Ion cyclotron waves at approximately 0.7 the ion gyrofrequency have been observed experimentally in the large volume helicon reactor WOMBAT. These waves are highly localized along the axis of the device where a 8 cm diameter, 2 m long. Ar II plasma column is produced. Spectral measurements reveal a four-wave interaction where energy is down-converted to the ion cyclotron mode from the helicon p...

Illuminating tissue with pulsed electromagnetic waves generates acoustic waves inside an object which can be measured and converted into a three dimensional (3d) image. This text is concerned with a twostep reconstruction method where the acoustic pressure is measured with circular integrating detectors. In the first step reconstruction formulas for some kind of projection of the source distrib...

We describe a methodology for modeling heart rhythms observed in electrocardiograms. In particular, we present a procedure to derive simple dynamic models that capture the cardiac mechanisms which control the particular timing sequences of P and R waves characteristic of different arrhythmias. By treating the cardiac electrophysiology at an aggregate level, simple network models of the wave gen...

A field trial was conducted to test the existence of subsonic (Vp < 331 m/s) P-waves previously reported in the literature. A 1-m-long reverse profile was acquired with three-component (3C) geophones on a sandy silt (unified classification ML). The silt had a porosity of 54%, a degree of water saturation of 63%, and a plasticity index of 10. No subsonic P-waves were observed, although highfrequ...

ANALYSIS of the P wave in the electro-I X cardiogram has been found to be a useful indicator of certain alterations of cardiac function. The patterns of P mitrale and P pulmonale are generally well recognized. Morris and co-workers' reported that differences in the contour of the terminal portion of the P wave in precordial lead V, separated subjects with essentially normal hemodynam-ic finding...

&lt;abstract&gt;&lt;p&gt;Photoacoustic tomography (PAT) is a novel and rapidly developing technique in the medical imaging field that based on generating acoustic waves inside of an object interest by stimulating non-ionizing laser pulses. This wave was measured using detector outside it then converted into image human body after several inversions. Thus, one mathematical problems PAT reconstru...