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Wyszukujesz frazę "ultrasound transmission" wg kryterium: Wszystkie pola


Wyświetlanie 1-4 z 4
Tytuł:
Modeling and Experimental Verification of Ultrasound Transmission in Electro Insulation Oil
Autorzy:
Wotzka, D.
Cichoń, A.
Boczar, T.
Powiązania:
https://bibliotekanauki.pl/articles/177158.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasound transmission
numerical simulations
electro-insulation oil
Opis:
A verification study of ultrasound transmission numerical simulation results with experiment results is presented in this paper. The work considers a model of a transformer tank which is filled with electro insulating oil. In the experiment, performed under laboratory conditions, an ultrasound wave is generated by a piezoelectric transducer that is fixed in the centre of the tank and measured by another transducer mounted inside the tank at three distances: 10, 20 and 30 cm from the sound source. The transducer is able to measure and generate acoustic waves in the ultrasound frequency band up to 1 MHz. The simulation considers numerical calculation of acoustic pressure distribution inside the tank in which acoustic source emits waves with frequency equal to 100 kHz. Verification analysis has confirmed consistency of the numerically calculated values with the measurement results.
Źródło:
Archives of Acoustics; 2012, 37, 1; 19-22
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Series Expanding of the Ultrasound Transmission Coefficient Through a Multilayered Structure
Autorzy:
Chitnalah, Ahmed
Aouzale, Noureddine
Jakjoud., Hicham
Powiązania:
https://bibliotekanauki.pl/articles/31339919.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
multilayered structure
Debye’s series
resonance formalism
ultrasonic NDT
Opis:
To calculate the transmission coefficient of ultrasonic waves through a multi-layered medium, a new approach is proposed by expanding it into Debye’s series. Using this formalism, the transmission coefficient can be put in the form of resonance terms series. From this point of view, the relative amplitude of the transmitted wave can be considered as an infinite summation of terms taking into account all possible reflections and refractions on each interface. Our model is then used to investigate interaction between the ultrasonic plane wave and the N-plane-layer structure. Obviously, the resulting infinite summation has to be reduced to a finite one, according to some level of accuracy. The numerical estimation of the transmission coefficient using the exact expression (Eq. (1)) is then compared to the one of our method in the case of two or three plane-layer structure. The effect of the order of the finite summation on the calculated value of the transmission coefficient is, as well, studied. Finally, our proposed method may be used, with the decomposition into Gaussian beams of a pressure field created by a circular source, to draw a 3D image of the pressure field transmitted through a multilayered structure.
Źródło:
Archives of Acoustics; 2023, 48, 1; 71-79
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasound Transmission Tomography Imaging of Structure of Breast Elastography Phantom Compared to US, CT and MRI
Autorzy:
Opieliński, K. J.
Pruchnicki, P.
Gudra, T.
Podgórski, P.
Kraśnicki, T.
Kurcz, J.
Sąsiadek, M.
Powiązania:
https://bibliotekanauki.pl/articles/176996.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasound transmission tomography
UTT
ultrasonography
US
computed tomography
magnetic resonance
MR
mammography
breast biopsy phantom
Opis:
The paper presents an analysis of the results of ultrasound transmission tomography (UTT) imaging of the internal structure of a breast elastography phantom used for biopsy training, and compares them with the results of CT, MRI and, conventional US imaging; the results of the phantom examination were the basis for the analysis of UTT method resolution. The obtained UTT, CT and MRI images of the CIRS Model 059 breast phantom structure show comparable (in the context of size and location) heterogeneities inside it. The UTT image of distribution of the ultrasound velocity clearly demonstrates continuous changes of density. The UTT image of derivative of attenuation coefficient in relation to frequency is better for visualising sharp edges, and the UTT image of the distribution of attenuation coefficient visualises continuous and stepped changes in an indirect way. The inclusions visualized by CT have sharply delineated edges but are hardly distinguishable from the phantom gel background even with increased image contrast. MRI images of the studied phantom relatively clearly show inclusions in the structure. Ultrasonography images do not show any diversification of the structure of the phantom. The obtained examination results indicate that, if the scanning process is accelerated, ultrasound transmission tomography method can be successfully used to detect and diagnose early breast malignant lesions. Ultrasonic transmission tomography imaging can be applied in medicine for diagnostic examination of women’s breasts and similarly for X-ray computed tomography, while eliminating the need to expose patients to the harmful ionising radiation.
Źródło:
Archives of Acoustics; 2013, 38, 3; 321-334
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Acoustic Field Distribution Inside the Ultrasonic Ring Array
Autorzy:
Staszewski, W.
Gudra, T.
Opieliński, K. J.
Powiązania:
https://bibliotekanauki.pl/articles/177105.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ultrasound transmission tomography
acoustic field
ultrasonic multi-element array
Opis:
This paper presents and analyses the results of a simulation of the acoustic field distribution in sectors of a 1024-element ring array, intended for the diagnosis of female breast tissue with the use of ultrasonic tomography. The array was tested for the possibility to equip an ultrasonic tomograph with an additional modality - conventional ultrasonic imaging with the use of individual fragments (sections) of the ring array. To determine the acoustic field for sectors of the ring array with a varying number of activated ultrasonic transducers, a combined sum of all acoustic fields created by each elementary transducer was calculated. By the use of MATLAB software, a unique algorithm was developed, for a numerical determination of the distribution of pressure of an ultrasonic wave on any surface or area of the medium generated by the concave curvilinear structure of rectangular ultrasound transducers with a geometric focus of the beam. The analysis of the obtained results of the acoustic field distribution inside the ultrasonic ring array used in tomography allows to conclude that the optimal number of transducers in a sector enabling to obtain ultrasound images using linear echographic scanning is 32 ≤ n ≤ 128, taking into account that due to an increased temporal resolution of ultrasonic imaging, this number should be as low as possible.
Źródło:
Archives of Acoustics; 2018, 43, 3; 455-463
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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