Thermal stability of polymethacrylic based ELIUM® resin: Effect of comonomers, antioxidants and aluminum trihydrate filler

This paper presents the study of the thermal degradation of methyl methacrylate resin based materials known as ELIUM® resin. Samples under investigation were made from MMA based resin (ELIUM® V1), ELIUM® V1 with a dimethacrylate comonomer (ELIUM® V2), and ELIUM® V2 with a stabilizer package (ELIUM® V3). They were used for trying to discuss the degradation mechanisms. Blocks differing by their thickness made from ELIUM® formulation filled with aluminum TriHydrate used as flame retardant were also investigated in order to better match some industrial materials. Degradation was observed to be mainly driven by unzipping, consistent with the methacrylic nature of ELIUM® resin. Occurrence of oxidation is also discussed depending on materials formulation and temperature. A blend of antioxidants was inefficient for limiting mass loss. At 200 °C, both ATH and ELIUM® degrade, which contributes to overall mass loss. At temperatures below 180 °C, ATH does not seem to induce new degradation mechanisms but would increase oxygen diffusivity. Finally, a first simple kinetic model is proposed to predict mass loss in thick composite blocks aged under air

Oxidation and unzipping in ELIUM resin: Kinetic model for mass loss

This paper gives a first study of the thermal and thermal oxidative ageing of ELIUM® resins. Chain ends unzipping was observed to be the main degradation mechanism under nitrogen whereas an oxidation mechanism with random chain scissions is shown to predominate in presence of oxygen. A first simplified kinetic model is proposed and fits experimental results for thin films at temperatures ranging from 230 to 310°C under oxygen or nitrogen

Comparaison lithostratigraphique, géochimique et structurale entre la zone axiale et les nappes du versant Sud dela Montagne Noire dans le district aurifère de Salsigne (Aude, France)

No english abstractCette étude montre que le domaine para-autochtone est, en fait, un ensemble structuralement hétérogène, une juxtaposition d'unités septentrionales (zone axiale) et d'unités méridionales (nappes du versant sud). En ce qui concerne la couche minéralisée de la mine de Salsigne, l'hypothèse d'une minéralisation stratiforme volcano-sédimentaire exhalative est mise en doute, elle s'intègrerait plutôt a l'ensemble des minéralisations filoniennes du district de Salsigne

Spent fuel transportation cask under accidental fire conditions: Numerical analysis of gas transport phenomena affecting heat transfer in shielding materials

International audienc

Protocol for venoarterial ExtraCorporeal Membrane Oxygenation to reduce morbidity and mortality following bilateral lung TransPlantation: the ECMOToP randomised controlled trial

Introduction Lung transplantation (LTx) aims at improving survival and quality of life for patients with end-stage lung diseases. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is used as intraoperative support for LTx, despite no precise guidelines for its initiation. We aim to evaluate two strategies of VA-ECMO initiation in the perioperative period in patients with obstructive or restrictive lung disease requiring bilateral LTx. In the control ‘on-demand’ arm, high haemodynamic and respiratory needs will dictate VA-ECMO initiation; in the experimental ‘systematic’ arm, VA-ECMO will be pre-emptively initiated. We hypothesise a ‘systematic’ strategy will increase the number of ventilatory-free days at day 28.Methods and analysis We designed a multicentre randomised controlled trial in parallel groups. Adult patients with obstructive or restrictive lung disease requiring bilateral LTx, without a formal indication for pre-emptive VA-ECMO before LTx, will be included. Patients with preoperative pulmonary hypertension with haemodynamic collapse, ECMO as a bridge to transplantation, severe hypoxaemia or hypercarbia will be secondarily excluded. In the systematic group, VA-ECMO will be systematically implanted before the first pulmonary artery cross-clamp. In the on-demand group, VA-ECMO will be implanted intraoperatively if haemodynamic or respiratory indices meet preplanned criteria. Non-inclusion, secondary exclusion and VA-ECMO initiation criteria were validated by a Delphi process among investigators. Postoperative weaning of ECMO and mechanical ventilation will be managed according to best practice guidelines. The number of ventilator-free days at 28 days (primary endpoint) will be compared between the two groups in the intention-to-treat population. Secondary endpoints encompass organ failure occurrence, day 28, day 90 and year 1 vital status, and adverse events.Ethics and dissemination The sponsor is the Assistance Publique–Hôpitaux de Paris. The ECMOToP protocol version 2.1 was approved by Comité de Protection des Personnes Ile de France VIII. Results will be published in international peer-reviewed medical journals.Trial registration number NCT05664204