ALBERT

Description: The wood anatomy of the Rosaceae is surveyed and analysed, based on the study of 280 species (c. 500 specimens) belonging to 62 genera from different parts of the world. Eighteen wood anatomical characters have been used for a phenetic and phylogenetic classification. In the phenetic classification, 12 groups are recognised and compared with Hutchinson\xe2\x80\x99s tribes. Groups I-V accommodate a mixture of representatives from Spiraeoideae and Rosoideae genera (or tribes); Groups VI-VII comprise the Maloideae plus Cercocarpus; Groups VIII-IX are composed mainly of the tribe Quillajeae, but include Prinsepia, and exclude Exochorda; Groups X-XII represent the Prunoideae. All woody tribes recognised by Hutchinson encompass few closely similar wood anatomical groups except the Cercocarpeae. The Quillajeae, characterised by presumably primitive macromorphological characters, appear to be quite derived wood anatomically, and, according to the phylogenetic analysis, should be included in the Prunoideae or be recognised as a separate subfamily close to the Prunoideae. The wood anatomical variation patterns support a broad generic delimitation in the Maloideae, and a narrow one in the Prunoideae. The wood anatomical evidence also suggests that Cercocarpus be moved to the Maloideae, and that Sorbaria is the most derived representative in the Spiraeoideae/ Rosoideae. Prinsepia, although distinct in its wood anatomy from the Prunus alliance, still forms part of a monophyletic group together with the latter. Based on wood anatomical evidence, the subdivision of the family and the origin of the Maloideae are discussed.\nWood anatomically the Rosaceae are isolated within the order Rosales. It is hypothesised that the Rosaceae might have originated in East Asia instead of in the tropics.\nIndividual generic descriptions, a family description and a tentative wood anatomical key to the genera studied are also presented.

Description: Wood density in relation to cambial age and ring width was studied in 23 trees of European oak (Quercuspetraea (Matt) Liebl. and Quercusrobur L.) from northeast France, and based on these relationships, a model predicting intratree wood density through cambial age and ring width was developed. Wood density is closely correlated with both cambial age and ring width, but its relationships with cambial age and ring width, to some extent, vary from tree to tree. The variation, however, does not show an appreciable pattern with tree height. The model developed is able to predict satisfactorily the average wood density of growth rings in European oak, and to explain the main part of the variation in wood density of individual trees. Furthermore, the model appears also possible to predict the average density of a given small piece of wood from any part of the merchantable bole of the trees. A general model, however, accounts for a relatively low percentage of the variation because there is large intertree variability of wood density in the species. The simulation results reveal that the dynamic silviculture applied to European oak might result in the production of denser and more uniform (in the sense of the radial variation of wood density) wood, compared with classical silviculture.

Description: The effect of growth rate on the specific gravity of East-Liaoning oak (Quercusliaotungensis Koidz.) wood was studied and statistically compared with the effect of age (ring number from the pith). Results revealed that age is a decisive factor in controlling the specific gravity of wood, while effect of growth rate on specific gravity is statistically less important. Furthermore, the effect of growth rate varies with ring width range, age, and position within one growth ring (earlywood, latewood, or the whole ring). Within narrower ring widths, specific gravity increases rapidly with increasing growth rate, then more slowly as ring width increases, and when ring width is beyond a specific range, specific gravity remains more or less constant. Growth rate shows little effect on specific gravity of juvenile wood, but with increasing age, the effect increases gradually to reach a significant level in mature wood. Growth rate does not affect specific gravity of latewood significantly, but it shows a greater effect on specific gravity of the whole ring.

Description: Strength properties and dimensional stability of medium-density fiberboard (MDF) panels made from black spruce (Picea mariana [Mill.] BSP.) 0–20, 21–40, and over 40 year old fiber were studied. An analysis of covariance (ANCOVA) was performed to examine the differences in modulus of rupture (MOR), modulus of elasticity (MOE), and thickness swell (TS) of the three types of panels, while panel density was treated as a covariate in order to adjust the mean values that were partly attributed to panel density. The results indicate that MOR, internal bond (IB), and water absorption of MDF panels made from 0–20 year old fiber, which contained 100% juvenile wood, were significantly superior to those of panels made from 21–40 and over 40 year old fiber; but linear expansion (LE) of MDF panels made from 0–20 year old fiber was significantly larger than that of panels from the other two age classes. The differences in MOR, IB, water absorption, and LE between panels made from 21–40 and over 40 year old fiber were not significant. The comparisons of panel MOE and TS were relatively dependent on panel density due to existence of interactions among the three age groups.

Description: Although three-dimensional (3D) internal log images are useful to wood scientists for assessing internal log features, little work has been carried out on this subject. The aim of this paper was to demonstrate how two-dimensional (2D) log images may be combined to create 3D images of internal log features. The selected log features include heartwood, sapwood, bark, and knots in a sugar maple log and a black spruce log. The 2D cross-sectional images of the logs were acquired through computed tomography (CT) scanning. For each log, 72 successive 2D cross-sectional CT images of the log were employed to create the corresponding 3D internal log images based on the marching cubes algorithm. The results suggest that the proposed method can produce clear 3D images for each selected internal log features in sugar maple and black spruce. The accuracy analysis of the 3D reconstruction is still a huge challenge and should be fully investigated in future work.

Description: Three major types of paper mill sludge, primary sludge (PS), secondary sludge (SS) and de-inking paper sludge (DPS) were characterized and evaluated as adhesive fillers. Plywood panels were made of formulations with phenol formaldehyde (PF) and sludges. Panels with PF/PS and PF/SS formulations had higher dry and wet shear strengths than those made with PF/Cocob® formulation. All wood failure values were comparable. Dry and wet shear strengths of the panels with PF/DPS formulation were comparable to those of the PF/Cocob® panels (with Cocob® as a commercial filler), but the former displayed a much lower wood failure value. Owing to this fact and its high ash content, DPS was not evaluated further as a potential component of adhesive formulations. Compared with SS, PS resulted in higher dry and wet shear strengths and higher wood failure values. However, granular SS was easier to disperse into the resin component than fibrous PS, and the PF/SS formulation was more easily dispensed on aspen veneer sheets than the PF/PS formulation. SS alone displayed adhesive properties with 0.87 MPa of dry shear strength, but PS alone did not exhibit any bond strength. PS and SS were further evaluated for their general thermal behavior and major functional groups using differential scanning calorimetry and Fourier transform infrared spectrometry, respectively.

Description: In this study, sugar maple samples were impregnated with three impregnants by a vacuum and pressure process and in situ polymerized by a catalyst-thermal procedure. The effects of polymeric monomers and their combinations on monomer retention by volume (MRV) and weight (MRW) and polymer retention (PR) were analyzed and the wood was examined by scanning electronic microscopy (SEM). The three methacrylates chosen as impregnants were methyl methacrylate (MMA), hydroxyethylene methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA). The formulation combinations were determined by a mixture design. MRV was similar, regardless of formulation combinations, which indicated that these methacrylates show similar permeability into sugar maple. However, MRW was different between formulation combinations due to differences in monomer density. MRV was inversely related to wood density. PR was related to the combination of impregnants and inversely related to wood density. The impregnants resided in the vessel and the lumen. The morphology of polymers in the wood was different for different treatments due to the distinct molecular structures formed from each polymer.

Description: In recent years, computed tomography (CT) was investigated to acquire internal log information non-destructively. This paper studied the feasibility of identifying internal log characteristics in CT images by means of maximum likelihood classifier. The log characteristics to be identified include heartwood, sapwood, inner bark, and knots in sugar maple. A total of 100 CT images were sampled from one log to develop the classifier and 20 images were selected from another log for validation. Besides spectral and distance features, textural features were also assessed. In total, nine of them were selected as the input features for the classifier based on the class separability analysis. The classifier developed in this study produced overall accuracies of 79.8% and 72.2% for the training images and the validation images, respectively. This study indicates that the developed maximum likelihood classifier relying on a combination of spectral, textural, and distance features may be applicable to identify the internal log characteristics in the CT images of sugar maple.