Simultaneous measurements of laser excited ultrasonic waves in a solid sample and in the surrounding air were used for characterizing the plasma shielding effect and for the evaluation of its influence in optoacoustic measurements. Typical modifications of ultrasonic waves are discussed and the acoustic energy distribution between the solid and the atmosphere is assessed by a comparative analys...

Bulk and Rayleigh (or surface wave) velocities of ultrasonic waves in chromium coatings on steel were measured and an experimental correlation was found between the surface velocity and the hardness. Since qualitative coating evaluation is commonly made using hardnesses as a guideline, the possibility is herewith presented of using the so und velocities of surface ultrasonic waves for this purp...

The aim of this paper is to present a system that detects the hand gesture motions using the principle of Doppler Effect. Ultrasonic waves are transmitted by a sensor module and are reflected by a moving hand. The received waves are frequency shifted due to Doppler Effect. These frequency shifts in the ultrasonic waves are characterized to determine gestures. The gestures once recognized are ma...

Mice produce ultrasonic vocalizations (USVs) in a variety of social contexts throughout development and adulthood. These USVs are used for mother-pup retrieval1, juvenile interactions2, opposite and same sex interactions3,4,5, and territorial interactions6. For decades, the USVs have been used by investigators as proxies to study neuropsychiatric and developmental or behavioral disorders7,8,9, ...

An ultrasonic sensor has been used for detecting the amount of adulteration in full cream milk with water. The sample under test is filled in a rectangular perplex glass cell, containing ultrasonic transmitter and receiver which is kept in through transmitter mode for generating the ultrasonic waves. The acoustic wave passing through the sample gets attenuated. The level of

High-amplitude ultrasound (u0 > 100 nm) generated by pulsed laser material processing carries important information about the mechanisms of light-material interaction and the propagation of the wave within the work-piece. In addition, it can also be applied for the purpose of non-destructive evaluation of the sample. The propagation of high-amplitude ultrasonic waves inside a plate is measured ...

Surface Acoustic Waves (SAW) provide a means of studying low temperature anelastic relaxations of crystal defects produced by irradiation. Due to their confinement near the surface where radiation induced defect concentrations are highest. SAW are more sensitive than bulk ultrasonic waves in these investigations. Furthermore. for piezoelectric materials. the use of photolithographically deposit...

time-of-flight diffraction method (tofd) is an amplitude-independent sizing method which is based on the measurement of time-of-flight of defect tip diffracted waves. although tofd can measure through-wall length of defect accurately, this method is not capable of measuring horizontal defect size. in this paper, a new tofd method for evaluating horizontal planar defects is presented. the finite...

High-intensity focused ultrasound therapy is a novel, emerging, therapeutic modality that uses ultrasound waves, propagated through tissue media, as carriers of energy. This completely non-invasive technology has great potential for tumor ablation as well as hemostasis, thrombolysis and targeted drug/gene delivery. However, the application of this technology still has many drawbacks. It is expe...

To modify the microstructure and enhance performances, the ultrasonic vibration is applied in the mould casting of TiAl alloy. The effects and mechanism of ultrasonic vibration on the solidifying microstructure and mechanical properties are investigated and the model for predicting lamellar colony size is established. After ultrasonic vibration, the coarse microstructure is well modified and la...