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The recognition of wood species is a laborious process, which is performed by experts, who attempt to distinguish the different species in different wood sections based on their macroscopic and microscopic characteristics. Most of these characteristics can be observed in the transverse or cross section of woods. According to experts, the next most important surface for wood species recognition is the tangential section while significant information can also be obtained from the radial section of woods. Based on the recent advances in the area of computer vision and pattern recognition, most researchers have proposed imagebased approaches attempting to address the problem either in microscopic or macroscopic scale. The main limitation is that in many cases there are some features that are not visible in each wood section. Firstly, we examine the contribution of each section in wood species recognition using two different computer-based texture analysis methods. Furthermore, we compare wood species recognition methods for both grayscale images and colorscale images. Finally, we propose a novel fusion method and we demonstrate that wood species recognition accuracy can be increased by fusing features from different wood sections. For the evaluation of the proposed method, a dataset, namely "WOOD-AUTH", consisting of more than 4272 wood images of twelve common wood species, was used. [ABSTRACT FROM AUTHOR]

Forest biomass originating from Mediterranean forest vegetation could be a potential source of renewable energy in the form of pellets, butdue to its diversity there is a need for better understanding and detailed examination of its main fuel characteristics. The aim of this work was the evaluation of the impact that bark percentage and barked stem diameter have on the ash content and heating value of thefollowing evergreen Mediterranean hardwood species: Arbutus unedo, Erica arborea, Quercus coccifera, Quercus ilex and Phillyrea latifolia. For all the above species, the barked diameter, bark thickness, bark percentage as well as the ash content and higher heating value of bark and wood have been determined. In all cases the ash content of bark was higher than that of wood and also higher than the requirement of the related EN standard. Therefore the bark of tested species could be used in the production of pellets provided that its ratio would be in a level corresponding to the maximum allowed ash content values. Taking into account the results of the determinations, the equations and graphs were used in order to calculate the minimum of the stem diameter requirements in order to meet with the ash content restrictions. The effect of stem diameter on the HHV (higher heating value) was also evaluated. Among the tested species, Erica arborea proved to be the most appropriate for the production of pellets showing the highest HHV and the lowest ash content. [ABSTRACT FROM AUTHOR]

In this study, Scots pine wood (Pinus sylvestris L.) was thermally treated at 200oC, for three different time periods of 4, 6 and 8 hours. The Bending strength (MOR) and Impact Bending strength of treated and untreated pine wood specimens were determined and measurements of wood colour were implemented before and after each thermal treatment, in order to evaluate the colour changes coming from the treatment processes. An attempt was made to correlate this colour change with the change of the mechanical properties of treated wood. The results indicated that MOR decreased as the intensity of the treatment increased, recording decrease percentages of between 0.34-25.9%, compared to untreated wood, while the impact bending strength values of treated specimens marked 0.69-22.34% lower strength. The noteworthy is that a strong and significant relationship was recorded between the colour change and the mechanical properties change. Based on the results of this study, it could be claimed that the mechanical strength values of treated pinewood could be sufficiently estimated by the corresponding colour change values that have been measured. Therefore, the measurement of colour coordinates and the calculation of the total colour change values offer the opportunity to estimate automatically, quite precisely and through a non-destructive way the mechanical properties of wood. [ABSTRACT FROM AUTHOR]