Hydrogen Generation from Mg Wastes by Cold Rolling and Ball Milling by Hydrolysis Reaction: Elektron 21 (UNS-M12310) in Simulated Seawater

Hydrolysis is an efficient way of producing hydrogen by using Mg-based waste. In this study, H2 production is realized in simulated seawater (i.e., 3.5 wt.% NaCl) using the Elektron21 (EL21) alloy as a reagent. This alloy is a magnesium-based alloy composed of 96 wt.% Mg and 4 wt.% rare earth (approx. 3 wt.% Nd and 1 wt.% Gd). EL21 is known for its excellent corrosion resistance and high tensile strength. The impact of different mechanical treatments (ball milling, cold rolling, cryo rolling, and cryo ball milling) on the hydrolysis yield of the material was discussed. A pretreatment with cryo rolling before ball-milling treatment shows the best hydrolysis performance, with a yield of 90.5% achieved in 10 min in salted water. The ductile-to-brittle transition induced a modification of the microstructure, which explains the good hydrolysis performances

Three-Dimensional Graphene Sheet-Carbon Veil Thermoelectric Composite with Microinterfaces for Energy Applications

Over the years, various processing techniques have been explored to synthesize three-dimensional graphene (3DG) composites with tunable properties for advanced applications. In this work, we have demonstrated a new procedure to join a 3D graphene sheet (3DGS) synthesized by chemical vapor deposition (CVD) with a commercially available carbon veil (CV) via cold rolling to create 3DGS-CV composites. Characterization techniques such as scanning electron microscopy (SEM), Raman mapping, X-ray diffraction (XRD), electrical resistance, tensile strength, and Seebeck coefficient measurements were performed to understand various properties of the 3DGS-CV composite. Extrusion of 3DGS into the pores of CV with multiple microinterfaces between 3DGS and the graphitic fibers of CV was observed, which was facilitated by cold rolling. The extruded 3D graphene revealed pristine-like behavior with no change in the shape of the Raman 2D peak and Seebeck coefficient. Thermoelectric (TE) power generation and photothermoelectric responses have been demonstrated with in-plane TE devices of various designs made of p-type 3DGS and n-type CV couples yielding a Seebeck coefficient of 32.5 μV K–1. Unlike various TE materials, 3DGS, CV, and the 3DGS-CV composite were very stable at high relative humidity. The 3DGS-CV composite revealed a thin, flexible profile, good moisture and thermal stability, and scalability for fabrication. These qualities allowed it to be successfully tested for temperature monitoring of a Li-ion battery during charging cycles and for large-area temperature mapping

The wide spectrum of COVID-19 neuropsychiatric complications within a multidisciplinary centre

International audienceA variety of neuropsychiatric complications has been described in association with COVID-19 infection. Large scale studies presenting a wider picture of these complications and their relative frequency are lacking. The objective of our study was to describe the spectrum of neurological and psychiatric complications in patients with COVID-19 seen in a multidisciplinary hospital centre over 6 months. We conducted a retrospective, observational study of all patients showing neurological or psychiatric symptoms in the context of COVID-19 seen in the medical and university neuroscience department of Assistance Publique Hopitaux de Paris-Sorbonne University. We collected demographic data, comorbidities, symptoms and severity of COVID-19 infection, neurological and psychiatric symptoms, neurological and psychiatric examination data and, when available, results from CSF analysis, MRI, EEG and EMG. A total of 249 COVID-19 patients with a de novo neurological or psychiatric manifestation were included in the database and 245 were included in the final analyses. One-hundred fourteen patients (47%) were admitted to the intensive care unit and 10 (4%) died. The most frequent neuropsychiatric complications diagnosed were encephalopathy (43%), critical illness polyneuropathy and myopathy (26%), isolated psychiatric disturbance (18%) and cerebrovascular disorders (16%). No patients showed CSF evidence of SARS-CoV-2. Encephalopathy was associated with older age and higher risk of death. Critical illness neuromyopathy was associated with an extended stay in the intensive care unit. The majority of these neuropsychiatric complications could be imputed to critical illness, intensive care and systemic inflammation, which contrasts with the paucity of more direct SARS-CoV-2-related complications or post-infection disorders

The cerebral network of COVID-19-related encephalopathy: a longitudinal voxel-based 18F-FDG-PET study

International audienc