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

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.

2005 ◽  
Vol 35 (1) ◽  
pp. 85-92 ◽  
Author(s):  
P D Jones ◽  
L R Schimleck ◽  
G F Peter ◽  
R F Daniels ◽  
A Clark III

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.


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 ◽  
...  

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.


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.


2003 ◽  
Vol 33 (12) ◽  
pp. 2297-2305 ◽  
Author(s):  
L R Schimleck ◽  
C Mora ◽  
R F Daniels

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.


2013 ◽  
Vol 89 (05) ◽  
pp. 639-645 ◽  
Author(s):  
Chi-Leung So ◽  
Jennifer H. Myszewski ◽  
Thomas Elder ◽  
Leslie H. Groom

There have been several recent studies employing near infrared (NIR) spectroscopy for the rapid determination of microfibril angle (MFA). However, only a few have utilized samples cut from individual rings of increment cores, and none have been as large as this present study, sampling over 600 trees from two test sites producing over 3000 individual ring samples for MFA analysis. This has allowed the use of individual growth ring models rather than using those based on earlywood, latewood, corewood or outerwood. It was observed that for both test sites, the strongest models were from the “All”, earlywood and latewood sample sets. The individual growth ring calibration models provided poorer RPD values despite using over 200 samples in the analyses. In general, the results from the test samples largely mirrored those from the corresponding calibration samples. Corresponding test sample predictions from the opposing site were noticeably poorer than test samples from the same site. Thus, a greater variation in the number of sites would provide improved model robustness. This study has found that the models based on individual ring samples were not as strong as those obtained in other studies based on the radial-longitudinal face of wood strips, spread over several growth rings.


Holzforschung ◽  
2005 ◽  
Vol 59 (2) ◽  
pp. 214-218 ◽  
Author(s):  
Laurence R. Schimleck ◽  
Reinhard Stürzenbecher ◽  
Christian Mora ◽  
P. David Jones ◽  
Richard F. Daniels

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.


2021 ◽  
Vol 21 (4) ◽  
pp. 2212-2220
Author(s):  
T. S. Gokul Raja ◽  
S. Balamurugan ◽  
A. Reshma

In this work, several attempts were made to prepare nanoceramic zirconate (Nd2Zr2O7) powder for pigment applications. The single pyrochlore phase, Nd2Zr2O7 was successfully synthesized with the aid of flux at relatively low temperature (1000 °C) upon milling the reaction mixture made from Nd2O3 and ZrO2 in a tungsten carbide vial. Several characterizations were done on the thermal analysis (TG/DTA), X-ray diffraction (XRD), High-resolution scanning electron microscope (HRSEM), energy dispersive X-ray (EDX) analysis, Fourier-transform infrared (FT-IR) analysis, and near-infrared (NIR spectroscopy). A single-phase nanocrystalline (˜28 nm) pyrochlore structure (Fd3m) was confirmed through XRD analysis. A highly uniform particle in the size of ˜110 nm was observed for the Nd2Zr2O7 phase in the microimages. The vibrational (FT-IR) peaks at 423 cm-1 and 510 cm-1 in FTIR spectroscopic study confirmed the formation of pyrochlore structure. Higher NIR reflectivity recorded for this material in the 750–2500 nm region shows its novel application in color cool pigments for energy-saving paints reminiscent of Bi2−xYxCe2O7, Bi2Ce2−xTbxO7, and Gd2Ti2O7.


2018 ◽  
Vol 6 (7) ◽  
pp. 9113-9119 ◽  
Author(s):  
Seunghyun Yoo ◽  
Ching-Chang Chung ◽  
Stephen S. Kelley ◽  
Sunkyu Park

TAPPI Journal ◽  
2011 ◽  
Vol 10 (2) ◽  
pp. 36-42 ◽  
Author(s):  
DAVID E. WHITE ◽  
CHARLES COURCHENE ◽  
THOMAS MCDONOUGH ◽  
LAURIE SCHIMLECK ◽  
GARY PETER ◽  
...  

The effects of wood properties on the strength of bleachable and linerboard grade kraft pulps from 13-year-old loblolly pine (Pinus taeda) trees were investigated. Eighteen trees were selected based on breast height wood cores to represent specified ranges of specific gravity and lignin content. Air-dry density and stiffness (modulus of elasticity [MOE]), tracheid coarseness, radial diameter, tangential diameter, specific surface area, wall thickness, and microfibril angle (MFA) were estimated using SilviScan wood analysis technology and near infrared reflectance (NIR) spectroscopy. NIR spectra collected in 10 mm sections from the surface radial strips correlated very well with air-dry density, MFA, MOE, and tracheid wall thickness and were used to develop whole tree predictions. In addition, chemical composition, fiber properties, and handsheet strength were measured for both pulp grades. Statistical analysis indicated that wood density, wood fiber coarseness, and pulp fiber length had the greatest effects on sheet properties.


Holzforschung ◽  
2004 ◽  
Vol 58 (4) ◽  
pp. 375-381 ◽  
Author(s):  
L.R. Schimleck ◽  
P.D. Jones ◽  
G.F. Peter ◽  
R.F. Daniels ◽  
A. ClarkIII

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.


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