Eating horns

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.

How the horned lizard got its horns.

Many descriptions of evolutionary adaptations are criticized as “just-so stories” (1) that are based more on intuition than on direct tests of adaptive hypotheses. The elaborate crowns of horns possessed by many species of horned lizards (genus Phrynosoma) are classic examples of intuitively adaptive features that lack direct tests of function. The bony horns that give horned lizards their name...