Locked Horns Indicate Struggle

Acoustic particle velocity horns.

The paper considers receiving acoustic horns designed for particle velocity amplification and suitable for use in vector sensing applications. Unlike conventional horns, designed for acoustic pressure amplification, acoustic velocity horns (AVHs) deliver significant velocity amplification even when the overall size of the horn is much less than an acoustic wavelength. An AVH requires an open-en...

Rep-tiles with woven horns

This paper describes a simple geometric construction for the visualization of Alexander’s horned sphere as a selfsimilar fractal curve in the plane. The construction is based on a recursive rep-2 rectangle progression to a specified depth. Parameterized curve generation and rendering details are briefly discussed. r 2005 Elsevier Ltd. All rights reserved.

Horns as particle velocity amplifiers.

Preliminary measurements and numerical predictions reveal that simple, and relatively small, horns generate remarkable amplification of acoustic particle velocity. For example, below 2 kHz, a 2.5 cm conical horn has a uniform velocity amplification ratio (throat-to-mouth) factor of approximately 3, or, in terms of a decibel level, 9.5 dB. It is shown that the velocity amplification factor depen...

Taking the bull by the horns.

The Struggle for Existence

"It is in the nature of things" is surely, today, just as good an explanation of a biological phenomenon as it ever was; and now, as always, it is singularly unilluminating. That some of the problems to which such an explanation is usually given are susceptible to analysis appears obvious; at least an approach can be made toward segregating the many factors which, acting independently ox throug...