The use of in-line quantitative analysis to follow polymer processing
In this work it is presented three applications of real time analysis during extrusion process using an optical device developed by our research group, which applies the concepts of light extinction. Monitoring of polymer blends morphology takes place to infer data concerned to dispersed phase size and concentration. The detector also enables information about melting temperature of polymer during extrusion and the level of viscous heating, and the exfoliation step during processing of a polymer-clay nanocomposite.
Robust Two-Dimensional Electronic Properties in Three-Dimensional Microstructures of Rotationally Stacked Turbostratic Graphene
We report on the electronic properties of turbostratic graphitic microdisks, rotationally stacked systems of graphene layers, where interlayer twisting leads to electronic decoupling resulting in charge-transport properties that retain the two dimensionality of graphene, despite the presence of a large number of layers. A key fingerprint of this reduced dimensionality is the effect of weak charge-carrier localization that we observe at low temperatures. The disks' resistivity measured as a function of magnetic field changes its shape from parabolic at room temperature to linear at a temperature of 2.7 K indicating further this type of two-dimensional transport. Compared to Bernal stacked gr…
ST-segment elevation myocardial infarction: Management and association with prognosis during the COVID-19 pandemic in France.
Systems of care have been challenged to control progression of the COVID-19 pandemic. Whether this has been associated with delayed reperfusion and worse outcomes in French patients with ST-segment elevation myocardial infarction (STEMI) is unknown.Aim: To compare the rate of STEMI admissions, treatment delays, and outcomes between the first peak of the COVID-19 pandemic in France and the equivalent period in 2019.Methods: In this nationwide French survey, data from consecutive STEMI patients from 65 centres referred for urgent revascularization between 1 March and 31 May 2020, and between 1 March and 31 May 2019, were analysed. The primary outcome was a composite of in-hospital death or no…
Turbostratic graphitic microstructures: electronically decoupled multilayer graphene devices with robust high charge carrier mobility
Carbon nanomaterials continue to amaze scientists due to their exceptional physical properties. Recently there have been theoretical predictions and first reports on graphene multilayers, where, due to the rotation of the stacked layers, outstanding electronic properties are retained while the susceptibility to degradation and mechanical stress is strongly reduced due to the multilayer nature. Here we show that fully turbostratic multilayer graphitic microstructures combine the high charge carrier mobilities necessary for advanced electronic and spintronic devices with the robustness of graphitic structures. Structural characterization of disk-shaped graphitic microstructures using Raman sp…