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Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on

Issue 12 • Date December 2009

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  • "IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control - Front cover"

    Publication Year: 2009 , Page(s): c1 - c2
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  • IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society

    Publication Year: 2009 , Page(s): i
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  • IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society - Elected Administrative Committee

    Publication Year: 2009 , Page(s): ii
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  • Table of contents

    Publication Year: 2009 , Page(s): iii - v
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  • Information for contributors with multimedia addition

    Publication Year: 2009 , Page(s): 2593 - 2596
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  • A multimedia example

    Publication Year: 2009 , Page(s): 2597
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  • Experimental and numerical investigations of vibration characteristics for parallel-type and series-type triple-layered piezoceramic bimorphs

    Publication Year: 2009 , Page(s): 2598 - 2611
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2847 KB) |  | HTML iconHTML  

    The dynamic characteristics of parallel-type and series-type piezoelectric bimorphs are analyzed in this study. The transverse (out-of-plane) and planar (in-plane) vibrations for piezoceramic bimorphs in normal and abnormal connections are investigated experimentally by 2 noncontact optical techniques and impedance analyzer. Electronic speckle pattern interferometry (ESPI) is the major experimental technique for measuring the resonant frequency and corresponding vibration mode shape. Out-of-plane and in-plane vibrations of piezoelectric bimorphs at resonance are obtained by a self-arranged ESPI optical setup. The laser Doppler vibrometer (LDV) is a point-wise measurement technique for out-of-plane displacement and is used to determine the out-of-plane resonant frequencies. The impedance analyzer is used to measure the resonant frequencies for in-plane motions. It is noted from the experimental results that the out-of-plane modes are the dominant motion for the normal connection and only symmetric vibration mode shapes can be excited. The in-plane motions are large enough to be measured using the ESPI method for normal connections. The in-plane resonant modes are observed for parallel-type piezoelectric bimorph in parallel connections; however, the in-plane mode shapes are similar to the out-of-plane mode shapes for the series-type piezoelectric bimorph in series connection. Hence, the particle motions of the piezoelectric bimorph at resonance are essentially 3-D for the normal connection. It is interesting to note that both symmetric and asymmetric out-of-plane vibration mode shapes can be excited with large applied voltage but no in-plane motion is observed for the abnormal connection. In addition to experimental methods, numerical computations based on the finite element method are used to verify the experimental results. Good agreements of the resonant frequencies and mode shapes are obtained for experimental and numerical results. View full abstract»

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  • Accelerated focused ultrasound imaging

    Publication Year: 2009 , Page(s): 2612 - 2623
    Cited by:  Papers (8)
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    One of the most basic trade-offs in ultrasound imaging involves frame rate, depth, and number of lines. Achieving good spatial resolution and coverage requires a large number of lines, leading to decreases in frame rate. An even more serious imaging challenge occurs with imaging modes involving spatial compounding and 3-D/4-D imaging, which are severely limited by the slow speed of sound in tissue. The present work can overcome these traditional limitations, making ultrasound imaging many-fold faster. By emitting several beams at once, and by separating the resulting overlapped signals through spatial and temporal processing, spatial resolution and/or coverage can be increased by many-fold while leaving frame rates unaffected. The proposed approach can also be extended to imaging strategies that do not involve transmit beamforming, such as synthetic aperture imaging. Simulated and experimental results are presented where imaging speed is improved by up to 32-fold, with little impact on image quality. Object complexity has little impact on the method's performance, and data from biological systems can readily be handled. The present work may open the door to novel multiplexed and/or multidimensional protocols considered impractical today. View full abstract»

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  • Optimal thresholds of feature tracking for blood velocity and tissue motion estimation

    Publication Year: 2009 , Page(s): 2624 - 2629
    Cited by:  Papers (1)
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    Feature tracking is an algorithm for estimating blood flow velocity and tissue motion using pulse-echo ultrasound. In contrast to cross-correlation speckle-tracking techniques, feature tracking identifies features at discrete locations and corresponds them from frame to frame. Prior studies have demonstrated that feature-tracking estimates exhibit lower variance than those obtained by the conventional autocorrelation method and require less computational complexity than either speckle tracking or autocorrelation. To date, not much attention has been paid to the process by which trackable features (normally local maxima) are selected from the set of all available features. In the selection process, it is desired to minimize flow estimate variance while providing sufficient spatial and temporal coverage of flow area. Flow studies were performed with a blood flow phantom, 3.5-MHz spherically focused transducer, and a pulser/receiver. Values were selected for the amplitude threshold (based on the RMS value) and width thresholds (based on the wavelength corresponding to transducer center frequency). The performance of this method using different threshold values was evaluated by the estimate standard deviation and number of features available to track. Results show that an optimal width threshold occurs at about 40 to 45% of the transmission wavelength, while a trade-off exists between amplitude thresholds and spatial flow field coverage. Both the standard deviation of estimated velocities and number of available features decrease with increasing threshold (either amplitude or width). This affords a user a method of determining optimal feature tracking thresholds depending on the specific flow application. Judicious selection of feature thresholds can decrease the estimate standard deviation by more than 25%. View full abstract»

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  • Reconstructive compounding for IVUS palpography

    Publication Year: 2009 , Page(s): 2630 - 2642
    Cited by:  Papers (1)
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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1783 KB) |  | HTML iconHTML  

    This study proposes a novel algorithm for luminal strain reconstruction from sparse irregularly sampled strain measurements. It is based on the normalized convolution (NC) algorithm. The novel extension comprises the multilevel scheme, which takes into account the variable sampling density of the available strain measurements during the cardiac cycle. The proposed algorithm was applied to restore luminal strain values in intravascular ultrasound (IVUS) palpography. The procedure of reconstructing and averaging the strain values acquired during one cardiac cycle forms a technique, coined as reconstructive compounding. The accuracy of strain reconstruction was initially tested on the luminal strain map, computed from 3 in vivo IVUS pullbacks. The high quality of strain restoration was observed after systematically removing up to 90% of the initial elastographic measurements. The restored distributions accurately reproduced the original strain patterns and the error did not exceed 5%. The experimental validation of the reconstructed compounding technique was performed on 8 in vivo IVUS pullbacks. It demonstrated that the relative decrease in number of invalid strain estimates amounts to 92.05 ?? 6.03% and 99.17 ?? 0.92% for the traditional and reconstructive strain compounding schemes, respectively. In conclusion, implementation of the reconstructive compounding scheme boosts the diagnostic value of IVUS palpography. View full abstract»

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  • Functional changes in arteries induced by pulsed high-intensity focused ultrasound

    Publication Year: 2009 , Page(s): 2643 - 2649
    Cited by:  Papers (2)
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    Continuous high-intensity focused ultrasound (HIFU) at various intensities has been shown to induce functional changes in arteries. The objective of the current study was to investigate the functional changes in arteries when pulsed HIFU is used at various acoustic power levels. Sonication was applied at an ultrasound frequency of 1 MHz with a burst length of 50 ms and a repetition frequency of 1 Hz. The duration of the whole sonication was 6 s. The femoral arteries and abdominal aortas of Sprague-Dawley rats were surgically exposed and sonicated with pulsed HIFU; the pulsed-HIFU beam was aimed using color images of the blood flow. The peak systolic velocity (PSV) of the blood flow, as measured by Doppler velocimetry, increased in the arteries to which pulsed HIFU had been applied at acoustic powers of 15, 30, and 45 W. The increase in PSV was correlated with the acoustic power of the pulsed HIFU. The temperatures recorded by the thermocouples placed above and below the aorta surfaces did not change significantly during the sonication. Furthermore, no histological changes were found and the vessel wall showed no obvious temperature rise. Therefore, our results indicate that the functional changes induced by pulsed-HIFU exposure are mainly due to mechanical effects. View full abstract»

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  • Autonomous corrosion detection in gas pipelines: a hybrid-fuzzy classifier approach using ultrasonic nondestructive evaluation protocols

    Publication Year: 2009 , Page(s): 2650 - 2665
    Cited by:  Papers (3)
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    In this paper, a customized classifier is presented for the industry-practiced nondestructive evaluation (NDE) protocols using a hybrid-fuzzy inference system (FIS) to classify the corrosion and distinguish it from the geometric defects or normal/healthy state of the steel pipes used in the gas/petroleum industry. The presented system is hybrid in the sense that it utilizes both soft computing through fuzzy set theory, as well as conventional parametric modeling through H? optimization methods. Due to significant uncertainty in the power spectral density of the noise in ultrasonic NDE procedures, the use of optimal H2 estimators for defect characterization is not so accurate. A more appropriate criterion is the H? norm of the estimation error spectrum which is based on minimization of the magnitude of this spectrum and hence produces more robust estimates. A hybrid feature set is developed in this work that corresponds to a) geometric features extracted directly from the raw ultrasonic A-scan data (which are the ultrasonic echo pulses in 1-D traveling inside the metal perpendicular to its 2 surfaces) and b) mapped features from the impulse response of the estimated model of the defect waveform under study. An experimental strategy is first outlined, through which the necessary data are collected as A-scans. Then, using the H? estimation approach, a parametric transfer function is obtained for each pulse. In this respect, each A-scan is treated as output from a defining function when a pure/healthy metal's A-scan is used as its input. Three defining states are considered in the paper; healthy, corroded, and defective, where the defective class represents metal with artificial or other defects. The necessary features are then calculated and are then supplied to the fuzzy inference system as input to be used in the classification. The resulting system has shown excellent corrosion classification with very low misclassificat- on and false alarm rates. View full abstract»

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  • Evaluation of the damage detection capability of a sparse-array guided-wave SHM system applied to a complex structure under varying thermal conditions

    Publication Year: 2009 , Page(s): 2666 - 2678
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    A sparse-array structural health monitoring (SHM) system based on guided waves was applied to the door of a commercial shipping container. The door comprised a corrugated steel panel approximately 2.4 m by 2.4 m surrounded by a box beam frame and testing was performed in a nonlaboratory environment. A 3-D finite element (FE) model of the corrugations was used to predict transmission coefficients for the A0 and S0 modes across the corrugations as a function of incidence angle. The S0 mode transmission across the corrugations was substantially stronger, and this mode was used in the main test series. A sparse array with 9 transducers was attached to the structure, and signals from the undamaged structure were recorded at periodic intervals over a 3-week period, and the resulting signal database was used for temperature compensation of subsequent signals. Defects in the form of holes whose diameter was increased incrementally from 1 to 10 mm were introduced at 2 different points of the structure, and signals were taken for each condition. Direct analysis of subtracted signals allowed understanding of the defect detection capability of the system. Comparison of signals transmitted between different transducer pairs before and after damage was used to give an initial indication of defect detectability. Signals from all combinations of transducers were then used in imaging algorithms, and good localization of holes with a 5-mm diameter or above was possible within the sparse array, which covered half of the area of the structure. View full abstract»

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  • Modeling and experimental study on near-field acoustic levitation by flexural mode

    Publication Year: 2009 , Page(s): 2679 - 2685
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (693 KB) |  | HTML iconHTML  

    Near-field acoustic levitation (NFAL) has been used in noncontact handling and transportation of small objects to avoid contamination. We have performed a theoretical analysis based on nonuniform vibrating surface to quantify the levitation force produced by the air film and also conducted experimental tests to verify our model. Modal analysis was performed using ANSYS on the flexural plate radiator to obtain its natural frequency of desired mode, which is used to design the measurement system. Then, the levitation force was calculated as a function of levitation distance based on squeeze gas film theory using measured amplitude and phase distributions on the vibrator surface. Compared with previous fluid-structural analyses using a uniform piston motion, our model based on the nonuniform radiating surface of the vibrator is more realistic and fits better with experimentally measured levitation force. View full abstract»

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  • Thermal behavior of BAW filters at high RF power levels

    Publication Year: 2009 , Page(s): 2686 - 2692
    Cited by:  Papers (7)
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    The temperature increase of bulk acoustic wave filters at high RF power levels has been investigated. Self-heating due to power dissipation in the filter leads to a nonuniform frequency shift of the insertion loss. At the right filter skirt, self-heating is amplified by the negative temperature coefficient of frequency. We demonstrate that at high RF power levels, this can cause thermal instabilities resulting in an abrupt step in the insertion loss. A novel frequency transformation is introduced to describe the nonuniform frequency shift of the insertion loss as well as the thermal instabilities. A condition for the occurrence of thermal instabilities is derived. It is argued that because of this nonuniform frequency shift at high power levels, accelerated lifetime tests can overestimate the lifetime, if the stress frequency is not compensated for self-heating. Here, the frequency transformation is used to determine the stress frequencies at high RF power levels from low-power S-parameter measurements. View full abstract»

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  • An exact analysis of surface acoustic waves in a plate of functionally graded materials

    Publication Year: 2009 , Page(s): 2693 - 2700
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (731 KB) |  | HTML iconHTML  

    Some traditional applications of structures and devices with homogeneous materials are being gradually replaced by functionally graded materials (FGM) with spatial variation of properties. The analysis of SAW propagating in FGM structures will be different primarily due to variations of material properties and resulting differential equations with variable coefficients. To provide an effective method and accurate results for the analysis of SAWs in FGM structures, we employed the Frobenius method as the only available method for a detailed analysis of SAW in materials with property variations in a linear pattern. Analytical examples are presented to demonstrate the effectiveness of the method and the effect of FGM on changes of surface displacements in SAW propagation. View full abstract»

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  • Micromachined thin film plate acoustic wave resonators (FPAR): Part II

    Publication Year: 2009 , Page(s): 2701 - 2710
    Cited by:  Papers (11)
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    Improved performance thin-film plate acoustic wave resonators (FPAR) using the lowest order symmetric Lamb wave (S0) propagating in highly textured AlN membranes have been previously demonstrated for the first time. In this work, an experimental study of the resonators' performance vs. a variety of design parameters is performed. Devices operating in the vicinity of the stopband center exhibiting a Q-value of up to 3000 at a frequency of around 875 MHz are demonstrated. Further, low-loss high-Q micromachined 2-port longitudinally coupled thin-film resonators using the S0 mode are demonstrated for the first time. For the analysis of the proposed structures, the coupling-of-modes (COM) approach is successfully employed. Initially, the COM model is used for the extraction of physical parameters from one-port FPAR measurements. Subsequently, using the COM model, a satisfactory agreement with the proposed experimental frequency characteristics of S0 2-port FPARs has been achieved, and possibilities for further improvements in the performance discussed. Finally, the frequency spectrum of the one-port devices has been studied and the excited plate modes at different frequencies identified and presented with their Q-factors and temperature coefficients of frequency (TCF). View full abstract»

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  • CMUT characterization by interferometric and electric measurements

    Publication Year: 2009 , Page(s): 2711 - 2721
    Cited by:  Papers (1)
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    Capacitive micromachined ultrasonic transducers (CMUTs) with 5.7 ??m radius, realized by wafer bonding, have been characterized by both optical and electrical measurements. These measurements are performed by our heterodyne interferometer and a network analyzer, respectively. The results from this article will be used to improve the fabrication of next-generation CMUTs. We have investigated the spread in resonance frequency of different CMUT membranes along the array. Q-factors have been obtained using both measurement methods, and the results from the 2 methods have been numerically compared. The relation between applied dc voltage and resonance frequency has been studied. Temperature measurements show that increasing temperature leads to a small decrease in the resonance frequency of the CMUTs; however, the decrease is small enough to ensure stable operation with small variations in room temperature. The heterodyne interferometer is used to inspect the vibration pattern of the CMUTs' higher harmonic modes. These modes are located at approximately 60 MHz in air. To the authors' knowledge, vibration modes at frequencies >40 MHz have not been previously studied. View full abstract»

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  • Design and experimental study of microcantilever ultrasonic detection transducers

    Publication Year: 2009 , Page(s): 2722 - 2732
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    This paper presents the analysis, design, and experimental study of a microcantilever optically-activated ultrasonic detection transducer. An analytical model was derived using 1-D cantilever structural dynamics, leading to the optimization of the transducer design. Finite element modeling enabled dynamic simulation to be performed, with results in good agreement with the analytical model. Transducers were fabricated using MEMS (microelectromechanical systems) techniques. Experimental results are presented on remote noncontact detection of ultrasound using the fabricated transducers; high SNR is achieved for the detected signals, even for relatively low ultrasonic amplitudes. Both analysis and experimental study show that the transducer has a sensitivity ~1 to 2 orders of magnitude higher than that of conventional optical detection techniques. Furthermore, we show that the dominant factor in the increased sensitivity of the transducer is the resonant nature of the finger structure. View full abstract»

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  • Exploitation of capacitive micromachined transducers for nonlinear ultrasound imaging

    Publication Year: 2009 , Page(s): 2733 - 2743
    Cited by:  Papers (6)
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    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1334 KB) |  | HTML iconHTML  

    Capacitive micromachined ultrasonic transducers (CMUTs) present advantages such as wide frequency bandwidth, which could be further developed for nonlinear imaging. However, the driving electrostatic force induces a nonlinear behavior of the CMUT, thus generating undesirable harmonic components in the generated acoustic signal. Consequently, the use of CMUT for harmonic imaging (with or without contrast agents) becomes challenging. This paper suggests 2 compensation approaches, linear and nonlinear methods, to cancel unwanted nonlinear components. Furthermore, nonlinear responses from contrast agent were evaluated using CMUT in transmit before and after compensation. The results were compared with those obtained using a PZT transducer in transmit. Results showed that CMUT nonlinear behavior is highly influenced by the excitation to bias voltage ratio. Measurements of output pressure very close to the CMUT surface allow the estimation of optimal parameters for each compensation approach. Both methods showed a harmonic reduction higher than 20 dB when one element or several elements are excited. In addition, the study demonstrates that nonlinear approach seems to be more efficient because it is shown to be less sensitive to interelement variability and further avoids fundamental component deterioration. The results from contrast agent measurements showed that the responses obtained using CMUT elements in transmit with compensation were similar to those from PZT transducer excitation. This experimental study demonstrates the opportunity to use CMUT with traditional harmonic contrast imaging techniques. View full abstract»

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  • Bilayer piezoelectric/electrostrictive (P/E) dome unimorph

    Publication Year: 2009 , Page(s): 2744 - 2749
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    We present a new type of actuator named bilayer piezoelectric/electrostrictive dome unimorph (BIPEDU), fabricated by attaching a piezoelectric-electrostrictive monolithic bilayer composites (PE-MBLC) to a metal plate. Various ratios of piezoelectric/electrostrictive (P/E) volume percent were used to form PE-MBLC. It was found that d33 eff and Keff in PE-MBLC follow the series 2-2 composite mixing rule. However, the measured results were slightly lower than those of the calculated values because of a large difference in dielectric displacement between piezoelectric and electrostrictive layers and because the electrostrictor acts as the resistor that impedes the domain switching in piezoelectric layer during poling. In addition, we have investigated the field-induced displacement in PE-MBLC and BIPEDU actuators. In comparison, the displacement of BIPEDU actuators was much higher than that of PE-MBLC actuators. This was attributed to the good quality of bonding between ceramic and metal, which contributed to the proper stress/force transfer, as well as the metal sheet, which acted as a flextentional structure for PE-MBLC to generate more axial displacement in BIPEDU actuators. The load dependence of displacement in BIPEDU was obtained. In addition, the BIPEDU showed high reliability during the displacement cyclic testing. View full abstract»

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  • Theoretical modeling of frequency-dependent magnetoelectric effects in laminated multiferroic plates

    Publication Year: 2009 , Page(s): 2750 - 2759
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    The recently derived 2-D equations for extensional, flexural, and thickness-shear motions of laminated plates of piezoelectric/piezomagnetic layers are employed in the analysis of the frequency dependence of magnetoelectric couplings in laminated plates of piezoelectric and piezomagnetic layers driven by time-harmonic magnetic fields. Four structures are analyzed. Two are symmetric about the middle plane and are for extensional motions. The other 2 are antisymmetric about the middle plane and are for flexural motions. Frequency-dependent magnetoelectric effects are calculated and compared. Near resonances, the time-dependent magnetoelectric coupling coefficients are found to be much larger than the static magnetoelectric coupling coefficients. View full abstract»

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  • Design and fabrication of PIN-PMN-PT single-crystal high-frequency ultrasound transducers

    Publication Year: 2009 , Page(s): 2760 - 2763
    Cited by:  Papers (1)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (489 KB) |  | HTML iconHTML  

    High-frequency PIN-PMN-PT single crystal ultrasound transducers at center frequencies of 35 MHz and 60 MHz were successfully fabricated using lead indium niobate-lead magnesium niobate-lead titanate (0.23PIN- 0.5PMN-0.27PT) single crystal. The new PIN-PMN-PT single crystal has higher coercivity (6.0 kV/cm) and higher Curie temperature (160??C) than PMN-PT crystal. Experimental results showed that the PIN-PMN-PT transducers have similar performance but better thermal stability compared with the PMN-PT transducers. View full abstract»

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  • A simple approximate formula for the physical focal length of spherically focused transducers

    Publication Year: 2009 , Page(s): 2764 - 2768
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    A simple approximate formula is presented to describe the relationship between the physical focal lengths and the geometric focal lengths of spherically focused transducers with ultrasonic fields. This simple expression applies regardless of whether the focus strength is strong or weak, and regardless of whether the fluids are non-attenuating or attenuating. Analysis results show that the average error of the simple approximate formula is certainly less than 2% relative to the numerical solution. View full abstract»

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  • 2009 Index

    Publication Year: 2009 , Page(s): 2769 - 2817
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Aims & Scope

IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control focuses on the theory, design, and application on generation, transmission, and detection of bulk and surface mechanical waves.

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Editor-in-Chief
Steven Freear
s.freear@leeds.ac.uk