Rapidly Prepared Nanocellulose Hybrids as Gas Barrier, Flame Retardant, and Energy Storage Materials

Cellulose nanofibril (CNF) hybrid materials show great promise as sustainable alternatives to oil-based plastics owing to their abundance and renewability. Nonetheless, despite the enormous success achieved in preparing CNF hybrids at the laboratory scale, feasible implementation of these materials remains a major challenge due to the time-consuming and energy-intensive extraction and processing of CNFs. Here, we describe a scalable materials processing platform for rapid preparation (<10 min) of homogeneously distributed functional CNF−gibbsite and CNF−graphite hybrids through a pH-responsive self-assembly mechanism, followed by their application in gas barrier, flame retardancy, and energy storage materials. Incorporation of 5 wt % gibbsite results in strong, transparent, and oxygen barrier CNF−gibbsite hybrid films in 9 min. Increasing the gibbsite content to 20 wt % affords them self-extinguishing properties, while further lowering their dewatering time to 5 min. The strategy described herein also allows for the preparation of freestanding CNF−graphite hybrids (90 wt % graphite) that match the energy storage performance (330 mA h/g at low cycling rates) and processing speed (3 min dewatering) of commercial graphite anodes. Furthermore, these ecofriendly electrodes can be fully recycled, reformed, and reused while maintaining their initial performance. Overall, this versatile concept combines a green outlook with high processing speed and material performance, paving the way toward scalable processing of advanced ecofriendly hybrid material

FIRST RESULTS OF AN EXPERIMENT ON ADVANCED COLLIMATOR MATERIALS AT CERN HIRADMAT FACILITY

A comprehensive, first-of-its-kind experiment (HRMT-14) has been recently carried out at CERN HiRadMat facility on six different materials of interest for Beam Intercepting Devices (collimators, targets, dumps). Both traditional materials (Mo, W and Cu alloys) as well as advanced metal/diamond and metal/graphite composites were tested under extreme conditions as to pressure, density and temperature, leading to the development of highly dynamic phenomena as shock-waves, spallation, explosions. Experimental data were acquired, mostly in real time, relying on extensive integrated instrumentation (strain gauges, temperature and vacuum sensors) and on remote acquisition devices (laser Doppler vibrometer and high-speed camera). The experiment was a success under all points of view in spite of the technological challenges and harsh environment. First measurements are in good agreement with results of complex simulations, confirming the effectiveness of the acquisition system and the reliability of advanced numerical methods when material constitutive models are completely available. Valuable information has been collected as to thermalshock robustness of tested materials

Limits on the production of scalar leptoquarks from Z (0) decays at LEP

A search has been made for pairs and for single production of scalar leptoquarks of the first and second generations using a data sample of 392000 Z0 decays from the DELPHI detector at LEP 1. No signal was found and limits on the leptoquark mass, production cross section and branching ratio were set. A mass limit at 95% confidence level of 45.5 GeV/c2 was obtained for leptoquark pair production. The search for the production of a single leptoquark probed the mass region above this limit and its results exclude first and second generation leptoquarks D0 with masses below 65 GeV/c2 and 73 GeV/c2 respectively, at 95% confidence level, assuming that the D0lq Yukawa coupling alpha(lambda) is equal to the electromagnetic one. An upper limit is also given on the coupling alpha(lambda) as a function of the leptoquark mass m(D0)

Assessing the effects of earlier snow melt-out on alpine shrub growth: The sooner the better?

International audience21 Enhanced shrub growth in a warming alpine climate has potential far-reaching implications, 22 including soil nutrient cycling, carbon storage, or water and surface energy exchanges. Growth 23 ring analysis can yield mid-to long-term, annually resolved records of shrub growth, and 24 thereby offer valuable insights into how growth is driven by interannual climate variability. In 25 the European Alps, dendroecological approaches have shown that dwarf shrub productivity is 26 influenced by interannual variations of growing season temperature but results also point to a 27 negative effect of winter precipitation on radial growth. However, as past work lacked snow 28 cover data, links between snow cover duration, growing season length, energy availability and 29 inter-annual shrub growth remain poorly understood. 30 In this paper, we combined multi-decadal shrub-ring series from 49 individuals sampled at three 31 sites along a 600-m elevational gradient in the Taillefer massif, located in the French Alps to 32 assess growth sensitivity of long-lived and widespread Rhododendron ferrugineum shrubs to 3