Results 21 to 30 of about 474 (141)

An optimization method for material sound absorption performance based on surrogate model

open access: yesActa Acustica, 2022
In some complex engineering design problems, the use of numerical simulation methods to solve the target value often consumes several hours or even longer, which limits the real-time response to the model.
Song Hao   +3 more
doaj   +1 more source

Experimental verification of the potential of superhydrophobic surfaces in reducing audible noise on HVAC overhead line conductors

open access: yesHigh Voltage, 2022
Overhead line conductors can generate audible noise across a wide frequency spectrum as a result of elevated electric fields at the conductor surface. Such fields are enhanced by the presence of surface defects, insects, water drops and pollution. Within
Xu Zhang   +6 more
doaj   +1 more source

A hybrid acoustic structure for low-frequency and broadband underwater sound absorption

open access: yesJournal of Low Frequency Noise, Vibration and Active Control, 2022
The underwater anechoic coating with local resonant units is an effective method to achieve low-frequency sound absorption. However, the structure obtained in this way is not satisfactory in the sound absorption effect of mid-high frequency bands ...
Xinyu Jia   +4 more
doaj   +1 more source

Acoustic behavior of composites with gradient impedance

open access: yesMaterials & Design, 2020
Conventional acoustic materials with uniform media which are of fixed impedance and density are unable to satisfy the requirements of the development of modern acoustic technology in volume, weight, pressure resistance and stealth performance.
Yiwen Feng, Jing Qiao, Longqiu Li
doaj   +1 more source

Ocular Morphology and Clinical Ophthalmic Parameters of Nile Tilapia Oreochromis niloticus. [PDF]

open access: yesVet Ophthalmol
ABSTRACT Objective To describe the ocular morphological characteristics and establish clinical and ophthalmic reference standards for Nile tilapia. Animals Studied Fresh carcasses were used for diaphanization, optical and electron microscopy, and computed tomography analyses.
da Silva DFF   +12 more
europepmc   +2 more sources

Numerical simulation of a viscoelastic sound absorbent coating with a doubly periodic array of cavities

open access: yesCogent Engineering, 2018
Nowadays, research on underwater sound absorbing coatings is important on marine combats. Due to high cost of acoustic experimental tests, determination of an accurate simulation method for assessment of the coating characteristics is an important goal ...
Sayed Hamid Sohrabi   +1 more
doaj   +1 more source

Analysis of the anechoic properties of viscoelastic coatings with periodically distributed cavities

open access: yesActa Physica Sinica, 2007
Using an exact Mie scattering solution, the scattering and vibration mode of a single air sphere in unbounded rubber are analyzed with reference to the elements of the scattering matrix. Then, using the multiple_scattering method, the anechoic properties of the viscoelastic rubber coating (with a thickness of 8mm) containing a plane of periodically ...
null Zhao Hong-Gang   +4 more
openaire   +1 more source

An ultra-thin quad-band metamaterial inspired absorber using symmetric bent-arrow shaped resonator for sensing and imaging in defense applications

open access: yesMaterials Research Express, 2020
In this paper, a novel compact quad-band polarization insensitive metamaterial absorber has been proposed to be employable in the microwave frequency regime.
Raghvenda Kumar Singh   +5 more
doaj   +1 more source

Partial hearing recovery after cochlear nerve surface transplantation of hair follicle‐derived neural crest stem cells in neural hearing loss rat

open access: yesAnimal Models and Experimental Medicine, EarlyView.
This study comprises three experimental parts. Part 1. Time‐course of ouabain‐induced hearing loss. Rats received ouabain (10 mM) via round window application. ABR/DPOAE tests and histological analyses were performed at 2, 7, and 30 days post‐treatment to characterize SGN and glial cell degeneration. Part 2.
Huidong Chen   +9 more
wiley   +1 more source

Modeling and Output Optimization of Triboelectric Microphone for Acoustic Energy Harvesting

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
This work elucidates the fundamental multiphysics coupling mechanisms governing acoustic T‐phone, providing a critical theoretical foundation and a predictive design paradigm for the future engineering and deployment of next‐generation, self‐powered acoustic sensors.
Dan Liu   +6 more
wiley   +1 more source

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