Showing papers in "Ultrasonics in 1977"

TL;DR: In this article, the linear, lumped-constant, behaviour of single bubbles is reviewed and formulated in terms of the physical constants of the medium liquid, the bubble gas and the interface between.

TL;DR: Ultrasonic Doppler blood-flow signals which seem to be associated with malignant tumour neovascularization have been detected in the female breast and this discovery may lead to the development of a highspeed ultrasonic doppler scanner which might make breast screening for cancer practicable.

TL;DR: In this article, corrections for this effect have been computed for a wide range of sample acoustic impedances and the results were confirmed by experiment and these corrections improve sound velocity measurements, particularly on low impedance materials.

TL;DR: In this paper, the cutting process of aluminium alloy, on a turner's lathe, was characterized by spectral analysis of the sound emitted by the process and the influence of the relevant cutting parameters on the spectral distribution were presented and a qualitative explanation of the corresponding effects was given.

TL;DR: In this article, the principles involved in the visualization of compressional, shear and Rayleigh waves are described, and a-scope displays are explained in terms of the visualized ultrasonic wave interactions within notched glass testpieces.

TL;DR: A computer system which may be used for analyzing Doppler signals obtained when measuring the blood velocity, and the velocity components in the blood vessel are obtained in real-time.

TL;DR: In this article, a numerical evaluation of the velocity of an ultrasonic wave in the porosity and pore shape of a porous ceramic medium is presented, and the theoretical results are combined with those obtained experimentally for different firing temperatures of the ceramic.

TL;DR: In this article, a resurgence of interest in the process, motivated mainly by the application of soldering all-aluminium heat exchangers, has been reported, and new uses in the electronics field may yet permit ultrasonic soldering to achieve the status of a major use of power ultrasound.

TL;DR: In this article, a simple electronic apparatus for plotting the effective directivity characteristics of pulsed, or continuously excited, ultrasound transducers has been built, where the beam profiles are plotted by recording a dc signal, derived from the peak amplitude of either the echo from a steel ball or the signal from a small hydrophone.

TL;DR: A new transient spectral analysis technique that is suitable for quantitative real-time monitoring of small decompression bubbles is described, and in a feasibility study using data from an implanted probe, an increase of 900% in bubble signal/noise ratio was observed.

TL;DR: The technique used for continuous registration of cervical dilation during the first stage of labour ensures maximum safety for the patients and does not influence the normal birth process.

TL;DR: In this article, photoelastic visualization of ultrasound has been applied to study the waves generated by variable-angle transducers, and two particular transducer designs have been investigated, in the first case a compressional wave is launched through a liquid, whereas in the second case a compressed wave propagates through perspex before striking the boundary of the testpiece.

TL;DR: In this paper, a method of shortening the transient response of a piezoelectric transducer is described, which can be applied to thickness mode transducers of arbitrary electromechanical coupling.

TL;DR: A modified version of the pulse echo technique was used to measure the velocity of propagation and attenuation of ultrasound in excised tissue of young-adult Sprague-Dawley rats, and it was observed that the Velocity of propagation in tissues showed a slight dispersion with frequency.

TL;DR: In this paper, the effect of ultrasonic vibrations on vapour phase decomposition of cumene to benzene and propylene, was investigated employing a silica-alumina cracking catalyst.

TL;DR: In this article, internal friction, modulus defects and the initial occurrence of slip lines on the surface of armco iron specimens were studied during and after loading at 22.5 kHz, at temperatures of 296, 333, 373 and 423 K.

TL;DR: Consideration of image sampling requirements and symmetry properties have led to the development of an efficient processing algorithm and good images of tissue samples in-vitro have been obtained.

TL;DR: In this paper, a second acousto-electronic system is described, which enables like the first the attainment of very high image rates in the B-scan mode, in order to reconstruct a true image of the insonified object.

TL;DR: An instrument which performs a direct conversion of real-time, two-dimensional echocardiographic images into standard television format and to store images on a videorecorder in standard video format is described.

TL;DR: In this article, the effect of ultrasonics on the extraction of acetic acid from a methyl isobutyl ketone-acetic acid mixture, with the use of water in an extraction column, was investigated.

TL;DR: In this article, the first step of a Fourier expansion is used to calculate particle velocities induced by disc-shaped transducers which are assumed perfectly damped and excited by a step wise function.

TL;DR: A grey-scale display system for ultrasound contact B-scanning has been developed that produces six shades of grey on a high resolution storage oscilloscope that produces images comparable to those of scan converter display systems at a significantly lower equipment cost.

TL;DR: In this paper, the authors provide a brief introduction to the application of frequency analysis in evaluating acoustic emission pulses, where background interference noise is high and it is necessary to characterize the pulses and correlate them with their sources.

TL;DR: In this paper, it is demonstrated that using a quarterwave buffer having a specific acoustic impedance higher than either transducer or sample considerably reduces this echo distortion. But this effect is particularly pronounced in low impedance materials.

TL;DR: The construction and imaging capabilities of a scanning high resolution ultrasonic microscope and some of the most important properties of the ultrasonic lenses are considered and a quasi-three-dimensional display mode is introduced.

TL;DR: In this article, an ultrasonic excitation of a horizontally-operating, continuous casting mould increased considerably the maximum throughput of the mold. But the average value of the inner wall temperature of the mould rose during ultrasonic activity and the force of removal was also reduced.

TL;DR: Preliminary clinical evaluation results are presented indicating the potential of the instrument for the general practitioner, a continuous wave swept frequency ultrasonic echo-location system which produces dynamic auditory signals corresponding to the positional change of internal structures of the heart.