This paper describes a simulation of signal pathway in an ultrasonic A-scan. It includes transient diffraction acoustic field, transducer response, absorption and dispersion in viscoelastic medium with arbitrary distribution function. The approach selected here aims at developing digital computer simulation of the physical process that underlies these effects. The soft tissue is considered as a...

We report on (to our knowledge) the first remote contactless photoacoustic imaging with short excitation pulses on semitransparent solid polymer samples for material inspection. In this work solid semitransparent samples are excited with pulses from a short pulse laser. The local absorption of the electromagnetic radiation leads to generation of broadband ultrasonic waves. Ultrasonic waves arri...

When the coat protein of the small icosahedral virus, brome mosaic virus, reassembles into capsids, the ultrasonic absorption of the solution greatly increases. Submitting the solution to an ultrasonic field thus appears to reveal spontaneous molecular motions within a protein assembly. Confirmatory evidence of a dynamics of a protein shell comes from measurements on brome mosaic virus at vario...

What we believe to be a novel multipass, acoustically open photoacoustic detector designed for fast-response, high-sensitivity detection of trace gases and pollutants in the atmosphere is demonstrated. The acoustic pulses generated by the absorption of the light pulses of a tunable optical parametric oscillator by target molecules are detected by an ultrasonic sensor at 40 kHz. The photoacousti...

2014 The sound velocity in water has been measured at ultrasonic and hypersonic frequencies and the results show a negative dispersion in the supercooled region. We present measurements of sound velocity and absorption obtained by Brillouin light scattering which show that the effect of structural relaxation is not observed at 0 °C and frequencies smaller than 7.2 GHz. A correction of the hyper...

Photoacoustic waves from hemoglobin solutions in dental roots are detected by using a 1064-nm laser and an ultrasonic soft probe based on a composite transducer on the tooth surface. The high-frequency ultrasonic waves are detected from a tooth with a hemoglobin solution in the pulp cavity due to the large heat transfer coefficient and absorption coefficient of hemoglobin. The spectral intensit...

Scanning thermoacoustic tomography was explored in the microwave region of the electromagnetic spectrum. Short microwave pulses were used to induce acoustic waves by thermoelastic expansion in biological tissues. Cross sections of tissue samples were imaged by a linear scan of the samples while a focused ultrasonic transducer detected the time-resolved thermoacoustic signals. Based on the micro...

The excess ultrasonic attenuation caused by adding glycogen and inorganic phosphate to liver homogenates has been studied to determine the underlying differences between attenuation coefficients of normal and diffusely diseased livers. Results show that glycogen has a higher than average specific absorption coefficient compared to other large molecular weight biomolecules. Since the glycogen co...

Ultrasonic Irradiation (UI) is an emerging technology that used to assist the CO 2 absorption process. Even for slow kinetic solvents without using any chemical promoter, high-frequency UI might enhance mass transfer during For this purpose, it essential study performance of a ultrasonic-assisted system under varied operating conditions. The ultrasonic power considered as one main parameters . ...