Tese em PDF - departamento de engenharia florestal - ufpr ...

ABSTRACT
This study sought to evaluate the NIRS technology potential to assess the
wood resistance regarding to bending and density for 27 years old Eucalyptus
grandis W. Mill ex Maiden population planted in a 3 x 2 m spacing. The nearinfrared
spectroscopy (NIR) is a non destructive and fast evaluation technique
that requires no material preparation so small samples are sufficient to be
reused in other tests and applicable in products whose molecules contain
mainly C-H, O-H, N-H, S-H or C=O bonds. To assess the NIR technique
potential reference analysis were made based in laboratory tests following the
standards for bending and density static test. The reading of samples were
taken (RD, TG and TR face) in NIR to perform the models calibration
correlated to the reference samples. Calibration to predict the physical and
mechanical wood characteristics were adjusted from 224 samples by RD face,
which according the literature shows the superior correlation values. The
wood properties calibration of these trees showed adjusted partial least
squares (PLS) regression models from the original spectra presented fine
correlation coefficients for the elasticity and resistance estimate to the rupture
module and specific mass in 0% E. grandis wood (R²cal= 0,66, R²val= 0,65,
RDP= 1,78 for MOE, R²cal= 0,63, R²val= 0,43, RDP= 1,40 for MOR, R²cal=
0,78, R²val= 0,74, RDP= 2,29 for ME0%).
Keywords: near-infrared, wood properties, Eucalyptus.
6