Xylem and phloem formation, as well as cambium and leaf phenology and their relation to weather factors were studied in beech (Fagus sylvatica L.) trees from two sites in Slovenia with different elevations and weather conditions. We described and explained main differences in these phenomena for trees growing in different environments where variable year to year conditions affect the amount and quality of wood and phloem formed in a particular year in this important tree species.
COBISS.SI-ID: 2115465
Dielectric analysis, rheometry and differential scanning calorimetry were used to analyse the curing process of low solvent liquefied wood. It was found that curing started after a temperature of 100 °C had been reached in the bond. Rheological measurements proved the influence of the substrate on the curing of the liquefied wood. Differential scanning calorimetry showed that the curing of liquefied wood occurs in two parts: first, the initial elimination of water and ethylene glycol from the liquefied wood, and then the chemical reaction of the liquefied wood at higher temperatures.
COBISS.SI-ID: 2112905
The research on the industrial production of pinosylvins and NTG from knots of pines showed aplicable conclusions. The composition of the extracts was determined by GC, GCMS, HP-SEC. The main phenolic compounds are the stilbenes pinosylvin and its monomethyl ether and the lignan nortrachelogenin (NTG), and their amounts vary a lot from sample to sample. The sequential extraction with a nonpolar solvent as a first step for removing the lipophilic compounds was the most efficient approach for the recovery of both pinosylvins and NTG. For food applications, hot water and 85% aqueous ethanol were good solvents for the production of the substances in focus.
COBISS.SI-ID: 2134665
Copper-ethanolamine-based wood preservatives are still the most important solutions for protecting wood in ground applications in Europe. Wood in the ground is exposed to a variety of organisms that can act synergistically. In order to simulate these conditions in the laboratory, Scots pine (Pinus sylvestris) specimens impregnated with copper-ethanolamine preservative of three different concentrations (cCu = 0.125%, 0.25%, and 0.5%) were exposed to three different soils according to procedure ENV 807, for periods between 12 and 32 weeks. After the relevant period of exposure, samples were isolated, and their mass loss, bending strength, and modulus of elasticity were determined. In the final step, the remaining copper in the samples was determined. The results showed that, in spite of significant copper leaching, the tested copper-ethanolamine-treated wood exhibited good performance in ground applications. Furthermore, a good correlation was found between the mechanical properties and mass loss, regardless of the chemical treatment applied.
COBISS.SI-ID: 2106505
An age effect on growth trends and wood quality as well as on climate/growth relationships of trees were studied by analysing the seasonal dynamics of xylem development in young and old Smith fir (Abies georgei var. smithii) trees on the Tibetan Plateau. Both young and old trees responded fast to changes of the minimum air temperature, confirming that this factor was dominant by controlling Smith fir wood formation and wood quality. The results are of general importance also for other tree species in other environments.
COBISS.SI-ID: 2076553