Showing papers in "Ultrasonics in 1975"

TL;DR: 'Bird-call' whistles are shown to have all the properties of rodent ultrasonic cries and to mimic them in almost every detail, concluding that rodents have two distinct sound production mechanisms.

TL;DR: In this article, a new type of acoustic levitator is used to position liquid and solid materials in a space processing chamber using a single source of sound and fine control of position may be obtained by motion of an acoustical reflector.

TL;DR: In this paper, a random signal correlation system for ultrasonic flaw detection is described and analyzed, and the use of correlation and time integration techniques gives it a signal-to-noise ratio correlation gain of the order of 10 4.

TL;DR: In this article, the degree of commercial usage of ultrasonic twist-drilling has been studied in various non-manufacturing applications, such as rock cutting and surgical and dental cutting tasks.

TL;DR: In this paper, the role of non-linear elastic wave propagation in the ultrasonic softening process called the Blaha effect is discussed, with particular emphasis on the role that nonlinear wave propagation may play in softening real crystalline solids.

TL;DR: In this article, the equations governing Rayleigh and Lamb mode propagation for free and liquid-loaded solids are examined for both free and non-free solids, and examples are given to show under what conditions the free-solid approach yields acceptable solutions for the velocities.

TL;DR: In this paper, the application of acoustic and ultrasonic energy in industrial processing is reviewed and a number of units using acoustic energy to enhance rates of conventional unit processes, for example, drying, solid-liquid extraction, etc., are described.

TL;DR: In this article, the authors discussed the literature published on the brightness of metals electrodeposited in ultrasonically-agitated solutions together with the two main theories which explain the formation of bright deposits.

TL;DR: In this article, the influence of the loading-cycle asymmetry on fatigue strength was studied for structural materials tested at 10 kHz frequency loading with a mean tensile and compressive stress, and the energy dissipation in materials were carried out during fatigue tests with symmetrical and asymmetrical loading cycles at high-frequency with large amplitude longitudinal vibrations of the specimen.

TL;DR: The findings are discussed with regard to the limitations of the Doppler technique for monitoring gas emboli in vivo and as an early warning for decompression sickness in divers.

TL;DR: In this paper, the transfer functions of a transducer at emission and reception of ultrasonic waves are recalled and verified, and an original method based on transmission lines properties is described.

TL;DR: In this article, the arrival time and the power density spectra of wide-band ultrasonic pulses are measured by a circular, cylindrical, solid inclusion in a matrix of aluminium.

TL;DR: In this paper, the authors describe how to calculate and produce a voltage waveform for any desired pressure waveform and show some examples of the voltage waveforms necessary to drive a loudspeaker to produce pulses shorter than the natural resonant period of the loudspeaker.

TL;DR: A transcutaneous Doppler device has been developed that measures primarily the directional transport velocity of blood, averaged over the vessel diameter, irrespective of its flow in adjacent vessels.

TL;DR: In this article, a method for measuring the electromechanical coupling factor of the thickness mode piezoelectric plates is proposed, based on the fact that samples have a smaller ratio of diameter to thickness than the usual ratio required in the resonanceantiresonance method.

TL;DR: In this article, the authors present the relation between the overall attenuation coefficient and its scattering component, the grain size and frequency, and two methods of evaluation of the structure of railway materials by ultrasonic inspection were derived.

TL;DR: In this paper, the propagation velocity of longitudinal ultrasonic waves in an elastic medium with spherical gaseous inclusions is considered in detail, the calculation method adopted consists of determining equivalent elasticity moduli of the porous medium.

TL;DR: In this article, the practical design and operation of two types of probe is discussed, one is a capacitor microphone with the accent on time resolution of the pressure cycle to allow the detailed study of the output from shock-excited heavily damped transducers.

TL;DR: In this paper, the authors describe the use of a computer program for the evaluation of elastic moduli of solid media, from data obtained using the critical angle reflection technique, expressed in terms of the longitudinal modulus K = λ + 2 μ, where λ and μ are the Lame constants.

TL;DR: A novel ultrasonic velocimeter is described and evaluated with a view to measuring blood flow in vivo and Experimental trials in vitro validate the concept although there is a factor of two disagreement with predictions.

TL;DR: It is hoped and believed, that this computer aided ultrasonic examination, with single scan display in colour or black and white, will further promote ultrasonic diagnosis in future.

TL;DR: In this article, two methods are presented which calculate the plastic strain and the total strain amplitude in a sample, subjected to high frequency fatigue, with the aid of temperature distribution measurements.

TL;DR: In this article, the authors performed longitudinal and shear ultrasonic measurements on castor, tung, soyabean and cottonseed oils in the frequency ranges 50 kHz-30 MHz and 10-150 MHz using reverberation, pulse and impedance techniques respectively.

TL;DR: An interface is described which links an ultrasonic B-scanner to a small digital computer and digitizes the image signals from the scanner to 10 levels, which are converted to four-bit binary words, four of which are packed into a 16-bit word.

TL;DR: In this paper, the internal friction and the third harmonic were analyzed in terms of the dislocation models of Granato-Lucke and Peguin et al. and a dynamic dislocation multiplication mechanism was suggested for the burst type emissions.

TL;DR: In this article, the curvature of the light rays inside the ultrasonic beam and diffraction of the system alone at the exit plane were taken into account, neglecting any diffraction effect in the liquid itself.

TL;DR: Very small fetal intervertebral and intercostal distances can be measured in B-mode echograms to provide a physiological test object which is freely available and devoid of artefact for assessing resolution by ultrasonic echoscopes.