scholarly journals Study of SH acoustic radiation field excited by a piezoelectric strip

2005 ◽  
Vol 54 (5) ◽  
pp. 2111
Author(s):  
Zhang Bi-Xing ◽  
Wang Cheng-Hao ◽  
Bostrm Anders
Keyword(s):  
Radiation Field ◽  
Acoustic Radiation ◽  
Piezoelectric Strip

ON THE ACOUSTIC RADIATION FIELD OF THE PIEZO-ELECTRIC OSCILLATOR AND THE EFFECT OF VISCOSITY ON TRANSMISSION: PART II

1934 ◽  
Vol 11 (4) ◽  
pp. 484-488 ◽  
Author(s):  
L. V. King
Keyword(s):  
Radiation Field ◽  
Sea Water ◽  
Acoustic Radiation ◽  
Wave Length ◽  
Numerical Data ◽  
Transmission Part ◽  
Coefficient Of Viscosity ◽  
Theoretical Results ◽  
Piezo Electric

Numerical data on the distance of transmission of sound in sea water from a 10-in. piezo-electric oscillator are discussed in the light of theoretical results obtained in a previous paper. It is shown how by the principle of similitude the chart for transmission at optimum wave-length calculated for a 50-watt, 60 cm. oscillator can be used for a transmitter of any given diameter and output. A comparison with some experiments of Boyle's points to the fact that at supersonic frequencies, in the neighborhood of 100,000 cycles, a considerably higher coefficient of viscosity than that obtained by flow methods must be used.

Numerical Analysis of a New-Style Ultrasonic Linear Array

2011 ◽  
Vol 58-60 ◽  
pp. 1043-1048
Author(s):  
Yong Wang ◽  
Quan Lu Li
Keyword(s):  
Numerical Analysis ◽  
Radiation Field ◽  
Acoustic Field ◽  
Linear Array ◽  
Acoustic Radiation ◽  
Acoustic Lens ◽  
Width Direction

In order to reduce the field of the acoustic radiation and improve the efficiency of energy using, a new-style ultrasonic linear array is present, which base on the special structural of the acoustic field produced by the cylindrical acoustic lens. The new-style linear array is composed of numbers of cylindrical acoustic lens, each lens act as an element distributed in a line along the width direction. Define x-direction is the direction of wave propagate. We have studied the acoustic field theoretically and have analyzed it numerically. Found that acoustic field have a better directivity in y-direction and the radiation field is much smaller than the traditional linear array, at the same time the focus ability is appear in the Z-direction if we control the number of element and the distance of center-to-center spacing of each element. This paper is helpful to the change and development of traditional liner array.

The Design and Realization of the Visualization System of Acoustic Radiation Based on NAH

2012 ◽  
Vol 271-272 ◽  
pp. 1451-1454
Author(s):  
Lin Na Zhou ◽  
Jing Jun Lou ◽  
Shi Jian Zhu
Keyword(s):  
Data Management ◽  
Radiation Field ◽  
Acoustic Radiation ◽  
Complete Solution ◽  
Measurement Data ◽  
Visualization System ◽  
Visualization Technology

The characteristic of the acoustic radiation of vibrating structure is the important factor in valuing its performance. This paper puts forward a visualization system of the acoustic radiation based on NAH which combines the measurement, data management and visualization. The visualization technology it adopts point a new way to the observation of the acoustic radiation. Experiments have shown that this system can offer a complete solution for the measurement and research of the radiation field.

ON THE ACOUSTIC RADIATION FIELD OF THE PIEZO-ELECTRIC OSCILLATOR AND THE EFFECT OF VISCOSITY ON TRANSMISSION

1934 ◽  
Vol 11 (2) ◽  
pp. 135-155 ◽  
Author(s):  
Louis V. King
Keyword(s):  
Radiation Field ◽  
Velocity Potential ◽  
Marked Effect ◽  
Acoustic Radiation ◽  
Wave Length ◽  
Practical Importance ◽  
Circular Disc ◽  
Circular Aperture ◽  
Constant Output ◽  
Infinite Integral

The radiation field due to a circular disc oscillating with uniform amplitude in a closely fitting circular aperture surrounded by an infinite rigid flange has been studied in detail, the velocity potential being expressed as an infinite integral involving cylindrical co-ordinates. The procedure adopted may be used to study the effect of viscosity on the characteristics of the radiation field. While having little effect on the field in the neighborhood of an oscillator generating waves in water, the viscosity has a marked effect on the range of distant transmission, which in consequence is appreciably affected by temperature. Of considerable practical importance is the existence of an optimum wave-length for constant output and a given distance of transmission. By means of a simple chart, it is possible to determine the optimum wave-length for a given transmitter when the level of reception for a given range is stated.

Rationale Abklärung von Lebererkrankungen

2017 ◽  
Vol 74 (3) ◽  
pp. 79-86
Author(s):  
Leona von Köckritz ◽  
Andrea De Gottardi
Keyword(s):  
Acoustic Radiation ◽  
Radiation Force ◽  
Acoustic Radiation Force ◽  
Acoustic Radiation Force Impulse ◽  
Alkalische Phosphatase ◽  
Gamma Glutamyltransferase ◽  
Alpha 1 Antitrypsin

Zusammenfassung. Im klinischen Alltag werden häufig erhöhte Leberwerte beobachtet. In der Regel erfordern sie weitere Abklärungen bezüglich der möglichen Ätiologie und des Schweregrad einer akuten oder chronischen Lebererkrankung. Die Abklärung sollte dabei neben einer gezielten Anamnese und sorgfältigen klinischen Untersuchung, auch die Bestimmung von laborchemischen Markern für Cholestase und Leberfunktionsstörungen (wie Alkalische Phosphatase, gamma-Glutamyltransferase, Bilirubin, Albumin und Gerinnungsfaktoren) umfassen. Die Bestimmung weiterer Parameter wie Ferritin und Transferrinsättigung, Autoimmunantikörper, Virusserologien, alpha-1 Antitrypsin und Coerulolasmin können weitere Hinweise für die kausalen Zusammenhänge der Leberfunktionsstörung liefern. Bei Patienten mit Lebererkrankungen ist eine sonografische Beurteilung der Leber obligat. Ergänzend zur Sonografie werden heute weitere nicht-invasive Methoden wie Fibroscan, Acoustic Radiation Force Impulse Elastometrie und Magnet-Resonanz-Elastografie zur Beurteilung der Leberfibrose eingesetzt. In ausgewählten Fällen ist eine Leberbiopsie notwendig, um den Grad der Fibrose und die Ätiologie der Lebererkrankung zu eruieren. Mithilfe eines Fallbeispiels, diskutieren die Autoren im Folgenden die rationale Anwendung diagnostischer Tests und deren korrekte Interpretation und schlagen eine Orientierungshilfe zur rationalen Abklärung von Patienten mit Lebererkrankungen vor.

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