Application of X-ray diffraction to assess the microfibril angle of green and dry Eucalyptus grandis wood

Trees ◽  
2021 ◽  
Author(s):  
Naiara Conceição Marques de Souza ◽  
José Tarcísio Lima ◽  
Bruno Charles Dias Soares
Holzforschung ◽  
2001 ◽  
Vol 55 (2) ◽  
pp. 176-182 ◽  
Author(s):  
R. Washusen ◽  
P. Ades ◽  
R. Evans ◽  
J. Ilic ◽  
P. Vinden

Summary Density and microfibril angle (MFA) of tension wood and normal wood were assessed in the sapwood and heartwood, from three provenanaces of 10-year-old Eucalyptus globulus Labill. Density was measured using a modified saturation method that also enabled the calculation of the extractives lost during saturation. Microdensity and MFA were determined by SilviScan 2, a rapid X-ray densitometry and X-ray diffraction system developed at CSIRO. Significant differences were found in density and extractives between provenances and also density between the sapwood and adjacent heartwood from each provenance. This result may explain some of the drying differences between provenances found in an earlier study (Washusen and Ilic 2000). Sapwood samples with high percentages of tension wood fibres had high density and a significant positive correlation was found between microdensity and tension wood fibre percentage. MFA was found to be very low in normal wood in the sapwood, where most tension wood was found, so tension wood could not be identified by MFA. The positive association between tension wood and wood density suggests that caution should be taken when selecting trees for high wood density in tree improvement programs.


2018 ◽  
Vol 17 (7) ◽  
pp. 1001-1010
Author(s):  
Chunhong Wang ◽  
Ni Wang ◽  
Shuhan Liu ◽  
Lin-P’ing Choo-Simth ◽  
Hongxia Zhang ◽  
...  

IAWA Journal ◽  
2003 ◽  
Vol 24 (4) ◽  
pp. 429-438 ◽  
Author(s):  
Laurence Schimleck ◽  
Robert Evans ◽  
Jugo Ilic

Near infrared (NIR) spectroscopy was applied to fifty-four species (59 samples in total) representing a diverse array of taxonomic affiliations, wood chemistry and physical properties. Acetone and ethanol were used to remove extractives from the wood samples used in this study. The extracted samples were characterized in terms of collapse-free density, microfibril angle and longitudinal modulus of elasticity (estimated using the collapse-free density and X-ray diffraction data obtained from Silvi- Scan-2). NIR spectra were obtained from the radial longitudinal face of each sample and used to generate calibrations for the measured physical properties. Extraction was found to improve the calibration statistics for all properties.


Holzforschung ◽  
2017 ◽  
Vol 71 (6) ◽  
pp. 491-497 ◽  
Author(s):  
Hankun Wang ◽  
Zixuan Yu ◽  
Xuexia Zhang ◽  
Dan Ren ◽  
Yan Yu

Abstract The combined effects of initial microfibril angle (MFA) and moisture content (MC) on the longitudinal tensile properties of Masson pine (Pinus massoniana Lamb.) wood foils has been investigated. Synchrotron X-ray diffraction (XRDsyn) combined with a custom-built microtensile device was applied for in situ monitoring of the MFA alterations in the foils under different initial MFAs and MCs conditions. The results demonstrate that the tensile properties are highly negatively correlated to both MFA and MC. Furthermore, the tensile modulus is more sensitive to MC change than tensile strength. At a higher MFA, the sensitivity of the two mechanical indicators to MC alteration is enhanced.


Author(s):  
Jan T. Bonarski ◽  
Wieslaw Olek

Investigations of the crystallograpically organized regions of mature and juvenile Scots pine wood were performed. Experimental methods of X-ray diffraction were applied. Incomplete pole figures were measured, in order to calculate the orientation distribution function. The differences in the texture of the mature and juvenile wood were determined. The traditional concept of the mean microfibril angle was enhanced by developing the misorientation parameters. Evident differences in the space arrangement of cellulose of the both zones of wood were identified and described.


2015 ◽  
Vol 39 (4) ◽  
pp. 751-758 ◽  
Author(s):  
Jerome Alteyrac

ABSTRACTFour stands of 28-year-old radiata pine (Pinus radiata D. Don) grown in the eighth region (Biobio) of Chile were sampled to determine the effect of tree spacing on the microfibril angle. The samples were taken at two different stem levels of the tree, 2.5 m and 7.5 m, with increment strip taken in the Nothern direction. The four experimental stands were characterized by the following spacing 2x2, 2x3, 3x4 and 4x4. The microfibril angle was measured by X-ray diffraction with the SilviScan technology at the FP-Innovation-Paprican Division in Vancouver, Canada. The results showed a significant effect of tree spacing on the microfibril angle in both juvenile wood and mature wood as well as at the two stem levels considered. The minimum (9.42º) was reached in 2x2 stand at 7.5 m in mature wood, while maximum microfibril angle (24.54º) was obtained in 2x3 stand at 2.5 m in juvenile wood. Regarding the effect of tree spacing, 4x4 stand had the lowest microfibril angle,except in mature wood at 7.5 m where 4x4 had the highest microfibril angle (11°) of the four stands.


IAWA Journal ◽  
2005 ◽  
Vol 26 (2) ◽  
pp. 203-210 ◽  
Author(s):  
Russell Washusen ◽  
Robert Evans ◽  
Simon Southerton

Experimental measurements of cellulose crystallite width and microfibril angle (MFA) by X-ray diffractometry on SilviScan-2 and by conventional microtechniques revealed that the branch wood of the two species exhibited very similar trends in cellulose crystallite width and MFA. Cellulose crystallite width was greater on the upper side of the branches. Tension wood, as defined by the occurrence of gelatinous fibres, was found where cellulose crystallite width was greater than 3.0 nm and 3.1 nm in Eucalyptus grandis and E. globulus respectively. In the tension wood zones, MFA was lower than in the rest of the samples and so could be used to differentiate tension wood. On the lower side of the branches MFA determined from X-ray diffractometry unexpectedly exceeded 40° and fibres were often buckled in both the tangential and radial directions in both species. This local variation in the direction of the fibre axes contributed only slightly to the magnitude of the MFA determined by SilviScan-2. Even given this misalignment, the additional evidence gained from pit angles and cracks in fibre walls suggested that the MFA was indeed around 40° in the lower radius of the branches. This MFA is considerably larger than would be expected for eucalypt stem wood and it is suggested that opposite wood in eucalypt branches may provide a complimentary structural role to that of the tension wood. Experimental measurements of crystallite width produced by SilviScan-2 may be used to accurately locate tension wood zones in both species.


IAWA Journal ◽  
2007 ◽  
Vol 28 (1) ◽  
pp. 1-12 ◽  
Author(s):  
L.R. Schimleck ◽  
E. Sussenbach ◽  
G. Leaf ◽  
P.D. Jones ◽  
C.L. Huang

The use of calibrated near infrared (NIR) spectroscopy for predicting the microfibril angle (MFA) of Pinus taeda L. (loblolly pine) wood samples is described. NIR spectra were collected from the tangential face of earlywood (EW) and latewood (LW) sections cut from eleven P. taeda radial strips. The MFA of these sections was measured using X-ray diffraction. Calibrations for MFA were determined using all samples combined, EW only and LW only. Relationships were good, with coefficients of determination (R2) ranging from 0.86 (EW) to 0.91 (LW). A calibration for MFA based on NIR spectra collected from sections of 8 strips was used to predict the MFA of sections from the remaining 3 strips. Prediction statistics were strong (R2p = 0.81, SEP= 5.2 degrees, RPDp = 2.23) however errors were greater than those reported previously for studies based on NIR spectra collected from the radial-longitudinal face. The results presented in this study demonstrate that it is possible to use tangential face NIR spectra to determine MFA variation for EW and LW within individual growth rings.


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