Initiatives européennes d’IPANEMA et du synchrotron SOLEIL pour l’étude des matériaux anciens

Les particularités du rayonnement synchrotron, notamment sa très grande brillance et son spectre blanc des rayons X à l’infrarouge lointain, en font une source de plus en plus employée pour l’étude de la composition chimique, des propriétés et de la réactivité des matériaux patrimoniaux. La construction de l’Institut photonique d’analyse non destructive européen des matériaux anciens, attenant au synchrotron SOLEIL, par l’État français et la Région Île-de-France permet un soutien fortement accru des équipes françaises et internationales travaillant à l’étude des matériaux anciens. Les allers-retours entre développement de méthodes et applications encouragent à la fois l’apparition de nouveaux instruments et un usage optimisé de techniques de spectroscopie et d’imagerie de pointe. Le développement d’IPANEMA sur le territoire de Paris-Saclay s’inscrit dans le cadre plus global de la mise en place de l’infrastructure européenne E-RIHS, dédiée à l’étude du patrimoine culturel et naturel.The specific features of synchrotron radiation, namely its very high brightness and its white spectrum from X-rays to far infrared light, make it an increasingly used source in the study of the chemical composition, properties and reactivity of ancient materials. Constructed by the French government and the Île-de-France region, adjacent to the SOLEIL synchrotron, IPANEMA (Institut photonique d’analyse non-destructive européen des matériaux anciens/European Institute of Non-Destructive Photonic Analysis of Ancient Materials), provides extensive additional support to French and international teams involved in research into ancient materials. Interaction between the development of methods and applications encourage both the emergence of new instruments and an optimized use of spectroscopic techniques and cutting-edge imaging. The building of IPANEMA on the Paris-Saclay site is part of a more global strategy within E-RIHS, the European Research Infrastructure for Heritage Science

X‐ray fluorescence spectroscopy of picrolite raw material on Cyprus

Picrolite artefacts comprise some of the most distinctive material remains in the prehistory of the island of Cyprus, in the Eastern Mediterranean. Picrolite exploitation dates from at least 12,000 years ago for the manufacture of personal ornaments and items with a symbolic function. It is commonly assumed that picrolite nodules were collected in secondary deposits on an ad hoc basis. This narrative, however, ignores the fact that picrolite carriers can only be found in very specific locations on the island, discrete from each other. Here we report initial outcomes of the application of handheld portable X-ray fluorescence (HHpXRF) and synchrotron-based X-ray fluorescence spectroscopy (SR-μXRF) to the analysis of picrolite raw materials performed at the newly opened PUMA beamline of the SOLEIL Synchrotron Radiation Facility. Our work refines the basic characteristics of the elemental constituents of the picrolite raw material and highlights key micro-structural differences between two distinct source regions on the Troodos Massif in western Cyprus. Picrolite source characterisation is expected to contribute significant new knowledge to the study of rare raw material consumption, prehistoric social organisation, networking and possible long-distance exchange of this idiosyncratic raw material within and beyond the island’s geographic boundaries

Fur glowing under ultraviolet: in situ analysis of porphyrin accumulation in the skin appendages of mammals

Examples of photoluminescence (PL) are being reported with increasing frequency in a wide range of organisms from diverse ecosystems. However, the chemical basis of this PL remains poorly defined, and our understanding of its potential ecological function is still superficial. Among mammals, recent analyses have identified free-base porphyrins as the compounds responsible for the reddish ultraviolet-induced photoluminescence (UV-PL) observed in the pelage of springhares and hedgehogs. However, the localization of the pigments within the hair largely remains to be determined. Here, we use photoluminescence multispectral imaging emission and excitation spectroscopy to detect, map, and characterize porphyrinic compounds in skin appendages in situ. We also document new cases of mammalian UV-PL caused by free-base porphyrins in distantly related species. Spatial distribution of the UV-PL is strongly suggestive of an endogenous origin of the porphyrinic compounds. We argue that reddish UV-PL is predominantly observed in crepuscular and nocturnal mammals because porphyrins are photodegradable. Consequently, this phenomenon may not have a specific function in intra- or interspecific communication but rather represents a byproduct of potentially widespread physiological processes.publishedVersio

A new 3D positioner for the analytical mapping of non-flat objects under accelerator beams

We report the development of a 3D positioner for the elemental mapping of non-flat surfaces of heritage targets and its implementation in the external beam of the AGLAE accelerator, a joint research activity of the IPERION-CH European program.The positioner operates in two steps: 1) object surface is digitized using a 3D scanner implemented in the beamline. Surface points are interpolated onto a rectangular grid suitable for beam scanning. 2) Object is scanned under the beam using X/Y/Z stages holding a hexapod robot for rotations. During scanning, target surface is positioned with the Z stage and oriented perpendicular to the beam using hexapod rotations. Areas up to 100 × 100 mm 2 with a resolution of 50 µ m and 30° curvature of can be mapped on objects of 200 mm and 5 kg max. System operation was tested by recording PIXE maps on the polychrome decoration of a curved porcelain pot

A new Early Triassic crinoid from Nevada questions the origin and palaeobiogeographical history of dadocrinids

Knowledge of the early evolution of post-Palaeozoic crinoids mainly relies on the well-preserved and abundant material sampled in Triassic Konservat-Lagerstätten such as those from the Anisian Muschelkalk (Middle Triassic) of the Germanic Basin. These crinoid-bearing Lagerstätten have been central to understanding the rapid evolution and diversification of crinoids after the dramatic Permian/Triassic Boundary biological crisis that led the class to near-extinction. The Encrinida are the emblematic crinoids of the Triassic. They are mainly known from rich fossil deposits where their abundant ossicles are at the origin of the extensive crinoidal limestone beds of the German Upper Muschelkalk. So far, they were first represented in the Middle Triassic by the family Dadocrinidae and genus Dadocrinus. In the present work, a new species Dadocrinus montellonis sp. nov., is described based on a well-preserved, almost complete articulated specimen from the Spathian (Lower Triassic) of Nevada (USA). The new species differs from other species of Dadocrinus by its palaeobiogeographic position but also by its earlier stratigraphic occurrence and ancestral morphology. It represents the first reported occurrence of Dadocrinus outside the Germanic Basin prior to the Middle Triassic and also the oldest firm evidence of its presence in the Early Triassic (middle–late Spathian). This discovery sheds new light on the origin of post-Palaeozoic crinoids. It suggests a much wider distribution than commonly assumed for the genus Dadocrinus and implies that the first dadocrinids originated either in the Panthalassa or Tethys oceans, and then dispersed over long distances in a relative short period of time

New thylacocephalans from the Early Triassic Paris Biota (Bear Lake County, Idaho, USA).

International audienceTwo new genera and species of thylacocephalans (Arthropoda, Thylacocephala), Parisicaris triassica Charbonnier and Ligulacaris parisiana Charbonnier, are described from the early Spathian Paris Biota. These new occurrences are the first reports of thylacocephalans from Triassic rocks in North America. They considerably enlarge the spatiotemporal distribution of these enigmatic arthropods and highlight their relatively high generic richness during the Early Triassic. It also confirms that the Triassic was the taxonomically richest period for Thylacocephala

Identification non-destructive des vernis des oeuvres d'art par fluorescence UV

For centuries, varnishes applied on works of art have been prepared with natural resins. These natural products degrade in the course of time and consequently modify the visual aspect of the work of arts. Thus, restorers must reduce the layer of varnish using solvents chosen according to the nature of varnish and not deteriorating the pictorial layer. The identification of varnishes is thus essential for the choice of the apt solvent. Until now, that identification was obtained by chemical analyses using samples. With UV fluorescence, we developed a technique allowing nondestructive identification of varnishes which can be carried out in-situ and giving results in real time. This method is based on the comparison of the spectrum of fluorescence of an unknown varnish with those of a database of recent, artificially and naturally aged varnishes of reference. Examples of identification of varnishes on several works of art are presented in this work. In parallel, the first step toward the separation and the identification of principal the fluorophores contained within the resins were carried out by liquid chromatography coupled with the electrospray mass spectrometry.Depuis des siècles, les vernis apposés sur des œuvres anciennes sont constitués de résines naturelles. Ceux-ci se dégradent au cours du temps et modifient l'aspect visuel de l'œuvre. Les restaurateurs doivent donc alléger la couche de vernis à l'aide de solvants choisis selon la nature du vernis et n'altérant pas la couche picturale. L'identification des vernis est donc essentielle pour le choix solvant. Elle était, jusqu'ici obtenue par des analyses chimiques faites à partir de prélèvements. A l'aide de la fluorescence UV, nous avons développé une technique d'identification non-destructive des vernis, réalisable in-situ et donnant des résultats en temps réel. Cette méthode s'appuie sur la comparaison du spectre de fluorescence d'un vernis inconnu avec ceux d'une base de données de vernis de référence récents, vieillis artificiellement ou naturellement. Des exemples de reconnaissance des vernis sur plusieurs œuvres d'art du patrimoine sont présentés. Parallèlement, la séparation et l'identification des principaux fluorophores contenus au sein des résines ont été réalisées par chromatographie liquide couplée à la spectrométrie de masse utilisant l'ionisation par électrospray

NIRMA Nano-imagerie Infrarouge pour les Matériaux Anciens

Présentation donnée au cours de l'atelier DOPAMINE (Les données en sciences du patrimoine DIM Matriaux anciens et patrimoniaux) au cour duquel . Laurent Romary, chercheur invité dans le cadre du DIM Matériaux anciens et patrimoniaux, a rencontré les porteurs de projet d'équipements soutenus par le DIM, mais également tous les scientifiques intéressés à déposer un projet d'équipement auprès du DIM. Cet Atelier a pris la suite de l'Atelier du 7 février, à destination prioritairement des jeunes scientifiques

Identification non-destructive des vernis des oeuvres d'art par fluorescence UV

PARIS-BIUSJ-Thèses (751052125) / SudocPARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF