References of "Strivay, David"
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See detailDevelopment of a translation stage for in situ non-invasive analysis and high resolution imaging
Strivay, David ULg; Clar, Mathieu ULg; Rakkaa, Saïd ULg et al

Poster (2016, March)

Non-invasive imaging techniques and analytical instrumentation for cultural heritage object studies have undergone a tremendous development over the last years. Many new miniature and/or handheld systems ... [more ▼]

Non-invasive imaging techniques and analytical instrumentation for cultural heritage object studies have undergone a tremendous development over the last years. Many new miniature and/or handheld systems have been developed and optimized. Nonetheless, these instruments are usually used with a tripod or a manual position system. This is very time consuming when performing point analysis or 2D scanning of a surface. The Centre Européen d’Archéométrie (CEA) has build a translation system made of pluggable rails of 1 m long with a maximum length and height of 3 m. Three motors embedded in the system allow the platform to be moved along these axis, toward and backward from the sample. The rails hold a displacement system, providing a continuous movement. Any position can be reached with a reproducibility of 0.1 mm. The displacements are controlled by an Ethernet connection through a laptop computer running a multiplatform homemade software written in JAVA. This software allows a complete control over the positioning using a simple, unique, and concise interface. Automatic scanning can be performed over a large surface of 3 meters on 3 meters. The Ethernet wires provide also the power for the different motors and, if necessary the detection head. The platform has been originally designed for a XRF detection head (with its full power alimentation) but now can accommodate many different systems like IR reflectography, digital camera, hyperspectral camera, Raman probes, etc. The positioning system can be modified to combine the acquisition software of the imaging or analytical techniques and the positioning software. [less ▲]

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See detailOn the processing of red pigment by late mousterian Neanderthals in Ormesson, Seine-et-Marne, France, 47000 years ago
Salomon, Hélène ULg; Bodu, Pierre; Geurten, Stéphanie et al

E-print/Working paper (2016)

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See detailRecent technical developments of non-invasive cultural heritage analysis at the University of Liège
Strivay, David ULg; Chene, Grégoire ULg; Calvo Del Castillo, Helena ULg et al

Conference (2015, December 07)

The University of Liège has more than twenty years of experience in the use of ion beam analysis techniques for cultural heritage research. We will present here some of the recent developments. First, we ... [more ▼]

The University of Liège has more than twenty years of experience in the use of ion beam analysis techniques for cultural heritage research. We will present here some of the recent developments. First, we have developed a high energy extracted beamline up to 20 MeV on our cyclotron with a good energy resolution of a few keV. These last years Ion Beam Analysis users show an interest in High Energy Alpha beam. These beams can be used for on-site analysis by means of radioactive sources e.g. for space application but they also offer a powerful combination of properties for the analysis of thick layers (about 10 to 20 µm). This kind of layers are often met in cultural heritage applications but can be also present on new materials. Contrary to this kind of materials where the principal information needed is the in-depth profiles as the sample are of known composition, for cultural heritage materials the combination of elemental analysis and their in-depth distribution is essential as the nature of the material is a-priori not known. We will also present the development around our first extracted beamline. We have indeed improved the automatic scanning system for macro-PIXE. Some examples will be shown. Finally we will show other non-invasive analysis developments related to cultural heritage. [less ▲]

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See detailUnraveling expressionism
truscott, tadd; Darbois-Texier, Baptiste ULg; lovett, benjamin et al

Conference (2015)

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See detailTowards portable X-ray spectroscopic imaging of Palaeolithic cave art. Insights into used pigments and wall taphonomy at three Palaeolithic key cave sites
Gay, Marine; Muller, Katharina; Plassard, Frédéric et al

Poster (2014, May)

Palaeolithic cave art has taken a more and more important place in our cultural heritage. Its preservation is one of the major issues and involves necessarily a better understanding of the cave ... [more ▼]

Palaeolithic cave art has taken a more and more important place in our cultural heritage. Its preservation is one of the major issues and involves necessarily a better understanding of the cave environments and of their evolution over time. However, the on-site geo-physico- chemical study of archaeological record stays dif cult and the conservation of its integrity imposes restrictions. Taking bene t of recent analytical developments in the X-ray eld, new perspectives of acquiring statistically relevant data for archaeological interpretation directly in the eld are provided by the implementation of portable and non-invasive characterization methods. It allows the improvement of archaeological and physico-chemical knowledge about the pigments used, the evaluation of the state of wall decorated surfaces over time and a better assessment of the relationship between pigment and wall support. For these purposes, complementary self-built portable spectrometers (X-ray uorescence in one and two dimensional mode, X-ray diffraction) are combined to perform qualitative and quantitative characterization of the pigments and cave walls as well as for chemical imaging on a decimetre scale. By using this combination of portable instruments the feasibility of analysis under very dif cult conditions speci c to the cave environments (humidity, temperature, dif cult access to the caves and to the decorated panels) was shown. Special spectrum evaluation procedures have been developed to take into account the heterogeneity of the cave walls in order to gain reliable data for chemical characterisation. The ef ciency of the analytical procedure has been demonstrated for three major cave sites featuring Palaeolithic art: Font-de-Gaume and Rouf gnac cave in Dordogne (France) and La Garma in Cantabria (Spain). A large assortment of colours can be observed in these caves (red, black, yellow and purple), associated to different mineral phases (iron and/or manganese oxides, charcoal and mixtures). Their detailed characterization provides an improved comprehension of the pictorial techniques used. Furthermore, it allows a better comparison between representations in a same cave, giving more detailed insights into its pictorial homogeneity and the different execution phases of its gures. As an example, the results obtained at Rouf gnac cave showed that heterogeneous mixtures of manganese oxides have been employed to design the 65 Great Ceiling gures whereas a unique pigment mixture has been used for the drawing of the Ten Mammoths Frieze. Further information has been obtained on the taphonomic wall processes. The spectroscopic study of these cave art illustrate the strong potential of such combined in situ and non-invasive analyses to better characterize the prehistoric gures in their cave environment and in a wider perspective to better understand the symbolic practices of past societies, appreciate possible cultural changes and relationships within the Franco-Cantabrian region. [less ▲]

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See detailPB15 as 20th and 21st Artists’ Pigments: Conservation Concerns
Defeyt, Catherine ULg; Strivay, David ULg

in E‐Preservation Science (2014), 11

Copper phthalocyanine (CuPc) provides the most important blue and green pigments from the 21st century artists’ paints. This paper focuses on the blue pigments of CuPc, which are referenced in the Colour ... [more ▼]

Copper phthalocyanine (CuPc) provides the most important blue and green pigments from the 21st century artists’ paints. This paper focuses on the blue pigments of CuPc, which are referenced in the Colour Index as PB15. The employment of PB15 as artists’ pigments since the very beginning until now is summarized through archives of artists’ color makers and current color charts. Moreover, for the first time, a review of the cases of PB15 identifica- tion encountered in the field of cultural heritage is presented. For each case reported in this study, the analytical methods that allowed identifying the blue pigment are specified. The significance and the relevance of various destructive and non-destructive methods, for this topic in particular are also discussed. Finally, the implications of PB15 in common conservation prac- tices are outlined. [less ▲]

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See detailÉtude technique et matérielle des tableaux liégeois
Defeyt, Catherine ULg; Strivay, David ULg

in Duchesne, Jean-Patrick (Ed.) L'art dégénéré selon Hitler (2014)

Les études dans le domaine du patrimoine culturel peuvent généralement se ranger en deux catégories. La première catégorie concerne les analyses physico-chimiques qui visent à une meilleure compréhension ... [more ▼]

Les études dans le domaine du patrimoine culturel peuvent généralement se ranger en deux catégories. La première catégorie concerne les analyses physico-chimiques qui visent à une meilleure compréhension de l'œuvre via le gain d'information sur les matériaux utilisés et la technologie mise en œuvre. Ces données peuvent conduire à une datation de l'objet et à l'identification de son origine géographique et permettent de documenter l'évolution et l'histoire des techniques artistiques. La seconde classe de ces études archéométriques se focalise sur l'état de conservation de l'œuvre et sur l'origine de ses éventuelles altérations apparues au cours du temps. L'objectif est donc d'identifier ces mécanismes de dégradations car ces dernières peuvent significativement altérer la perception de l’œuvre et compliquer le travail de restauration, dont le but premier est de respecter l’intention initiale de l’artiste. Le but ultime de ce type d'études est d'optimiser les conditions de conservation des œuvres existantes et d'améliorer la durabilité des matériaux artistiques modernes qui seront utilisés dans le futur. Le Centre Européen d’Archéométrie de l’Université de Liège, fondé en 2003, s’est spécialisé dans l’étude du patrimoine culturel mobilier et immobilier. La bonne conduite des projets de recherches menés au Centre d’Archéométrie nécessite une étroite collaboration entre scientifiques et archéologues, conservateurs et historiens d’art. Le centre se veut un acteur dynamique dans la conservation du patrimoine culturel belge. Pour ce faire, il est nécessaire de dresser un premier bilan de l'état des objets conservés et de poser un diagnostic de leur état de conservation. Dans de nombreux cas, il est très difficile, voire inconcevable, de déplacer ou de prélever les objets du patrimoine culturel étudiés. C’est pourquoi les recherches sur les techniques d’analyse non invasives et mobiles connaissent un développement très important ces dernières années. Actuellement, l’utilisation combinée de plusieurs techniques mobiles, telles que la fluorescence X, la diffraction X, la spectroscopie Raman ou infrarouge à transformée Fourier reste très restreinte et peu exploitée lors des campagnes d’analyses in situ. La plateforme d’instruments portables du Centre Européen d’Archéométrie permet de documenter de manière complète et systématique les œuvres des collections et de poser un constat de l’état de conservation et d’altération de ces objets. Dans le cadre du partenariat de recherche entre le CEA et les musées de la Ville de Liège récemment mis en place et grâce à un financement du Fonds Jean-Jacques Comhaire (Fondation Roi Baudouin), nous avons étudié les tableaux de la vente de Lucerne de 1939. Ces œuvres majeures ne peuvent être déplacées et ont donc été étudiées par des méthodes mobiles. L'utilisation de la plate-forme expérimentale mise en place au Centre Européen d’Archéométrie a permis d'identifier les matériaux utilisés et de caractériser les techniques picturales des différents artistes. Nous montrons ici les résultats concernant les tableaux de Paul Gauguin, Pablo Picasso et James Ensor. [less ▲]

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See detailDistinction by micro-Raman spectroscopy and chemometrical analysis of copper phthalocyanine blue polymorphs in oil-based and acrylic samples
Defeyt, Catherine ULg; Van Pevenage, Jolien; Learner, Tom et al

in Van den berg, K.J.; Burnstock, A.; de Tagle, A. (Eds.) et al Issues in Contemporary Oil Paints (2014)

Copper phthalocyanine (CuPc) blue, commonly named phthalo blue is the most important synthetic organic blue pigment in the 20th and 21st century artists paints. Phthalo blue, which is adopted by artists ... [more ▼]

Copper phthalocyanine (CuPc) blue, commonly named phthalo blue is the most important synthetic organic blue pigment in the 20th and 21st century artists paints. Phthalo blue, which is adopted by artists since 1936, is a polymorphous pigment. Currently, the alpha, beta and epsilon CuPc polymorphs are used in artists paint formulations. The identification of the CuPc crystal form provides technical and chronological information relevant for studying artworks. Raman Spectroscopy (RS) is a very valuable technique for the detection of phthalo blue in paint layers. However, the spectral interpretation is not straightforward concerning the CuPc polymorph distinction. To overcome the problem we have previously developed a procedure combining RS and chemometrical analysis. The experimental results that we obtained have demonstrated its efficiency for predicting the CuPc crystal form in unknown paint samples. In the present work, this procedure was applied on oil-based and acrylic paints from Sam Francis’ studio and the Getty Conservation Institute (GCI) Reference Collection. [less ▲]

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See detailLes vitraux alto-médiévaux de Stavelot (Belgique)
Van Wersch, Line; Biron, Isabelle; Neuray, Brigitte et al

in ArchéoSciences (2014), 38

This paper is about the early medieval window glass from the monastery of Stavelot. The number of fragments, the surface and the quality of conservation are quite exceptional and Stavelot appears as a ... [more ▼]

This paper is about the early medieval window glass from the monastery of Stavelot. The number of fragments, the surface and the quality of conservation are quite exceptional and Stavelot appears as a very important site for the study of ancient glass, especially glass from the early Middle Ages that is still little known. Beside their interest for the history of the site and its comprehension, these glass artifacts give us the possibility to reach the history of stained-glass window and glass fabrication techniques. The archaeological study allows us to quantify and characterize the artifacts (shapes, color, shaping techniques). The analyses in PIXE-PIGE provide the glass composition. Further the coexistence of soda and potash glass in the same archaeological contexts, it points out compositional groups revealing various recipes. Thanks to it, we can also reach coloration recipes. Finally, the question of glass production on the site is debated. [less ▲]

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See detailAnalytical study of “La Famille Soler” by Picasso: from the Blue Period to Cubism
Defeyt, Catherine ULg; Vekemans, Bart; Vandenabeele, Peter et al

Poster (2013, September 23)

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See detailPIXE Analysis for the pigment identification in the Nizet manucript (18th century)
Machowski, Mélanie ULg; Calvo Del Castillo, Helena ULg; Oger, Cécile ULg et al

Poster (2013, September)

Written in 1740, the Nizet Manuscript is a heraldry book compiling the genealogy of the Nizet family (Verviers, Belgium). It presents a large number of hand-painted heraldries in traditional heraldic ... [more ▼]

Written in 1740, the Nizet Manuscript is a heraldry book compiling the genealogy of the Nizet family (Verviers, Belgium). It presents a large number of hand-painted heraldries in traditional heraldic colours; the gold- and silver-like colours have undergone alteration and induced the degradation of the paper. The first inspection of the book with a binocular lens and UV-visible spectroscopy has led to the selection of representative points to be studied by PIXE analysis for the different groups of pigments. The PIXE measurements have been conducted with the cyclotron of the Institute of Nuclear and Atomic Physics and of Spectrometry of the University of Liege. Some pigments have been clearly identified, such as vermillion, umber or brass, while the presence of some others needs to be confirmed, for example azurite or lapis-lazuli. In the case of the green pigments and the organic ones (red, pink and black colours), the PIXE results must be completed by a molecular analysis. In order to exactly identify all the pigments, Raman analyses will be done to complete the pigment identification of the Nizet Manuscript. [less ▲]

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See detailArchaeometry Research on the Wall Paintings in the Tomb Chapel of Menna
Garcia Moreno Rodriguez, Renata ULg; Hocquet, François-Philippe ULg; Mathis, François ULg et al

in Hartwig, Melinda (Ed.) The Tomb Chapel of Menna (TT 69): The Art, Culture, and Science of Painting in an Egyptian Tomb (2013)

Detailed reference viewed: 90 (17 ULg)
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See detailDetermination of activation yield curves for fusion escaping particle diagnostics
Strivay, David ULg; Bonheure, George; Delvigne, Thierry et al

Conference (2013, June)

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See detailDetermination of activation yields for fusion plasma escaping charged particles diagnostics
Chene, Grégoire ULg; Bonheure, George; Delvigne, Thierry et al

Conference (2013, June)

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See detailRelationship between the Synthesis of Prussian Blue Pigments, Their Color, Physical Properties, and Their Behavior in Paint Layers
Samain, Louise ULg; Grandjean, Fernande ULg; Long, Gary J. et al

in Journal of Physical Chemistry C (2013), 117(19), 96939712

Prussian blue pigments, highly insoluble mixed-valence iron(III) hexacyanoferrate(II) complexes of typical stoichiometry Fe4III[FeII(CN)6]3·xH2O or KFeIII[FeII(CN)6]·xH2O, have been used as pigments in ... [more ▼]

Prussian blue pigments, highly insoluble mixed-valence iron(III) hexacyanoferrate(II) complexes of typical stoichiometry Fe4III[FeII(CN)6]3·xH2O or KFeIII[FeII(CN)6]·xH2O, have been used as pigments in oil paintings and watercolors for 300 years. For poorly understood reasons, these pigments often fade with time. Although the preparation methods have been recognized since the mid-eighteenth century as a contributory factor in the fading of the pigment, the spectral and physical properties of Prussian blue that vary with the type of synthesis were not precisely identified. Several Prussian blue pigments have been prepared by different methods and characterized by thermogravimetric analyses, high-energy powder X-ray diffraction, atomic absorption and flame emission, UV–visible, iron-57 Mössbauer, iron K-edge X-ray absorption, and Raman spectroscopy. The type of synthesis influences the hue, tinting strength, and hiding power properties of the Prussian blue pigments. Two major features appear to be strongly dependent on the preparative methods, the particle size and the local disorder. Both a nitrogen atmosphere and an intermediate aging step of the Berlin white, Fe2II[FeII(CN)6], during the synthesis are required to obtain a highly colored pigment through the optimization of particle size, minimization in the perturbations to the FeII–CN–FeIII intervalence electron transfer pathway, and the minimization of disordered vacancies. The potassium containing Prussian blue structure has been revisited. It can be described with the Pm3m space group, where approximately one-quarter of the [FeII(CN)6]4– sites are vacant and where the potassium cation is located at a zeolitic-like position inside the lattice cavities. The degree of ordering of the [FeII(CN)6]4– vacancies in all Prussian blues was quantified using atomic pair distribution analysis, an ordering that is consistent with the iron K-edge X-ray absorption spectra. The presence of strain in the crystals is observed by both powder X-ray diffraction and Mössbauer spectroscopy. The structural similarity between the alkali-free, improperly referred to as “insoluble”, and the alkali containing, “soluble”, Prussian blues may explain why the two varieties are almost undistinguishable by spectroscopic techniques. [less ▲]

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See detailLes perles en verre de la nécropole de Bossut–Gottechain : recettes et fabrication
Mathis, François ULg; Vrielynck, Olivier; Leroy, Amandine et al

Conference (2013, April)

La nécropole de Bossut Gottechain est une des plus grandes nécropoles mérovingiennes jamais trouvée en Belgique. Les fouilles conduites entre 2002 et 2006 ont permis de mettre au jour 436 tombes sur une ... [more ▼]

La nécropole de Bossut Gottechain est une des plus grandes nécropoles mérovingiennes jamais trouvée en Belgique. Les fouilles conduites entre 2002 et 2006 ont permis de mettre au jour 436 tombes sur une période d’occupation s’étalant de 470 à 670 ap J.C. Ces tombes contenaient un matériel funéraire important composé d’armes, d’accessoires de vêtement, de récipients en céramique, en métal et en verres, et de bijoux parmi lesquels une quantité inhabituellement importante de perles. Plus de 8000 spécimens ont été retrouvés, la majorité en verre (environ 6800 soit 82% du corpus), mais aussi en ambre, pierre, céramique ou métal. L’abondance de ce matériel et la datation fine de ce site ont permis de dresser une typo-chronologie précise de cette production affinant la description des types et des périodes d’utilisation déjà connus. Nous avons voulu en plus de l’étude purement archéologique de ces perles porter une attention particulière au matériau qui les compose. Une campagne d’analyse physico-chimique a donc été engagée. La méthode choisie a été la spectroscopie PIXE- PIGE en faisceau extrait, cette méthode d’analyse non invasive et très sensible aux éléments légers étant particulièrement adaptée à notre corpus d’objets nombreux mais précieux. Ces analyses ont été conduites sur la ligne de faisceau extrait ARCHEO de l’accélérateur de l’Institut de Physique Nucléaire, Atomique et de Spectroscopie de l’université de Liège. Nous avons pu analyser plus de trois cent perles. Une attention particulière a été portée sur les perles en verres jaune et noire, abondamment représentées dans le corpus, ainsi que sur plusieurs perles dont le type rare ou unique sur le site nous interrogeait. Les résultats de cette recherches ont été particulièrement fructueux car nous avons pu mettre en exergue la pratique connue du remploi de perles en verre romain ou protohistorique à l’époque mérovingienne, et confirmer le changement de recettes d’opacifiant/colorant dès le tout début de la période mérovingienne où l’utilisation d’oxydes d’étain ou de stannates de plomb est généralisée et celle des antimoniates complètement abandonnée. Enfin nous avons pu mettre en évidence l’utilisation d’un verre très riche en plomb pour la fabrication de perles noires dès le début de la période d’occupation du site, verre qui à notre connaissance n’a jamais été documenté [less ▲]

Detailed reference viewed: 109 (3 ULg)