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Brokerhof A.W.,Cultural Heritage Agency of the Netherlands | Bulow A.E.,British Museum
Journal of the Institute of Conservation | Year: 2016

Over the past two decades a number of heritage institutions have conducted different forms of risk assessments. Despite the generally agreed profound changes such assessments make to an organization's approach to the care of its collection, there remains a general apprehension concerning the significant effort required to execute such an assessment. This paper describes the development of the QuiskScan, a quick risk scan, which yields an overview over a collection, its values and vulnerabilities with comparatively little effort. The QuiskScan uses a matrix-based approach to map value and vulnerability to the agents of deterioration for different collection units to highlight where significant losses to the collection might occur. Like other risk assessment approaches the QuiskScan involves expert input from across the organization thus helping to create a shared insight into the collection, and an institutional awareness of risks. The method should be regarded as a tool that fits in between relying on best practice and conducting a comprehensive risk assessment.

Joordens J.C.A.,Leiden University | Joordens J.C.A.,VU University Amsterdam | D'Errico F.,French National Center for Scientific Research | D'Errico F.,University of Bergen | And 23 more authors.
Nature | Year: 2015

The manufacture of geometric engravings is generally interpreted as indicative of modern cognition and behaviour. Key questions in the debate on the origin of such behaviour are whether this innovation is restricted to Homo sapiens, and whether it has a uniquely African origin. Here we report on a fossil freshwater shell assemblage from the Hauptknochenschicht ('main bone layer') of Trinil (Java, Indonesia), the type locality of Homo erectus discovered by Eugène Dubois in 1891 (refs 2 and 3). In the Dubois collection (in the Naturalis museum, Leiden, The Netherlands) we found evidence for freshwater shellfish consumption by hominins, one unambiguous shell tool, and a shell with a geometric engraving. We dated sediment contained in the shells with 40 Ar/ 39 Ar and luminescence dating methods, obtaining a maximum age of 0.54 ± 0.10 million years and a minimum age of 0.43 ± 0.05 million years. This implies that the Trinil Hauptknochenschicht is younger than previously estimated. Together, our data indicate that the engraving was made by Homo erectus, and that it is considerably older than the oldest geometric engravings described so far. Although it is at present not possible to assess the function or meaning of the engraved shell, this discovery suggests that engraving abstract patterns was in the realm of Asian Homo erectus cognition and neuromotor control. © 2015 Macmillan Publishers Limited. All rights reserved.

Bayliss S.,Somerset House | Van den Berg K.J.,Cultural Heritage Agency of the Netherlands | Burnstock A.,Somerset House | de Groot S.,Cultural Heritage Agency of the Netherlands | And 2 more authors.
Microchemical Journal | Year: 2015

The observation of disfiguring yellow oil-like material on the surface of paintings by the contemporary Dutch artist Erik Oldenhof led to an investigation of the material and environmental factors causing the migration and surface deposition of the exudate. A combination of material analysis, the examination of artificially aged reconstructions and information provided by the artist and paint manufacturer, Royal Talens, provided evidence that the phenomenon is related to the drying properties of the safflower oil used, the artist's use of thick paint layers and the availability of light while the paint is drying. Reconstructions demonstrated that the exudation phenomenon can be reproduced and is not restricted to one particular range of oil paint or manufacturer.Visual characteristics of the exudate, including its appearance in UV light and SEM back-scattered images, were documented, and the organic and inorganic components of the paint were characterised by SEM-EDX, XRF, THM-PyGC-MS and FTIR. Results confirmed that the exudate is composed of safflower oil derived from the paint binding medium, and that a difference in P/S ratio between the exudate and paint bulk is due to the presence of metal stearates in the paint that have not migrated to the surface. © 2015 Elsevier B.V.

Pozzi F.,School of the Art Institute of Chicago | Van Den Berg K.J.,Cultural Heritage Agency of the Netherlands | Fiedler I.,School of the Art Institute of Chicago | Casadio F.,School of the Art Institute of Chicago
Journal of Raman Spectroscopy | Year: 2014

The Art Institute of Chicago (AIC) owns one of the largest and very finest collections of 19th century French Impressionist and Post-Impressionist paintings in the world. While the palette of the Impressionists has been extensively characterized for what concerns both traditional and innovative inorganic pigments, to date, the identification of the red organic lakes - widely used for their intense, brilliant color - has posed an analytical challenge. In this work, firstly, surface-enhanced Raman spectroscopy has been applied to the analysis of red lake paint reconstructions prepared according to 19th century historical recipes. Results demonstrated that dye identification can be successfully accomplished on Lee-Meisel colloids after hydrolysis with hydrofluoric acid, even when inorganic pigments, extenders, ground materials or binding media are associated with the red lake in the sample analyzed. Subsequently, the same protocol was used to examine samples from Manet, Pissarro, Renoir, Monet and Gauguin paintings in the AIC collection. Results showed the predominant use of madder and cochineal lakes, sometimes in combination, thus greatly enhancing our knowledge of the Impressionist usage of different types of red lakes. Copyright © 2014 John Wiley & Sons, Ltd.

Pereira C.,New University of Lisbon | Busani T.,New University of Lisbon | Branco L.C.,New University of Lisbon | Joosten I.,Cultural Heritage Agency of the Netherlands | Anca Sandu I.C.,New University of Lisbon
Microscopy and Microanalysis | Year: 2013

This work establishes a multiscale and multitechnique nondestructive approach as valid methodology for monitoring surface properties and evaluating the effectiveness of enzymatic removal of varnishes from paintings/polychrome artefacts. Mock-up samples (documented reconstructions of oil, tempera, and gilded layers on canvas and wooden supports) were covered with different proteinaceous varnishes (egg white, animal and fish glue, casein) and then characterized before and after the removal of these coatings with enzyme-based solutions. The varnish was cleaned in several steps (two dry swabs and two wet swabs) with a clearance step for removing the residues from proteinaceous varnish or from enzyme solution. Microscopy [stereomicroscopy (SM), optical microscopy (OM), atomic force microscopy (AFM), and scanning electron microscopy (SEM)] and colorimetric (CIE L*a*b* system) techniques were used for characterization of the reconstruction surfaces at different scales (macro-scale by SM and OM; micro-scale by SEM and nano-scale by AFM). These techniques were also used to monitor the cleaning treatment. Although results presented in this work were obtained for the specific treatment of enzyme removal, the methodology could be extended to other types of materials and cleaning. Further experiments on real works of art are needed for a complete validation of the methodology. Copyright © 2013 Microscopy Society of America.

van Dam E.P.,Cultural Heritage Agency of the Netherlands | van den Berg K.J.,University of Amsterdam | Proano Gaibor A.N.,Cultural Heritage Agency of the Netherlands | van Bommel M.,University of Amsterdam
International Journal of Mass Spectrometry | Year: 2016

An LC-ESI-MS method is presented as a novel approach for the study of aged drying oils and oil paints in various stages of oxidation and hydrolysis. The method involves separation and detection of glycerides and fatty acids on a reversed phase column using a polar gradient ranging from methanol/water to methanol/isopropanol with post-column addition of NH4Ac to facilitate electrospray ionisation. This setup allows for a reasonable separation of non-polar triglycerides in drying oil as well as very polar oxidised and hydrolysed tri, di and monoglycerides as well as free fatty acids. Detection is performed by using both positive and negative ionisation mode: positive ions for glycerides, negative ions for carboxylic acid containing degradation products and free fatty acids.In this way, distinction can be made between components in oil and metal stearate mixtures by independently probing the palmitic acid/stearic acid (P/S) ratios of the free fatty acids which mostly derive from the metal stearates, and the glycerides which derive only from the drying oil components.Analyses of 10 year-old titanium white oil paints with medium exudations and 62 year-old paints from Winsor&Newton are presented as examples to show the applicability of the method. © 2016 Elsevier B.V.

van Geel B.,University of Amsterdam | Brinkkemper O.,Cultural Heritage Agency of the Netherlands | Weeda E.J.,Veerallee 28 | Sevink J.,University of Amsterdam
Geologie en Mijnbouw/Netherlands Journal of Geosciences | Year: 2016

We studied a Holocene peat fill of a small depression in Pleistocene coversand, in the western border zone of Het Gooi, to assess the early local and regional vegetation history in relation to sea-level rise, soil development and potential human impact. In the fourth millenium BC, a podzol which had formed in the depression became stagnative, leading to the development of a moorland pool. The local vegetation changed from dry heathland, through an amphibic vegetation type with, among others, Littorella uniflora and Lycopodiella inundata, to a permanently moist Sphagnum-dominated vegetation. The existence of moorland pools and the development of such habitats into Sphagnum-dominated vegetation are known from Late-Holocene anthropogenic, more or less open landscapes that were formed on a podzolising sandy soil under ericaceous vegetation. However, the recorded vegetation succession did not show any recognisable local human impact and therefore is attributed to natural succession. In the period concerned, sea level was still about 4 m below the land surface in the depression, implying that water logging occurred independent from a rise in sea level and associated groundwater level. It took until the Late Middle Ages before such rise led to significant water logging and peat growth in this border zone, but the mean groundwater level never reached to above NAP (Dutch Ordnance Datum). Copyright © Netherlands Journal of Geosciences Foundation 2016

van Lanen R.J.,University Utrecht | van Lanen R.J.,Cultural Heritage Agency of the Netherlands | Kosian M.C.,Cultural Heritage Agency of the Netherlands | Groenewoudt B.J.,Cultural Heritage Agency of the Netherlands | And 2 more authors.
Geoarchaeology | Year: 2015

This study focuses on reconstructing landscape prerequisites for Roman and early-medieval routes in the Netherlands. We applied spatial modeling to modern and paleogeographical landscape data in order to determine geographical obstacles for possible translocation in ca. A.D. 100 and 800 via land and water. Network-friction values were calculated to produce a spatial model of possible movement corridors and to enable the integration of archaeological data. Results show that in geographically dynamic lowland regions such as the current Netherlands, landscape units such as water, peat, and levees must have had a high impact on route orientation. The lower parts of the western Netherlands were almost inaccessible by land, implying that its inhabitants largely must have depended on rivers and streams for transportation. In Dutch coastal and river areas, the landscape changed drastically between A.D. 100 and 800, the largest changes occurring along the coast. © 2015 Wiley Periodicals, Inc.

PubMed | University of Amsterdam, University of Glasgow and Cultural Heritage Agency of the Netherlands
Type: | Journal: Journal of chromatography. A | Year: 2016

This research makes the first attempt to apply Ultra High Performance Liquid Chromatography (UHPLC) coupled to both Photodiode Array detection (PDA) and Electrospray Ionisation Mass Spectrometer (ESI-MS) to the chemical characterisation of common textile dyes in ancient China. Three different extraction methods, respectively involving dimethyl sulfoxide (DMSO)-oxalic acid, DMSO and hydrochloric acid, are unprecedentedly applied together to achieve an in-depth understanding of the chemical composition of these dyes. The first LC-PDA-MS database of the chemical composition of common dyes in ancient China has been established. The phenomena of esterification and isomerisation of the dye constituents of gallnut, gardenia and saffron, and the dye composition of acorn cup dyed silk are clarified for the first time. 6-Hydroxyrubiadin and its glycosides are first reported on a dyed sample with Rubia cordifolia from China. UHPLC-PDA-ESI-MS with a C18 BEH shield column shows significant advantages in the separation and identification of similar dye constituents, particularly in the cases of analysing pagoda bud and turmeric dyed sample extracts.

PubMed | Technical University of Delft and Cultural heritage agency of the Netherlands
Type: | Journal: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy | Year: 2016

Titanium white (TiO

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