Luminescence dating applied to medieval architecture

Avranches’ keep remains constitute a witness of Anglo-Norman knowledge on castle building. Their similarity with other buildings such as Ivry-la-Bataille castle or London Tower required determining the place of Avranches keep in this group: pioneer or imitation? Therefore, samples of brick for luminescence dating were taken from the remaining little tower. Results indicate a chronology later than assumed: second part of the 12th century and first part of 13th century. These dates tend to prove that north-east tower remains would correspond to a reconstruction phase and not to the original construction.Le donjon d’Avranches représente un des rares témoins de l’architecture castrale anglo-normande. Son plan présente d’importantes resemblance avec d’autres edifices de du même contexte chrono-culturel, comme le donjon d’Ivry-la-Bataille ou la Tour de Londres. Ces ressemblances posent la question de la place du donjon d’Avranches dans cet ensemble : s’agit-il d’un édifice précurseur ou d’une imitation ? C’est pourquoi plusieurs prélèvements de brique ont été prélevés dans les vestiges de ce bâtiment, afin de procéder à la datation de la sa construction. Les résultats semblent suggérer une construction plus tardive qu’on ne l’envisageait, entre la deuxième moitié du xiie siècle et la première moitié du xiiie siècle. Ces dates pourraient suggérer une reconstruction partielle du donjon, sans correspondre à la phase de construction originale du château

SuperRail - Premier câble supraconducteur au monde à être installé sur un réseau ferré à usage commercial

PosterNational audienceLe réseau ferroviaire français est soumis à de nombreuses contraintes, notamment liées à l'augmentation du trafic de 60% entre 1998 et 2008 et qui devrait encore augmenter de 4 fois d'ici 2030. Pour renforcer les capacités de transport en ville tout en réduisant les pertes électriques, il peut être intéressant d'installer des câbles supraconducteurs. C’est le choix retenu par la SNCF dans le cadre du projet SuperRail, lancé en février 2022 et qui consiste en le développement, la fabrication et l'installation de câbles supraconducteurs à haute température critique (HTc) pour renforcer l'alimentation électrique de la gare Montparnasse à Paris. Deux câbles HTc de 1,5 kV-3,5 kA et 80 m de long seront installés en parallèle et reliés à la sous-station électrique de Ouest-Ceinture pour alimenter deux faisceaux de voies. Dans cet article, nous détaillerons les innovations mises en œuvre dans le cadre de ce projet, notamment : le câble supraconducteur, les terminaisons et le système de refroidissement fournissant 2 kW à 68 K. Pour finir, des études prospectives visant à améliorer davantage l’efficacité énergétique du système en optimisant ou remplaçant certains éléments seront présentées

SuperRail - World-first HTS cable to be installed on a commercial railway network in France

Large scale oral sessionsInternational audienceThis paper presents the SuperRail project, launched in June 2022 and consisting in the development, the manufacturing and the installation of a high temperature superconducting HTS DC cable system. The objectives of the project are to reinforce the power supply of the Montparnasse railways station in Paris, to increase the traffic and to participate to the reduction of CO2 emission. The saturated underground in the centre of Paris does not allow to create new right of ways and only the HTS cable technology allows to carry the required power to railway tracks using the few available 100 mm ducts left. The cable system and the ancillary services have to answer to a load chart with a high level of requirements corresponding to the connection of a standard supply cell in a substation to a group of railways tracks in very constraints areas. The technologies developed have the potential to be reproduced in similar cases existing in large cities. In the case of SuperRail, two 80 m long 1.5 kV-3.5 kA HTS DC cables made of 2G conductors will be installed in parallel. They will need to sustain a 67 kA-200 ms short-circuit current. The cryogenic system to cool the HTS cables is specifically designed for this project. It is based on a Reverse Turbo-Brayton cycle providing cooling power of about 2 kW at 67 K. This system intends to ensure low maintenance during life cycle, high reliability and would be scalable for future application (unlimited to railway). Efforts are being done to reduce the losses in the 4 current leads, and to optimize the space required by the pipes for the circulation of the liquid nitrogen. In parallel, prospective studies are being carried out in order to find original solutions to replace the current leads by other systems integrating a part of the power converter and the transformer at cryogenic temperature. SuperRail is a landmark project, as it is the first time that a DC HTS cable system is installed on a commercially operated railway network

Test results of the SuperRail HTS cable system for the French railway electric grid

PosterInternational audienceThe SuperRail project, backed by the French government, will be the first installation of a high-temperature superconducting (HTS) cable system on a commercially operated railway electric grid. The project's goal is to develop, manufacture, and install a HTS DC cable system at the Montparnasse railways station in Paris. Due to the restricted space available in the city's saturated underground, the HTS technology provides the only viable solution for increasing the power supply from the railway substation to a group of railway tracks. This will allow for an increase in train traffic while simultaneously reducing CO2 emissions. Two 80 m long 1.5 kV-3.5 kA HTS DC cables made of 2G conductors will be installed in parallel. They are designed to meet stringent load chart requirements and to sustain a 67 kA-200 ms short-circuit current. Prior to the installation at Montparnasse, a complete 35-m HTS cable type test loop was successfully installed and tested at the SNCF Vitry test facility. This system includes two terminations, one splice, and a fully automated cooling system that manages the thermal cycles between room temperature and cryogenic rated conditions

Validation and Comparison of Two Calibration Methods for the Measurement of Stable Iodine in the Urinary Matrix by ICP-MS: Standard Addition vs. External Calibration

International audienceBackground : In the context of a nuclear reactor accident, thyroid is the main target organ of radioactive iodines. To avoid as much as possible thyroid disorders or even cancer development, it is recommended to administer a single dose of potassium iodide to people at risk of exposure. Nevertheless, the Fu-kushima Dai-ichi disaster has pointed out many questions about the conditions of stable iodine prophylaxis implementation highlighting the need for reflection further revision of the actual "iodine doctrine". Therefore, providing useful data is required notably through the implementation of animal experiments to strengthen current knowledge and to edit new recommendations. Methods : Urinary iodine constitutes a very good indicator to investigate the function of thyroid, its interpretation demands reliable analyses. Prior to perform animal experiments, two calibration methods were designed by our lab and compared together (standard addition and external calibration) to assess the urinary concentration of stable iodine in urine by ICP-MS. They were validated based on several key parameters especially linearity, accuracy and limits of detection (LOD) and quantification (LOQ). Results : The results were nicely satisfying. Indeed, both calibration methods have indicated very good coefficients of correlations, accuracies with low expanded relative uncertainties were obtained. The estimated LOD in the sample for standard addition method and external calibration were fully acceptable, 0.39 µg·L −1 and 0.35 µg·L −1 , respectively. All performance criteria have been thus fulfilled successfully. The established methods were proven to be accurate, robust and sensitive. Once validated, both calibration methods were applied to rat urine samples and the results of z-score and Wilcoxon W test concluded that there were no statistically significant differences between both methods

SuperRail − World-first HTS cable to be installed on a railway network in France

We would like to thank our colleagues at SNCF, Nexans, Absolut System, University Paris-Saclay and the University of Lorraine for the valuable insights they provided and the in-depth discussions we had.The SuperRail project consists in the development, manufacturing, installation and long-term operation of a high temperature superconducting (HTS) DC cable system for railway applications. The objectives of the project are to reinforce the power supply of the Montparnasse railway station in Paris, to increase the traffic and to participate to the reduction of CO2 emission. The saturated underground in the center of Paris does not allow to create new right of ways and only the HTS cable technology allows to carry the required power to railway tracks using the few available 100 mm conduits left. The HTS cable system must answer to a load chart with a high level of requirements corresponding to the connection of a substation to a set of railways tracks in very constraints areas. In the case of SuperRail, two 60-meter long 1.5 kV-3.5 kA HTS DC cables made of second-generation (2G) conductors will be installed in parallel. They need to sustain a 67 kA-200 ms short-circuit current. The cryogenic system is specifically designed for this project. It is based on a Reverse Turbo-Brayton cycle producing cooling power of about 1700 W at 67 K. This system intends to ensure low maintenance during life cycle, high reliability and would be scalable for future application (not limited to railways). In parallel, prospective studies are being carried out to simulate superconducting cables in railway networks, and to find original solutions to replace the current leads. SuperRail is a landmark project, as it is the first time that a DC HTS cable system is installed on a commercially operated railway network. The technologies developed have the potential to be reproduced in similar cases existing in large cities

LIA@RepLab 2013

International audienceIn this paper, we present the participation of the Computer Science Laboratory of Avignon (LIA) to RepLab 2013 edition. RepLab is an evaluation campaign for Online Reputation Management Systems. LIA has produced a important number of experiments for every tasks of the campaign: filtering, topic priority detection, Polarity for Reputation and topic detection. Our approaches rely on a large variety of machine learning methods. We have chosen to mainly exploit tweet contents. In several of our experiments we have also added selected metadata. A fewer number of our proposals have integrated external information by using provided links to Wikipedia and users homepage

From a Cone Snail Toxin to a Competitive MC4R Antagonist

International audienceThe melanocortin 4 receptor (MC4R) plays a role in energy homeostasis and represents a target for treating energy balance disorders. For decades, synthetic ligands have been derived from MC4R endogenous agonists and antagonists, such as setmelanotide used to treat rare forms of genetic obesity. Recently, animal venoms have demonstrated their capacity to provide melanocortin ligands with toxins from a scorpion and a spider. Here, we described a cone snail toxin, N-CTX-Ltg1a, with a nanomolar affinity for hMC4R but unrelated to any known toxins or melanocortin ligands. We then derived from the conotoxin the linear peptide HT1-0, a competitive antagonist of G s , G 15 , and β-arrestin2 pathways with a low nanomolar affinity for hMC4R. Similar to endogenous ligands, HT1-0 needs hydrophobic and basic residues to bind hMC4R. Altogether, it represents the first venom-derived peptide of high affinity on MC4R and paves the way for the development of new MC4R antagonists

Identification of Modulators of the C. elegans Aryl Hydrocarbon Receptor and Characterization of Transcriptomic and Metabolic AhR-1 Profiles

International audienceThe Aryl hydrocarbon Receptor (AhR) is a xenobiotic sensor in vertebrates, regulating the metabolism of its own ligands. However, no ligand has been identified to date for any AhR in invertebrates. In C. elegans, the AhR ortholog, AHR-1, displays physiological functions. Therefore, we compared the transcriptomic and metabolic profiles of worms expressing AHR-1 or not and investigated the putative panel of chemical AHR-1 modulators. The metabolomic profiling indicated a role for AHR-1 in amino acids, carbohydrates, and fatty acids metabolism. The transcriptional profiling in neurons expressing AHR-1, identified 95 down-regulated genes and 76 up-regulated genes associated with neuronal and metabolic functions in the nervous system. A gene reporter system allowed us to identify several AHR-1 modulators including bacterial, dietary, or environmental compounds. These results shed new light on the biological functions of AHR-1 in C. elegans and perspectives on the evolution of the AhR functions across speci