تحقیقات علوم چوب و کاغذ ایران (Sep 2001)
ACOUSTICAL PROPERTIES OF WOOD IN 2000, 4000 AND 8000 IN HERTZ FERQUENCIES
Abstract
In this research solid wood properties of sound absorption coefficient in over frequency were investigated. Sound absorption at 2000, 4000 and 8000 in Hertz Frequencies was measured on the influence of effective factors in solid wood. Solid wood variable factors were species (Beech, Poplar and Alder), fiber direction (Longitudinal, Radial and Tangential) and Frequencies (2000, 4000 and 8000 in hertz). Data was analyzed using factorial experimental design at completely random blocks and DMRT test. The measurements were taken using the sound absorption with standing waves apparatus type 4002. The results of this research indicate that sound absorption at frequencies 2000, 4000 and 8000 in hertz were in maximum level for poplar wood. Longitudinal direction in solid wood had sound absorption maximum levels. Radial and Tangential direction have less sound absorption than Longitudinal direction respectively. Therefore this investigation showed that sound absorption with increasing frequency of 2000 to 8000 hertz, maximum level was considered.
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