coins and a pendant, all dating back to the Roman period. Raman spectroscopy was used to identify the corrosion products that compose the patina covering the objects. To facilitate and support their identification, spectra were then processed using principal components analysis. This chemometric technique allowed the identification of two main compounds, classified as atacamite and clinoatacamite, which formed the main components of the patinas. The results of this investigation can help in assessing the conservation state of artefacts and defining the correct restoration strategy
