0000000000360044
AUTHOR
G. Rousseau
Synthesis and characterization of nanometric powders of UO2+x, (Th,U)O2+x and (La,U)O2+x
This paper describes a new way of preparing nanometric powders of uranium oxide, to fit the needs of studies on UO{sub 2} oxidation, through the electrochemical reduction of U(VI) into U(IV). These powders can also be doped with radionuclides if necessary. The precipitation of oxides occurs in reducing and anoxic conditions. This original method makes it possible to synthesize nanometric UO{sub 2} powders with a calibrated size, as well as the Th- and La-doped UO{sub 2} powders with a predefined composition. The powder characterization by the X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron Microscopy shows the formation of spherical crystallites of UO{sub 2+x},…
Synchrotron diffraction study of the isothermal oxidation of uranium dioxide at 250°C
ABSTRACTThe structural evolution of UO2 during its oxidation to U3O8 at 250°C in air was studied by in-situ synchrotron X-ray diffraction on the D2AM-CRG beamline at ESRF. The aim of this study is to determine the phases that are likely to appear during the long-term storage of spent nuclear fuel. Our results are in disagreement with the literature in which the existence of an intermediate cubic phase is not reported. Instead, an α-U3O7 tetragonal phase (c/a < 1) was mentioned but not definitively observed. These previous interpretations may have been the result of poor instrumental resolution.
The Association of Intraoperative driving pressure with postoperative pulmonary complications in open versus closed abdominal surgery patients – a posthoc propensity score–weighted cohort analysis of the LAS VEGAS study
Abstract Background It is uncertain whether the association of the intraoperative driving pressure (ΔP) with postoperative pulmonary complications (PPCs) depends on the surgical approach during abdominal surgery. Our primary objective was to determine and compare the association of time–weighted average ΔP (ΔPTW) with PPCs. We also tested the association of ΔPTW with intraoperative adverse events. Methods Posthoc retrospective propensity score–weighted cohort analysis of patients undergoing open or closed abdominal surgery in the ‘Local ASsessment of Ventilatory management during General Anaesthesia for Surgery’ (LAS VEGAS) study, that included patients in 146 hospitals across 29 countries.…