References in periodicals archive ?
Hence, the sound transmission loss (TL) and the sound absorption coefficient of epoxy foams exhibit tunability by adjusting foaming temperature and microsphere content.
Sound absorption coefficient measurements (BS EN ISO 10534-2: 2001) on the three different density foams (HD, MHD and MLD) show that the HD Ekoprena foam performed best at a frequency range of 250 Hz to 2,000 Hz (figure 6); whereas with the MHD and MLD Ekoprena foams, the absorption coefficient is at its maximum (1.0) at a frequency range from 3,000 Hz to 4,000 Hz.
Due to specificity of the ODEON programme, the simulation excluded materials with sound absorption coefficient ([alpha]) higher than 1 as the input data in ODEON must be within 0 to 1.
Sound absorption coefficient expressed as [alpha] is a frequently used parameter to gage the sound absorption ability of an acoustic material.
Keywords: Oil Palm Trunk (OPT); Sound Absorption Coefficient ([alpha]); Impedance Tube Method
[8] investigated the effect of the porous layer backing and a perforated panel on the sound absorption coefficient of coconut coir fiber.
Therefore, according to the definition of the mean sound absorption coefficient [17], [bar.[alpha]] can be expressed as follows:
In Section 4, the sound absorption is validated by experimental data and the influences of the fractal dimensions on the specific surface acoustic impedance, the complex wave number, and the sound absorption coefficient are discussed.
Once the reflection coefficient is determined, the normal incidence sound absorption coefficient (a) and specific boundary impedance ([z.sub.n] can be found using
For that purpose, surface mean texture depth (using traditional sand patch method according to standard LST EN 13036-1: 2010 Road and Airfield Surface Characteristics --Test Methods--Part 1: Measurement of Pavement Surface Macrotexture Depth Using a Volumetric Patch Technique) and sound absorption coefficient were determined.
Finally, the sound absorption coefficient and the strength of the samples are examined.