Imaging Spiral Grain in Pinus radiata with X-ray Microtomography

Wood is Good ◽  
2017 ◽  
pp. 29-36
Author(s):  
Jimmy Thomas ◽  
David A. Collings
Keyword(s):  
Pinus Radiata ◽  
Spiral Grain ◽  
X Ray

The potential of SilviScan’s X-ray diffractometry method for the rapid assessment of spiral grain in softwood, evaluated by goniometric measurements

2007 ◽  
Vol 42 (2) ◽  
pp. 95-102 ◽  
Author(s):  
Christoph Buksnowitz ◽  
Ulrich Müller ◽  
Robert Evans ◽  
Alfred Teischinger ◽  
Michael Grabner
Keyword(s):  
Rapid Assessment ◽  
Spiral Grain ◽  
X Ray ◽  
Goniometric Measurements

Inheritance of spiral grain in the juvenile core of Pinus radiata

2007 ◽  
Vol 37 (1) ◽  
pp. 116-127 ◽  
Author(s):  
Washington Gapare ◽  
Adrian Hathorn ◽  
Dominic Kain ◽  
Colin Matheson ◽  
Harry Wu
Keyword(s):  
Pinus Radiata ◽  
Genetic Gain ◽  
Radiata Pine ◽  
Correlated Response ◽  
Lower Grade ◽  
Tangential Plane ◽  
Individual Tree ◽  
Spiral Grain ◽  
Grain Angle ◽  
Selection For

Spiral grain is the angular arrangement of fibres in a tangential plane with reference to the pith or vertical tree axis. Spiral grain angles exceeding 5° can cause wood to twist, which may result in a considerable amount of waste and degrade. We assessed spiral grain at breast height in two related progeny tests of radiata pine (Pinus radiata D. Don) aged 8 and 9 years established at two different sites in Australia. Radial trends for grain angle at the two sites were similar. Mean spiral grain (MSG) across the two trials was 4.3° with a standard deviation of 1.5° and a range of 0.8–10°. Estimates of individual tree heritabilities on a single-site basis for individual rings and MSG suggested that spiral grain is lowly to highly inherited (h2 = 0.11 ± 0.08 to 0.66 ± 0.21 for individual rings and 0.44 ± 0.12 for MSG). Additive genotypic correlations between individual rings grain angle and MSG were generally high, above 0.71, suggesting a favourable expected correlated response of mean grain angle in the juvenile wood to selection for grain angle of individual rings. Selection to reduce spiral grain on any of rings 2–4 (at a selection intensity of 1.755, i.e., selecting the best 10% of trees) would result in a predicted correlated genetic gain in MSG of 1.0°. Our results suggest that selection could be performed in any of the individual rings 2, 3, or 4 (equivalent to ages 4–6) and still achieve at least 75% of the genetic gain possible from selection on the mean of all rings 1–5 (MSG). This suggests that there is an optimum stage (rings 2–4) in which selection for this trait should take place. Our results suggest that a reduction in spiral grain angle in the juvenile core is one strategy to reduce the amount of lower grade timber owing to twist.

Homogeneity in cellulose crystallinity between samples of Pinus radiata wood

Holzforschung ◽  
2004 ◽  
Vol 58 (1) ◽  
pp. 91-96 ◽  
Author(s):  
R. H. Newman
Keyword(s):  
Pinus Radiata ◽  
Ring Width ◽  
Crystallinity Index ◽  
Mean Value ◽  
Cellulose Content ◽  
Cellulose Crystallinity ◽  
X Ray ◽  
Opposite Wood ◽  
Least Squares Fit ◽  
Peak Widths

Abstract Wood was sampled from 22 locations in 3 Pinus radiata trees and characterized by solid-state 13C NMR spectroscopy. Values of a cellulose crystallinity index were confined to the range 0.486 to 0.541 despite inclusion of earlywood and latewood, compression wood and opposite wood, juvenile wood and mature wood. The mean value was 0.515 and the standard deviation was 0.015. Highest crystallinity was associated with relatively slow radial growth, with a correlation coefficient of R=−0.79 for a linear least-squares fit against ring width. The NMR results were consistent with published studies based on X-ray peak widths. Crystallinity indices based on X-ray peak heights or areas have shown wider ranges of variation, attributed to differences in cellulose content rather than cellulose crystallinity.

scholarly journals VARIATION OF MICROFIBRIL ANGLE OF Pinus radiata D. Don IN RELATION TO TREE SPACING IN CHILEAN PLANTATIONS

2015 ◽  
Vol 39 (4) ◽  
pp. 751-758 ◽  
Author(s):  
Jerome Alteyrac
Keyword(s):  
Pinus Radiata ◽  
Juvenile Wood ◽  
Microfibril Angle ◽  
Radiata Pine ◽  
Mature Wood ◽  
X Ray Diffraction ◽  
X Ray

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.

Urea-formaldehyde resin penetration into Pinus radiata tracheid walls assessed by TEM-EDXS

Holzforschung ◽  
2015 ◽  
Vol 69 (3) ◽  
pp. 303-306 ◽  
Author(s):  
Adya P. Singh ◽  
Arif Nuryawan ◽  
Byung-Dae Park ◽  
Kwang Ho Lee
Keyword(s):  
Pinus Radiata ◽  
Cell Walls ◽  
Urea Formaldehyde ◽  
Radiata Pine ◽  
Formaldehyde Resin ◽  
X Ray ◽  
Uf Resin ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Resin Penetration

Abstract This paper reports a new method of detecting urea-formaldehyde (UF) resin penetration into the cell walls of radiata pine (Pinus radiata D. Don) by means of transmission electron microscopy (TEM) in combination with energy-dispersive X-ray spectroscopy (EDXS). The quantifications of penetrated UF resin in the ultrathin cuts of cell walls were realized by detecting nitrogen (N) element by TEM-EDXS. Both line scan and area mapping revealed N in cell walls in contact with resin-filled lumens but not in those in contact with empty lumens. Thus, UF resin had penetrated the cell walls from the lumen side.

scholarly journals The Nature of Reaction Wood II. The Cell Wall Organization of Compression Wood Tracheids

1950 ◽  
Vol 3 (1) ◽  
pp. 1 ◽  
Author(s):  
AB Wardrop ◽  
HE Dadswell
Keyword(s):  
Cell Wall ◽  
Pinus Radiata ◽  
Compression Wood ◽  
Large Angle ◽  
Reaction Wood ◽  
Micellar Structure ◽  
X Ray ◽  
Similar Length ◽  
Tracheid Length ◽  
Cell Wall Organization

Optical and X-ray methQds have been used in the examinatiQn Qf the secQndarycell wall Qf cQmpressiQn WQQd tracheids from a number Qf species QfgymnDsperms.By these methQds it has been shQwn that the cell wall Qf CQmpressiQn WQQd tracheidscDnsists Qf two. layers. In the Quter layer the micelles are inclined at a large angle 'to. the lQngitudinal axis Qf the tracheid, while in the inner layer the micelles areinclined at a relatively smaller angle. In the inner Df the two. layers there exist radialdiscQntinuities in the spiral micellar structure, which are visible as IQngitudinal striatiQnsin the cell wall. These discQntinuities also. aCCQunt for the radial distributiQn Qflignin which is observed in transverse sectiQns Qf cQmpressiQn WQQd tracheids. Bydetermining the average tracheid length Qf the last-fDrmed late WQod in the variQusgrowth rings Df several eccentric stems Qf Pinus radiata D.DQn it has been shDwn thatthe tracheids Qf cQmpressiQn WQQd are appreciably shQrter than WQuld be the case ifno. cQmpressiQn WQQd were present. A study Qf the change in micellar QrientatiQn withchange in tracheid length has indicated that the angle Qf micellar QrientatiQn in CQmpressiQnWQQd tracheids dQes nQt differ signific(mtly frQm that existing in nQrmalWQQd tracheids Qf similar length. In so. far as the prQperties Qf WQQd are determinedby cell wall QrganizatiQn, it is cQncluded that cQmparisQns between cQmpressiQn WQDdand normal WQQd shQuld be made Qn material Qf the same tracheid length and spiralQrganizatiDn. It is suggested that bQth the reductiQn in tracheid length and eccentricradial growth in stems cQntaining cQmpressiQn WQQd are to. be attributed to. an increasein the number Df bDth transverse and tangential lQngitudinal divisiQns Qf thefusifQrm initials Qf the cambium.

Space and Time Distribution of Hard X-Ray Emission in a Loop at the Beginning of a Flare

1994 ◽  
Vol 144 ◽  
pp. 275-277
Author(s):  
M. Karlický ◽  
J. C. Hénoux
Keyword(s):  
Time Distribution ◽  
Electron Bombardment ◽  
Spatial Evolution ◽  
Superthermal Electrons ◽  
Flare Loop ◽  
X Ray ◽  
Superthermal Electron ◽  
Flare Loops ◽  
Chromospheric Evaporation ◽  
Temporal And Spatial

AbstractUsing a new ID hybrid model of the electron bombardment in flare loops, we study not only the evolution of densities, plasma velocities and temperatures in the loop, but also the temporal and spatial evolution of hard X-ray emission. In the present paper a continuous bombardment by electrons isotropically accelerated at the top of flare loop with a power-law injection distribution function is considered. The computations include the effects of the return-current that reduces significantly the depth of the chromospheric layer which is evaporated. The present modelling is made with superthermal electron parameters corresponding to the classical resistivity regime for an input energy flux of superthermal electrons of 109erg cm−2s−1. It was found that due to the electron bombardment the two chromospheric evaporation waves are generated at both feet of the loop and they propagate up to the top, where they collide and cause temporary density and hard X-ray enhancements.

Some Problems in Understanding the Solar Corona

1994 ◽  
Vol 144 ◽  
pp. 1-9
Author(s):  
A. H. Gabriel
Keyword(s):  
Solar Corona ◽  
Solar Atmosphere ◽  
Theoretical Modelling ◽  
Total System ◽  
Major Advance ◽  
X Ray ◽  
Proper Perspective ◽  
Space Observations

The development of the physics of the solar atmosphere during the last 50 years has been greatly influenced by the increasing capability of observations made from space. Access to images and spectra of the hotter plasma in the UV, XUV and X-ray regions provided a major advance over the few coronal forbidden lines seen in the visible and enabled the cooler chromospheric and photospheric plasma to be seen in its proper perspective, as part of a total system. In this way space observations have stimulated new and important advances, not only in space but also in ground-based observations and theoretical modelling, so that today we find a well-balanced harmony between the three techniques.

White-Light Coronal Structures: Streamers and CMEs

1994 ◽  
Vol 144 ◽  
pp. 82
Author(s):  
E. Hildner
Keyword(s):  
Emission Line ◽  
Electron Density ◽  
White Light ◽  
Coronal Mass Ejections ◽  
X Rays ◽  
Solar Cycles ◽  
Temperature Function ◽  
X Ray ◽  
Eclipse Observations ◽  
Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

Iron K-Line Emission from X-Ray Binaries

1988 ◽  
Vol 102 ◽  
pp. 47-50
Author(s):  
K. Masai ◽  
S. Hayakawa ◽  
F. Nagase
Keyword(s):  
Accretion Disk ◽  
Radiative Recombination ◽  
Characteristic Temperature ◽  
Line Emission ◽  
Ionization Front ◽  
Continuum Radiation ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx> 10 keV is likely due to fluorescence outside the He II ionization front.

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