A comprehensive examination of the local- and long-range structure of SbO pyrochlore oxide.

The crystal structure of the SbO oxide, exhibiting a defect pyrochlore crystal structure with atomic vacancies, has been studied using a complete set of state-of-the-art techniques. The degree of antimony disproportionation in Sb and Sb valence states has been directly determined around 36% and 64%, respectively, using X-ray absorption near edge structure (XANES). These findings are in excellent agreement with our Rietveld analysis of synchrotron X-ray (SXRD) and neutron powder diffraction (NPD) results.

Structure-properties relationship in the hydronium-containing pyrochlores (HO)SbTeO with catalytic activity in the fructose dehydration reaction.

A series of defect pyrochlores of the composition (H3O)1+pSb1+pTe1-pO6 have been prepared by ion exchange from K-containing pyrochlores K1+pSb1+pTe1-pO6 in sulfuric acid at 280 °C for 24 h. The structural characterization of the hydronium-containing pyrochlores, including the location of the H3O+ units within the three-dimensional framework, was possible from neutron powder diffraction data in undeuterated samples. The crystal structure for all the compounds is defined in the Fd3[combining macron]m space group, and consists of a covalent framework of SbVO6 and TeVIO6 octahedra distributed at random and connected by their vertices with (Sb,Te)-O1-(Sb,Te) angles close to 136°, conforming to large cages where the hydronium species are located off-center.

Probing the Catalytic Activity of Sulfate-Derived Pristine and Post-Treated Porous TiO(101) Anatase Mesocrystals by the Oxidative Desulfurization of Dibenzothiophenes.

Mesocrystals (basically nanostructures showing alignment of nanocrystals well beyond crystal size) are attracting considerable attention for modeling and optimization of functionalities. However, for surface-driven applications (heterogeneous catalysis), only those mesocrystals with excellent textural properties are expected to fulfill their potential. This is especially true for oxidative desulfuration of dibenzothiophenes (hard to desulfurize organosulfur compounds found in fossil fuels).

In vitro cavity and crown preparations and direct restorations: A comparison of performance at the start and end of the FD programme.

Aim To assess the performance and thereby the progress of the FDs when they carried out a number of simulated clinical exercises at the start and at the end of their FD year.Methods A standardised simulated clinical restorative dentistry training exercise was carried out by a group of 61 recently qualified dental graduates undertaking a 12 months' duration foundation training programme in England, at both the start and end of the programme. Participants completed a Class II cavity preparation and amalgam restoration, a Class IV composite resin restoration and two preparations for a porcelain-metal full crown.