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A combined deep inelastic neutron scattering andab initiolattice dynamics study of the hydride anion dynamics and bonding in La2LiHO3 oxyhydride
Get PDFKobayashi et al (6279) (Science 2016, 351) reported recently the existence of pure H- conductivity in the oxyhydride La2−x−y Sr x+y LiH1−x+y O3−y , while demonstrating its functionality through a prototype solid-state Ti/La2LiHO3/TiH2 battery. In this study, we probe the atomistic motion of La2LiHO3 obtained by the promising halide salt flux method, via a combination of deep inelastic neutron scattering (DINS) and ab initio lattice dynamics (LD) calculations verified by vibrational inelastic neutron spectroscopy (INS). We successfully describe the measured momentum distributions from DINS via our LD calculations, without observing any diffusion activation over the temperature range reported by Kobayashi et al. This observation is corroborated by model predictions from our LD study, which reveals that the hydride anions remain bound within a 3D-harmonic potential. We conclude that with the current synthesis parameters, the method produces a vacancy free lattice, and that a necessary ingredient for diffusive motion of H- is the presence of a large population of vacancies. Based on the harmonic prediction for the hydrogen kinetic energy, we derive a picture of the evolution of the effective bonding potential for the hydride anions, and link this to the dynamics associated with decomposition of the oxyhydride.publishedVersio
Discovery of shale gas in organic rich Jurassic successions, Adventdalen, Central Spitsbergen, Norway
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Two-phase gas-liquid flow in concentric and fully eccentric annuli. Part I: Flow patterns, holdup, slip ratio and pressure gradient
Get PDFHorizontal and upward low-inclination gas-water and gas-oil flows are investigated using an annulus pipe configuration in a high-pressure system (~400 kPa). The annulus test section, or the so-called pipe-in-pipe configuration, consists of an outer pipe of 99 mm inside diameter and an inner pipe of 50 mm outside diameter. Two different vertical positions of the inner pipe with respect to outer pipe have been tested; namely concentric configuration where both pipes have the same centreline and fully eccentric where the inner pipe is placed at the bottom wall of outer pipe. The flow is studied using high-speed photography, differential pressure transducers, and broad-beam gamma densitometers to characterise the flow as function of the liquid phase properties, annulus eccentricity, and pipe inclination. Flow regime maps reveal that slug flow appears to be the most common flow feature across the conditions studied in this paper. Flow in the eccentric annulus shows a more consistent behaviour (i.e. well-defined flow structures axially and in time) than that observed in the concentric annulus. Gas-oil flows show more stable phase fraction behaviour across the cross-section compared to that observed in gas-water flows in which the interface shows significant activity promoting the formation of droplets and ligaments that break from the liquid film. This is especially the case with the concentric annulus configuration. The oil phase regardless of the geometrical configuration tends to fully wet the pipe (made of PVC) as the gas velocity increases, creating a continuous film along the pipe walls. Conversely, the thin film in gas-water flow is not continuous. Discontinuity in the thin film increases with an increase in effective pipe roughness. Given the same inlet flow conditions, the concentric annulus configuration causes larger pressure drop along the pipe than that obtained in the eccentric. acceptedVersio
Electrochemical studies and phase-structural characterization of a high-capacity La-doped AB(2) Laves type alloy and its hydride
No full textA high-accuracy calibration method for temperature dependent photoluminescence imaging
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Comparative phase transformation and magnetocaloric effect study of Co and Mn substitution by Cu in MnCoGe compounds
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Effect of SO2, O2, NO2, and H2O Concentrations on Chemical Reactions and Corrosion of Carbon Steel in Dense Phase CO2
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Crystal structure of LaSr3Fe3O9 and its phase relation with LaSr3Fe3O10
Get PDFThe Ruddlesden-Popper phase LaSr3Fe3O10 and its reduced derivatives with nominal composition LaSr3Fe3O10–x, with 0 0.85. The phases are separated by a two-phase region 0.51 350 K and with a G-type magnetic structure, magnetic space group PCbcm. Based on unit cell volume considerations, local oxygen vacancy ordering schemes are suggested.acceptedVersio