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1
Ultrasound Transmission Tomography Image Distortions Caused by the Run-Time Measurement Inacurracy
100%
Opieliński K. , Gudra T.
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1999
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tom Vol. 20
169-179
2
Komputerowa analiza wielowarstwowych układów dopasowujących do przetworników piezoceramicznych pracujących w powietrzu
100%
Gudra T. , Kosmalski R.
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2001
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tom Vol. 83, nr 27
399-406
PL
Opracowany program komputerowy pozwala na badanie wpływu liczby warstw na kształt i wartość funkcji przenoszenia, a także na ocenę wpływu impedancji i grubości warstw oraz obciążenia części tylnej przetwornika na tę funkcję. Kształt funkcji przenoszenia może być w ten sposób odpowiednio modyfikowany w zależności od potrzeb; można np. zwiększyć wartość przesyłanej przez przetwornik energii lub poszerzyć pasmo przenoszenia przetwornika. Dobór impedancji o obliczonej wartości jest jedynie ograniczony posiadaniem materiałów o ściśle określonych wartościach, nie zawsze jednak możliwych do zrealizowania w praktyce. Przedstawiona metoda wyznaczania impedancji poszczególnych warstw dopasowujących oparta o zasadę dopasowania energetycznego oraz zależności wyprowadzonych przez Czebyszewa, De Siletsa i Souqueta pozwala na wyznaczenie wartości impedancji i charakterystyki funkcji przenoszenia dla układów o dowolnej liczbie warstw.
EN
The paper presents the problem of calculating multiplayer matching systems to apply in piezoceramic transducers radiating energy into gas medium. The relations enabling the calculation of acoustic impedance for various numbers of layers on the basis of the Tschebyschev, De Silets and Souquet formulas are presented. A software was elaborated, which allows to calculate the impedance of particular layers, the investigation of influence of quantity of layers on the shape and value of the transmittance function, and also allows to estimate the influence of impedance and layer thickness on the transmittance function.
3
Investigation of Biological Structures and Their Phantoms Using Ultrasound Transmission Tomography
100%
Gudra T. , Opieliński K.
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2001
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tom Vol. 22
85-94
EN
The paper contains introductory of investigation of different biological structures and their phantoms carried aut by using the UTT method. The otained images of internal structure cross-sections were compared with images obtained by means of classical ultrasonic reflection methods. The results of tis analysis allow us to conclude that investigations using UTTenable obtaning more information aboute the internal structure of the investigated object than ultrasonic investigations consisting in visualising differences of acoustic impedances. In addition, UTT enables both qualitative and quantitive measurement.
4
Non-contacting examination of materials using airborne ultrasonic transducer
80%
Gudra T. , Opieliński K. J. , Kozłowski P. P.
Molecular and Quantum Acoustics
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2008
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tom Vol. 29
93-108
EN
In the paper a non-contacting ultrasonic examination of materials is presented. This method is based on the use of air or another gas as a transmission medium for ultrasonic waves between probes and the examined material. This paper concentrates on examination of three materials: polyurethane foam, balsa wood along and across fibres and porous ceramics. It was shown that quality assessment of different material is possible on the basis of spectral analysis of ultrasonic signal transmitted through a sample.
5
Badania aglomeracji dźwiękowej pęcherzyków gazu w cieczy
80%
Czyż H. , Gudra T. , Opieliński K.
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2001
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tom Vol. 83, nr 27
251-256
EN
This paper presents the results of an experiment, which is a continuation of our research series about the sound agglomeration of gas bubbles in the liquid. An idea of the experimental system has been presented so far. The process of gathering the gas bubbles around the equilibrium positions in the ultrasonic standing wave (the loops of the ultrasonic standing wave) was observed. The concentration of the gas bubbles increases around such points and decreases in the regions between the loops and the nodes of the ultrasonic standing wave. The time required to obtain an equilibrium distribution of the gas bubbles near the stable equilibrium points has been measured. The result of the measurement indicates that it's the value of the same order of magnitude as the sound agglomeration times calculated theoretically. The experimental results show that the speed of process of gathering the gas bubbles depends on; the parameters of acoustic field and gas bubbles size. The theoretical results are in good agreement with the experimental data. The measuring method and the method of its analysis were described in the paper.
6
Wstępne wyniki badań fantomów i struktur biologicznych metodą ultradźwiękowej tomografii transmisyjnej
80%
Gudra T. , Opieliński K. , Jeleń M.
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2001
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tom Vol. 83, nr 27
329-336
EN
The paper contains introductory results of investigation of different biological structures and their phantoms carded out by using the UTT method. The obtained images of internal structure cross-sections were compared with images obtained by means of classical ultrasonic reflection methods. The results of this analysis allow us to conclude that investigations using UTT enable obtaining more information about the internal structure of the investigated object than ultrasonic investigations consisting in visualising differences of acoustic impedances. In addition, UTT enables both qualitative and quantitative measurement. The results of microscopic histopathological examination of selected fragments of structures have corroborated the occurrence of pathological changes visible in tomographic images in the form of areas of different sound velocity values.
7
Content available remote Experimental Study of Simultanoeus Transmission of a Light Wave and an Ultrasonic Wave in an Optical Fiber with the use of a Mach-Zehnder Interferometer
80%
Muc S. , Gudra T. , Bereś-Pawlik E.
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2009
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tom Vol. 34, No. 4
697-714
EN
The possibility of acoustic wave propagation in optical waveguides creates new prospects for the simultaneous use of a light wave and an ultrasonic wave in, for instance, medicine for cutting biological tissues with a surgical ultrasonic laser knife. A Mach–Zehnder optical waveguide interferometer was used in the experimental studies of simultaneous transmission of those two wave types. If ultrasonic vibrations are delivered to one of the interferometer arms, a light modulation effect is produced. This paper presents measurement results for different methods of delivering ultrasonic waves to the optical fiber, i.e. using radial vibrations of a piezoelectric disk or longitudinal vibrations generated by a sandwich ultrasonic transducer with a velocity transformer.
8
Analysis f Possibilities of Biological Structure Phantom Building for Purposes of Ultrasound Transmission Tomography
80%
Gudra T. , Opieliński K. , Zarzycki-Reich A.
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2000
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tom Vol. 21
69-78
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