Showing papers in "Ultrasonics in 2000"

TL;DR: Different aspects of subharmonic imaging are reviewed including implementation, in-vitro gray-scale imaging and sub Harmonic aided pressure estimation.

TL;DR: A technique to measure the contact stiffness and the Young's modulus of sample surfaces quantitatively, with a resolution of approximately 20 nm, exploiting the contact resonance frequencies of standard cantilevers used in atomic force microscopy.

TL;DR: Ensemble tracking, a recent speckle tracking method based upon parallel receive processing, is described, and Experimental results with ensemble tracking indicate the ability to measure laminar flow in a phantom at a beam-vessel angle of 60 degrees, which had not been possible with previous 2D speckel tracking methods.

TL;DR: Transporting apparatuses and an ultrasonic motor have been fabricated and their characteristics measured and the theory of near-field acoustic levitation both for a piston-like sound source and a flexural vibration source is briefly described.

TL;DR: Although the results of conventional second harmonic imaging are still not optimal for perfusion imaging applications, in combination with Doppler techniques it is one of the most sensitive techniques currently available in terms of agent-to-tissue ratio.

TL;DR: A new motor is presented which is judged to be capable of surpassing the characteristics of other piezoelectric motors because of its unique design which allows the piez Zoelectric drive elements to be pre-stressed in the direction of their polarization.

TL;DR: This paper deals with the application of acoustic energy to assist fluid/solid separation processes in gas and liquid suspensions and presents some theoretical and experimental results in specific applications.

TL;DR: The results of a programme to study the nonlinear propagation in the fields of circular, focused and rectangular transducers are described, and comparisons made with numerical predictions obtained using a finite difference solution to the Khokhlov-Zabolotskaya-Kuznetsov equation are made.

TL;DR: The BiCMOS process has been modified to meet the demands for ultrasound generation and reception, and the electromechanical coupling is now almost comparable with that for piezoelectric transducers.

TL;DR: Applications of standing wave radiation forces to clarify cell suspensions, enhance particle agglutination immunoassay detection of cells or cellular products and examine and enhance cell-cell interactions in suspension are described.

TL;DR: A coded excitation system based on a modified commercial scanner is presented and a predistorted FM signal is proposed in order to keep the resulting range sidelobes at acceptably low levels.

TL;DR: It is considered that the ultrasonic NDE of concrete strength is feasible and the ultrasound velocity and frequency component on ultrasonic propagation as a function of the water content in concrete are reported.

TL;DR: It is shown how corrected displacement estimates can also be used to estimate and image the shear strain components, which may allow us to identify regions of decorrelation noise in the normal strain measurement that are due toShear strain.

TL;DR: A method of optimisation is the improvement of the solid-liquid interface of the sludge flocs and the mass transfer rate of gas and nutrients in the liquid.

TL;DR: A new type of optical fiber hydrophone is constructed with a fiber Bragg grating based on the intensity modulation of laser light in an FBG under the influence of sound pressure, which can measure amplitude and phase of an acoustic field in real time and operates in a wide range of acoustic frequency.

TL;DR: In this article, the authors examined the hypothesis that the phase drifts are due to temperature fluctuations and compared the changes in diffuse field phase with the measured velocities of a 7 cm aluminum block.

TL;DR: In this work, an ultrasonic NDE technique to estimate the porosity of concrete is developed based on the analysis of the mechanical behaviour of mortar probes built with calibrated sand, in which the concentration of water-cement mixture has been varied.

TL;DR: The results show that, in spite of the complexity of the turning process, the state of the process can be well characterized by just a few proper characteristics extracted from a representative sensor signal.

TL;DR: It is shown that acoustic aerosol preconditioning meets all the requirements to reduce the fine particle output of conventional filter systems and the need for new, more efficient particle filtration technologies is demonstrated.

TL;DR: The use of on-line monitoring systems with process-integrated measurement of acoustic emission to evaluate hard turning and grinding processes to analyse the progression of the processes and the workpiece quality is described.

TL;DR: The Champ-Sons model, developed at the French Atomic Energy Commission for predicting field radiated by arbitrary transducers into pieces, has to be extended to sources directly in contact with pieces of complex geometry.

TL;DR: An anechoic 'one-dimensional' sonication chamber has been developed that produces propagating waves, which differ from standing waves in that the pressure amplitude remains constant as the wave travels in a medium with negligible attenuation.

TL;DR: The acousto-electric interaction signal was shown to be directly proportional to both the applied acoustic pressure and current, and the interaction factor was found to be 5.3 microVmA(-1) MPa(-1).

TL;DR: An ultrasonic micro-motor, which can be driven by a single signal and in which the change of the direction of the rotor movement can be made easily by selecting the electrode to apply the driving signal, can easily construct a self-oscillating circuit and simplify the driving circuit.

TL;DR: A number of different ultrasonic systems can be categorized into one of three key generic approaches: pulse-echo exploration, intensity mapping, and phase-amplitude measurement, and each of these categories can be combined with the others to produce hybrid systems for which an unambiguous categorization is difficult or impossible.

TL;DR: Suspension conditioning by ultrasound induced particle aggregation in a 3.3 MHz standing wave field was investigated in lab- and pilot scale sedimentation reactors equipped with a variable number of acoustically transparent film (ATF) elements, inserted perpendicular to the sound propagation direction.

TL;DR: The present study quantitatively addressed the linkage between the ultrasonic attenuation and the physiological parameters of the flesh of the fruits with respect to avocado and mango fruits.

TL;DR: The design and testing of a flow-through ultrasonic separation device that allows the concentration of particles within a fluid, and three models are used to examine the behaviour of the cell, dealing with acoustic-particle interaction, electro-acoustic characteristics, and fluid flow.

TL;DR: The implementation of SAFT in a CAD environment allows us to present stacked 2D reconstructions dynamically and finalizes the overview of two decades of experience in applying this technique.

TL;DR: The method of second harmonic generation promises to give early information about failure of adhesive layers and the dependence of the calculated and measured effects on the layer thickness, the velocity of sound, and the nonlinearity coefficient beta are reported.