Nick Schiavon

Universidade de Évora | uevora · Laboratório HERCULES - Herança Cultural, Estudos e Salvaguarda

The impact of wavelength and pulse duration in laser cleaning of hard blackish contaminants crust from archaeologically significant Pleistocene bone is investigated in this research. The objective is to determine the practical cleaning procedures and identify adequate laser parameters for cleaning archaeological bone from Sima de los Huesos (Spain)...

The Bell Beaker site near Brodek u Prostějova (Czechia) has yielded remains of a large timber construction accompanied by four symmetrical ritual deposits with numerous artefacts, including more than fifty ceramic vessels. Their decoration consists of incised patterns, in nineteen cases with preserved white inlaid incrustations. To investigate the...

A multidisciplinary approach has been applied to investigate the production technology of a collection of copper-based artefacts found during archaeological excavation campaigns carried out in the Almohad neighbourhood of Mārtulah, the Islamic name of modern Mértola (South of Portugal). In stark contrast to other Islamic materials found in the same...

Samples of orange patinas found on a limestone window tracery and an ornament of the Batalha Monastery have been investigated by X-ray micro-diffractometry (μ-XRD) and low-vacuum scanning electron microscopy coupled with energy dispersive spectrometry (LV-SEM + EDS). The aim of the study was to determine the composition of the layered patinas, asse...

Stained-glass windows play an important role in cultural heritage. Human and environmental factors have subjected these pieces to risks of damage. Mechanical and chemical-based cleaning methods have been used for their restoration and conservation. Additionally, short-pulse lasers have opened new opportunities for safe and controlled cleaning and r...

A multidisciplinary approach has been applied to investigate the production technology of a collection of copper-based artefacts found during archaeological excavation campaigns carried out in the Almohad neighbourhood of Mārtulah, the Islamic name of modern Mértola (South of Portugal). In stark contrast to other Islamic materials found in the same...

Controlled laser irradiation parameters using recently developed sub-nanosecond pulsed laser technology with emission wavelength in the near Infrared regime (1064 nm) have been assessed on a Pleistocene bone from the archaeological site of Sierra de Atapuerca, Spain. Burst pulse mode was employed to explore contaminant removal efficiency, while at...

A diachronic, multi-analytical approach combining EDXRF, µ FTIR, µ Raman, SEM-EDS, and Py-GC/MS has been adopted with the aim to study for the first time the painting materials used to decorate Egyptian funerary masks and sarcophagi ranging from the Late Period to the Roman Period and stored in the Archaeological National Museum (MNA) and the Carmo...

Plasma etching is an innovative technique that has been recently applied in the cleaning of soiled archaeological objects. This research investigated the use of low-pressure plasma etching in cleaning microbial contaminations on an oolitic limestone from an UNESCO World Heritage listed monument: the Batalha Monastery in Central Portugal. The cleani...

p class="Abstract">To assess the provenance of the limestones used in the construction and restoration of the Batalha Monastery in central Portugal, stone samples collected from the monument and from five limestone quarries in the region surrounding the building were investigated by energy-dispersive X-ray fluorescence spectroscopy (ED-XRF), powder...

Samples of orange patinas found on a limestone balustrade and an ornament of the Batalha Monastery have been investigated by X-ray micro-diffractometry (µ-XRD) and Low-Vacuum Scanning Electron Microscopy coupled with Energy Dispersive Spectrometry (LV-SEM + EDS). Aim of the study was to determine the composition of the layered patinas, assess wheth...

Hypogenic caves represent unique environments for the development of specific microbial communities that need to be studied. Caves with rock art pose an additional challenge due to the fragility of the paintings and engravings and to microbial colonization which may induce chemical, mechanical and aesthetic alterations. Therefore, it is essential t...

An experimental study was conducted to assess the nature and extent of the biodeterioration of the limestone in the Batalha Monastery in Portugal. Stone fragments covered with microbial biofilms and lichenous crusts were investigated using Optical Microscopy (OM), Low Vacuum Scanning Electron Microscopy with Energy Dispersive Spectroscopy (LV-SEM +...

Twenty transparent glass fragments from Miranduolo were analysed by Variable Pressure - Scanning ElectronMicroscopy - Energy Dispersive System (VP-SEM-EDS), Particle Induced X-Ray Emission and Particle InducedGamma-Ray Emission (PIXE/PIGE) and Laser Ablation - Inductively Coupled Plasma - Mass Spectrometry (LA-ICP-MS). The fragments are dated from...

The authenticity and provenience of what is known as the Francisco Pizarro’s Banner of Arms, stored at the National Museum of Colombia and related to the Spanish conquest of the Inca Empire, has been the object of debate amongst both historians and conservation experts for the last two centuries. In this study, a multi-analytical approach has been...

The study presents and discuss the results obtained by the archaeometrical investigation carried out on Islamic and post Islamic ceramic recovered from the town of Santarém, located on the right bank of the river Tagus, at 80 km from Lisbon, Portugal. The objects of this study come from several archaeological excavations covering a chronological ti...

In this study, Monte Carlo (MC) simulations combined with energy dispersive X-ray fluorescence (EDXRF) spectroscopy have been used to characterize non-destructively a collection of Cu-based artifacts recovered from two archeological sites in southern Portugal: (a) the Chalcolithic E.T.A.R. site of Vila Nova de Mil Fontes and (b) the Middle Bronze A...

The Lalibela rock-hewn churches are one of the most important religious pilgrimage sites in Ethiopia. These churches are carved from the scoriaceous basalt rock substrate, which has been exposed to attack by biological agents with significant loss of surface material. Particularly, the widespread growth of lichens and other microorganisms on the ca...

Archaeometric research on the historical banner of the National Museum of Colombia, attributed to Francisco Pizarro and its campaign of conquering the Inca empire (nowadays Peru), with aims to clarify its provenance, authenticity and characterize its material composition.

A non-invasive multi-analytical approach combining optical microscopy (OM), micro- X-ray diffraction (µXRD), in-situ X-ray fluorescence spectroscopy (XRF), variable pressure scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (VP-SEM-EDS) and Raman micro-spectroscopy has been employed for the first time to investigate the...

The chemical mapping of corrosion layers by PIXE/PIGE was performed on medieval (1250-1350 AD) tableware glass from Miranduolo, Chiusdino, Italy.

Synchrotron-based XRD spectra from rat bone of different age groups (w, 56 w and 78w), lumber vertebra at early stages of bone formation, Calcium hydroxyapatite (HAp) [Ca10(PO4)6(OH)2] bone fill with varying composition (60% and 70%) and bone cream (35–48%), has been acquired with 15 keV synchrotron X-rays. Experiments were performed at Desy, Hambu...

Microorganisms play a crucial role in Cultural Heritage’s context by inducing structural and aesthetical damages. Among stone related artworks, Cave Art is primordial in the understanding of the development of art in humans’ societies. Although, they were preserved during millennia, these paintings and engravings are extremely fragile and suffer ch...

A spectrometric protocol combining Energy Dispersive X-Ray Fluorescence Spectrometry with Monte Carlo simulations of experimental spectra using the XRMC code package has been applied for the first time to characterize the elemental composition of a series of famous Iron Age small scale archaeological bronze replicas of ships (known as the “Navicell...

Synchrotron-based high-resolution X-ray powder diffraction spectra from the body parts of a snail and bivalve (CaCO3), have been recorded with Pilatus area detector. Experiments were performed at Desy, Hamburg, Germany, utilizing the Resonant and Diffraction beamline (P9), with 15 keV X-rays (λ=0.82666A0). The external shell of these living organis...

The hoard from Coles de Samuel is one of the largest Cu-based metal collections from the Late Bronze Age (LBA) (13th–8th centuries BC) ever found in Central Portugal, consisting of 18 artefacts which typologically display a strong regional identity. In the present study, an integrated multi-analytical approach combining Energy Dispersive X-Ray Fluo...

An innovative methodological approach based on XRF measurements using a polychromatic X-ray beam combined with simulation tests based on an ultra-fast custom-made Monte Carlo code has been used to characterize the bulk chemical composition of restored (i.e., cleaned) and unrestored multilayered Peruvian metallic artifacts belonging to the twelfth-...

The study and conservation of Cultural Heritage materials is a research area with a strong multidisciplinary, interdisciplinary and even transdisciplinary connotation that requires highly specialized skills spanning across the Humanities, Hard Science, Management, and Business research fields. In fact, the need for a common integrated platform brea...

Depuis plus d'un siècle, l'analyse des matières picturles de l'art pariétal du Paléolithique Supérieur en Europe occidentale a permis d'étudier les recettes et techniques des populations préhistoriques. Grâce aux progrès technologiques de ces quarante dernières années, de nombreuses études se sont portées sur les matières colorantes et pigments pré...

The chemical composition of a unique bronze artifact known as the “Cesta” (“Basket”) belonging to the ancient Nuragic civilization of the Island of Sardinia, Italy has been analyzed by combining X-ray Fluorescence Spectroscopy (XRF) with Monte Carlo simulations using the XRMC code. The “Cesta” had been discovered probably in the XVIII century with...

Tarascan ceramic sherds from two Postclassical archaeological sites (900–1450 AD) at the Malpaís of Zacapu, Michoacán, Mexico, were investigated by combining Back-Scattered Scanning Electron Microscopy and Energy Dispersive Spectroscopy (BSEM-EDS), μ-X-Ray Diffractometry (μ-XRD), μ-X-ray Fluorescence Spectroscopy (μ-XRF) and μ-Raman Spectroscopy. T...

Laser cleaning, as a conservation technique, is a selective, precise and minimal intrusive method of removing corrosion product layers. Nevertheless, in order to optimise this method as a standard conservation technique, it is still necessary to define different laser cleaning methodologies. In this study, laser cleaning was performed with near-IR...

The micro-chemical/mineralogical composition of samples of grey-paste imitations of Italic Late Republican black gloss tableware displaying a particular kind of lozenge-shaped decoration (“Losanga pottery”) from Portuguese and Spanish archaeological sites in SW Iberia has been analysed by BSEM + EDS, μXRD, Powder XRD, Portable XRF and μRaman spectr...

The artwork “Smoke Rings: Two Concentric Tunnels, Non- communicating” by Bruce Nauman represents a case study of corrosion of a black patina-coated Al-alloy contemporary artwork. The main concern over this artwork was the widespread presence of white spots on its surface. Alloy substrate, patina, and white spots were characterized by means of energ...

An innovative spectrometric non-destructive approach has been adopted to analyze Iron-age small-scale bronze replicas of ships, known as “Navicelle”, belonging to the Nuragic civilization in Sardinia, Italy. By combining EDXRF with Monte Carlo simulation of experimental spectra, the approach proved itself as an useful tool when compared with EDXRF...

The micro-chemical/mineralogical composition of samples of grey-paste imitations of Italic Late Republican black gloss tableware displaying a particular kind of lozenge-shaped decoration (“Losanga pottery”) from Portuguese and Spanish archaeological sites in SW Iberia have been analyzed by BSEM +EDS, µXRD, PXRF and µRaman Spectroscopy. “Losanga” de...

In this work we evaluate the composition of a bronze alloy using X-ray fluorescence spectrometry (XRF) and Monte Carlo (MC) simulations. For this purpose, a 7th Century BC archaeological vase from the SW Iberian Peninsula, displaying a well formed corrosion patina was analysed by means of a portable X-ray fluorescence spectrometer. Realistic MC sim...

The artwork "Smoke Rings: Two Concentric Tunnels, Non-Communicating" by Bruce Nauman represents a case study of corrosion of a black patina-coated Al-alloy contemporary artwork. The main concern over this artwork was the widespread presence of white spots on its surface. Alloy substrate, patina, and white spots were characterized by means of energy...

Recent development of post-medieval archeology in Italy over the last 20 years highlighted the need for detailed chemical characterisation of the main types of pottery objects that had a wide circulation throughout the Mediterranean between the 18th and 19th centuries. A particular typology of glazed ceramic believed to have been produced in Sicily...

This study focusses on the development and application of an innovative protocol which combines chemical data, GIS (geographical information system) and PCA, involving numeric (chemical composition) and categorical (typology of object, archaeological context, chronology and geographical areas) variables, as a simple tool to help in the visualisatio...

A multi-analytical approach combining Optical Microscopy (OM), Backscattered Variable Pressure Scanning Electron Microscopy + Energy Dispersive X-ray Spectroscopy (VP-BSEM + EDS), Powder X-ray Diffractometry (PXRD), Raman Spectroscopy and Microbiological techniques has been applied to characterize decay products and processes occurring at the surfa...

A simple, fast and non destructive analytical methodology combining X-ray Fluorescence (EDXRF) and Back-scattered Electron Microscopy coupled with Energy Dispersive Spectroscopy (BSEM+EDS) has been applied to characterize the alloy’s composition of ex-votos metal statuettes of unknown provenance and age stored in the Museum of Évora in Southern Por...

The systematic characterization of the painting’s palette and technique applied on the execution of the mural paintings of the Batalha Monastery (Batalha, Leiria, Portugal) is presented. These are the oldest mural paintings known in Portugal (apart from Roman frescoes) and represent the beginning of an artistic Portuguese tradition that continues u...

In this paper a general method based on energy-dispersive X-ray fluorescence (EDXRF) analysis has been 32 tested to assess its possible use as a tool to reconstruct the structure and determine the thickness of two 33 and/or multi-layered materials. The method utilizes the X-ray intensity ratios of Ka/Kb or La/Lb peaks (or 34 the ratio of these peak...

AAS is overall easier to set up and run, with simpler method development and vast bibliography data available. Whenever the researcher needs to choose the analytical methodology to apply to a set of samples, several considerations should be taken into account, namely, analytical performance (detection limits, precision, dynamic range, possible inte...

Back-scattered Scanning Electron Microscopy (BSEM) has been used to identify weathering mechanisms occurring in two oolitic limestones from urban areas in London and Cambridge, United Kingdom. From a petrographical point of view, the two stones can be described as oosparite and oomicrite, their main distinctive feature being the crystal size of the...

An overview of applications of Small Angle X-ray Scattering (SAXS) techniques to topics of interest in the field of Cultural Heritage is presented. The basic concepts of the technique, a description of sources and laboratory instrumentation and some models and methods for data analysis are discussed. Applications of SAXS to various kinds of materia...

An integrated, multi-analytical approach combining the high sensitivity of SR-mXRF, the light element capability of PIXE/PIGE under a helium flux and the spatial resolution of BSEM + EDS was used to characterize chemical composition and corrosion of glass samples (first to fourth centuries AD) from an important, but scarcely investigated, Roman reg...

As part of a wider project on aerosol composition in the Southwestern part of the Iberian peninsula, an intensive field monitoring/sampling/analytical campaign has been conducted in August and December 2011 to assess indoor and outdoor atmospheric aerosol optical and microphysical parameters (Nephelometry), number/mass/size distribution (TEOM, MAAP...

This paper reports a preliminary study concerning two brass lamps belonging to the Évora Museum collection and one brass lamp belonging to a private collection. The main objective of this study was to acquire scientific data to assess the production technology used in the making of these lamps. Optical microscopy, X-ray digital radiography and scan...

Historical mortars from sixteenth to seventeenth century military forts located at the mouth of the Tagus River in Lisbon have been characterized by polarized light microscopy (PLM), thermal analysis (TG/DTA), X-ray diffractometry (XRD) and scanning electron microscopy+energy dispersive spectroscopy (SEM+EDS). The results indicate that the mortars...

Concretions cemented mainly by siderite, Mg-calcite and iron monosulphide are common in late Holocene marsh and sandflat sediments on parts of the north Norfolk coast. Field experiments have shown that the concretions are actively forming in reduced sediments in which sulphate-reducing bacteria are active. δ13C values ranging from −3 to −11.8‰ (mea...

The chemical-mineralogical composition of the sand fractions of mortars found in Roman villas dating from the 1 st century A.C. located in Northern Italy has been investigated by optical microscopy, scanning electron microscopy plus energy dispersive spectroscopy microanalysis and x-ray diffractometry. The petrographic results on the mortar sam-ple...

Surficial and bulk samples of historical bricks of different age (from XII to XVIII centuries) recovered from a campaign of archaeological excavations recently carried out at the site of a medieval monastery in the S. Giacomo in Paludo Island in theVenice Lagoon have been characterised by FT-IR, TGA-DTG and DTA, XRD, SEM+EDS. The samples belong to...

Under natural acid and wet conditions, one of the main weathering processes affecting granitic rocks is the kaolinisation of Na, Ca and K-feldspar minerals by H2O+CO2 attack. We here report the occurrence of authigenic kaolinite on the surface of an eighteenth century granitic monument covered with sulphate-rich weathering patinas. We suggest that,...

Concretions cemented mainly by siderite, Mg-calcite and iron monosulphide are common in late Holocene marsh and sandflat sediments on parts of the north Norfolk coast. Field experiments have shown that the concretions are actively forming in reduced sediments in which sulphate-reducing bacteria are active. δ13C values ranging from −3 to −11·8% (mea...

The inorganic and organic chemical composition of weathering sulphate patinas on the limestone walls of Emmanuel College, Cambridge, UK, have been analysed by FT-IR spectroscopy, pyrolysis gas-chromatography/mass spectrometry and scanning electron microscopy. The College location is characterized by heavy vehicular exhaust emissions including those...

Scanning electron microscopy in secondary (SEM) and back-scattered (BSEM) mode associated with energy-dispersive X-ray spectroscopy has been used to investigate decay features associated with biological colonization of calcareous and granitic building stones in monuments and rock outcrops in the UK, Portugal and Spain. In combination with physical...

Under natural acid and wet conditions, one of the main weathering processes affecting granitic rocks is the kaolinization of Na, Ca, and K feldspar minerals by water (H20) and carbon dioxide (CO2) attack. The gypsum crystallisation on granitic building stone surfaces is attributed to SO2 air pollution. This chapter describes the study wherein scann...

Wood-grained chert is an unusual type of banded nodular chert that is characterized by alternating thin dark-coloured bands and thicker light-coloured bands, which give the chert a texture reminiscent of the growth rings of wood. The wood-grained texture found in some chert nodules in the Portland Limestone Formation of southern England is the r...

Sulfate-rich dark crusts are acommondecay feature on the surface of urban monuments and buildings. They are composed mainly of a framework of gypsum crystals (CaSO4â2H2O) originating from the reaction between atmospheric SO2 and Ca-rich building materials; within the gypsumcrystalline framework, soil dust and anthropogenic airborne particles derive...

A detailed microscopical and chemical examination by SEM + EDAX, XRD and of black patinas coating the surfaces of urban granitic monuments in Aberdeen and Dublin has revealed a variety of decay features together with a complex chemical composition. Beside sulphate-rich thick patinas composed of a framework of gypsum crystals in which both particula...

Black crust samples, a weathering product of decay on the limestone surface of two famous London monuments, Westminster Palace and Westminster Cathedral, have been collected and examined under SEM with an ED AX attachment. The black crusts are mainly composed of a framework of needle-like and platy gypsum crystals. Aerosol particles, soil dust and...

SULPHATE attack is a significant problem which locally affects concrete and other construction materials in the United Kingdom and overseas. The mechanisms of sulphate attack are fairly well understood, but in some instances it has proved difficult to establish the origin of the sulphate. Possible sulphate sources include soils and ground water, se...

The Woburn Sands (Lower Greensand Group, Aptian–Albian age), in Billington Crossing quarry, Leighton Buzzard, Bedfordshire, England, show, along bedding planes of tabular cross-stratification, foreset alternations of quartz grains and goethitic ooids. Field and petrographic evidence suggest that: (a) the goethite in the layers and cores is primary;...