Biased Brownian motion of point-size particles in a three-dimensional tube with varying cross-section is investigated. In the fashion of our recent work, Martens et al. [Phys. Rev. E 83, 051135 (2011)] we employ an asymptotic analysis to the stationary probability density in a geometric parameter of the tube geometry. We demonstrate that the leading order term is equivalent to the Fick-Jacobs a...

The influence of recycling on double-pass solar air collectors with welding of the V-corrugated absorber has been studied experimentally and theoretically. Welding the V-corrugated absorber and the recycle-effect concept to the solar air collector was proposed to strengthen the convective heat-transfer coefficient due to turbulence promotion. Both the recycle effect and the V-corrugated absorbe...

This paper extends the theory of the diffraction of sound on 1D corrugated surfaces to 2D corrugated surfaces. Such surfaces, that are egg crate shaped, diffract incoming sound into all polar directions, which is fundamentally different from 1D corrugated surfaces. A theoretical justification is given for extending the classical grating equation to the case of incident inhomogeneous waves, for ...

An axially corrugated horn antenna with an elliptically shaped taper is proposed for satellite communication applications. This structure is a good candidate for the feed of reflectors and also for improving the electrical properties of reflector antennas. A tapering method is used to justify the horizontal location of the corrugation profile which improves the electrical performance of the pre...

Dear Sir, In the April 1950 edition of your Journal, Dr. Esplen illustrated a metal anaesthetic screen for use in thoracotomies in the lateral position. I agree that such a screen is essential to maintain a good view of the patient's airway, and more particularly to facilitate bronchoscopy without disturbing the operative field should it become necessary during operation. Such a screen can well...