Quiet Zone Design in Diffuse Fields Using Ultrasonic Transducers

Quiet Zone Design in Broadband Diffuse Fields

In this paper design of quiet zones in broadband diffuse fields has been present by using the method of acoustic pressure minimization over various spaces and frequencies. The technique is squared acoustic pressure minimization. The theory and simulations of pressure minimization over space and frequency using two-channel and three-channel systems are presented. The work presented in this paper...

Analysis of Quiet Zones in Diffuse Fields

Ultrasonic tomographic imaging of temperature and flow fields in gases using air-coupled capacitance transducers

A pair of air-coupled ultrasonic capacitance transducers with polished metal backplates have been used to image temperature and flow fields in gases using ultrasonic tomography. Using a filtered back-projection algorithm and a difference technique, cross-sectional images of spatially variant changes in ultrasonic attenuation and slowness caused by the presence of temperature and flow fields wer...

Feature-based localization using fixed ultrasonic transducers

We describe an approach for mobile robot localization based on geometric features extracted from ultrasonic data. As is well known, a single sonar measurement using a standard POLAROIDTM sensor, though yielding relatively accurate information regarding the range of a reflective surface patch, provides scant information about the location in azimuth or elevation of that patch. This lack of suffi...

Ultrasonic mixing in microfluidic channels using integrated transducers.

This paper presents a microfluidic mixer that uses acoustic stirring created by ultrasonic waves. The ultrasound is introduced into the channel by integrated piezoelectric transducers. The transducers are made of a zinc oxide thin film, which is deposited on the bottom surface of a quartz substrate. The poly(dimethylsiloxane) channel is aligned to the transducers on the top surface of the subst...