Yazar "Ung, Tony" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    Effects of delayed drying and CO2 application on copper amine fixation in ACQ treated red pine
    (Springer, 2009) Taşçıoğlu, Cihat; Cooper, Paul; Ung, Tony
    Fixation of copper and amine in alkaline copper quaternary (ACQ-C) wood preservative was investigated to determine the effects of delayed drying and application of CO2 gas under pressure. Unlike the fixation of CCA preservative, where the rate of fixation reaction is slowed down by evaporative cooling during drying, delayed drying of ACQ treated wood had no observable effect on the copper fixation rate. However, at 50 degrees C, delayed drying resulted in a higher degree of copper fixation, while this effect was not observed at 22 degrees C. Post-treatment of ACQ treated wood with pressurized CO2 immediately after treatment, reduced the pH of the solution in wood and resulted in rapid fixation of the copper. However, in time, the pH increased as CO2 dissipated from the solution allowing the copper to re-solubilize.
  • Küçük Resim
    Öğe
    Effects of fixation temperature and environment on copper speciation in ACQ treated red pine
    (Walter De Gruyter Gmbh, 2008) Taşçıoğlu, Cihat; Cooper, Paul; Ung, Tony
    Red pine (Pinus resinosa Ait.) sapwood samples treated with alkaline (amine) copper quaternary (ACQ) were conditioned at different temperatures and under wet or dry conditions to evaluate the stability of copper (Cu) to leaching and conversion of divalent copper (Cu-II) to monovalent copper (Cud). Significant Cu-II was reduced to Cud during post-treatment stabilization, especially at elevated temperatures (105 degrees C and 120 degrees C). The percent conversion to Cu-I was higher at lower retentions; in some cases, at low retentions and high fixation temperatures, all of the cupric Cu was reduced to Cud, raising the possibility of reduced activity of Cu as a biocide when high temperature conditions are used to fix ACQ treated wood. However, exposure of wood to a leaching procedure (rewetting, re-drying) generally resulted in a significant component of the Cu-I in wood being oxidized back to Cu-II. Steaming of weathered ACQ treated wood at 120'C also converted significant amounts of Cu-II to Cu-I.