Earlywood and latewood elastic properties in loblolly pine

Holzforschung ◽  
2005 ◽  
Vol 59 (5) ◽  
pp. 531-538 ◽  
Author(s):  
Steven Cramer ◽  
David Kretschmann ◽  
Roderic Lakes ◽  
Troy Schmidt
Keyword(s):  
Specific Gravity ◽  
Shear Modulus ◽  
Elastic Properties ◽  
Loblolly Pine ◽  
Modulus Of Elasticity ◽  
Compression Wood ◽  
Microfibril Angle ◽  
Testing Procedures ◽  
Pine Trees ◽  
Longitudinal Modulus

Abstract The elastic properties of earlywood and latewood and their variability were measured in 388 specimens from six loblolly pine trees in a commercial plantation. Properties measured included longitudinal modulus of elasticity, shear modulus, specific gravity, microfibril angle and presence of compression wood. Novel testing procedures were developed to measure properties from specimens of 1 mm×1 mm×30 mm from earlywood or latewood. The elastic properties varied substantially circumferentially around a given ring and this variation was nearly as large as the variation across rings. The elastic properties varied by ring and height, but while the modulus of elasticity increased with height, the shear modulus decreased with height. A strong correlation was found between modulus of elasticity and shear modulus, but only at low heights and inner rings. Specific gravity and microfibril angle were the strongest predictors of elastic properties and explained 75% of the variation in modulus of elasticity for latewood. Despite being the best predictors in this study, these parameters accounted for less than half of the variability of earlywood modulus of elasticity, earlywood shear modulus and latewood shear modulus.

Predicting the longitudinal modulus of elasticity of Sitka spruce from cellulose orientation and abundance

Holzforschung ◽  
2010 ◽  
Vol 64 (4) ◽  
Author(s):  
J. Paul McLean ◽  
Robert Evans ◽  
John R. Moore
Keyword(s):  
Bulk Density ◽  
Modulus Of Elasticity ◽  
Microfibril Angle ◽  
Sitka Spruce ◽  
Picea Sitchensis ◽  
Model Parameters ◽  
Bending Tests ◽  
Wood Stiffness ◽  
Using Data ◽  
Longitudinal Modulus

Abstract Sitka spruce (Picea sitchensis) is the most widely planted commercial tree species in the United Kingdom and Ireland. Because of the increasing use of this species for construction, the ability to predict wood stiffness is becoming more important. In this paper, a number of models are developed using data on cellulose abundance and orientation obtained from the SilviScan-3 system to predict the longitudinal modulus of elasticity (MOE) of small defect-free specimens. Longitudinal MOE was obtained from both bending tests and a sonic resonance technique. Overall, stronger relationships were found between the various measures of cellulose abundance and orientation and the dynamic MOE obtained from the sonic resonance measurements, rather than with the static MOE obtained from bending tests. There was only a moderate relationship between wood bulk density and dynamic MOE (R2=0.423), but this relationship was improved when density was divided by microfibril angle (R2=0.760). The best model for predicting both static and dynamic MOE involved the product of bulk density and the coefficient of variation in the azimuthal intensity profile (R2=0.725 and 0.862, respectively). The model parameters obtained for Sitka spruce differed from those obtained in earlier studies on Pinus radiata and Eucalyptus delegatensis, indicating that the model might require recalibration before it can be applied to different species.

Effects of early pruning on ring specific gravity in young loblolly pine trees

2020 ◽  
Vol 52 (2) ◽  
pp. 139-151
Author(s):  
Harold E. Burkhart ◽  
Ralph L. Amateis
Keyword(s):  
Specific Gravity ◽  
Loblolly Pine ◽  
Pine Trees

Effects of Specific Gravity and Wood Chemical Content on the Pulp Yield of Loblolly Pine

TAPPI Journal ◽  
2009 ◽  
Vol 8 (4) ◽  
pp. 31-36 ◽  
Author(s):  
DAVID E. WHITE ◽  
CHARLES COURCHENE ◽  
THOMAS MCDONOUGH ◽  
LAURIE SCHIMLECK ◽  
DAVID JONES ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Loblolly Pine ◽  
Kraft Pulp ◽  
Near Infrared ◽  
Genetic Selection ◽  
Nir Spectroscopy ◽  
Pulp Yield ◽  
Wood Specific Gravity ◽  
Pine Trees ◽  
Chemical Content

We quantified the effects of wood density (chip specific gravity) and wood chemical composition (cellulose, hemicellulose, and lignin) on the kraft pulp yield of 13-year-old loblolly pine trees (Pinus taeda) grown as part of a genetic selection study. Both bleachable (kappa No. 30) and linerboard grade (kappa No. 100) pulps were made from 18 trees selected for combinations of wood specific gravity and cellulose:hemicellulose:lignin ratios. Statistical analysis indicated that digester pulp yield correlated significantly with wood xylan content and cellulose-to-lignin ratio but was not strongly correlated to wood specific gravity. Near infrared (NIR) spectra were collected from wood samples and correlated with the total kraft pulp yields. The analyses for both kappa No. 30 and kappa No. 100 pulps provided strong calibration statistics, suggesting that papermakers can use NIR spectroscopy to esti-mate the bleachable and linerboard grade pulp yields of P. taeda whole-tree samples.

scholarly journals Genetic Variation in the Microfibril Angle of Loblolly Pine From Two Test Sites

2004 ◽  
Vol 28 (4) ◽  
pp. 196-204 ◽  
Author(s):  
Jennifer H. Myszewski ◽  
Floyd E. Bridgwater ◽  
William J. Lowe ◽  
Thomas D. Byram ◽  
Robert A. Megraw
Keyword(s):  
Specific Gravity ◽  
Loblolly Pine ◽  
Combining Ability ◽  
Growth Traits ◽  
Genetic Relationships ◽  
Wood Quality ◽  
Genetic Correlations ◽  
Microfibril Angle ◽  
Narrow Sense Heritability ◽  
Individual Tree

Abstract In recent years, several studies have examined the effect of microfibril angle (MFA) on wood quality. However, little research has been conducted upon the genetic mechanisms controlling MFA. In this study, we examined the heritability of MFA in loblolly pine, Pinus taeda L.,and its genetic relationships with height, diameter, volume, and specific gravity. Increment cores were collected at breast height from 20 to 25 progeny from each of 12 to 17 crosses (among 11 parents) in two modified partial-diallels in different locations in southern Arkansas. Specific gravitywas measured on segments containing rings 1 through 5 and on segments containing rings 6 through 20. MFA was measured on the earlywood and latewood sections of rings 4, 5, 19, and 20. Rings 4 and 5 were chosen as representative of core wood and rings 19 and 20 as representative of outer wood. Analyses of variance revealed statistically significant genetic and environmental influences on MFA. Significant general combining ability (GCA), specific combining ability (SCA), and SCA × block effects indicated that there are both additive and nonadditive genetic influences on MFA. Individual-tree, narrow-sense heritability estimates were variable, ranging from 0.17 for earlywood (ring) 4 MFA to 0.51 for earlywood (ring) 20 MFA. Genetic correlations between MFA, specific gravity, and the growth traits were nonsignificant due to large estimated standard errors. South.J. Appl. For. 28(4):196–204.

Nanocontact Measurements in Superlattices

1986 ◽  
Vol 77 ◽  
Author(s):  
T. Baumann ◽  
J. B. Pethica ◽  
M. Grimsditch ◽  
Ivan K. Schuller
Keyword(s):  
Shear Modulus ◽  
Elastic Properties ◽  
Indentation Depth ◽  
Applied Force ◽  
Elastic Behavior ◽  
Displacement Curve ◽  
Hardness Tester ◽  
Loading And Unloading ◽  
Longitudinal Modulus ◽  
Modulation Wavelength

ABSTRACTMany metallic superlattices are known to exhibit dramatic anomalous elastic properties as a function of modulation wavelength. All measurements to date measure either a shear modulus or a longitudinal modulus in the superlattice plane. Here we present a method which also probes longitudinal elastic behavior perpendicular to the layers using a nano-hardness tester. In this method, a diamond tip is indented into the material and both the indentation depth and applied force are constantly monitored during loading and unloading. The elastic properties are extracted from the unloading part of the force versus displacement curve. Contrary to the anomaly found in a shear modulus, no anomaly in Young's modulus was found in the present study on Mo/Ni superlattices.

Properties of young Araucaria heterophylla (Norfolk Island pine) reaction and normal wood

Holzforschung ◽  
2014 ◽  
Vol 68 (7) ◽  
pp. 817-821 ◽  
Author(s):  
Monika Sharma ◽  
Clemens Michael Altaner
Keyword(s):  
Pinus Radiata ◽  
Modulus Of Elasticity ◽  
Compression Wood ◽  
Microfibril Angle ◽  
Normal Wood ◽  
Opposite Wood ◽  
Araucaria Heterophylla ◽  
Norfolk Island ◽  
Anatomical Properties

Abstract Young Araucaria heterophylla (Salisb.) Franco seedlings have been grown tilted to obtain compression wood (CW), opposite wood (OW), and normal wood (NW). Mechanical and anatomical properties of these wood tissues have been assessed. CW had characteristics associated with low severity. OW and NW did not differ significantly in their properties and were found to have a considerably lower microfibril angle and higher modulus of elasticity than those of juvenile corewood of Pinus radiata D. Don.

APPLICATION OF NEAR INFRARED SPECTROSCOPY TO A DIVERSE RANGE OF SPECIES DEMONSTRATING WIDE DENSITY AND STIFFNESS VARIATION

IAWA Journal ◽  
2001 ◽  
Vol 22 (4) ◽  
pp. 415-429 ◽  
Author(s):  
Laurence Schimleck ◽  
Robert Evans ◽  
Jugo Ilic
Keyword(s):  
Physical Properties ◽  
Modulus Of Elasticity ◽  
Near Infrared ◽  
Microfibril Angle ◽  
Nir Spectroscopy ◽  
Wood Properties ◽  
Mixed Species ◽  
Diverse Range ◽  
Wide Range ◽  
Longitudinal Modulus

The application of near infrared (NIR) spectroscopy to a large number of mixed species that display extremely wide variations in wood chemistry, anatomy and physical properties, is described. The mixed species samples were characterized in terms of density, longitudinal modulus of elasticity and microfibril angle. NIR spectra were obtained from the radial / longitudinal face of each sample and used to generate calibrations for the measured physical properties. The calibrations developed for density and longitudinal modulus of elasticity had the highest coefficients of determination (R2) and demonstrated that it is possible to develop general calibrations for these important wood properties across a wide range of species.The mixed species calibrations were used to estimate wood properties of two species, Eucalyptus delegatensis R.T. Baker and Pinus radiata D.Don. The results obtained for density and longitudinal modulus of elasticity indicated that mixed species calibrations can be used to rank trees. In practice the extreme variation of samples selected for this study would not be required. It is expected that refinement of calibrations, through sample selection, would provide more accurate prediction of physical properties.

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