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Sensors (Basel)
January 2025
College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266590, China.
Underwater acoustic transducers need to expand the coverage of acoustic signals as much as possible in most ocean explorations, and the directivity indicators of transducers are difficult to change after the device is packaged, which makes the emergence angle of the underwater acoustic transducer limited in special operating environments, such as polar regions, submarine volcanoes, and cold springs. Taking advantage of the refractive characteristics of sound waves propagating in different media, the directivity indicators can be controlled by installing an acoustic lens outside the underwater acoustic transducer. To increase the detection range of an underwater acoustic transducer in a specific marine environment, a curvature-determining method for the diverging acoustic lens of an underwater acoustic transducer is proposed based on the acoustic ray tracing theory.
View Article and Find Full Text PDFSensors (Basel)
January 2025
School of Biomedical Engineering, Tsinghua University, Shuang Qing Road, Beijing 100084, China.
Mastoidectomy is critical in acoustic neuroma surgery, where precise planning of the bone milling area is essential for surgical navigation. The complexity of representing the irregular volumetric area and the presence of high-risk structures (e.g.
View Article and Find Full Text PDFSensors (Basel)
January 2025
School of Electrical and Electronic Engineering, Harbin University of Science and Technology, Harbin 150080, China.
This study addresses the challenges of electromagnetic interference and unstable signal transmission encountered by traditional sensors in detecting partial discharge (PD) within stator slots of large motors. A novel Extrinsic Fabry-Perot Interferometer (EFPI) sensor with a vibration-coupling air gap was designed to enhance the narrowband resonant detection sensitivity for PD ultrasonic signals by optimizing the diaphragm structure and coupling interface. The sensor features a quartz diaphragm with a thickness of 20 μM, an effective constrained radius of 0.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Research and Testing Institute Pilsen, 30100 Plzen, Czech Republic.
In this study, we investigated the effect of spray angle on the microstructure, bonding quality, and scratch resistance of cold-sprayed SS316L coatings on SS304 substrates. The coatings were deposited at spray angles of 45°, 60°, 75°, and 90° using a high-pressure cold spray system. A comprehensive analysis of the relationship between the spray angle and coating properties was conducted, with a particular focus on fracture toughness and porosity.
View Article and Find Full Text PDFMicromachines (Basel)
January 2025
Department of Astronautical, Electrical and Energy Engineering, University of Rome "La Sapienza", Via Eudossiana 18, 00184 Rome, Italy.
The propagation of interface acoustic waves (IAWs) in 128° YX-LiNbO/SU-8/overcoat structures was theoretically studied and experimentally investigated for different types of overcoat materials and thicknesses of the SU-8 adhesive layer. Three-dimensional finite element method analysis was performed using Comsol Multiphysics software to design an optimized multilayer configuration able to achieve an efficient guiding effect of the IAW at the LiNbO/overcoat interface. Numerical analysis results showed the following: (i) an overcoat faster than the piezoelectric half-space ensures that the wave propagation is confined mainly close to the surface of the LiNbO, although with minimal scattering in the overcoat; (ii) the presence of the SU-8, in addition to performing the essential function of an adhesive layer, can also promote the trapping of the acoustic energy toward the surface of the piezoelectric substrate; and (iii) the electromechanical coupling efficiency of the IAW is very close to that of the surface acoustic wave (SAW) along the bare LiNbO half-space.
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