Resumo em Inglês:

Abstract The impact of forestry practices was evaluated on Eucalyptus’s growth variables and mortality dynamics. An experiment was conducted in Uruguay over sixteen years, sixteen spacing and thinning treatments were compared depending on the genetic material and productive objective. Tree height and diameter at breast height were assessed annually. All variables were analyzed using linear mixed models. Kaplan-Meier survival analysis and the Log Rank test were used to compare tree survival. 460 trees ha-1 from seed material resulted in the highest individual basal area (0.023 m2), while treatments with 2000 trees ha-1, without thinning, generated a greater yield per hectare (1014 m3 ha-1). Variations in mortality were detected in higher-density treatments (above 800 trees ha-1). This study underscores the critical importance of managing spacing, genetic material, and thinning practices to optimize Eucalyptus growth.

Resumo em Inglês:

Abstract The work proposes the use of multi-walled carbon nanotubes in various concentrations treated in nitric acid (f-MWCNT) as a filler for urea-formaldehyde resin to produce birch plywood with improved physical-mechanical, water-resistant and thermal properties. The MWCNTs were characterized using transmission electron microscopy, IR and Raman spectroscopy, and the zeta potential was determined. The thermal stability of plywood on the UFR/f-MWCNT adhesive composition was assessed and a higher thermal stability of plywood was revealed when a nanofiller was added to the resin. The modulus of rupture increased by 62.7% and the modulus of elasticity by 113% with the addition of 1.5% f-MWCNT. A decrease in water absorption was established by 43%. A steady decrease in the emission of free formaldehyde from plywood was determined. The possibility of intermolecular interaction between the functional groups of f-MWCNT and urea-formaldehyde resins has been established.