Katherine Cross, Heirs of the Vikings. History and Identity in Normandy and England, c. 950-c. 1015

Pourquoi et comment l’identité viking en vint à acquérir des significations différentes en Angleterre et en Normandie ? La réponse à cette question forme l’essentiel du propos du livre de Katherine Cross. Partant principalement de sources textuelles, généalogies, œuvres historiographiques, hagiographies et sources diplomatiques, l’a. explore le rapport que les Normands et les habitants de l’Angleterre entretinrent avec leur passé viking. Les limites chronologiques retenues englobent six décen..

Les sources de l’histoire du duché. Publications et inventaires récents

Les travaux récents sur l’histoire du duché se sont largement appuyés sur le regard nouveau porté sur les sources mises à la disposition des chercheurs. L’effort de publication des textes narratifs ne s’est pas uniquement traduit par la réédition des œuvres majeures des chroniqueurs normands. Il a aussi conduit à une redécouverte de la première historiographie normande et alimenté les débats portant sur les processus de transmission de la mémoire et l’appropriation, par une société, de son passé. L’examen de cette production doit prendre en considération les autres témoignages sur l’histoire du duché. Bien qu’il subsiste de nombreux actes inédits, le corpus des textes diplomatiques publiés s’est enrichi et des travaux récents ont inséré le dossier documentaire normand dans le vaste débat sur la « mutation documentaire » du XIe siècle. Egalement sollicitées, les « archives du sol » ont enfin rappelé l’intérêt d’un rapprochement de toutes les données fournies par les textes et l’archéologie pour appréhender l’évolution de la société normande.Recent studies on the history of the duchy have largely drawn on the new light shed on sources available to scholars. The endeavours to publish the narrative texts have materialised not only intonew editions of the major works of the Norman chroniclers, but have also led to a rediscovery of the earliest Norman historiography and sustained debates concerning the processes of transmission of memory and the appropriation by a society of its past. The analysis of this production must take into consideration the other accounts of the history of theduchy. Although many acts remain unpublished, the corpus of diplomatic texts has grown and recent studies have inserted the Norman documentary evidence into the large debate on the "documentary transformation" which took place in the 11th century. Finally, the "underground archives", which were also resorted to, have drawn our attention to the importance of bringing together all the data provided by the texts and by archaeological evidence in order to seize the evolution of Norman society

Formulation et imitation : jalons d’une étude diplomatique des premiers actes de la principauté normande

International audienceNous avons conservé deux chartes autographes de Dudon de Saint-Quentin en faveur de Saint-Ouen de Rouen (1011) et du chapitre de Saint-Quentin (1015). Les préambules de ces actes trahissent la signature littéraire de l’auteur, par l’emploi de mots ou d’expressions utilisées dans le De Moribus… et l’emprunt possible à un traité de rhétorique. Dudon réemploie également de manière habile des formules diplomatiques bien attestées à l’époque carolingienne, qui placent deux des patrons de son œuvre le duc Richard II et l’oncle de ce dernier, Raoul d’Ivry, au sommet de la hiérarchie civile des pouvoirs. L’étude de ces deux actes porte ainsi à se pencher sur leurs relations avec le projet littéraire de l’auteur. Au-delà, elle conduit à s’interroger sur l’élaboration des premiers actes écrits émis dans le duché de Normandie, que l’on suivra ici à partir de l’exemple des formules de légitimation employées dans les actes de Richard Ier et de Richard II. On en retiendra une grande labilité des expressions employées, qu’aucun formulaire ne semble pouvoir fixer. Si l’influence royale est perceptible, elle n’est pas une simple imitation des diplômes capétiens et renvoie aussi à des modèles plus anciens et plus éloignés, y compris, semble-t-il, venus du royaume de Germanie

Liliane Irlenbusch-Reynard, Rollon : de l’histoire à la fiction. État des sources et essai biographique

Rollon demeure un personnage mystérieux, pour lequel la légende le dispute à l’histoire. S’il n’existe pratiquement aucune source contemporaine attestant le fondateur du duché de Normandie, le personnage suscita postérieurement une riche tradition médiévale, qui est l’objet du volume publié par Liliane Irlenbusch-Reynard. L’objectif était ici une présentation minutieuse de toutes les données historiographiques médiévales, pour tenter de reconstituer ce que put être la trajectoire historique d..

Imposing minimum and maximum member size, minimum cavity size, and minimum separation distance between solid members in topology optimization

This paper focuses on density-based topology optimization and proposes a combined method to simultaneously impose Minimum length scale in the Solid phase (MinSolid), Minimum length scale in the Void phase (MinVoid) and Maximum length scale in the Solid phase (MaxSolid). MinSolid and MinVoid mean that the size of solid parts and cavities must be greater than the size of a prescribed circle or sphere. This is ensured through the robust design approach based on eroded, intermediate and dilated designs. MaxSolid seeks to restrict the formation of solid parts larger than a prescribed size, which is imposed through local volume restrictions. In the first part of this article, we show that by proportionally restricting the maximum size of the eroded, intermediate and dilated designs, it is possible to obtain optimized designs satisfying, simultaneously, MinSolid, MinVoid and MaxSolid. However, in spite of obtaining designs with crisp boundaries, some results can be difficult to manufacture due to the presence of multiple rounded cavities, which are introduced by the maximum size restriction with the sole purpose of avoiding thick solid members in the structure. To address this issue, in the second part of this article we propose a new geometric constraint that seeks to control the minimum separation distance between two solid members, also called the Minimum Gap (MinGap). Differently from MinVoid, MinGap introduces large void areas that do not necessarily have to be round. 2D and 3D test cases show that simultaneous control of MinSolid, MinVoid, MaxSolid and MinGap can be useful to improve the manufacturability of maximum size constrained designs

Polymeric Surfactant P84/Polyoxometalate α-PW12O403- A Model System to Investigate the Interplay between Chaotropic and Hydrophobic Effects

Low charge density nanometric ions were recently shown to bind strongly to neutral hydrated matter in aqueous solution. This phenomenon, called the (super-)chaotropic effect, arises from the partial dehydration of both the nano-ion and the solute, leading to a significant gain in enthalpy. Here, we investigate the chaotropic effect of the polyoxometalate α-PW12O403− on the triblock copolymer P84: (EO)19(PO)43(EO)19 with (EO)19 the polyethoxylated and (PO)43 the polypropoxylated chains. The combination of phase diagrams, spectroscopic (nuclear magnetic resonance) and scattering (small angle neutron/X-ray scattering) techniques revealed that: (i) below the micellization temperature of P84, PW12O403− exclusively binds to the propylene oxide moiety of P84 unimers; and (ii) above the micellization temperature, PW12O403− mostly adsorbs on the ethylene oxide micellar corona. The preferential binding of the PW12O403− to the PPO chain over the PEO chains suggests that the binding is driven by the chaotropic effect and is reinforced by the hydrophobic effect. At higher temperatures, copolymer micellization leads to the displacement of PW12O403− from the PPO chain to the PEO chains. This study deepens our understanding of the subtle interplay between the chaotropic and hydrophobic effects in complex salt-organic matter solutions

Laser-generated Pt/Ni nanocatalysts-carbon nanofibers enabling self-calibrated enzyme-free glucose detection at physiological pH

We propose a bimetallic alloy composed of Pt and Ni embedded within laser-induced carbon nanofibers (Pt/Ni-LCNFs) as an enzyme-free transducer for the detection of glucose under physiological pH. Laser exposure on electrospun polyimide nanofibers, embedded with Pt and Ni precursors, facilitated not only the formation of LCNFs but also the generation of Pt/Ni nanoparticles with a radius of approximately 2 nm and a distinctive crystalline structure. X-ray photoelectron spectroscopy revealed the oxidation states of the laser-generated Pt/Ni and confirmed the formation of the Pt/Ni alloy nanocatalysts. Additionally, small-angle X-ray scattering has shown that the graphitic structures of the LCNFs strongly depend on the metal salt concentrations and molar ratio. Pt/Ni-LCNFs were exploited as enzyme-free electrodes for glucose sensing at physiological pH. The presence of Pt in the alloy enabled a low potential (−0.9 V for 20 s) in situ generation of highly localized OH− which facilitated glucose electrooxidation by Ni. Under optimized conditions, Pt/Ni-LCNFs achieved reliable glucose detection in physiological conditions (pH 7.4), with detection limit of 0.3 mM, linearity from 0.1 to 4 mM, and minimal interference from other electroactive species. Self-calibrated data acquisition strategy provided an excellent recovery rate (95 ± 10%) in diluted human serum. Furthermore, unlike enzyme-based sensors, the catalytic activity of Pt/Ni LCNFs was maintained after sterilization, highlighting their robustness and potential in biomedical applications and bioprocess monitoring

Polyoxometalates in the Hofmeister series

We propose a simple experimental procedure based on the cloud point measurement of a non-ionic surfactant as a tool for (i) estimating the super-chaotropic behaviour of polyoxometalates (POMs) and for (ii) establishing a classification of POMs according to their affinity towards polar surfaces

Self-assembly of short chain Poly-N-isopropylacrylamid (PNIPAM) induced by superchaotropic Keggin Polyoxometalates: from globules to sheets

We show here for the first time that short chain poly(N-isopropylacrylamide) (PNIPAM), one of the most famous thermoresponsive polymers, self-assembles in water to form (i) discrete nanometer-globules and (ii) micrometric sheets with nm-thickness upon addition of the well-known Keggin-type polyoxometalate (POM) H3PW12O40 (PW). The type of self-assembly is controlled by PW concentration: at low PW concentrations, PW adsorbs on PNIPAM chains to form globules consisting of homogeneously distributed PWs in PNIPAM droplets of several nm in size. Upon further addition of PW, a phase transition from globules to micrometric sheets is observed for PNIPAMs above a polymer critical chain length, between 18 and 44 repeating units. The thickness of the sheets is controlled by the PNIPAM chain length, here from 44 to 88 repeating units. The PNIPAM sheets are electrostatically stabilized PWs accumulated on each side of the sheets. The shortest PNIPAM chain with 18 repeating units produces PNIPAM/PW globules with 5 -20 nm size but no sheets. The PW/ PNIPAM self-assembly arises from a solvent mediated mechanism associated with the partial dehydration of PW and of the PNIPAM, which is related to the general propensity of POMs to adsorb on neutral hydrated surfaces. This effect, known as superchaotropy, is further highlighted by the significant increase in the lower critical solubilization temperature (LCST) of PNIPAM observed upon the addition of PW in the mM range. The influence of the POM nature on the self-assembly of PNIPAM was also investigated by using H4SiW12O40 (SiW) and H3PMo12O40 (PMo), i.e. changing the POM's charge density or polarizability in order to get deeper understanding on the role of electrostatics and polarizability in the PNIPAM self-assembly process. We show here that the superchaotropic behavior of POMs with PNIPAM polymers enables the formation and the shape control of supramolecular organic-inorganic hybrids