An investigation of the hydrogen desorption from Nd2Fe17Hx, and Dy2Fe17Hx compounds by differential scanning calorimetry

International audienceHydrogen desorption from R2Fe17Hx, (R=Nd and Dy) compounds with x <= 5 has been studied using differential scanning calorimetry (DSC). Overall hydrogen binding energies are very similar in both systems regardless their different crystal structures. The heat of hydrogen desorption is 29.2 +/- 0.8 kJ mol H-1 for both R2Fe17Hx family compounds. Desorption activation energies are also very close: 78 +/- 8 kJ and 79 +/- 4 kJ mol H-1 for Nd and Dy-containing compounds, respectively. The rare earth nature modifies however the local interaction between hydrogen and the intermetallic compound. For Nd, H-atoms occupy two non-equivalent and well-defined energy sites whereas a unique energy site with a broad energy distribution is detected for Dy. This peculiar behavior is discussed in terms of the different structural properties of the light (Nd) and heavy (Dy) rare-earth R2Fe17 compounds

Impact of Mutations in Arabidopsis thaliana Metabolic Pathways on Polerovirus Accumulation, Aphid Performance, and Feeding Behavior

During the process of virus acquisition by aphids, plants respond to both the virus and the aphids by mobilizing different metabolic pathways. It is conceivable that the plant metabolic responses to both aggressors may be conducive to virus acquisition. To address this question, we analyze the accumulation of the phloem-limited poleroviru

Structural, thermal and magnetic properties of ErMn2D6 synthesized under high deuterium pressure

A new phase of ErMn2D6 has been prepared by applying high hydrogen pressure on C14 ErMn2. This phase is isostructural to YMn2D6 and crystallizes with a K2PtCl6 type structure having an ordered anion and a partially disordered cation arrangement as Er and half the Mn atoms are randomly substituted in the same 8c site. This hydride is very stable and decomposes into ErD2 and Mn at about 630 K. The reverse susceptibility follows a Curie - Weiss law with an effective moment of 10 mu(B) similar to that of ErMn2. Although a saturation magnetization of 5 mu(B) is measured at 4.2 K, smaller than that of ErMn2 (8 mu(B)), no long range magnetic order is observed in the neutron patterns. Short range magnetic order, corresponding to both ferromagnetic and antiferromagnetic correlations, is observed in the neutron patterns up to 5 K. The chemical disorder of Er and Mn atoms on the 8c site should prevent the long range magnetic order and favour a distribution of Er spin orientation

Lancet

International audienceSince the introduction of so-called less-lethal weapons in France in the late 1990s, there has been no legal requirement to collect data on injuries induced by kinetic impact projectiles, and no epidemiological surveys have been planned. To estimate the number of patients with ocular injuries caused by the use of these defensive tools, a retrospective survey was sent to all ophthalmology department chairs in French university hospitals, which are where the most severe cases are managed. Demographic data, date of trauma, initial ophthalmological examination and any specialised investigations, initial and immediate surgical management of the injury, follow-up, and visual prognosis were documented and transmitted anonymously.We compiled data from patients seen between February, 2016, and August, 2019 (figure). 43 cases were identified, of which 20 (47%) were managed in Paris. The cases included 38 men and five women, with a median age of 26 years (range 15–59)