We have developed a novel instrument for measuring the surface tension of liquids. It utilizes ultrasonic and optical methods to excite and detect a capillary wave packet. A focused ultrasonic transducer is used to generate a mound on the surface of a liquid. Capillary waves propagate radially outward from the mound, and a noncontacting confocal optical microscope measures the amplitude of the ...

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...

Using ultrasonic spectroscopy, the frequency dispersions of ultrasonic velocity and attenuation were measured for single crystal 0.72 Pb(Mg1/3Nb2/3)20.28 PbTiO3 (PMN228%PT! with engineered domain structures in the frequency range of 50–110 MHz. We found that the velocity dispersion and attenuation are very small for the longitudinal wave propagating along @001# of the pseudotetragonal state. Ou...

The subject of the paper is simulation and measurements of an ultrasonic field in an isotropic homogeneous medium with attenuation. The complex problem of simultaneous influence of wave diffraction, attenuation, and velocity dispersion occurs. Only few publications can be mentioned on this subject. For example in [1] is presented an investigation of the complex problem of ultrasound field distr...

This work focuses on the ultrasonic characterization and hardness of Austenitic stainless steel in thermal variation. The sample which was heat treated at 1050 o C has the highest hardness value and plays a dominant role in dispersion of carbides. Shear wave velocity and hardness show similar trend in variation with temperature. The effect of volume expansion would be to decrease the elastic co...

In this study, diamond turning of an aluminiumbased metal matrix composite (MMC) reinforced with SiC particles was conducted with the assistance of ultrasonic vibrations. A simple and small size vibration device was designed to mount a piezoelectric transducer and a diamond insert onto a CNC machine. Turning experiments were carried out using a factorial design to investigate the effects of vib...

A novel ultrasonic dispersion system for the dispersing of particles which are mixed in liquid has been proposed in this paper. The frequency of produced ultrasonic wave varies from 30 kHz to 60 kHz with 100 Hz steps. It means that the operating frequency band of designed system is 30 kHz. The maximum and optimum energy of ultrasonic wave can be transfer inside the liquid container with the hig...

In order fully to exploit energy of wind power the construction elements of the wind turbine should be inspected periodically. Ultrasonic air-coupled technique using guided waves has been selected for inspection of wind turbine blades, because only one side access is enough and no contact is needed. Dispersion curves of phase velocities as well as leakage losses versus frequency were calculated...

The theory of the acoustics of dilute bubbly liquids is reviewed, and the dispersion relation is modified by including the effect of liquid compressibility on the natural frequency of the bubbles. The modified theory is shown to more accurately predict the trend in measured attenuation of ultrasonic waves. The model limitations associated with such high-frequency waves are discussed.

In the four previous parts of this series of articles, level measurement using a floating system, using pressure instruments, using radar waves and using ultrasonic waves were discussed. The instruments offered by Indumart company applicable for each method were also recommended. In the final part of this article, level measurement using capacitance, conductivity probes, vibration forks, therma...