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The relationships between climate and wood density components, i.e., minimum ring density, maximum ring density and mean ring density have been studied mainly in dominant trees. However, the applicability of the findings to trees of other dominance classes is unclear. The aim of this study was to address whether climate differentially influences wood density components among dominance classes. X-ray densitometry data was obtained from 72 black spruce (Picea mariana (Mill.) B.S.P.) trees harvested in Northwestern Ontario, Canada. Dominant, co-dominant and intermediate trees were sampled and the data analysed using mixed-effect modelling techniques. For each density component, models were first fitted to the pooled data using ring width and cambial age as predictors, before monthly climatic variables were integrated into the models. Then, separate models were fitted to the data from each dominance class. In general, the addition of climatic factors led to a small but significant improvement in model performance. The predicted historical trends were well synchronized with the observed data. Our results indicate that trees from all dominance classes in a stand should be sampled in order to fully characterize wood density-climate relationships. [ABSTRACT FROM AUTHOR]

Phenolic bio-oil produced by the direct liquefaction of Eastern white pine ( Pinus Strobus L.) sawdust in a hot-compressed ethanol-water (1:1 w/w) medium at 300 °C was used to partially substitute for phenol in the synthesis of bio-oil-phenol-formaldehyde (BPF) resol resins. Bio-based resol resins with high levels of phenol substitution (up to 75 wt%) could be used as plywood adhesives because of the low molecular weights found for the phenolic bio-oil (weight-average molecular weight = 1072 g/mol, number-average molecular weight = 342 g/mol). The properties of the BPF resol resins were analyzed by differential scanning calorimetry, Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis. All of the experimental BPF resins possessed broad molecular weight distributions but had similar chemical/thermal properties compared to a conventional phenol-formaldehyde (PF) resol resin reference (or 0 wt % BPF resin). The BPFs exhibited the typical properties of a thermosetting PF resin, for example, an exothermic curing temperature of 140-150°C and an acceptable residual carbon yield of 48-72 wt % nonvolatile content at 700°C. The experimental BPFs were applied as adhesives in the assembly of plywood, and then, the dry/wet tensile strengths were evaluated. The tensile strengths of the dry plywood samples bonded with the BPF resins up to a high ratio value of 75 wt % bio-oil exceeded or were comparable to that of the conventional pure PF resin adhesive. All of the BPF-resin-bonded plywood samples gave wet tensile strengths comparable to those of the conventional PF adhesive. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

The article presents author's views on redefining risk and uncertainty for risk mangers. The author carried out an experiment to study a different way of giving instructions, and the results are evidence of another potentially useful approach. The study was done online. Volunteers who participated were first given a choice among four scenarios likely to be familiar to most people. This was to ensure that respondents would be working on something about which they had some knowledge. If one has ever tried leading a meeting with managers in which they have to think about risks and how they are being managed, one knows that people tend to ignore the instructions one gives them.

The article offers information on the forestry extension work and forestry programs of the Lakehead University in Ontario. When the 44-hectare Hogarth Plantations was burned in 2007, students helped in salvage logging where they were able to observe when burnt wood was felled as biomass recovery to provide fuel to the local Abitibi-Bowater mill and see how some of the recovered logs have been built into custom log homes by a local entrepreneur. The university has entered into a partnership with FPInovations Forintek Division to further enhance the capabilities of the Lakehead University Centre for Wood Science & Testing Facility (LUWSTF) to service new and existing forest industries. Wood Science and Technology courses are also being offered at the undergraduate and postgraduate level.

Cornstalk powders were effectively liquefied in a hot-compressed phenol–water medium (1:4 wt/wt). The optimum liquefaction temperature was around 350°C, where the liquid yield attained a maximum at about 70wt%. The addition of sodium carbonate showed negligible effect over the Liquefaction product yields. When liquefied in phenol–water medium, essentially no phenol was combined with the liquid products, and the cornstalk-derived bio-oils were partially degraded monomeric and oligomeric products with a broad molecular distribution. Resol type bio-based phenol formaldehyde resins were readily synthesized from the cornstalk-derived bio-oils catalyzed by sodium hydroxide. [Copyright &y& Elsevier]