Results 11 to 20 of about 22,575 (260)
A Perforated Plate with Stepwise Apertures for Low Frequency Sound Absorption [PDF]
Applied Sciences, 2021 A perforated plate with stepwise apertures (PPSA) is proposed to improve sound absorption for low frequencies. In contrast with an ordinary perforated plate with insufficient acoustic resistance and small acoustic mass, the perforated plate with stepped ...
Xin Li, Bilong Liu, Chong Qin
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Viscoelastic structural damping enables broadband low-frequency sound absorption. [PDF]
Proc Natl Acad Sci U S ALow-frequency sound absorption has traditionally relied on air-resonant structures, such as Helmholtz resonators, which are made of stiff materials that undergo negligible deformation. In these systems, energy dissipation arises primarily from air motion and thermal–viscous effects, resulting in inherently narrowband performance and bulky, complex ...
Zhang Y +5 more
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Low-frequency sound absorption in air [PDF]
The Journal of the Acoustical Society of America, 1984 An extensive set of sound absorption measurements was taken in air over a range of frequency from 20–2500 Hz, of temperature from 20°–50 °C, and of relative humidity from 0.3%–100%. Over the lower portion of this frequency range, where relaxation in N2 is prominent (except in very dry air), prior measurements are scanty.
Allan J. Zuckerwar, Roger W. Meredith
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Low-frequency sound absorption in the ocean [PDF]
The Journal of the Acoustical Society of America, 1977 Recent work on low-frequency sound absorption in the ocean and laboratory has been examined with regard to temperature dependence, pH dependence, and boron concentration in an effort to arrive at a practical expression consistent with existing knowledge for use in sonar prediction and design applications.
M. Schulkin, H. W. Marsh
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Design of phononic crystal for enhancing low-frequency sound absorption in mufflers. [PDF]
Sci RepTo enhance the low-frequency sound absorption capabilities of expansion chamber mufflers, a novel Helmholtz-ring phononic crystal cell was developed. This innovative design integrates ring Helmholtz resonators as the phononic crystal scatterer, which is periodically arranged within the expansion chamber of a muffler to achieve enhanced sound ...
Bai Y, Chen Y, Zheng J.
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Absorption of Sound in Humid Air at Low Frequencies [PDF]
The Journal of the Acoustical Society of America, 1956 The reverberation technique of Knudsen has been applied to the measurement of the absorption of sound over the frequencies 300 to 3000 cps in air with mole ratio concentrations of water vapor ranging from 0 to 0.02. Pressures from 5 cm Hg to atmospheric and temperatures from 0°C to 65°C were employed in the study. With the use of a 66-in.
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Study of the Sound Absorption Performance of Ethylene-Vinyl Acetate Foam Materials
Medžiagotyra, 2019 Ethylene-Vinyl Acetate (EVA) polymer foam was prepared using a mold for this investigation. The effect of the cell structure parameters and pore filling gas type on the sound absorption performance of the EVA foam materials were analyzed in terms of ...
Wei GONG +5 more
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Journal of Low Frequency Noise, Vibration and Active Control, 2023 Low-frequency noise pollution in substations has a significant impact on the physical and mental health of workers. Reduction low-frequency noise pollution is an urgent problem to solve for researchers. In this paper, the different structures of Al 2 O 3
Yuan Binxia +5 more
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Broadband low frequency sound absorption using a monostable acoustic metamaterial [PDF]
The Journal of the Acoustical Society of America, 2020 This Letter presents a monostable acoustic metamaterial that has the potential to implement broadband sound absorption in low frequencies. The proposed metamaterial is realized by placing a flexible panel with a magnetic proof mass in a symmetric magnetic field.
Xianhui, Li +3 more
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Theoretical and Applied Mechanics Letters, 2016 We present a design method for calculating and optimizing sound absorption coefficient of multi-layered porous fibrous metals (PFM) in the low frequency range.
Wenjiong Chen +3 more
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