Isolated neonatal rat ventricular cardiomyocytes were used to study the influence of ultrasound on the chronotropic response in a tissue culture model. The beat frequency of the cells, varying from 40 to 90 beats/min, was measured based upon the translocation of the nuclear membrane captured by a high-speed camera. Ultrasound pulses (frequency = 2.5 MHz) were delivered at 300-ms intervals [3.33...

If a large amplitude density pulse is launched into a plasma having equal electron and ion temperatures, Te 5Ti , Landau damping prevents the formation of a sharp leading edge ~‘‘shock’’! and the pulse spreads out. If the Landau damping is eliminated, the pulse steepens as it propagates and a shock structure is formed. This has been observed experimentally, for example, by increasing the Te /Ti...

Responses of neurons in the primary auditory cortex were compared in gerbils receiving intracochlear electric or acoustic stimulation. Stimuli were trains of periodic electric pulses or of acoustic clicks. Interspersed between intervals of equal length were single intervals which were longer, by some Delta t. The Delta t and the repetition rate of these prolonged intervals were varied. The degr...

Criteria for the design of an acoustic pulse reflectometer specifically intended for musical instrument research are discussed. Different types of pulse source are considered, and various approaches to the signal processing of the reflected pulse are evaluated., Finally, the practical utility of the technique for instrument designers and manufacturers is discussed.

A multilayer encapsulated coating has been developed for underwater acoustic attenuation purposes. This coating provides an option for electronically activating encapsulated piezoelectric devices to increase the coatings passvie sound attenuation performance through active control methods. These methods include the ability to sense the incident and reflected acoustic pressure field and produce ...

We present a theory of acoustically induced pulse interaction in a ring fiber laser cavity. In most cases the acoustic interaction leads to pulse bunching, but in some cases it leads to regular pulse spacing. Our results compare well with the experimental data.

We report 5.1 dB of squeezing from a fiber interferometer pumped with a 1-GHz pulse source that successfully eliminates guided-acoustic-wave Brillouin scattering in significant frequency regimes. The pulse source is a diode-pumped Nd:YLF laser actively mode locked at 1.314 microm. The squeezing results are consistent with the limits imposed by the Gaussian pulse shape and the detection quantum ...

An aerodynamic sound source extraction from a general flow field is applied to a number of model problems and to a problem of engineering interest. The extraction technique is based on a variable decomposition, which results to an acoustic correction method, of each of the flow variables into a dominant flow component and a perturbation component. The dominant flow component is obtained with a ...

Asymptotic expansions as e--,0 that are uniformly valid in t are obtained for the membrane's motion and the scattered acoustic pressure field. The small parameter ß is the density ratio of the acoustic fluid and the membrane. For simplicity of presentation, only plane, compact incident pulses are considered. The scattered field depends on the pulse's tructure. If it is a sufficiently narrow ban...