Arbitrary angle waveguiding applications of two-dimensional curvilinear-lattice photonic crystals

We introduce a fresh class of photonic band-gap materials, curvilinear-lattice photonic crystals, whose distinctive feature is that their individual scatterers are arranged in a curvilinear lattice. We show that adhering to some restrictions in the acceptable lattice transformations, one can achieve omnidirectional photonic band gaps for an entire subclass of such structures. We demonstrate, designing an efficient arbitrary-angle waveguide bend, that curvilinear-lattice photonic crystals can be employed for creation of original types of nanophotonic devices

Neutron reflection study of the adsorption of the phosphate surfactant NaDEHP onto alumina from water.

The adsorption of a phosphorus analogue of the surfactant AOT, sodium bis(2-ethylhexyl) phosphate (NaDEHP), at the water/alumina interface is described. The material is found to adsorb as an essentially water-free bilayer from neutron reflection measurements. This is similar to the behavior of AOT under comparable conditions, although AOT forms a thicker, more hydrated layer. The NaDEHP shows rather little variation with added salt, but a small thickening of the layer on increasing the pH, in contrast to the behavior of AOT.We thank BP plc and EPSRC for financial support for this work as well as the ISIS and ILL staff and scientists for the allocation of beam time and technical assistance with NR measurements. We also appreciate Chris Sporikou at Department of Chemistry, University of Cambridge, for help with the surfactant synthesis.This is the final version of the article. It first appeared at http://dx.doi.org/10.1021/la504837

Polarized Neutron Reflectometry of Nickel Corrosion Inhibitors.

Polarized neutron reflectometry has been used to investigate the detailed adsorption behavior and corrosion inhibition mechanism of two surfactants on a nickel surface under acidic conditions. Both the corrosion of the nickel surface and the structure of the adsorbed surfactant layer could be monitored in situ by the use of different solvent contrasts. Layer thicknesses and roughnesses were evaluated over a range of pH values, showing distinctly the superior corrosion inhibition of one negatively charged surfactant (sodium dodecyl sulfate) compared to a positively charged example (dodecyl trimethylammonium bromide) due to its stronger binding interaction with the surface. It was found that adequate corrosion inhibition occurs at significantly less than full surface coverage.X-ray photoelectron spectra were obtained at the National Engineering and Physical Sciences Research Council (EPSRC) XPS User’s Service (NEXUS) at Newcastle University, an EPSRC midrange facility. NR data were obtained on the D17 instrument, and samples were treated in the laboratories of the Partnership for Soft Condensed Matter (PSCM) at the Institut Laue-Langevin. M.H.W. is grateful for funding from the Oppenheimer Trust.This is the final version of the article. It first appeared from the American Chemical Society via http://dx.doi.org/10.1021/acs.langmuir.5b0171

Effect of GapSeal® as a Sealing Material on Microgap and Microleakage at External Hexagon Implant Connections Following Cyclic Loading: An In Vitro Study

Background and Aim: The mismatch of the implant-abutment connection can produce instant stress and microleakage which result in mechanical and biological complications. This study aimed to investigate the influence of GapSeal® as a sealing material on the extent of microgap and microleakage at the external hexagon implant platform following cyclic loading. Materials and Methods: Sixteen implants with an external-hexagon connection (BioHorizons External dental implant) were employed in this in-vitro experimental study. All implant-abutment sets were assigned to two groups and were molded in acrylic resins. GapSeal® was injected into the implants in the experimental (test) group. Then, implant assemblies were tightened with the torque of 30 N/cm, and 1200,000 loading cycles with the force of 100 N and the frequency of 1 Hz were applied. Every sample was immersed in a methylene blue dye to evaluate microleakage. Microgap was measured in six regions randomly using a scanning electron microscope (SEM). The data were entered into SPSS 22 and were analyzed using t-test. Results: The mean±SD microgap was 0.87±0.35 µm and 3.43±1.61 µm in the test and control groups, respectively. Methylene blue dye was observed in all of the specimens of the control group, while no liquid was seen in the test group. A significant statistical difference was found between the groups regarding the microgap and microleakage (P<0.0001). Conclusion: Application of GapSeal® reduced the dimension of the microgap and decreased microleakage at the implant-abutment interface

Doit-on encore donner de l'halofantrine aux enfants ? (épidémiologie et traitement des accès simples à Plasmodium Falciparum chez l'enfant à l'hôpital Delafontaine de 1999 à 2003)

PARIS-BIUM (751062103) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocSudocFranceF