Temat: ultrasonic - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: A new type of high power ultrasonic generator for welding and cutting processes
Autorzy:: Kardyś, W.
Milewski, A.
Kogut, P.
Kluk, P.
Kiełbasiński, M.
Tematy:: ultrasonic
ultrasonic welding
ultrasonic cutting
ultrasonic generator; Pokaż więcej
Wydawca:: Polskie Towarzystwo Akustyczne
Powiązania:: https://bibliotekanauki.pl/articles/332326.pdf Link otwiera się w nowym oknie
Opis:: The paper presents a new type of high power ultrasonic generator for welding and cutting processes developed by the Tele & Radio Research Institute. The new generator can provide up to 5 kW of electrical power to an ultrasonic transducer in the frequency range of 16 kHz up to 60 kHz with regulation step down to 0.1 Hz. The device utilizes an innovative microcontroller with built-in high resolution timing blocks that enable direct synthesis of control signals for the generator's resonant converter, without the need of an external DDS unit or programmable device. This new approach to designing ultrasonic generators can benefit in greater flexibility and reliability of the device. New algorithms with cycle-by-cycle parameter control, and precise regulation of output frequency and power delivery, have been developed. Various parameters of ultrasonic stack, such as impedance and resonant frequency, are measured by the generator in real-time, and can be used for ultrasonic stack wear monitoring and fault detection.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Narrow Beam Ultrasonic Transducer Matrix Model for Projection Imaging of Biological Media
Autorzy:: Opieliński, K. J.
Gudra, T.
Pruchnicki, P.
Tematy:: ultrasonic projection
directional ultrasonic transducer matrix
multielement ultrasonic probe
electrode attachment optimisation; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/178004.pdf Link otwiera się w nowym oknie
Opis:: The following paper presents an idea of minimising the number of connections of individual piezoelectric transducers in a row-column multielement passive matrix system used for imaging of biological media structure by means of ultrasonic projection. It allows to achieve significant directivity with acceptable input impedance decrease. This concept was verified by designing a model of a passive ultrasonic matrix consisting of 16 elementary piezoceramic transducers, with electrode attachments optimised by means of electronic switches in rows and columns. Distributions of acoustic field generated by the constructed matrix model in water and results of the calculations conformed well.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: A Digitally Controlled Model of an Active Ultrasonic Transducer Matrix for Projection Imaging of Biological Media
Autorzy:: Opieliński, K. J.
Gudra, T.
Pruchnicki, P.
Tematy:: ultrasonic projection
active ultrasonic transducer matrix
multielement ultrasonic probe
electrode attachment optimisation; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/178008.pdf Link otwiera się w nowym oknie
Opis:: The following work presents the idea of constructing a digitally controlled active piezoceramic transducer matrix for ultrasonic projection imaging of biological media in a similar way as in case of roentgenography (RTG). Multielement ultrasonic probes in the form of flat matrices of elementary piezoceramic transducers require attaching a large number of electrodes in order to activate the individual transducers. This paper presents the idea of minimising the number of transducer connections in an active row-column matrix system. This idea was verified by designing a model of a matrix consisting of 16 ultrasonic transducers with electrode attachments optimised by means of electronic switches in rows and columns and miniature transistor switches in the nodes of the matrix allowing to activate selected transducers. The results of measurements and simulations of parameters of the designed matrix show that it is suitable to be used in projection imaging of biological media as a sending probe. In to use the matrix as a universal sending or receiving probe, it was suggested to add further switches that would eliminate the undesired effect of crosstalks in case of switches used for toggling the transducers in the nodes of the matrix.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Modelling and Designing of Ultrasonic Welding Systems
Autorzy:: Milewski, A.
Kluk, P.
Kardyś, W.
Kogut, P.
Tematy:: ultrasonic welding and cutting system
ultrasonic stack modelling and designing
digitally controlled ultrasonic power supply
ultrasonic stack e-diagnosis; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/176732.pdf Link otwiera się w nowym oknie
Opis:: This article presents the main stages and challenges in modelling and designing of modern ultrasonic welding and cutting systems. First, the key components of such a system, such as an ultrasonic stack (consisting of a high power ultrasonic transducer and a sonotrode) and a digitally controlled ultrasonic power supply with precise control of the output power, have been considered. Next, a concept of measurement system for verification and validation of mathematical models of ultrasonic stacks and its components has been presented. Finally, a method of ultrasonic stack e-diagnosis based on ultrasonic transducer electrical impedance measurement during welding and cutting process has been described.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Annular Array Transducer and Matched Amplifier for Therapeutic Ultrasound
Autorzy:: Secomski, W.
Nowicki, A.
Wójcik, J.
Lewandowski, M.
Walczak, M.
Tymkiewicz, R.
Tematy:: ultrasonic therapy
annular array transducer
ultrasonic field; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/177840.pdf Link otwiera się w nowym oknie
Opis:: The use of therapeutic ultrasound continues to grow. A focused ultrasonic wave can increase the tissue temperature locally for the non-invasive cancer treatment or other medical applications. The authors have designed a seven-element annular array transducer operating at 2.4 MHz. Each element was excited by sine burst supplied by a linear amplifier and FPGA control circuits. The acoustic field, generated by a transducer was initially numerically simulated in a computer and next compared to water tank hydrophone measurements performed at 20, 40 and 60 mm focal depth. The results showed good agreement of the measurements with theory and the possibility to focus the ultrasound in the preselected area. The total acoustic power radiated by the annular array was equal to 2.4 W.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Two-Phase Flow Measuring with Ultrasonic Tomography
Autorzy:: Qorbani, Omid
Aghdam, Esmaeil Najafi
Tematy:: two-phase flowmeter
ultrasonic flowmeter
ultrasonic tomography; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:: https://bibliotekanauki.pl/articles/176579.pdf Link otwiera się w nowym oknie
Opis:: The exact measurement of multiphase flow is an important and essential task in the oil and petrochemical related industries. Several methods have already been proposed in this field. In the existing methods, flow rate measurement depends on the fluid flow pattern. Flow pattern recognition requiring calibration has created instability in such systems. In this paper, a imple and reliable method is proposed which is based on ultrasonic tomography. It is free from calibration and instability problems that existing methods have. The obtained data from a 32-digit array of ultrasonic sensors have been used and the two-phase flow rate including liquid and gas phases have been calculated through a simple algebraic algorithm. Simulation results show that while applying this method the measurement technique is independent from the fluid flow pattern and the system error is decreased. For the proposed algorithm, the average amount of the spatial imaging error (SIE) for a bubble at different positions inside the pipe is about 5%.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Investigation of Ultrasonic Emulsifying Processes of a Linseed Oil and Water Mixture
Autorzy:: Skumiel, A.
Józefczak, A.
Heller, K.
Hornowski, T.
Wielgusz, K.
Tematy:: ultrasonic cavitation
ultrasonic emulsifying processes
emulsion
cavitation threshold; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/177596.pdf Link otwiera się w nowym oknie
Opis:: Ultrasonic emulsifying processes of immiscible liquids can be used to obtain stable emulsions. The authors used an ultrasonic sandwich head with an energy concentrator to obtain a suitable value of the energy density necessary for the emerge of ultrasonic cavitation. Two piezoelectric ring (D_ext = 50 mm) transducers of Pz-26 type produced by FERROPERM were used to design the ultrasonic sandwich head. The frequency of the ultrasonic wave was 18.4 kHz and the excitation time of the ultrasonic transducer exiting 5 minutes. Visible bubbles during the generation of ultrasonic waves appeared in the mixture after exceeding the cavitation threshold. The authors determined also the cavitation threshold by measuring the electrical voltage conducted to the transducers. To receive long-lasting emulsion, the electrical voltage attained 300 Vpeak. The dispersion dependence on the emulsifying time was determined. The emulsion of linseed oil and water was stable through some months without surfactants.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Application of the Ultrasonic Ring Array Used in UTT for the Reflection Method Examinations of Structures
Autorzy:: Staszewski, Wiktor
Gudra, Tadeusz
Opieliński, Krzysztof J.
Tematy:: ultrasonic reflection tomography
dynamic focusing
ultrasonic ring array; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:: https://bibliotekanauki.pl/articles/1945647.pdf Link otwiera się w nowym oknie
Opis:: The ultrasonic ring array, designed for examining the female breast with the use of ultrasonic transmission tomography (UTT), has been adapted for reflection method trials. By altering the activation time of ultrasonic elementary transducers, the parameters of the focus were changed with the aim at improving the quality of the obtained ultrasound image. For this purpose, a phantom consisting of rods having varying thicknesses was analyzed when moving the position of the focus with the use of dynamic focusing along the symmetry axis of the ring array ranging from 30 to 130 mm from central transducers. In previous trials, which applied an algorithm using the sum of all the acoustic fields, a series of simulations was performed in conditions identical to the phantom trial. This paper documents attempts at improving the parameters of the acoustic field distribution during unconventional focusing. The research here presented is a continuation of examinations focusing on the acoustic field distribution inside the ultrasonic ring array with the aim at finding the best possible cross-section of the female breast using the reflection method.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Zastosowanie metod ultradźwiękowych w procesie regeneracji części maszyn
Application of ultrasonic methods in regeneration process of machinery elements
Autorzy:: Wilczarska, J.
Tematy:: metody ultradźwiękowe
fale ultradźwiękowe
cyfrowy defektoskop ultradźwiękowy
ultrasonic methods
ultrasonic waves
digital ultrasonic flaw detector; Pokaż więcej
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Powiązania:: https://bibliotekanauki.pl/articles/2071977.pdf Link otwiera się w nowym oknie
Opis:: Wzrost zainteresowania badaniami ultradźwiękowymi wynika z ich nieniszczącego charakteru, który zapewnia ocenę trwałości elementów maszyn podczas działania obciążeń, identyfikację przydatności technologicznej i eksploatacyjnej materiału oraz ocenę niezawodności i bezpieczeństwa maszyny, nie ingerując znacząco w jego strukturę i właściwości użytkowe. W pracy przedstawiono metody badań ultradźwiękowych oraz aparaturę badawczą wykorzystywaną do tych badań. Szczególną uwagę zwrócono na możliwości cyfrowego ultradźwiękowego defektoskopu CUD.
Increased interest in ultrasonic inspection methods providing the assessment of machine elements' stability during load operation, identification of material performance and technological suitability, and finally machine reliability and safety assessment, without interfering significantly into their structure and properties, is caused by non-destructive nature of these methods. A method of ultrasonic testing and research equipment used for these studies are presented in the paper. Particular attention is drawn to possibilities and characteristics of the digital ultrasonic flaw detector CUD.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Material Ultrasonic Attenuation Influence on Conventional Ultrasonic Non-Destructive Copper Alloy Cast Testing
Autorzy:: Koňár, R.
Mičian, M.
Tematy:: ultrasonic testing
ultrasonic attenuation
copper alloy casting
centrifugal casting; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/353084.pdf Link otwiera się w nowym oknie
Opis:: Internal casting defects that are detected by radiography may also be detected by ultrasonic method. Ultrasonic testing allows investigation of the cross-sectional area of a casting, it is considered to be a volumetric inspection method. The high frequency acoustic energy travels through the casting until it hits the opposite surface or an interface or defect. The interface or defect reflects portions of the energy, which are collected in a receiving unit and displayed for the analyst to view. The pattern of the energy deflection can indicate internal defect. Ultrasonic casting testing is very complicated in practice. The complications are mainly due to the coarse-grain structure of the casting that causes a high ultrasound attenuation. High attenuation then makes it impossible to test the entire volume of material. This article is focused on measurement of attenuation, the effect of probe frequency on attenuation and testing results.
Dostawca treści:: Biblioteka Nauki

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