In the radial flow of gas into a black hole (i.e. Bondi accretion), the infall of any entropy or vorticity perturbation produces acoustic waves propagating outward. The dependence of this acoustic flux on the shape of the perturbation is investigated in detail. This is the key process in the mechanism of the entropic-acoustic instability proposed by Foglizzo& Tagger (2000) to explain the instab...

Guided wave technique could be a possible method for monitoring components working in high temperature above 350 °C. However, this would require the design of an appropriate waveguide bar to transmit the wave, so that its sensing part is not influenced by the high temperature. In the present study, the shape of waveguide bars is designed based on the analysis of wave source characteristics. The...

The multi-chamber reactive silencers are widely used to reduce engine exhaust noise as well as blower intake and discharge noise. Davis et al. [1] developed a one-dimensional analytical approach, which assumes plane wave propagation in the axial direction in silencers, to predict the acoustic attenuation performance of double expansion chamber reactive silencers, and compared the predictions wi...

BACKGROUND In most patients with rheumatoid arthritis (RA), Disease Activity Score 28-joint count C reactive protein (DAS28-CRP) is lower than DAS28 erythrocyte sedimentation rate (DAS28-ESR), suggesting that use of the DAS28-ESR cut-off to assess high disease activity (HDA) with DAS28-CRP may underestimate the number of patients with HDA. We determined the DAS28-CRP value corresponding to the ...

In a recent preprint Kong et al, arXiv: 0902.0642v1 (2009) claimed to calculate the lattice thermal conductivity of single and bi-layer graphene „from first principles”. The main findings were that the Umklapp-limited thermal conductivity is only slightly higher than that of high-quality bulk graphite along the basal plane, and that it does not strongly depend on the number of atomic layers. He...

We analyze the degree distribution’s cut-off in finite size scale-free networks. We show that the cut-off behavior with the number of vertices N is ruled by the topological constraints induced by the connectivity structure of the network. Even in the simple case of uncorrelated networks, we obtain an expression of the structural cut-off that is smaller that the natural cut-off obtained by means...

Background: Anti-Mullerian hormone (AMH) has been suggested as a marker of ovarian reserve and predictor of ovarian response to controlled ovarian hyper stimulation. The aim of this study is to determine the role of AMH in prediction of success ART cycles in patients with normal FSH serum levels. Materials and Methods: This prospective cohort study included 80 infertile women under 4o years, wh...