bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photoacoustic differential attenuation spectrum for bone assessment
Authors: Xu Wenyi , Xie Weiya , Yu Dong , Sun Haohan , Gu Ying , Tao Xingliang , Qian Menglu , Cheng Liming , Wang Hao , Cheng Qian 
Published: October 2024

Abstract
Photoacoustic (PA) technology shows great potential in bone microstructure assessment. Due to the solid-liquid two-phase characteristics of cancellous bone, the PA signal received by transducers is aliasing of distributed PA source characteristics and acoustic propagation characteristics of cancellous bone. The contribution of various multi-scale distributed PA sources to the PA signal complexity leads to difficulty in identifying the sound propagation characteristics, making it difficult for quantitative assessment of bone microstructure. To eliminate the spectrum contribution of the PA source to the PA signal, we proposed an eccentric excitation-differential detection system and the acoustic propagation characteristics of cancellous bone can be obtained by calculating the PA differential attenuation spectrum (PA-DAS). The PA-DAS quantization parameter-slope is further extracted to quantify the attenuation of different frequency components. Simulation results show that slope strongly correlates to the porosity of cancellous bone, demonstrating the eccentric excitation-differential detection system combined with the PA-DAS method can realize the quantitative bone assessment.
CNN applied to ultrasonic guided wave spectrum image classification
Authors: Cisternas Williams Flores , Aguilera Ana , Olivares Rodrigo , Munoz Roberto , Minonzio Jean-Gabriel 
Published: October 2024

Abstract
Osteoporosis is a worldwide problem associated with an increasing number of fragility fractures. Currently, the standard for identifying patients at risk of fragility fracture is through Dual X-ray Absorptiometry (DXA). Different altenatives have been proposed, such as magnetic resonance imaging (MRI), three-dimensional X-rays, ultrasound or algorithms providing scores from clinical data. Among ultrasonic techniques, Bi-Directional Axial Transmission (BDAT) has been used to classify patients with or without fragility fractures, initially using ”classical” ultrasound parameters, such as velocities and latter using Support Vector Machine and automatic features, with performances close to the gold standard DXA. The aim of this study was to investigate the use of Convolutional Neural Networks (CNN) applied to patient classification using ultrasonic guided wave spectrum images, using a previous database of post menopausal women with or without fragility fractures. Two networks will be tested, a reference one, ResNet, successfully applied in classification and diagnosis in medical images, and a tailored one, denoted BDAT-Net, which hyperparameters will be optimized through a grid approach. The obtained accuracy, using BDAT-Net and clinical data (age, body mass index, cortisone intake) was found equal to 0.66 [0.64-0.69] comparable with the one obtained with DXA and significantly better than the one obtained with ResNet. These encouraging results open the door to the use of robust ultrasonic devices for fracture risk assessment, in particular in countries where DXA is not widely available.
Photoacoustic/ultrasound dual-modality imaging of Sentinel lymph node with carbon nanoparticles
Authors: Deng Handi , Gu Liujie , Bai Yizhou , Ma Cheng , Luo Bin 
Published: October 2024

Abstract
Sentinel lymph node (SLN) biopsy is a widely used method for identifying axillary lymph node metastasis in breast cancer patients, offering an avoidance of unnecessary axillarydissections and a lower incidence of lymphedema and other complications. However, the nuclide localization has added complexity to the procedure due to its accessibility. Methylene blue and other small molecule dyes have been widely used due to their convenience, but they have been found to have lower specificity and sensitivity. Carbon nanoparticles (CNPs), as a new type of tracer, are safe and show improved specificity. However, the significant optical absorption in human tissues still renders the detection of deep lymph nodes challenging. To overcome these challenges, we developed a high-sensitivity ultrasound probe optimized for photoacoustic imaging. Based on the new probe, we constructed a high-sensitivity photoacoustic/ultrasound dual-modality imaging system. A pilot clinical study has been conducted on two patients, preliminarily verifying the system’s ability to locate SLN when combined with the CNPs.
Finite element analysis of a Helmholtz transducer jointly driven by a trilaminar ring and a piezoelectric circular tube
Authors: Zhu Chenhui , Dai Yuyu , Zhou Yinqiu , Zhang Xiumei , Zhao Jiaheng 
Published: October 2024

Abstract
Crosswell seismic survey can image the crosswell geological anomalies with high resolution in 3D. To effectively conduct crosswell seismic survey, it is necessary to use a seismic source capable of transmitting low-frequency and high-power signals in a compact size. In this paper, a novel Helmholtz transducer is proposed, which utilizes both the bending vibrations of the trilaminar ring and the radial vibrations of the piezoelectric circular tube to simultaneously drive the vibration of the Helmholtz liquid cavity. This design reduces the resonant frequency of the liquid cavity while enhancing the transmitting voltage response at the liquid cavity resonant frequency. The influence of the inner radius of the trilaminar ring, the outer radius of the ceramic ring and the length of the piezoelectric circular tube on the liquid cavity resonant frequency and the transmitting voltage response at the liquid cavity resonant frequency is simulated using the finite element method. The simulation results provide a theoretical foundation for optimizing the design of such transducers.
A novel cryogenic acoustic microscope to evaluate electronic components
Authors: Bond L.J. , Barnard D. , Doran S. , Edayath S. , Feng Y. , Krennrich F. , Poonthottathil N. , Weinstein A. 
Published: October 2024

Abstract
Electronics to operate at cryogenic temperatures is key to many areas of science, including space exploration and in particle physics. Ensuring circuit functional reliability is mission critical. One system that will use tens of thousands of custom designed application specific integrated circuits (ASIC) is the Deep Underground Neutrino Experiment (DUNE), which will have sensor circuits operating in liquid argon (87 K) for decades. Both functional and nondestructive testing are being used to ensure circuit quality and reliability. Part of this work involves design, testing and data analysis using a cryogenic acoustic microscope operating at frequencies up to 50 MHz. Image analysis and correlations are used to compare differences seen before and after cryogenic cycling. Data are reported that were collected at room temperature (300 K) and when cooled using liquid nitrogen (77 K).
Analysis of electromechanical equivalent circuit model for the functionally graded tubular piezoelectric transducer
Authors: Wang Sha , Zhu Yazhou , Lin Shuyu 
Published: October 2024

Abstract
In this paper, a functionally graded tubular piezoelectric transducer (FG-tPET) is proposed. Based on the constitutive equation and wave equation, the electromechanical equivalent circuit model (EECM) of FG-tPET is obtained. When the non-uniformity coefficient tends to zero, the EECM can be simplified as the EECM of the traditional single-tube piezoelectric ceramic transducer. The correctness of the theoretical model is verified in comparison with the experimental results in the literature. Based on the theoretical model, the influence of the geometric size and the non-uniform coefficient of the transducer on the resonance/anti-resonance frequency is analyzed. The results show that the geometric size and the non-uniform coefficient can realize the coordinated adjustment of the resonance/anti-resonance frequency.
Measurement of thickness and ultrasonic velocities based on imaging method using laser-generated ultrasonic waves at thermoelastic regime
Authors: Dung N T , Arai Y 
Published: October 2024

Abstract
This study introduces a simple method for determining thickness and ultrasonic velocities, including skimming longitudinal waves, longitudinal waves, and shear waves, utilizing laser-induced ultrasonic waves at the thermoelastic regime and the time-position imaging technique. Laser scanning was performed on two aluminum samples with thicknesses of 6 mm and 10 mm, generating data on the arrival time of multiple wave modes according to the separated distances of two laser spots. Using the least squares technique, the data obtained from the experiment were employed to fit theoretical curves of various waves, enabling the simultaneous determination of several material parameters. The proposed method exhibits high accuracy in determining thickness, with a maximum relative error of 1% for thicknesses up to 10 mm. Additionally, comparisons with theoretical calculations reveal maximum errors of 1 % for shear wave velocity and 0.8 % for longitudinal wave velocity. The ratio between the velocity of skimming longitudinal wave and bulk longitudinal wave of 0.95 was established, providing a prospective method to calculate longitudinal wave velocity through guided waves along the surface.
Signal recognition based on transfer learning for Φ-OTDR fiber optic distributed disturbance sensor
Authors: Gan Jiaqi , Xiao Yueyu 
Published: October 2024

Abstract
Traditional classification models for optical fiber vibration signals can achieve good recognition results when there are a large number of samples. However, it is difficult to obtain sufficient training samples in real scenes. A method of Φ-OTDR sensor signal recognition based on VGGish transfer learning is proposed in this paper. Firstly, a selection indicator is designed to filter out vibration signals from sparse signals. Then, the VGGish network pretrained for sound classification is used for transfer learning as a feature extractor for optical fiber vibration signals. This method was applied to classify 6 kinds of optical fiber vibration signals. When the number of training samples is reduced to 480 samples, the method can still achieve 84.17% classification accuracy. Compared to the method of training from scratch, this proposed method reduces training time by 73.9%.
Internal Quality Inspection and Characterization of Casting Billets Based on Ultrasonic Microscopy
Authors: Liu Yanbo , Pan Fushuai , Li Hangkai , Yang Denbin , Li Min 
Published: October 2024

Abstract
For evaluating the internal quality of casting billets, the low-power experimental and metallographic methods have the disadvantages of the complex process, the small detection range and the destructive evaluation. In addition, the internal defects of the casting billet are analyzed by the one-dimensional waveform and two-dimensional image for the traditional ultrasonic testing, which can not describe directly the three-dimensional spatial information. Hence, a new method is proposed based on ultrasonic microscopy to detect and characterize the internal defection of the casting billet. In this paper, 42CrMo casting billet is regarded as objective, five sets of samples are fabricated by adjusting temperature gradient field and the number of presses. The ultrasonic sequence images of the present samples are achieved by using ultrasonic microscopy, and the spatial distributions, number, and sizes are obtained for the defects of the casting billet by reconstructing the three-dimensional appearance of microdefects to characterize the internal mass of the casting billet. Finally, the effective and accuracy of the proposed method are validated by using metallographic method.
Influence of sweep duration on debonding detection of honeycomb structures based on acoustic band gap
Authors: Yuan Ye , Liu Bin , Jia Han , Zhang Zhiguo 
Published: October 2024

Abstract
Honeycomb structure is widely used in many fields, and its bond quality needs to be tested during manufacture process and in service. However, the efficiency, sensitivity, and feasibility can hardly be achieved simultaneously for traditional non-destructive testing methods. In the previous work, we have proposed a new debonding detection method using the acoustic band gap of honeycomb structures. Nevertheless, the influence of the detection parameters on the testing result has not been thoroughly investigated. In this paper, the effect of duration variation of the sweep signal used for exciting on the results is studied. Experimental results demonstrate that the transmission frequency response (TFR) of both the intact and the debonding area almost keep unchanged as the sweep duration varies from 1 s to 0.001 s. Theoretical analysis shows that the upper limit of the sweep rate is about 500 MHz/s, i.e., the minimum sweep duration is about 1.2 × 10−5 s to detect a bandgap with a bandwidth of about 6 kHz. Therefore, a shorter sweep duration can be used to further improve the detection efficiency.
Phased Array Ultrasonic Inspection of Composite Fuselage Panel
Authors: Zhiying Li , Feifei Liu , Yusen Yang , Songping Liu 
Published: October 2024

Abstract
The composite fuselage panel is a crucial component in large civil aircraft, necessitating higher detection rates and efficiency. Phased array ultrasonic testing can enhance the efficiency and defect detection rate; however, it is essential to consider the structural characteristics of the fuselage to ensure reliable identification of design defects. Based on the material properties, structural features, and defect detection requirements of composite fuselage panels, a test block reflecting their characteristics was designed and fabricated with various prefabricated defects. Ultrasonic phased array method was employed for a series of testing parameter optimization experiments and defect detectability analysis. The detected flaws were quantitatively analyzed and compared with those obtained using conventional ultrasonic automatic scanning techniques to validate the effectiveness of the developed ultrasonic phased array method. The feasibility of utilizing phased array ultrasonics for nondestructive evaluation of wide-body airliner composite fuselage panels is confirmed.
Study of ultrasonic parameters for quality monitoring of plate heat exchanger
Authors: Dubey P , Declercq N F 
Published: October 2024

Abstract
Heat exchangers are crucial heat transfer devices widely used in energy industries such as power generation, oil production, and engine cooling. The plate heat exchanger is one of the most economical and efficient types of exchangers. It transfers heat using metal plates and has a high heat transfer efficiency because the fluid is exposed to a higher plate surface area. However, due to the presence of dissolved or suspended particles in the heat-exchanging fluids, a layer of deposit (fouling layer) is formed on the heat exchanger plates. It results in reduced efficiency of the device. Thus, a common cleaning method, such as chemical-based or manual methods, is employed. However, it always poses a risk of over-cleaning or removal of the protective oxide layer. Thus, an efficient mechanism to monitor the onset of the fouling layer would greatly help to achieve increased efficiency and cost reduction in the cleaning of the plates. Recent advances show ultrasound as one of the promising non-destructive inspection techniques to monitor the growth of the fouling layer. However, the variation in heat-exchanging fluid temperature affects the investigated acoustical parameter measurement. Thus, this research aims to study the linear and nonlinear ultrasonic parameters incorporating temperature-dependent effects from the fluid to provide an accurate real-time monitoring tool. The nonlinear acoustics analysis is experimentally employed in the research using the Second harmonic generation method (SHGM). The proposed research will help design ultrasound-assisted plate heat exchangers for maximum heat transfer efficiency.
Airframe Icing Properties and Geometry Reconstruction using Ultrasonic Full Waveform Inversion Method
Authors: Leon Kaswango Kanama , Dawei Wu 
Published: October 2024

Abstract
Recently, Non-destructive Ultrasonic Techniques have been utilized to detect aircraft icing. Traditional methods like ultrasound pulse-echo, guided waves, and optics are unsuitable due to ice’s complex properties and shape. Pulse-echo ultrasound, reliant on surface layer travel time, becomes ineffective with thin ice layers and variable ice properties. This research aimed to reconstruct ice properties and geometry on aircraft surfaces using ultrasonic full waveform inversion (FWI). For simulation COMSOL software is used to verify wave propagation through a nonlinear, thinly layered model. Wave propagation is then modelled using the 2D acoustic equation and finite differential methods, generating synthetic data. The FWI algorithm implemented, utilizes this synthetic data to reconstruct material properties and ice shape. Crucially, ultrasound transducers are discreetly positioned beneath the aircraft skin to non-destructively gather ice information without affecting aerodynamics.
Phase-modulated pulsing coherent acoustic tweezers for dynamic adjustable spaced particle patterning
Authors: Li Xin , Pan Hemin , Wang Xinyue , Mei Deqing , Wang Yancheng 
Published: October 2024

Abstract
Acoustic tweezer technique with non-contact micro-object manipulation capability has been widely utilized for particle patterning in the fields of cell arraying, target drug delivery, and functional composite fabrication. However, the manipulation resolution of acoustic tweezer device is decided by the configuration of interdigital transducers (IDTs), which is half the wavelength of surface acoustic waves (SAWs). This limitation severely reduces the manipulation versatility of acoustic tweezer devices. To address this limitation, we propose a novel approach that employs phase-modulated pulsing coherent SAWs. This method can halve the patterning spacing and allows for customization of the spacing based on specific manipulation demands. Our proposed technique increases the flexibility and manipulation resolution of acoustic tweezer device, and thus can be widely applied to reconfigurable assembly and precise manipulation of particles and cells.
Particle manipulation based on curved, slanted-finger interdigital transducer
Authors: Jue Bingjin , Zhang Xiaofeng 
Published: October 2024

Abstract
In this paper, an acoustic particle manipulation device is proposed to realize multi-function particle operation in a droplet. A curved slanted-finger interdigital transducer is designed to excite surface acoustic wave (SAW) in different resonance frequency. Diversity acoustic pressure field can be formed by turning the excitation frequency of the transducer. Moreover, through switching the excitation combination of the interdigital transducers, different acoustic field distributions can be aotained and diversity acoustic stream can be formed in the droplet. A finite element model is setup to study the acoustic field distribution and acoustic stream. Simulation results show that when a single frequency SAW is excited, acoustic streaming can be formed in the fluid and the particles can be rotated in the droplet. By switching the excitation frequency of the interdigital transducer, the direction of acoustic stream can be changed. In addition, the interdigital transducer can simultaneously excite multiple surface acoustic waves of different frequencies, which can manipulate the particles move in different tragectory. The study provides an effectively device to multi-function particle manipulation.
Remote liquid level monitoring based on coda wave interferometry
Authors: Jin Chunyan , Zhang Yuxiang , Duclos Aroune 
Published: October 2024

Abstract
Accurate monitoring of liquid level is important for both liquid stocking and related industrial procedures, it is however difficult under extreme circumstances where the inner space of the container is inaccessible or out of reach. Therefore, this paper proposes a remote liquid level monitoring method based on the use of ultrasonic coda wave interferometry. Coda waves stem from multiply scattering of elastic waves under the interactions with the boundary of propagation medium or scatters during their propagation, they are commonly observed in complex propagation medium. For having propagation trajectories much longer than the coherent waves, coda waves are capable of sampling the propagation medium repeatedly and more comprehensively, which in turn provides coda waves with higher sensitivity to its propagation medium. Letting ultrasonic waves propagate within the liquid container, which is often elastic medium, they are capable of probing the solid-liquid interface globally and repeatedly. As the changing in liquid level alters such solid-liquid interfaces inevitably, the propagation of coda wave is thus affected even without any contact with the liquid level. In this manuscript, experimental study is represented, of which the results show that waveform distortion of coda waves, estimated by remnant decorrelation coefficients, is quantitatively related with the change of liquid level, demonstrates the feasibility of remote liquid level measurement and continuous monitoring of liquid level with ultrasonic techniques.
Circular phase shift migration based photoacoustic computational tomography
Authors: Qin Kang , Jin Junyue , Lou Yucai , Liu Siyu 
Published: October 2024

Abstract
In the recent several decades, photoacoustic technique has proved to be capable of noninvasive biomedical imaging with scalable spatial resolution and high penetration depth. To achieve faithful image reconstruction, various method has been proposed, such as back projection, phase shift migration, model-based method, etc. These methods have simple implementations in homogeneous media, whereas in the cases of heterogeneous media (e.g., layered media), complicated modifications with respect to wave propagation at layer interface are always necessary. Here, we propose a frequency domain algorithm extension of phase shift migration in polar coordinates, which is obtained by making second order approximation to the optoacoustic point spread function in cylindrical coordinates and thereafter step by step wavenumber-frequency domain wave field extrapolation along the axial direction. Theoretical simulation and phantom experimental results demonstrate that the proposed circular phase shift migration method can well solve the layered heterogeneous reconstructive problem without modifying the wave propagation model. The acoustic diffraction limited acoustic resolution (up to 225 μm) and high imaging SNR (at least 16 dB) are obtained.
Broadband acoustic waves in plate-like structures for acoustic material characterisation
Authors: Claes Leander , Johannesmann Sarah , Zeipert Henning , Henning Bernd 
Published: October 2024

Abstract
Guided acoustic waves can be used for a multitude of different testing and material characterisation purposes. The options for evaluation are especially plentiful if a method for broadband excitation, e.g. thermoelastic excitation using focused, pulsed laser radiation, is used, and if the distance between excitation and detection of the acoustic waves can be varied. In this contribution, methods to infer different quantitative material properties from the recorded spatiotemporal measurement data are presented, ranging from isotropic elastic properties to parameters describing absorption for complex absorption models.