Estimation of Microfibril Angle and Stiffness by near infrared Spectroscopy using sample sets having Limited wood Density Variation

IAWA Journal ◽  
2005 ◽  
Vol 26 (2) ◽  
pp. 175-187 ◽  
Author(s):  
Laurence R. Schimleck ◽  
Robert Evans ◽  
P. David Jones ◽  
Richard F. Daniels ◽  
Gary F. Peter ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Near Infrared ◽  
Microfibril Angle ◽  
Nir Spectroscopy ◽  
Radiata Pine ◽  
Density Variation ◽  
Density Range ◽  
Wood Stiffness

Near infrared (NIR) spectroscopy offers a rapid method for the estimation of microfibril angle (MFA) and SilviScan-estimated wood stiffness (EL(SS)). The success of these NIR calibrations may be related to airdry density, because density varies in wood simultaneously with MFA and stiffness. The importance of density variation was investigated by developing calibrations for MFA and EL(SS) using Pinus radiata D. Don (radiata pine) and Pinus taeda L. (loblolly pine) sample sets where the density range was small and the relationships between density and MFA and density and EL(SS) were poor. Excellent calibrations for MFA and EL(SS) were obtained, particularly when sets had densities greater than 500 kg/m3, can provide strong relationships for MFA and stiffness even when density variation is limited. Examination of loading plots from the MFA and EL(SS) calibrations indicates that variation in wood components such as cellulose, lignin and possibly hemicellulose is important.

Nondestructive estimation of Pinus taeda L. wood properties for samples from a wide range of sites in Georgia

2005 ◽  
Vol 35 (1) ◽  
pp. 85-92 ◽  
Author(s):  
P D Jones ◽  
L R Schimleck ◽  
G F Peter ◽  
R F Daniels ◽  
A Clark III
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Near Infrared ◽  
Microfibril Angle ◽  
Nir Spectroscopy ◽  
Wood Properties ◽  
Small Sample ◽  
Dry Density ◽  
Wide Range ◽  
Pinus Taeda L

Preliminary studies based on small sample sets show that near infrared (NIR) spectroscopy has the potential for rapidly estimating many important wood properties. However, if NIR is to be used operationally, then calibrations using several hundred samples from a wide variety of growing conditions need to be developed and their performance tested on samples from new populations. In this study, 120 Pinus taeda L. (loblolly pine) radial strips (cut from increment cores) representing 15 different sites from three physiographic regions in Georgia (USA) were characterized in terms of air-dry density, microfibril angle (MFA), and stiffness. NIR spectra were collected in 10-mm increments from the radial longitudinal surface of each strip and split into calibration (nine sites, 729 spectra) and prediction sets (six sites, 225 spectra). Calibrations were developed using untreated and mathematically treated (first and second derivative and multiplicative scatter correction) spectra. Strong correlations were obtained for all properties, the strongest R2 values being 0.83 (density), 0.90 (MFA), and 0.93 (stiffness). When applied to the test set, good relationships were obtained (Rp2 ranged from 0.80 to 0.90), but the accuracy of predictions varied depending on math treatment. The addition of a small number of cores from the prediction set (one core per new site) to the calibration set improved the accuracy of predictions and importantly minimized the differences obtained with the various math treatments. These results suggest that density, MFA, and stiffness can be estimated by NIR with sufficient accuracy to be used in operational settings.

Estimation of the physical wood properties of green Pinus taeda radial samples by near infrared spectroscopy

2003 ◽  
Vol 33 (12) ◽  
pp. 2297-2305 ◽  
Author(s):  
L R Schimleck ◽  
C Mora ◽  
R F Daniels
Keyword(s):  
Moisture Content ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Near Infrared ◽  
Microfibril Angle ◽  
Independent Set ◽  
Nir Spectroscopy ◽  
Wood Properties ◽  
Dry Density ◽  
Green Wood

The application of near infrared (NIR) spectroscopy to the green wood of radial samples (simulated increment cores) and the development of calibrations for the prediction of wood properties are described. Twenty Pinus taeda L. (loblolly pine) radial strips were characterized in terms of air-dry density, microfibril angle (MFA), and stiffness. NIR spectra were obtained in 10-mm steps from the radial longitudinal and transverse faces of each sample and used to develop calibrations for each property. NIR spectra were collected when the wood was green (moisture content ranged from approximately 100% to 154%) and dried to approximately 7% moisture content. Relationships between measured and NIR estimates for green wood were good; coefficients of determination (R2) ranged from 0.79 (MFA) to 0.85 (air-dry density). Differences between calibrations developed using the radial longitudinal and transverse faces were small. Calibrations were tested on an independent set. Predictive errors were relatively large for some green samples and relationships were moderate; R2p ranged from 0.67 (MFA) to 0.81 (stiffness). Dry wood calibrations demonstrated strong predictive relationships with R2p ranging from 0.87 (air-dry density) to 0.95 (stiffness). NIR spectroscopy has the potential to predict the air-dry density, MFA, and stiffness of 10-mm sections of green P. taeda wood samples.

Microfibril Angle Prediction of Pinus Taeda Wood Samples Based on Tangential Face Nir Spectra

IAWA Journal ◽  
2007 ◽  
Vol 28 (1) ◽  
pp. 1-12 ◽  
Author(s):  
L.R. Schimleck ◽  
E. Sussenbach ◽  
G. Leaf ◽  
P.D. Jones ◽  
C.L. Huang
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Near Infrared ◽  
Microfibril Angle ◽  
Nir Spectroscopy ◽  
Individual Growth ◽  
X Ray Diffraction ◽  
Growth Rings ◽  
Pine Wood ◽  
X Ray

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.

ESTIMATION OF MICROFIBRIL ANGLE OF INCREMENT CORES BY NEAR INFRARED SPECTROSCOPY

IAWA Journal ◽  
2002 ◽  
Vol 23 (3) ◽  
pp. 225-234 ◽  
Author(s):  
Laurence R. Schimleck ◽  
Robert Evans
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Standard Error ◽  
Near Infrared ◽  
Microfibril Angle ◽  
Nir Spectroscopy ◽  
Radiata Pine ◽  
Coefficient Of Determination ◽  
Increment Core ◽  
Large Numbers

Eight Pinus radiata D. Don (Radiata pine) increment core samples representative of a total of thirty-two increment cores were selected. NIR spectra were obtained from the radial–longitudinal face of each core in 10-mm increments and used to develop a microfibril angle (MFA) calibration. The MFA calibration was developed using seven factors giving an excellent relationship between SilviScan-2 determined MFA and NIR fitted MFA (coefficient of determination (R2) = 0.95) and a standard error of calibration (SEC) of 1.8 degrees.The MFA calibration was used to predict the MFA of NIR spectra obtained in 10-mm sections from the radial–longitudinal face of two intact P. radiata increment cores. NIR predicted MFA was found to be in excellent agreement with MFA determined by SilviScan-2, with R2 of 0.98 (core A) and 0.96 (core B). The standard error of prediction (SEP) for core A (1.0 degree) was much lower than for core B (2.5 degrees). Both sets of predictions closely followed the patterns of MFA radial variation determined by SilviScan-2. NIR spectroscopy provides a rapid method for determining MFA variation in increment cores and is suitable for the routine analysis of large numbers of samples.

Nondestructive estimation of tracheid length from sections of radial wood strips by near infrared spectroscopy

Holzforschung ◽  
2004 ◽  
Vol 58 (4) ◽  
pp. 375-381 ◽  
Author(s):  
L.R. Schimleck ◽  
P.D. Jones ◽  
G.F. Peter ◽  
R.F. Daniels ◽  
A. ClarkIII
Keyword(s):  
Infrared Spectroscopy ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Near Infrared ◽  
Fiber Quality ◽  
Nir Spectroscopy ◽  
Weighted Mean ◽  
Tracheid Length ◽  
Quality Analyzer ◽  
Nondestructive Estimation

Abstract The use of calibrated near infrared (NIR) spectroscopy for predicting tracheid length of Pinus taeda L. (loblolly pine) wood samples is described. Ten-mm sections of 14 P. taeda radial strips were selected and NIR spectra obtained from the radial longitudinal face of each section. The fibers in these sections were characterized in terms of arithmetic and length-weighted mean tracheid length using a fiber quality analyzer, and calibrations with NIR spectra were developed for both measures of tracheid length. Relationships were good, with coefficients of determination (R 2) of 0.88 for arithmetic tracheid length and 0.96 for length-weighted tracheid length. The accuracy of NIR predicted length-weighted tracheid length was sufficient for ranking purposes.

Estimation of Wood Stiffness and Strength Properties of Hybrid Larch by Near-Infrared Spectroscopy

2007 ◽  
Vol 61 (8) ◽  
pp. 882-888 ◽  
Author(s):  
Takaaki Fujimoto ◽  
Hiroyuki Yamamoto ◽  
Satoru Tsuchikawa
Keyword(s):  
Near Infrared ◽  
Nir Spectroscopy ◽  
Strength Properties ◽  
Density Variation ◽  
Modulus Of Rupture ◽  
Cellulose Content ◽  
Hybrid Larch ◽  
Absorption Bands ◽  
Wood Stiffness ◽  
Predicted Values

This work was undertaken to investigate the feasibility of near-infrared (NIR) spectroscopy for estimating wood mechanical properties, i.e., modulus of elasticity (MOE) and modulus of rupture (MOR) in bending tests. Two sample sets having large and limited density variation were prepared to examine the effects of wood density on estimation of MOE and MOR by the NIR technique. Partial least squares (PLS) analysis was employed and it was found that the relationships between laboratory-measured and NIR-predicted values were good in the case of sample sets having large density variation. MOE could be estimated even when density variation in the sample set was limited. It was concluded that absorption bands due to the OH group in the semi-crystalline or crystalline regions of cellulose strongly influenced the calibrations for bending stiffness of hybrid larch. This was also suggested from the result that both α-cellulose content and cellulose crystallinity showed moderate positive correlation to wood stiffness.

Success in Using near Infrared Spectroscopy to Estimate Wood Properties of Pinus Taeda Radial Strips Not Due to Autocorrelation

2005 ◽  
Vol 13 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Laurence R. Schimleck ◽  
P. David Jones ◽  
Gary F. Peter ◽  
Richard F. Daniels ◽  
Alexander Clark
Keyword(s):  
Infrared Spectroscopy ◽  
Pinus Taeda ◽  
Rapid Method ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Wood Properties

Near infrared (NIR) spectroscopy provides a rapid method for estimating several important wood properties of 10 mm sections of radial wooden strips. Successful calibrations have been obtained with NIR spectra collected from 3 to 16 consecutive 10 mm sections of the same wood core. The success of these calibrations might be due to an autocorrelation that exists between the adjacent sections of a core. In this study, we compared calibrations with spectra collected from consecutive 10 mm sections to calibrations obtained with spectra collected from unrelated 10 mm sections. Very similar calibration statistics were obtained with both sets of spectra, demonstrating that existing calibration success is not due to an autocorrelation.

APPLICATION OF NEAR INFRARED SPECTROSCOPY TO THE EXTRACTED WOOD OF A DIVERSE RANGE OF SPECIES

IAWA Journal ◽  
2003 ◽  
Vol 24 (4) ◽  
pp. 429-438 ◽  
Author(s):  
Laurence Schimleck ◽  
Robert Evans ◽  
Jugo Ilic
Keyword(s):  
Infrared Spectroscopy ◽  
Physical Properties ◽  
Near Infrared ◽  
Microfibril Angle ◽  
Nir Spectroscopy ◽  
X Ray Diffraction ◽  
Wood Chemistry ◽  
Diverse Range ◽  
X Ray ◽  
Longitudinal Modulus

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.

Comparison of Pinus taeda L. wood property calibrations based on NIR spectra from the radial-longitudinal and radial-transverse faces of wooden strips

Holzforschung ◽  
2005 ◽  
Vol 59 (2) ◽  
pp. 214-218 ◽  
Author(s):  
Laurence R. Schimleck ◽  
Reinhard Stürzenbecher ◽  
Christian Mora ◽  
P. David Jones ◽  
Richard F. Daniels
Keyword(s):  
Pinus Taeda ◽  
Loblolly Pine ◽  
Near Infrared ◽  
Microfibril Angle ◽  
Wood Property ◽  
Morphological Characteristics ◽  
Dry Density ◽  
Increment Core ◽  
Pinus Taeda L ◽  
Radial Strip

Abstract When a radial strip is cut from an increment core it can potentially be cut with two orientations: parallel to longitudinal tracheids, i.e., a radial-longitudinal (RL) strip (the orientation of SilviScan samples), or at an orientation of 90° to the tracheids, i.e., a radial-transverse (RT) strip. Both strips could be used for near-infrared (NIR) analysis, but it is unknown how calibrations based on RT-face NIR spectra compare with those based on RL-face NIR spectra. A total of 20 Pinus taeda L. (loblolly pine) RL strips were characterized in terms of air-dry density, microfibril angle (MFA), stiffness and several tracheid morphological characteristics. NIR spectra were collected in 10-mm increments from the RL and RT faces of matching strips and used to develop calibrations for each property. In general, RL-face NIR spectra gave calibrations that provided stronger relationships. Differences between the two sets of calibrations were small, indicating that either face could be used for NIR analysis.

Stiffness Prediction of Radiata Pine Clearwood Test Pieces Using near Infrared Spectroscopy

2001 ◽  
Vol 9 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Armin Thumm ◽  
Roger Meder
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Pinus Radiata ◽  
Modulus Of Elasticity ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Radiata Pine ◽  
Model Based ◽  
Test Pieces ◽  
The Mean

Near infrared (NIR) spectroscopy has been used to predict the modulus of elasticity (stiffness) of samples taken from knot-free sapwood specimens of radiata pine ( Pinus radiata D. Don). The method shows the potential of using NIR spectroscopy for assessment of lumber stiffness. A model based on NIR spectra taken on the radial face of 404 samples of radiata pine clearwood was established to predict stiffness. Samples were moved past the detector at a rate of 900 mm min−1. This model then was used to predict the stiffness of a further 80 samples and the results show an error in prediction of 14% of the mean measured value.

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