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Granget Elodie

Assistant-e HES

Contrat principal

Assistant-e HES

Haute Ecole Arc - Conservation-restauration
Espace de l'Europe 11, 2000 Neuchâtel, CH

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En cours

Liquor

Rôle: Collaborateur/trice

Description du projet :

Investigation and conservation of botanical wet collections

The aim of this project is to deepen the knowledge of conservation issues of botanical wet collections (plants in fluid) in order to propose adapted protocol for their correct preservation.

From a material point of view, the correct combination of fixing procedures, preservation fluid, container and sealant for a long lasting specimen’s conservation will be investigated for various categories of plant species. From an immaterial point of view, part of the research will be dedicated to the investigation of the cultural values owned by these artefacts and the optimal way to maintain them in time.

Equipe de recherche au sein de la HES-SO: Granget Elodie

Durée du projet: 01.02.2021 - 31.08.2022

Url du site du projet: http://projets.he-arc.ch/liquor/

Statut: En cours

2024

Neutron tomography and image registration methods to study local physical deformations and attenuation variations in treated archaeological iron nail samples

Article scientifique ArODES

Elodie Granget, Ocson Cocen, Jan Hovind, David Mannes, Anders Kaestner, Laura Brambilla, Mahdieh Shakoorioskooie

Applied Physics A, 2024, 130, 849

Lien vers la publication

Résumé:

This study presents a preliminary examination of the effects of environment changes post-excavation on heavily corroded archaeological Roman iron nails using neutron tomography and image registration techniques. Roman nails were exposed to either a high relative humidity environment, or fast thermal drying as primary experiments to show the power of this imaging technique to monitor and quantify the structural changes of corroded metal artifacts. This research employed a series of pre- and post-treatment tomography acquisitions (time-series) complemented by advanced image registration methods. Based on mutual information (MI) metrics, we performed rigid body and affine image registrations to meticulously account for sample repositioning challenges and variations in imaging parameters. Using non-affine local registration results, in a second step, we detected localized expansion and shrinkage in the samples attributable to imposed environmental changes. Specifically, we observed local shrinkage on the nail that was dried, mostly in their Transformed Medium (TM), the outer layer where corrosion products are cementing soil and sand particles. Conversely, the sample subjected to high relative humidity environment exhibited localized expansion, with varying degrees of change across different regions. This work highlights the efficacy of our registration techniques in accommodating manual removal or loss of extraneous material (loosely adhering soil and TM layers around the nails) post-initial tomography, successfully capturing local structural changes with high precision. Using differential analysis on the accurately registered samples we could also detect and volumetrically quantify the variation in moisture and detect changes in active corrosion sites (ACS) in the sample. These preliminary experiments allowed us to advance and optimize the application of a neutron tomography and image registration workflow for future, more advanced experiments such as humidity fluctuations, corrosion removal through micro-blasting, dechlorination and other stabilization treatments.

About metal soaps in ethnographic collections :

Article scientifique ArODES

à propos des savons métalliques dans les collections ethnographiques

Silvia Russo, Elodie Granget, Alexis Malefakis, Laura Brambilla, Jean-Baptiste Thomas, Edith Joseph

CeROArt, 2024, 13, Varia 2023-2024

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Résumé:

Cet article discute de la valeur des objets ethnographiques dans les musées et les collections, ainsi que des défis liés à leur conservation en raison de leur composition complexe et de leur poly-matérialité. L'étude se concentre sur la formation de savons métalliques sur des objets en métal en contact avec des parties en cuir ou en bois. Elle propose une approche collaborative entre conservateurs-restaurateurs et scientifiques pour identifier les savons métalliques présents sur une sélection d'objets du Musée ethnographique de l'Université de Zurich. Les auteurs souhaitent sensibiliser à la dégradation matérielle dans les collections ethnographiques et promouvoir la communication entre les différents acteurs impliqués, tout en permettant aux professionnels de la conservation de confirmer la présence de savons métalliques en l’absence de techniques analytiques spécifiques.

Developing a quantitative multimodal and multi-scale, fully non-destructive technique for the study of iron archaeological artefacts

Article scientifique ArODES

Elodie Granget, Ocson Cocen, Mahdieh Shakoorioskooie, Qianru Zhan, Marian-Nida Lumongsod-Thompson, Anders Kaestner, David Mannes, Laura Brambilla

Acta IMEKO, 13, 2, 1-7

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Résumé:

This article presents the methodology and initial findings of the SNSF Sinergia project CORINT. The project's objective is to elucidate the corrosion mechanisms affecting iron-based structures entrapped in various porous media. This paper focuses specifically on iron archaeological artefacts (IAAs) in soil. A novel multimodal quantitative imaging technique, which integrates neutron and X-ray computed tomography (NX-CT), is under development for non-destructive examination of corrosion processes. The method involves registering and fusing neutron and X-ray tomography data, followed by Gaussian mixture model (GMM) clustering for phase segmentation. Imaging was conducted on two IAAs, Vrac C and BdC1. Additionally, random cross-sections of these samples underwent analysis through optical microscopy, μRaman spectroscopy, and SEM-EDS to characterize and correlate corrosion layers with NX-CT results. This study yields valuable insights into the corrosion of IAAs, enabling the non-destructive investigation of corrosion processes in porous media. The implications extend beyond the preservation of cultural heritage, to the examination of long-term corrosion behaviors in contemporary iron structures, steel within concrete, and nuclear waste disposal plans.

2022

Losing colour :

Article scientifique ArODES

the discolouration of plants in spirit preserved collections

Elodie Granget, Marion Dangeon, Laura Brambilla

Journal of natural science collections, 2022, vol. 10, pp. 60-80

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Résumé:

The Research unit of the Haute-École Arc Conservation-Restauration (UR-arc CR), Neuchâtel, Switzerland, is carrying out a research project that aims to understand the discolouration of botanical spirit preserved collections and strives to propose practical solutions to these problems. This article reports on the results of the initial phase of this project, which focused on creating experiment jars of representative plants specimens immersed in fluids and monitored using the following protocol: photography of the jars, colorimetric measurements, and analysis by UV spectroscopy of the fluid as well as closer observations of the specimens. Colorimetric measurements tracked the colour changes over time. UV spectroscopy was used to identify the pigments present in the fluid. Thereby, different behaviours could be observed, depending both on the type of pigment and on the fluid. Specimens containing pigments with strong dying properties tend to opacify the fluid while keeping their colour, whereas other specimens such as colourful flowers or leaves show clear discolouration problems. Depending on the preservative fluid, the leached pigments degrade at different rates. Moreover, the botanical specimens show other alterations: they may not only assume a lighter or darker colour, but can also shrink, stiffen or soften

2021

Prévenir le brunissement du fluide de conservation des spécimens botaniques

Article scientifique ArODES

Joane Latty, Elodie Granget, Marion Dangeon, Laura Brambilla

Bulletin de la société neuchâteloise des sciences naturelles, 2021, vol. 141, pp. 25-39

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Résumé:

Les spécimens botaniques conservés en fluide tendent à se décolorer et à rendre le fluide brunâtre. C'est en particulier problématique dans le cas où ceux-ci doivent être exposés. Les principaux composés mis en cause sont diverses espèces de tanins. Plusieurs méthodes pour contrer ce phénomène ont été évaluées. L'adjonction de SO2, aq comme antioxydant et l'usage de paraffine liquide comme solvant apolaire empêchant la migration ont été testés sur des spécimens d'Orobanche hederae un spécimen aux tissus clairs. Enfin, la fixation au formaldéhyde a été évaluée sur des échantillons d'écorce de Pinus nigra, dont les tissus sont déjà foncés. La plupart des variantes testées ont réussi à significativement retarder le brunissement du fluide, mais aucune n'a pu maintenir les couleurs originales des spécimens.

2023

Development of a quantitative multimodal imaging technique for in-situ study of iron archaeological artefacts

Conférence ArODES

Elodie Granget, Ocson Reginald Cocen, Mahdieh Shakoorioskooie, Zhan Qianru, Marian Nida Lumongsod-Thompson, Anders Kaestner, Davis Mannes, Laura Brambilla

IMEKO TC-4 International Conference on Metrology for Archaeology and Cultural Heritage

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2022

DiscoveryMat :

Conférence ArODES

a freeware electrochemical tool for the in situ analysis of aluminum alloys in the cooling systems of historical vehicless

Elodie Granget, Brice Chalnaçon, Christian Degrigny

Metal 2022, proceedings of the interim meeting of the ICOM-CC metals working group

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Résumé:

Corrosion of aluminium alloys is frequently observed in the cooling systems of functional vehicles dating from 1920 to 1940 in the Musée National de l'Automobile in Mulhouse, France. This paper shows how DiscoveryMat, a freeware analytical tool, has been successfully used for the in situ analysis of the materials concerned. The tool is based on the monitoring of the electrochemical behavior of metals in different test solutions and relies on a database to propose possible alloy compositions. The analysis of a corpus of detached parts representative of this problem has made it possible to enrich the database, thus enabling the precise identification of the problematic aluminium alloys in real conditions directly on the vehicles. The results of these analyses showed that the corroded parts are all made of AI-Cu(-Si) alloys, whereas the most recent and stable parts are made of AI-Si alloys.

2021

Optimisation de la base de données DiscoveryMat pour l’analyse des alliages d’aluminium des circuits de refroidissement d’automobiles anciennes

Conférence

Granget Elodie, Christian Degrigny, Brice Chalançon

JERI 2021, 04.06.2021 - 04.06.2021, Toulouse

Réalisations

PEOPLE@HES-SO Annuaire et Répertoire des compétences

Granget Elodie

Assistant-e HES

Assistant-e HES

PEOPLE@HES-SO
Annuaire et Répertoire des compétences