Results 41 to 50 of about 205,968 (297)

Ternary and quadriphase sequence diffusers [PDF]

, 2006
A room acoustic diffuser breaks up reflected wavefronts, and this can be achieved by presenting a spatially varying surface impedance. In hybrid surfaces, varying impedance is achieved by patches of absorption and reflection, giving reflection ...
Angus, JAS, Cox, TJ, D'Antonio, P
core   +2 more sources

Research on the sound absorption characteristics of porous metal materials at high sound pressure levels

Advances in Mechanical Engineering, 2015
Porous metal materials are widely used in noise control with high sound pressure applications such as aircraft engine liners and combustion chambers for rocket engines due to their excellent performance of sound absorption characteristics and ...
Xiaopeng Wang, Yinggang Li, Tianning Chen, Zhiping Ying   +3 more
doaj   +1 more source

Sound absorption of warp knitted spacer fabrics based on knit structure and nanofiber enhancement

Journal of Industrial Textiles, 2022
In this work, the sound absorption properties of warp knitted spacer fabrics enhanced with nanofiber were studied. The angle of connecting yarns at two different spacing was considered as knit structure variable. Also, the effect of layering on the sound
M Davoudabadi Farahani, M Jamshidi Avanaki, Ali AA Jeddi   +2 more
doaj   +1 more source

Sound propagation in and low frequency noise absorption by helium-filled porous material [PDF]

, 2009
Low-frequency noise is difficult to deal with by traditional porous material due to its inherent high acoustic impedance. This study seeks to extend the effective range of sound absorption to lower frequencies by filling a low density gas, such as helium,
Choy, YS, Huang, L, Wang, C
core   +1 more source

Characterization of Defect Distribution in an Additively Manufactured AlSi10Mg as a Function of Processing Parameters and Correlations with Extreme Value Statistics

Advanced Engineering Materials, EarlyView.
Predicting extreme defects in additive manufacturing remains a key challenge limiting its structural reliability. This study proposes a statistical framework that integrates Extreme Value Theory with advanced process indicators to explore defect–process relationships and improve the estimation of critical defect sizes. The approach provides a basis for
Muhammad Muteeb Butt, Varma Kvvssn, Hossein Laieghi, Zia Uddin, Peyman Ansari, E. Kıvanç Sadak, Can Barış Toprak, Hüseyin Kızıl, Enrico Salvati   +8 more
wiley   +1 more source

Topology optimization of multi-material acoustic metamaterials for low-frequency and broadband sound absorption

Materials & Design
This paper uses a non-gradient topology optimization method for designing multi-material acoustic metamaterials with low-frequency and broadband sound absorption performance.
Feifei Feng, Lei Diao, Chuan He, Meng Tao   +3 more
doaj   +1 more source

Acoustical characteristic of empty fruit bunch (EFB) fibre with influence of sodium hydroxide treatment time and decay lifespan [PDF]

, 2019
Research on natural fibres has gain much interest in recent years due to the sustaibability and avaibility in which demand for green renewable reinforced composites. Natural fibres can be considered as the alternative way to replace the synthetic fibre
Mat Wan, Lauren
core   +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

Experimental and Theoretical Investigation of the Acoustic Absorbers Fabricated from Natural Kenaf Fibres and Rice Husk

Journal of Natural Fibers, 2022
Fabrication of acoustic absorbers from a combination of natural waste materials is a novel approach in the field of noise control. The aim of this study was to investigate the acoustic absorption performance of several sample sound absorbers made from ...
Siavash Etemadinezhad, Seyed Ehsan Samaei, Ebrahim Taban, Mohammad Faridan   +3 more
doaj   +1 more source

On the Influence of Antioxidants and Recycled MgO–C Source Material on the Mechanical Properties of Carbon‐Bonded Magnesia Refractories

Advanced Engineering Materials, EarlyView.
The presented study focuses on the fracture behaviour of carbon‐bonded magnesia MgO–C refractories, where environmentally friendly fructose, collagen and lignin serve as temporary binding agents. The partial substitution of the source material with recycled MgO–C reduces the fracture resistance, which can be counteracted by the additional introduction ...
Marc Neumann, Tom Weber, Jana Hubálková, Florian Kerber, Dinesh Kumar Gunasekar, Hans Jelitto, Christos G. Aneziris   +6 more
wiley   +1 more source