Search results for "Métal"
showing 10 items of 112 documents
L’épée à poignée métallique de Niffer (Haut-Rhin) : un exemple de production occidentale au Bronze moyen
2018
National audience
Were Bronze Age metalworkers skilled?: Perspectives from the study of the making of Bronze Age swords
2019
International audience; Beyond the provocation of the title, the question of ancient metalworkers’ skills, that has been recently discussed by Maikel Kuijpers for Bronze Age axes, makes perfect sense concerning Bronze Age swords, especially when equipped with a metallic hilt. These weapons are indeed almost always described as masterpieces of metalwork made by skilled and specialized craftsmen. This does not take into account the breakthroughs made since the 1960s in the study of the fabrication techniques of bronze artefacts. Even if it is true that most Bronze Age swords are looking flawless on the surface, imaging techniques such as X-ray or CT-scan enable archaeologists to have a glimps…
Dépôts de bronzes et relations visuelles autour du Camp du Château à Salins-les-Bains (Jura, France) à la fin du Bronze moyen et au début du Bronze f…
2017
Systematic field surveys have been carried out in the surroundings of the Camp du Château near Salins-les-Bains for several years. These investigations led to the discovery of forty-odd hoards dating mainly from the end of the Middle Bronze Age and the beginning of the Late Bronze Age. The good accuracy of their localization allows us to study how they were integrated into the landscape. Their positioning suggests that the choice of location favored topographical criteria. We are interested in the question of intervisibility between the place of hoarding and the remarkable points of the natural and social landscape, especially the hill-forts. The results of GIS analysis show the constitutio…
Bric-à-brac pour les dieux ?
2017
This book accompanies the exhibition "Bric-à-brac pour les dieux?", produced by the Lons-le-saunier museum in 2017. Some fifteen specialists present the Bronze Age and the state of knowledge concerning the practice of depositing objects in a non-funerary context: analysis of the composition of the sets, study of the forms of the deposits and the places chosen for these practices, morphometric approaches to the objects, etc. The most significant sets are presented in the form of inserts, along with the various summary texts.
Elaboration of metal / ceramic functionally graded materials by SPS for ballistic protection
2016
The objective is to improve ballistic performance of armors. A perfect armor combines ductility to resistto the impact and high hardness to stop projectile’s fragments. However, such an association of properties is inconsistent witha single material. The solution is to perform a functionally graded material (FGM) with a ductile metal at the back side of thesample and a hard ceramic on the top side. Non-conventional technologies like Spark Plasma Sintering allow joining orsintering all types of materials with different and additional properties. Furthermore, with this technique, high heating ratescan be achieved, limiting grain growth and resulting in a fine microstructure. The goal is to st…
Porphyrines et tétraazamacrocycles dérivés du DOTA : association de deux ligands pour la chélation de métaux d'intérêt en imagerie médicale multimoda…
2012
The goal of my PhD thesis was to synthesize new molecules, which give access to heterobimetallic complexes with interesting properties for multimodal imaging. In this manuscript, several main points have been studied. The first part of this work concerns the synthesis and characterization of ligands. We describe here the synthesis of five new ligands based on the association of one porphyrin and one or several cyclen derivatives. Those ligands are water-soluble. During the synthesis, we have targeted improvements to our work and developed a new synthetic pathway, which allowed us to obtain one ligand incorporating a porphyrin, a cyclen derivative and a free amine function. This function cou…
Conditioning metallic aluminum in magnesium phosphate cements
2016
This work deals with the stabilization / solidification of radioactive waste using cement.More particularly, it aims at assessing the chemical compatibility between metallic aluminum and mortars based on magnesium phosphate cement. The physical and chemical processes leading to setting and hardening of the cement are first investigated. X-ray diffraction (XRD), thermogravimetry (TGA) and nuclear magnetic resonance spectroscopy (31P and11B MAS-NMR) arefirst used to characterize the solid phases formed during hydration, while inductively coupled plasma atomic emission spectroscopy analysis (ICP-AES), electrical conductimetry and pH measurementsprovide information on the pore solution composit…
Classification et chronologie de bas fourneaux de réduction du fer à usage unique au sud-ouest du Niger
2016
In southwestern Niger, near Niamey, several thousand single-use bloomery furnaces have been mapped and identified. The archaeological study of approximately 30 furnaces and their slag reveals the existence of four methods for iron smelting: three types of pit furnace and one slag-tapping type. The slag pit furnaces are clearly differentiated by the form and volume of their pits. All slag-tapping furnaces drain off slag through small openings. The slag is tapped either vertically or laterally. According to radiocarbon dates, the smelting activity developed in the 2 nd century AD and intensified through to the 14 th century. It continued to evolve until the middle of the 20 th century. The lo…
Quelques considérations sur la réparation et le réutilisation du métal à l'âge du Bronze : aspects techniques, culturels et symboliques
2019
International audience; La métallurgie du cuivre et des alliages cuivreux, apparue en Europe au IVe millénaire avant notre ère, connaît un fort développement à l’âge du Bronze avec le développement de la production en série par moulage au début du IIe millénaire. Ces nouveaux matériaux et procédés transforment fondamentalement le rapport que les Hommes entretiennent avec l’objet : d’unique, celui-ci devient reproductible à l’infini grâce au moulage, modifiable à souhait par déformation plastique, suppression et/ou ajout de matière, et même renouvelable grâce au recyclage par refonte, qui permet de produire un objet neuf à partir de métal usagé. Ces nouvelles possibilités modifient ainsi les…
Caractérisation et prédiction du rendement de projection lors du procédé de projection à froid – cas de la métallisation des polymères
2020
This thesis work deals with the cold spray metallization of polymer substrates by aiming at an optimal deposition efficiency using experimental analysis combined with numerical simulation. Experimental observations of the powder jet using an ombroscopic analysis have revealed a generic behavior consisting of a uniform confined zone at the immediate exit of the nozzle followed by a dispersed zone. The supersonic flow at the nozzle exit being essentially axial, the powders are entrained to form a uniform jet. Beyond a certain distance, a dispersion appears. This distance is very important because it characterizes the behavior of the powders. It can alter the conditions for the elaboration of …