The creep and wear behaviour of highly cross-linked polyethylene and standard polyethylene liners were examined in a prospective, double-blind randomised, controlled trial using radiostereometric analysis. We randomised 54 patients to receive hip replacements with either highly cross-linked polyethylene or standard liners and determined the three-dimensional penetration of the liners over three...

Low-ionization nuclear emission-line regions (LINERs) exist in the nuclei of a large fraction of luminous galaxies, but their connection with the active galactic nucleus (AGN) phenomenon has remained elusive. We present Hubble Space Telescope (HST) narrowband ([O III]λ5007 and Hα+[N II]) emission-line images of the central regions of 14 galaxies with LINER nuclei. This is the first such study o...

An analysis of linear wave modes associated with supersonic jets con ned inside an acoustically lined rectangular duct is presented. Mathematical formulations are given for the vortex-sheet model and continuous mean ow model of the jet ow pro les. Detailed dispersion relations of these waves in a two-dimensional con ned jet as well as an uncon ned free jet are computed. E ects of the con ning d...

In order to determine the incidence of black hole accretion-driven nuclear activity in nearby galaxies, as manifested by their radio emission, we have carried out a high-resolution Multi-Element Radio-Linked Interferometer Network (MERLIN) survey of LINERs and composite LINER/Hii galaxies from a complete magnitude-limited sample of bright nearby galaxies (Palomar sample) with unknown arcsecond-...

PURPOSE The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts we...

We study a complete and distance-limited sample of 25 LINERs, 21 of which have been imaged with the Hubble Space Telescope to study their physical properties and to compare their radio and optical properties with those of other samples of local AGNs, namely Seyfert galaxies and low-luminosity radio galaxies (LLRG). Our results show that the LINERs population is not homogeneous, as there are two...

Aim: To evaluate the surface alterations of soft liners with or without sealer coating after mechanical brushing abrasion. Methods: Thirty specimens were made of a methacrylate(Coe-Soft) and a siloxane-based material (Ufi-Gel SC), and 15 received two coatings of surface sealer. The specimens were submitted to a mechanical brushing-dentifrice assay under 200 g of force at 250 cycles/min. Mechani...

Four liners are investigated experimentally via tests in the NASA Langley Grazing Flow Impedance Tube. These include an axially-segmented liner and three liners that use reordering of the chambers. Chamber reordering is shown to have a strong effect on the axial sound pressure level profiles, but a limited effect on the overall attenuation. It is also shown that bent chambers can be used to red...

Noise reduction inside waveguide systems has gained momentum owing to a great interest in it. To attenuate the sound broad frequency range, this study aims compare effects of two acoustic liners, perforated plate backed by an air cavity (PP-Air cavity), or porous material (PP-PM), on behaviour lined ducts using numerical model compute multimodal scattering matrix. From matrix, reflection and tr...