The normalized change in ultrasonic "natural" velocity as a function of stress and temperature was measured in a unidirectional laminate of T300/5208 graphite/epoxy composite using a pulsed phase locked loop ultrasonic interferometer. These measurements were used together with the linear (second order) elastic moduli to calculate some of the nonlinear (third order) moduli of this material.

The present paper is a short explanation related to what happen in ultrasonic calibration process. The material velocity and zero offset functions are related with the two known distance peaks classical requirement for setup. The autocalibration function is also explored and explained. The aim is to help beginners to understand the foundations of ultrasonic setup.

8.1 Historical Background 8.2 Theory of Wave Propagation 8.3 Pulse Velocity Test Instrument 8.4 The Pulse Velocity Method 8.5 Factors Affecting Pulse Velocity Effects of Concrete Properties • Other Effects • Temperature of Concrete 8.6 Standardization of the Pulse Velocity Method 8.7 Applications Estimation of Strength of Concrete • Establishing Homogeneity of Concrete • Studies on the Hydratio...

This paper presents an integrated high temperature ultrasonic transducer (HTUT) on a sensor insert and its application for real-time diagnostics of the conventional hot embossing process to fabricate V-cut patterns. The sensor was directly deposited onto the sensor insert of the hot embossing mold by using a sol-gel spray technique. It could operate at temperatures higher than 400 °C and uses a...

Ultrasonic cross-correlation flow meters using natural turbulences in a fluid must be calibrated. The reason is that the most frequent components in the fluid are determined by this method deviating from the average flow velocity. The calibration characteristic is nonlinear and depends on the flow velocity and profile, respectively. This disadvantage can be avoided by small artificially generat...

Echo-PIV is a novel contrast-based ultrasonic technique for measuring multi-component velocity vectors in opaque flows. Ultrasound contrast microbubbles are used as flow tracers, and digitally acquired RF-data are converted into B-mode images. A pair of sequential images is cross-correlated to determine particle displacement, using algorithms derived from optical particle image velocimetry (PIV...

The correlation between the increase in velocity of blood flow in both the internal carotid and vertebral arteries during a carotid compression and the cerebrovascular resistance (CVR) was investigated in 11 patients with chronic ischemic cerebrovascular disease and 4 without organic brain lesions. The velocity of blood flow was measured by an ultrasonic Doppler flowmeter. CVR was calculated fr...

This research demonstrates the feasibility of utilizing nondestructive ultrasonic sensors to monitor the effects of oxygen content, processing time and temperature on the resultant mechanical, structural, and electrical properties of high temperature ceramic superconductors. Ultrasonic velocity changes, as a function of processing time and temperature, have clearly been shown to indicate the tr...

Ultrasonic velocities, u, and densities, ρ of 0.5 m, 1.0 m and 1.5 m aqueous ethylene glycol and propylene glycol solutions in iso-propanol have been measured over the entire composition range at 308.15 K. From this experimental data, deviation in ultrasonic velocity, ∆u, deviation in isentropic compressibility, ∆ks, excess intermolecular free length, E f L , excess acoustic impedance, Z E and ...

The refractive indices, densities and ultrasonic velocities of binary liquid mixtures of tetrahydrofuran (THF) with methanol and o-cresol over the entire composition range have been measured at 293, 303 and 313 K. Refractive index, density and ultrasonic velocity data have been used to evaluate the molar refraction deviation ∆Rm, deviation in ultrasonic velocity ∆u, excess internal pressure π i...