We report picosecond ultrasonic measurements of phonon attenuation in a 56 μm thick Si wafer coated with a 25 nm Al film. The measurements are of interest for picosecond ultrasonic imaging schemes, and for investigations of nanoscale heat transport. An ultrafast laser was used to perform the pump-probe experiment. A probe delay stage with a range of several nanoseconds allowed detection of cohe...

The unusual form of sexual signaling, the drumming produced by the wolf spider Hygrolycosa rubrofasciata, allows exceptionally detailed studies of female preference patterns against signal characteristics. It is easy to manipulate the signals and to use large numbers of females in playback experiments. Males of H. rubrofasciata produce drums by striking their abdomen against dry leaves on the g...

In this work, we describe a novel pulse mode shear horizontal-surface acoustic wave (SH-SAW) polymer coated biosensor that monitors rapid changes in both amplitude and phase. The SH-SAW sensors were fabricated on 36 degrees rotated Y-cut X propagating lithium tantalate (36 YX.LT). The sensitivity of the device to both mass loading and visco-elastic effects may be increased by using a thin guidi...

Solitons are a unique class of pulse-shaped waves that propagate in nonlinear dispersive media. In the course of propagation, they maintain spatial confinement of wave energy within the pulse shape without dispersion and exhibit remarkable nonlinear dynamics. Solitons are found throughout nature where fine balance between nonlinearity and dispersion is achieved. Dispersion alone would flatten o...

Increasing traffic on the Internet demands faster optical transmission networks. Future high-speed communication networks may rely largely on all-optical components that are intrinsically faster than their electronic counterparts. To achieve such networks, however, one needs to overcome a number of obstacles that exist at levels from devices to systems. For example, the lack of all-optical memo...

Abstract: In order to adapt to all kinds of spectral mask and utilize the full frequency band and avoid interference to/from the existing wireless systems for ultra wideband (UWB), this paper investigates two pulse designs for ultra wideband-cognitive radio (UWB-CR) by using multiple modified transform domain communication system (M-TDCS). By applying multiple M-TDCS and installing a different ...

Vocalizations from the northern right whale dolphin, Lissodelphis borealis, were recorded during a combined visual and acoustic shipboard survey of cetacean populations off the west coast of the United States. Seven of twenty single-species schools of L. borealis produced click and pulsed vocalizations. No whistles were detected during any of the encounters. Clicks associated with burst-pulse v...

During the Acoustic Engineering Test ~AET! of the Acoustic Thermometry of Ocean Climate ~ATOC! program, acoustic signals were transmitted from a broadband source with 75-Hz center frequency to a 700-m-long vertical array of 20 hydrophones at a distance of 3252 km; receptions occurred over a period of six days. Each received pulse showed early identifiable timefronts, followed by about 2 s of hi...