45

20

Coa

ted

y = 0.82x, R2 = 0.84y = 1.00x, R2 = 0.98y = 1.02x, R2 = 0.29y = 1.00x, R2 = 0.23

12

5

Coa

ted

(b)

y = 0.69x, R2 = 0.48y = 0.95x, R2 = 0.99y = 1.00x, R2 = -0.41y = 1.01x, R2 = -0.37

20 45Raw wood

(a) Specific modulus Pa.m^3 kg-1 Coated with opaquepolyester varnish

Coated with shellacCoated with Sandrous 5% and Ethnol 95%Coated with Sandrous 50% and Ethnol 50%Linear (Coated withopaque polyester varnish)Linear (Coated with Shellac)Linear (Coated withSandrous 5% and Ethnol 95%

Linear (Coated with Sandrous 50% and

ethnol 50%)

Acoustic coefficient m^4 kg.s

20 Raw wood 12

0.005 Raw wood 0.025

Damping due to internal friction (Tanδ)(c)0.025

0.005

Coa

ted

y = 0.61x, R2 = 0.52y = 1.02x, R2 = 0.61y = 0.96x, R2 = 0.18y = 1.00x, R2 = 0.29

y = 0.44x, R2 = 0.41y = 0.93x, R2 = 0.88y = 1.05x, R2 = 0.27y = 1.01x, R2 = 0.14

(d)1400

200200 1400

6^10

Raw wood

Acoustical converting effiviency m^4 kg.s

Coa

ted

6^10