Showing papers in "Ultrasonics in 1974"

TL;DR: In this article, the design, fabrication, performance, and applications of the SAW oscillator were discussed and the author sets out to show that this device has considerable commercial potential and will the first SAW device to find widespread application at microwave frequencies.

TL;DR: Reported physiological effects resulting from the exposure of small animals to ultrasound cannot be transposed directly to man, and there is no evidence of permanent biological changes, including hearing loss, as a result of normal industrial exposures to pure ultrasound.

TL;DR: Those factors which are important in production ultrasonic cleaning systems are reviewed, finding that cavitation, chemical cleaning techniques and process control are important.

TL;DR: Comparison between the fields of square, circular and rectangular transducers is made showing that the field of a rectangular transducer, by comparison with that produced by square and circular transducers, may be divided into three zones rather than two: the very nearfield, the nearfield and the farfield.

TL;DR: In this article, the authors applied ultrasound to an aqueous starch suspension and the erosion of starch grains that are free to move and whose dimensions approximate those of cavitational bubbles has been examined.

TL;DR: In this paper, both thermosetting and thermoplastic powders have been experimentally moulded into small cylinders by the application of high-intensity 20 kHz ultrasonic energy and pressure without the use of external heat.

TL;DR: In this paper, a new electrical hypothesis was proposed to explain sonoluminescence, chemical actions and other effects produced in gaseous cavitation, based on the internal charge of the bubble and its rapid discharge when compressed.

TL;DR: In this article, a wideband transducers for pulse-echo systems can be produced, and a spectrum analysis of the ultrasonic pulses is carried out by a novel, inexpensive spectrum analyser.

TL;DR: In this paper, the transparencies are projected onto a set of ground perspex screens mounted along a helix on the circumference of a rotating drum to improve the color contrast.

TL;DR: It is concluded that automatic sensitivity control allows acceptable ultrasonic images to be produced and involves the operator in little manipulation of controls.

TL;DR: An outline of the historical development of oscillatory metal-drawing equipment and its application to the deep drawing, wire drawing, fixed and floating plug tube drawing processes is traced in this article.

TL;DR: Since the system operates by rapidly moving a standard transducer, it is possible to use it to perform the more established ultrasonic techniques for heart examination such as time-motion scanning.

TL;DR: In this article, a complete survey of studies of ultrasonic wave propagation in flat carbon fiber reinforced plastic (CFRP) laminates is presented, with the current extent of interpretation.

TL;DR: Non-linear interactions of propagating waves, particularly surface acoustic waves, can be exploited to perform several signal processing functions including correlation and are discussed in the context of programmable matched filtering.

TL;DR: In this article, the potential of controlling crystal size by the regulation of ultrasonic power input during a crystallization process has been investigated and the experimental results have shown that direct sonification of the surface to be considerably more efficient.

TL;DR: In this paper, an investigation was made to determine the increase in drying rate which could be obtained through the addition of ultrasound to low temperature drying of heat sensitive fine particles, and the limitations of the use of ultrasound in assisting drying were also studied.

TL;DR: In this article, ultrasonic powdering of Al, Al/Al2O3 alloys has been described by constructing a suitable run-off vessel and introducing vibrator materials of high resistance.

TL;DR: In this paper, a 0.001 in (0.025 mm) thick foil of polyethylene teraphthalate is metallized upon one side and a dc voltage is applied to the metallizing, then the foil will adhere firmly to any conducting surface.

TL;DR: Initial work indicates that although the application of ultrasonic holography will depend critically upon the development of satisfactory clinical techniques, the usefulness of a fast almost real-time B-scan is beyond doubt.

TL;DR: The ultrasonic holographic apparatus now undergoing evaluation at Moorfields Eye Hospital is capable of obtaining A-scan, B-scan and holographic displays of the living human eye, and the clinical application of the machine is described and some early results presented.

TL;DR: Two-beam optical interferometry as mentioned in this paper provides a highly sensitive new technique for the measurement of both Rayleigh waves and dilatational waves, which can be used to measure the phase and amplitude of Rayleigh wave to within a fraction of a wavelength from a discontinuity on any fully or partly reflecting surface.

TL;DR: In this article, energy partitioning equations for oblique longitudinal waves incident on an interface were coded for a HP 9820 calculator, including phase angles and imaginary surface wave intensities that have not been previously published.

TL;DR: In this paper, a nomogram is described for the determination of the sound pressure reflection coefficient R and the round-trip loss 2 α L when using the pulse-echo buffer rod technique.

TL;DR: This inexpensive design allows the operator to obtain parallel echograms at any desired interval and in any plane of the body with ease and accuracy, increasing both the research and diagnostic potential of the apparatus.

TL;DR: The basic design strategy is described and the limitations on available performance are emphasized and a number of experimental designs are illustrated.

TL;DR: In this article, a review of the results of this classical type of loading is given and a method of broadening the bandwidth by backing the transducers with one or several metallic layers of variable thickness followed by a semi-infinite medium is proposed.

TL;DR: In this paper, a comb transducer consisting of a periodically corrugated plate bonded to a pie-zoelectric crystal was used for non-destructive testing of surfaces.

TL;DR: An ultrasonic compound scanning system has been developed specifically for ophthalmology with a hand-operated scanning mechanism and special circuitry used to attain the high-resolution displays needed in ultrasonic investigations of the eye region.