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We report on the photocatalytical properties of pure and barium-doped nickel oxide nanofilms synthesised on glass substrates using a simple spray pyrolysis method. The nanofilms were prepared from different solution concentrations obtained from pure nickel chloride hexahydrate (NiCl2:6H2O) powder in distilled water. Doping has been obtained at various concentrations of barium (0–5%) by simultaneously dissolving (BaCl2:2H2O) in the distilled water. The structure and the morphology of the NiO and Ba-NiO nanofilms were investigated by means of X-ray diffraction and atomic force microscopy. The observed principal (111), (200) and (220) XRD patterns peaks correspond to cubic NiO adopting the NaCl-type structure. AFM observations revealed a textured and rough surface. Optical reflectance and transmittance measurements showed an optical band gap corresponding to that of NiO, only slightly affected by the barium doping. The photocatalytic properties of the films were enhanced by barium doping as revealed by the degradation of methylene blue (MB) aqueous solution under ultraviolet irradiation. Between 70–80% of MB was consumed after 300 min ultraviolet irradiation with the addition NiO with Ba concentrations in the range 0–3%. [ABSTRACT FROM AUTHOR]

The age and shell growth rate of deep-sea hydrothermal bivalves were investigated for the first time using in situ chemical staining combined with high-resolution micro-increment analysis. A staining chamber developed for this purpose was applied to a patch of Bathymodiolus thermophilus mussels at 2,500 m depth at the 9°47′N vent field on the East Pacific Rise (EPR) in May 2010. This approach minimizes disturbance of the mussels in their habitat. Bathymodiolus thermophilus grows according to a circalunidian rhythm, with one increment formed each day, and displays tide-related growth rate variability. Based on the von Bertalanffy growth rate model, the largest shell collected (SL = 20.5 cm) would be 10.0 year old, with a growth rate of 4.2-1.1 cm year as the shell ages. This fast growth rate is consistent with the instability of the environment in this section of the EPR and observed recolonization rates and could reflect a specific adaptation of this species. [ABSTRACT FROM AUTHOR]

High-resolution analysis (2277 samples) of magnetic susceptibility (MS) was performed on ∼700-m-thick Early–Middle Oxfordian marine marls of the Terres Noires Formation, SE France. MS variations within these sediments record sub-Milankovitch to Milankovitch frequencies with long-term eccentricity (405 kyr and ∼2 Myr) being the most prominent. The 405 kyr cycle was used as a high-resolution geochronometer for astronomical calibration of this poorly constrained interval of Late Jurassic time. The estimated duration of this Early–Middle Oxfordian interval concurs with the current International Geologic Time Scale GTS2004 (∼4 Myr), but the estimated durations of the corresponding ammonite zones are notably different. The calibration improves the resolution and accuracy of the M-sequence magnetic anomaly block model that was previously used to establish the Oxfordian time scale. Additionally, the 405 kyr cyclicity is linked to third-order sea-level depositional sequences observed for Early–Middle Oxfordian time. Strong ∼2 Myr cycles are consistent with long-term eccentricity modulation predicted for the Late Jurassic. These cycles do not match second-order sequences that have been documented for European basins; this raises questions about the definition and hierarchy of depositional sequences in the Mesozoic eustatic chart. Our results require substantial revisions to the chart, which is frequently used as a reference for the correlation of widely separated palaeogeographic domains. Finally, a long-term trend in the MS data reflects a progressive carbonate enrichment of the marls expressing an Early Oxfordian global cooling followed gradually by a warming in the Middle Oxfordian. This trend also records a major transgressive interval likely peaking at the Transversarium ammonite zone of the Middle Oxfordian. [ABSTRACT FROM AUTHOR]

Classic stratigraphic methods rarely provide high-resolution correlations between intrabasinal sedimentary sequences, which are important to understand the origin of sedimentation process and its environmental change. In this study, we investigate high-resolution cyclostratigraphic correlation from magnetic susceptibility in two Early Kimmeridgian pelagic marl-limestone successions, at La Méouge and Châteauneuf-d'Oze, southeastern France. Spectral analysis reveals the complete suite of orbital frequencies (precession, obliquity, and eccentricity) with the marl-limestone couplets being primarily precession-driven. Frequencies detected by the spectral analysis are similar between the sections, but their relative amplitudes are somewhat different, linked to the palaeoenvironmental position and the completeness of the sections. High-resolution correlation reveals two significant hiatuses at Châteauneuf-d’Oze. Early Kimmeridgian Platynota, Hypselocyclum, and Divisum ammonite zones were orbitally calibrated for an ultra-high resolution assessment of geological time. Finally, strong 405-kyr eccentricity cycles are recorded as third-order depositional sequences. [ABSTRACT FROM AUTHOR]