Results 21 to 30 of about 21,419 (265)

Influence of Boundary Impedance of 3D Cavity on Targeted Energy Transfer between a Damped Acoustic Mode and a Nonlinear Membrane Absorber

Machines, 2022
In order to apply the nonlinear energy sink (NES) to reduce the low-frequency noise inside a 3D acoustic cavity with an impedance boundary, a two degrees-of-freedom (DOF) dynamic model of the coupled system of one damped acoustic mode of a regular 3D ...
Jianwang Shao, Qimeng Luo, Tao Zeng, Xian Wu   +3 more
doaj   +1 more source

Click emission in Dall's porpoise Phocoenoides dalli, focusing on physical properties of tissues. [PDF]

PLoS ONE, 2018
Dall's porpoise (Phocoenoides dalli) is one of most common North Pacific porpoise species, for which information on sound-emitting processes is limited.
Mika Kuroda, Motoki Sasaki, Kazutaka Yamada, Nobuhiro Miki, Natsuki Matsui, Takashi Matsuishi   +5 more
doaj   +1 more source

Acoustic Impedance Study of Peritubal Myoclonus

Acta Oto-Laryngologica, 2002
An audible clicking sound coexistent with the contractions of the peritubal muscles is thought to be an isolated form of palatal myoclonus that presents with myoclonal contractions of the soft palate, larynx, pharynx and, sometimes, cervicofacial area.
Yetiser, S., Kazkayasi, M., Civitci, D.
openaire   +2 more sources

Adjustable Phase-Amplitude-Phase Acoustic Metasurface for the Implementation of Arbitrary Impedance Matrices

Research
Impedance metasurfaces enable accurate regulation of acoustic fields. However, they can hardly supply a flexible response as such perfect operation is accompanied by stringent requirements on the design of unit cells.
Yu-Ze Tian, Zhuo-Run Wei, Yan-Feng Wang, Vincent Laude, Yue-Sheng Wang   +4 more
doaj   +1 more source

Design and experimental evaluation of a travelling wave thermoacoustic engine

Energy Reports, 2020
In a thermoacoustic engine, acoustic impedance plays a key role to improve the system performance. A matching stub is a component which can be applied to adjust the acoustic impedance.
Patcharin Saechan, Isares Dhuchakallaya
doaj   +1 more source

Ultra-Broadband Sound Absorbing Materials Based on Periodic Gradient Impedance Matching

Frontiers in Materials, 2022
Ultra-broadband sound absorption with periodic gradient impedance matching is of great concern in the research of acoustic materials. This study investigates the impedance matching of composite acoustic metamaterials comprising micro-perforated plates ...
Fei Wu, Xiao Zhang, Zegang Ju, Jiang Zhao, Man Hu, Mingyuan Gao, Jun Luo, Huayan Pu   +7 more
doaj   +1 more source

Laser Powder Bed Fusion of Alumina: Effects of Scanning Strategies on External and Internal Defects

Advanced Engineering Materials, EarlyView.
This study investigates how scanning strategies affect pure alumina in laser powder bed fusion. Linear 45° scanning yields uniform surfaces but high porosity, while the island‐concentric strategy provides higher density with through‐holes favorable for infiltration. Findings highlight pathways toward optimizing defect‐free alumina parts.
Mohamed Abdelmoula, Gökhan Küçüktürk, Duran Kaya, David Grossin, Christophe Tenailleau, Benjamin Duployer, Enrique Juste, Fabrice Petit   +7 more
wiley   +1 more source

Prediction of Surface Topography Parameters in Direct Laser Interference Patterning of Stainless Steel Using Infrared Monitoring and Convolutional Neural Networks

Advanced Engineering Materials, EarlyView.
This study presents an infrared monitoring approach for direct laser interference patterning (DLIP) combined with a convolutional neural network (CNN). Thermal emission data captured during structuring are used to predict surface topography parameters.
Lukas Olawsky, Marcelo Sallese, Leander Kläber, Clemens Kuhn, Keming Du, Andrés Fabián Lasagni   +5 more
wiley   +1 more source

Air‐Pressure–Actuated Vibroacoustic Metamaterial With Tunable Bandgap: Design, Modeling, and Characterization

Advanced Engineering Materials, EarlyView.
This article presents the design, modeling, and characterization of air‐pressure–actuated programmable vibroacoustic metamaterials (PVAMM). The study focuses on leveraging air pressure to dynamically tune resonance frequencies for effective noise attenuation.
William Kaal, Michael M. Becker, Sarah C. L. Fischer   +2 more
wiley   +1 more source

Theoretical research on the application of impedance calculation in the design of high-intensity low-frequency acoustic generator

Journal of Low Frequency Noise, Vibration and Active Control
The impedance matching is essential in producing high-intensity acoustic waves. This paper studies the impedance calculation methods of modulators and double-chamber Helmholtz resonators based on fluid mechanics, aeroacoustics, and electro-acoustic ...
Baoguo Zhang, Mingrong Dong, Xubin Liang, Min Zhang, Tianqing Zhao, Bin He, Deyu Sun   +6 more
doaj   +1 more source