Results 11 to 20 of about 456 (152)

A low-frequency anechoic coating under high hydrostatic pressure by pressure balancing strategy

Journal of Low Frequency Noise, Vibration and Active Control
It has always been a challenge to develop low-frequency anechoic coatings under high hydrostatic pressure. Based on active pressure balancing strategy (APBS), the airbag embedding in Helmholtz resonator model is proposed to achieve low-frequency and ...
Ningdong Hu, Jun Jin, Hongping Hu
doaj   +2 more sources

Investigation of Acoustic Target Strength of a Cylindrical Shell Partially Covered with Anechoic Coating

水下无人系统学报
The primary structural configuration of underwater equipment consists of cylindrical shells. To study the characteristics of the acoustic target strength(TS) of a cylindrical shell partially covered with anechoic coatings, an anechoic coating with an ...
Qi MA, Shifeng NI, Hao GENG, Haibin YANG
doaj   +2 more sources

Investigation on Low-Frequency and Broadband Sound Absorption of the Compact Anechoic Coating Considering Hydrostatic Pressure

Journal of Marine Science and Engineering
The anechoic coating capable of absorbing sound energy in low frequencies within broadband is essential to conceal underwater vehicles. However, the geometric deformation and modification of mechanical parameters under hydrostatic pressure affect the ...
Xinsheng Fang, Xiao Pan, Xiaowei Zhang, Dongsheng Li, Xuewen Yin, Yabin Jin, Weibo Wang, Wenwei Wu   +7 more
doaj   +2 more sources

Global Sound Absorption Prediction for a Composite Coating Laid on an Underwater Submersible in Debonding States

Journal of Marine Science and Engineering, 2023
To address the problem that anechoic coatings frequently fall off from modern submersible hulls and are detrimental to the realization of underwater acoustic stealth, this paper focuses on the broadband sound absorbing of acoustic coverings in debonding ...
Zhifu Zhang, Yizhe Huang, Jiaxuan Wang, Zhuang Li, Shiyuan Zhang, Xirui Zhang   +5 more
doaj   +1 more source

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

Vet 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, Vieira LG, Brito PVA, Báo SN, da Silva IGM, Navarro RD, de Carvalho CM, Galera PD, da Silva DHV, Barbosa WS, Araújo RLS, Paludo GR, Hirano LQL.   +12 more
europepmc   +2 more sources

Investigation of Alberich Coating to Optimise Acoustic Stealth of Submarines

Acoustics, 2022
Due to the nature of their deployment, very few people know the location and course of a submarine during its time at sea, including only a handful of the ship’s crew.
Callum Daniels, Noel Perera
doaj   +1 more source

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

Acta 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, Su Lin, Yan Xiaowei, Liu Jinshi   +3 more
doaj   +1 more source

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

High 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, Ian Cotton, Qi Li, Simon M. Rowland, Christopher Emersic, Chengxing Lian, Wenyuan Li   +6 more
doaj   +1 more source

Study on Sound Absorption Characteristics in Seepage State of Anechoic Coating

Highlights in Science, Engineering and Technology, 2022
Aiming at the sound absorption problem of anechoic coating in water seepage state, firstly, the sound absorption coefficient of anechoic coating in infinite water area with steel plate as backing is calculated based on transfer function method and finite element method, anAd the solution results are compared with the analytical result of uniform ...
Xianwen Zhao, Zhengwei Wang, Zhou Chen, Zhigang Liu   +3 more
openaire   +1 more source

A novel semi-analytical methodology for predicting sound absorption of anechoic coatings with arbitrary rotary cavities dependent on temperature and frequency

Results in Physics, 2021
In response to the shortcomings of existing studies on the sound-absorbing characteristics of an anechoic coating, which most ignore the frequency factor and are expensive for temperature-tunable hydroacoustic experiments, a novel semi-analytical ...
Zhifu Zhang, Jiaxuan Wang, Qibai Huang
doaj   +1 more source