Un fals umayyade rare au nom d’Atrabuls/Tripoli: étude du type, de conjoncture et d’atelier

Monnaies et sources littéraires nous apprennent que la réforme monétaire islamique commença progressivement au premier siècle de l’hégire depuis le califat d’'Umar b. al-Khittab'. Elle fut achevée sous le calife umayyade ‘Abd al- Malik b. Marwan dans la partie orientale du monde islamique. Quant au Maghreb islamique la réforme ne s’atteignit que deux décennies après la date de l’arabisation finale en 77 H. C’est en effet, vers la fin du I/VII s. et le début du II/VIII s. que l’arabisation et l’islamisation complètes du système monétaire ifriqiyen s’aboutirent. Nous possédons un témoignage numismatique appartenant à cette conjoncture et constitue l’objet essentiel de la présente étude; c’est un fals frappé en 100 H./718 au nom d’Atrabuls (Tripolis). Ce fals est, fort probablement, rare, puisque nous n’en connaissons que trois autres exemplaires: l’un publié par Lane Poole, le deuxième par Ostrup et le troisième par Walker. Étudier ce fals convenablement à la lumière des données textuelles et archéologiques à la disposition des chercheurs notamment les données numismatiques fournies essentiellement par le nombre très réduit de fals portant le même toponyme est l’objectif de la présente contribution

La balance des changeurs d’après les sources littéraires arabes

The balance of the exchange was an indispensable instrument in the Islamic societies in the Middle Ages and at the beginning of modern period. In spite of his importance, some types of Arabic books only presented a description more at least detailed. We suggest in this study gathering the various texts which relate to it to reconstitute it and determine his elements and his functioningLa balance du change était un instrument indispensable dans les sociétés islamiques au Moyen Âge et au début de l’époque moderne. Malgré son importance, quelques types de livres arabes seulement en ont présenté une description plus au moins détaillée. Nous proposons dans cette étude de réunir les différents textes qui s’y rapportent afin de la reconstituer et déterminer ses éléments et son fonctionnement

La balance des changeurs d’après les sources littéraires arabes

The balance of the exchange was an indispensable instrument in the Islamic societies in the Middle Ages and at the beginning of modern period. In spite of his importance, some types of Arabic books only presented a description more at least detailed. We suggest in this study gathering the various texts which relate to it to reconstitute it and determine his elements and his functioningLa balance du change était un instrument indispensable dans les sociétés islamiques au Moyen Âge et au début de l’époque moderne. Malgré son importance, quelques types de livres arabes seulement en ont présenté une description plus au moins détaillée. Nous proposons dans cette étude de réunir les différents textes qui s’y rapportent afin de la reconstituer et déterminer ses éléments et son fonctionnement

Le monnayage des dirhams du Maghreb islamique (Afriqiyah et al-Andalus) et son rapport avec le monnayage califal à l’époque umayyade jusqu’à 132 H. : la convergence et la divergence

Introduction En étudiant les monnaies réformées du Maghreb islamique et en particulier les dirhams depuis 97 H., nous constatons l’existence d’une grande similarité avec les dirhams frappés en Orient. Ils partagent les mêmes caractéristiques métrologiques, typologiques et calligraphiques. Cette similitude ne peut pas, cependant, cacher les singularités des frappes aux noms d’Afriqiyah et d’al-Andalus. Les éléments distinctifs résident essentiellement dans la mention du lieu de frappe et dans ..

Effect of cobalt on structural, magnetic and magnetocaloric properties of La 0.8 Ba 0.1 Ca 0.1 Mn 1-x Co x O 3 (x = 0.00, 0.05 and 0.10) manganites

International audienc

Composition for manufacturing an electrode, electrode and associated method

A composition for manufacturing an electrode, the composition including an electrically conductive carbon-based compound, at least one species able to form a catalyst, and cellulose microfibrils encapsulating chitosan. The cellulose microfibrils create a fibrous mesh binding the composition while limiting coating of the catalyst. Thus, the catalyst remains accessible to the surrounding environment, to allow the redox reactions at the electrode. The electrochemical performances of the electrode are consequently improved. The composition is furthermore particularly adapted for shaping an electrode by 3D printing

Flexible doctor blade coated abiotic cathodes for implantable glucose/oxygen biofuel cells

International audienceImplantable devices powered by batteries have been used for sixty years [1]. In recent devices, lithium-based batteries are the most widely used power source [2]. However, lithium batteries have many disadvantages in terms of safety, reliability, and longevity and require regular monitoring and substitution. Implantable glucose biofuel cells are increasingly seen as a potential future technology for replacing lithium-based batteries because they do not require a surgical replacement after 8-10 years and have a theoretically unlimited lifetime thanks to the continued recovery of glucose and oxygen present in the human body. In this paper, we show the fabrication of flexible implantable abiotic cathodes, based on Nitrogen/iron-doped graphene catalyst, for glucose/oxygen biofuel cells application. An ink, based on nitrogen-iron doped graphene as the abiotic catalyst and chitosan as a binder, was prepared and coated on a flexible teflonated gas diffusion layer using doctor blade coating. The characterization of the biocathode shows an open potential circuit corresponding to the potential of the abiotic catalyst and a high oxygen reduction current density up to 66 µA/cm 2 under physiological conditions. Those cathodes remain stable for up to two years with a current density loss of only 25%. The flexible abiotic electrode was tested in an assembled biofuel cell where an enzymatic anode, previously fabricated by our group, was used. The hybrid biofuel cell delivers a high-power density up to 220 µW cm −2 and an open-circuit voltage of 300 mV under physiological conditions (5 mmol l −1 glucose, pH=7.4)

Flexible doctor blade-coated abiotic cathodes for implantable glucose/oxygen biofuel cells

Implantable devices powered by batteries have been used for sixty years. In recent devices, lithium-based batteries are the most widely used power source. However, lithium batteries have many disadvantages in terms of safety, reliability, and longevity and require regular monitoring and substitution. Implantable glucose biofuel cells (BFCs) are increasingly seen as a potential future technology for replacing lithium-based batteries because they do not require surgical replacement after 8–10 years and have a theoretically unlimited lifetime thanks to the continued recovery of glucose and oxygen present in the human body. This paper shows the fabrication of flexible implantable abiotic cathodes, based on a nitrogen/iron-doped graphene catalyst, for glucose/oxygen biofuel cell application. An ink, based on nitrogen-iron doped graphene as the abiotic catalyst and chitosan as a binder, was prepared and coated on a flexible teflonated gas diffusion layer using doctor blade coating. The characterization of the biocathode shows an open potential circuit corresponding to the potential of the abiotic catalyst and a high oxygen reduction current density of up to 66 μA cm−2 under physiological conditions. Those cathodes remain stable for up to two years with a current density loss of only 25%. The flexible abiotic electrode cytotoxicity was evaluated by cell culture experiments showing living cells' high tolerance on the biocathode surface. This work demonstrates that this abiotic catalyst can be a promising alternative for the development of implantable glucose BFCs due to its stability and its cytocompatibility