A classification of CO spaces which are continuous images of compact ordered spaces

A topological space X is called a CO space, if every closed subset of X is homeomorphic to some clopen subset of X. Every ordinal with its order topology is a CO space. This work gives a complete classification of CO spaces which are continuous images of compact ordered spaces.     

Decomposition of Mixing Layer Turbulence into Coherent Structures and Background Fluctuations

The eduction of coherent structures from cross-wire rake data in a fully turbulent incompressible mixing layer confirms the feasibility of a decomposition of a turbulent flow field, first suggested by Farge, as non-periodic non-equilibrium coherent structures interacting with a ‘thermalized’ broad-band turbulence. A simple wavelet coefficient decimation algorithm and orthogonalization yields non-periodic dominant flow structures and a background field that has a Gaussian distribution of velocities at the centerline. The coherent structures are classified in terms of their topology. The non-coherent background field has flat energy spectra and normal distribution of velocity components. Most background field statistics depend only weakly on the type of structure on which they are superposed. It may be possible to adapt existing subgrid scale models to this decomposition. This revised version was published online in July 2006 with corrections to the Cover Date.     

Single walled nanotubes/amylose/SDBS complex

In this study, we prepare and characterize single walled carbon/amylose complexes formed in aqueous medium in presence of a surfactant, where amylose is an helical polysaccharide. We show that at low amylose content, nanotubes based complexes are formed which show a strong infra-red fluorescence. Electron microscopy and atomic force microscopy suggest that the complex morphology implies also the surfactant. We propose a supramolecular architecture of the complex where the nanotubes are protected from the aqueous environment by the surfactant/amylose molecules. These complexes may be of interest for biosensing applications.     

A stabilization process applied to a hidden variables method for evaluating the uncertainties on foundation impedances and their effect on vibrations induced by railways in a building

The paper is devoted to stochastic foundation impedance modeling for buildings submitted to vibrations. The hidden-variables method used in seismic engineering is revisited, due to a larger frequency range used in vibration prediction. Indeed, in this new context, instability of the solution and non-physical nature of mass and stiffness random matrices have been observed. The hidden variable method has been therefore implemented by enforcing explicitly the stability of the solution and the positiveness of mass and stiffness matrices. The effects of numerical parameters used throughout the process are shown and the improved hidden-variables method has been used for predicting the level of vibrations inside a building induced by railway sources. We present here steps of stabilization process, and then discuss on an example of application.     

Brillouin scattering study of the orientationally disordered phase of cyclohexanol

Brillouin scattering was used to measure the velocity and attenuation of longitudinal hypersonic waves in the orientationally disordered (OD) phase of a cyclohexanol single crystal and at the OD-liquid transition. Our results show that the coupling with a high-frequency relaxation mechanism, which dominates the behaviour of the hypersonic waves in the liquid, is still efficient in the OD phase.     

Structure électronique du phénol,de l'ion phénate et du phénol perturbé par l'établissement d'une liaison hydrogène

The improved LCAO method is used to study the electronic structure of phenol, phenoxide ion, and phenol perturbed by a hydrogen bond. The calculated transition energies are in good agreement with experiment. A new method is proposed to determine the differences of reactivity between the different atoms of the aromatic ring. The results are satisfactory.