scholarly journals Распределение механических свойств древесины лиственных пород в годовых кольцах, выявленных методом сканирующего наноиндентирования

Author(s):  
Ю.И. Головин ◽  
А.И. Тюрин ◽  
А.А. Гусев ◽  
С.М. Матвеев ◽  
Д.Ю. Головин ◽  
...  

The paper presents the results of mechanical properties scanning by means of nanoindentation across the annual growth rings of deciduous trees wood, small-leaved lime (Tilia cordata) and common oak (Quercus robur) in particular. Significant variations in microhardness H and Young’s modulus E radial dependencies have been found for any of the studied species. Results can be useful 1) to amend the understanding the nature of macromechanical properties of various wood species and to reveal the details of their formation depending upon microstructural characteristics, 2) to optimize the technologies of growing, reinforcement and subsequent usage of the wood, 3) to develop new independent methods in dendrochronology and dendroclimatology

2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Iriwi Louisa S. Sinon

<p><em>Study dendrochronology or tree-ring dating is defined as the study of chronological sequence of annual growth rings in trees. Teak (Tectona grandis) is one of various tree species that has been identified for the use of tree-ring studies in tropical regions. Teak is found to be suitable for dendrochronology as it is long-lived and develops defined annual growth rings. In Java, teak cans growth naturally or intensively in plantation. The two silviculture conditions will give different sensitivity on climate effect. Therefore, the effect of silviculturer will on natural teak and plantation teak in Saradan, Madiun, and East Java. As a part of the study, ten core samples from natural- growth teak were measured. The samples of growth rings is spanned from 1832 – 2004. Using the COFECHA program, the correlation of the samples (r) was found to be 0.44 point, which is satisfactory to the standard used in dendrochronology. Thus, from this study it can be concluded that natural teak could still be used in dendrochronology, although the sensitivity are not as high as plantation teak. </em></p>


2012 ◽  
pp. 87-100
Author(s):  
Milan Jaic ◽  
Tanja Palija

This paper investigates the impact of the top coating on the basic mechanical properties of a lacquered surface, including indentation hardness, scratch resistance and abrasion resistance. Three types of the top coating were used, including a 2K polyurethane coating, a 2K acrylate-isocyanate coating and a 2K alkyd-urethane coating. Samples of two wood species, spruce (Picea abies Karst.) and oak (Quercus robur L.), were used in this study, in order to determine whether the wood species, which is not in direct contact with the top coating, has an impact on the mechanical properties of a lacquered surface. The samples coated with a 2K acrylate-isocyanate coating showed the highest values of indentation hardness, in the samples of both wood species (1.34 N for spruce; 1.4 N for oak). The samples coated with a 2K alkyd-urethane coating showed the highest values of scratch resistance (20 N for both wood species) and abrasion resistance (mass loss of 480 mg after 700 cycles for both wood species). The results have shown that the wood species does not affect the value of indentation hardness, scratch resistance and abrasion resistance of a lacquered surface.


1986 ◽  
Vol 16 (2) ◽  
pp. 423-426 ◽  
Author(s):  
Laurance D. Hall ◽  
Vasanthan Rajanayagam ◽  
Wendy A. Stewart ◽  
Paul R. Steiner

A magnetic resonance scanner has been used to obtain images at 0.14 T, based on the water in aspen (Populustremuloides Michx.). In addition to visualization of the expected structural features such as annual growth-rings and knots, several additional features appear that require further study. Kiln-dried wood does not contain sufficient water to give an image, but can do so after impregnation with water.


Trees ◽  
2008 ◽  
Vol 22 (5) ◽  
pp. 663-670 ◽  
Author(s):  
Gustavo Calderucio Duque Estrada ◽  
Cátia Henriques Callado ◽  
Mário Luiz Gomes Soares ◽  
Cláudio Sérgio Lisi

1999 ◽  
Vol 124 (2-3) ◽  
pp. 217-229 ◽  
Author(s):  
D.W Stahle ◽  
P.T Mushove ◽  
M.K Cleaveland ◽  
F Roig ◽  
G.A Haynes

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