Comparison of stress-associated coda attenuation and intrinsic attenuation from ultrasonic measurements

Interlaboratory comparison of ultrasonic attenuation and speed measurements.

A set of test samples, all containing ultrasonically equivalent tissue-mimicking material, was produced and measurements of ultrasonic speed and ultrasonic attenuation coefficients were made at seven laboratories using various techniques. The ultrasonic speed values agree well with one another, having a spread of about 0.3 per cent; thus, speed values for tissue parenchyma appearing in the lite...

Interlaboratory comparison of ultrasonic backscatter, attenuation, and speed measurements.

In a study involving 10 different sites, independent results of measurements of ultrasonic properties on equivalent tissue-mimicking samples are reported and compared. The properties measured were propagation speed, attenuation coefficients, and backscatter coefficients. Reasonably good agreement exists for attenuation coefficients, but less satisfactory results were found for propagation speed...

Determination of ultrasonic parameters based on attenuation and dispersion measurements.

In the measurement of acoustic attenuation that obeys a power-low alpha = beta f, the traditional through-transmission method uses only the amplitude information of the recorded pulses to determine the two parameters, beta and n. In this paper, we propose a new method that utilizes both the amplitude and phase information of the pulses to determine the two parameters. According to this method, ...

Impurity Effects on the Recovery of Copper Studied by Ultrasonic Attenuation Measurements under Cyclic Bias Stress

High purity Cu single crystals doped with Mg, Ag, Pb, Sb, Bi (20-50 ppm) were isochronally annealed between 373 K and 923 K after 0.12% deformation at room temperature. After each annealing step the dependence of sound attenuation on frequency (10 200 MHz) and bias stress (cyclic compression/tension; peak amplitudes below plastic yield) was measured. From the latter experiment specific informat...

Ultrasonic attenuation measurements in sinter-forged YBa2Cu3O7-b