Showing papers in "Ultrasonics in 1976"

TL;DR: In this paper, a survey of recent developments and applications of piezoelectric polymers is presented, with a focus on the use of polyvinylidene fluroide (PVDF).

TL;DR: The local application of theraputic ultrasound has been shown to stimulate the healing of chronic varicose ulcers and it was found that healing of insonated ulcers was significantly more marked than that exhibited by the controls.

TL;DR: Spectral analysis of ultrasonic reflections from biological tissues can be used to determine basic tissue parameters for use in differential diagnosis and is described under circumstances encountered in several types of clinical examinations.

TL;DR: In this article, the development of a pulse compression system applicable to ultrasonic flaw detection is described, which permits a pulse-echo detection system to operate with long transmitted pulses for increased sensitivity, but without sacrificing resolution.

TL;DR: The calorimetric and radiation force methods are discussed as a technique whose capabilities have not been fully exploited while the latter demands attention both because of its simplicity and its controversial theoretical basis.

TL;DR: A new method of measuring blood flow velocity and acceleration using analogue and phase locked loop techniques is described, which can be obtained on-line and displayed on simple recording systems.

TL;DR: In this article, power ultrasound is used in joining thermoplastics and forming operations such as staking and metal-in-plastic insertion, spot-welding, and continuous joining of films and synthetic fabrics.

TL;DR: In this article, the scaling law for underwater explosion shock waves was generalized and included short distances and very small charge weights typical of laboratory conditions, and the peak pressure, time constant, impulse and energy flux density as a function of charge weight and distance have been worked out.

TL;DR: Histological preparations of ultrasonically produced lesions in cat brain, at 3 and 4 MHz, are studied microscopically and it is suggested that universal responses to ultrasonic exposure may exist for different tissues.

TL;DR: The technical details of a real time 2-dimensional ultrasonic scanning system capable of being used with existing ultrasonic equipment extending certain standard ultrasonic machines for use as real time 1-dimensional scanners conveniently and at little cost are described.

TL;DR: In this paper, the influence of the concentrator mass on the operation of the magnetostrictive vibrator is considered with a view to the design and construction of an acoustical concentrator.

TL;DR: In this article, a computer program has been written to compute mean and median frequency, mean amplitude spectral density, mean energy spectral density and amplitude spectrum variance from real data, from specially prepared reactor-grade zirconium test pieces.

TL;DR: Two frequency scanning ultrasonic spectrographs utilizing time-delay signal processing techniques have been developed and are used to monitor changes in velocity as a function of frequency during coagulation in purified human fibrinogen solution and human plasma.

TL;DR: A simple multi-element transducer array capable of converting an A-scan unit to a real-time, hand-held section scanner and application as an inexpensive alternative to conventional B-scanners is discussed.

TL;DR: In this article, a computerized system designed to detect cracks by rotating a shear wave transducer around installed fasteners or bolt holes is described, where reflected ultrasonic signals from the cracks are digitized in 2° intervals, processed, and displayed in either polar or rectangular coordinates by the computer.

TL;DR: In this paper, a finite difference iterative formulation for Rayleigh wave propagation in anisotropic materials is proposed. But the authors only consider the case of a single wave and do not consider the effect of the wave propagation on the propagation of a layered waveguide.

TL;DR: In this article, a new method of investigating the portion of plastic deformation during fatigue tests of copper samples has been developed, which can only be estimated as opposed to being directly measured.

TL;DR: In this paper, an equation describing the kinetic process of sonic coagulation is presented which accounts for changes in particule concentration, resulting from changing conditions in the sonic field and dust gas flow.

TL;DR: In this article, a symmetrical doublet with an aperture of F 1 and aberrations much less than λ4 at 2 MHz was designed for nondestructive testing, medical diagnostics and short range underwater applications.

TL;DR: In this paper, high-intensity ultrasonics at 23 kHz were applied to mild-steel specimens and a change in hardness was detected at a temperature of 20°C, but when the temperature was allowed to increase by energy-absorption the hardness increased in a subsurface layer.

TL;DR: This research was designed to prepare a series of relative power indices and temperature profiles for several ultrasonic cell disruptors to make available relative cavitational and temperature data.

TL;DR: In this paper, the influence of ultrasound on the behavior of metal drawn through a conical converging die has been analyzed by means of an energy method and the effect of the ultrasonic field is considered on the basis of experimental data and used to determine the drawing stress.

TL;DR: The relation between the attenuation and theoustic frequency was found to be approximately linear over the frequency range tested and the velocity of propagation in the active state did not change appreciably from its value in the relaxed state and was observed to be independent of the acoustic frequency in the range used.

TL;DR: In this article, an equivalent circuit of the piezoelectric transducer with the step-by-step non-uniformity of PES properties is obtained by means of solving an inhomogenous wave equation by the method of Green's functions.

TL;DR: In this paper, the authors discuss several methods used on longitudinally vibrating horns, and describe a new electronic method of measuring acoustic power, which is used for measuring high power ultrasonic equipment and determining the efficiency of transducers.