WOOD RESEARCH Volume 69, Number 3, 2024
SENDER ALTANGEREL, IKUMI NEZU, JYUNICHI OHSHIMA, SHINSO YOKOTA, and FUTOSHI ISHIGURI

CHANGES IN WOOD QUALITY OF BETULA ERMANII LOGS BY HEATING TREATMENT

Logs of Betula ermaniiCham. were heated at a temperature inside the logs of 80°C for different heating durations of 0, 20, 40, and 60 h using a laboratory oven. After heating treatment, several wood qualities were examined, including residual stresses, moisture content, wood color, and physical and mechanical properties. The effects of the heating treatment duration on wood quality were analyzed using linear mixed-effect modeling. The developed models revealed that heating treatment affected residual stresses and wood color but not mechanical properties. The obtained results also suggest that a heating treatment duration of 20 h is sufficient to reduce residual stresses in B. ermaniilogs without reducing the physical and mechanical properties of wood

WOOD RESEARCH Volume 61, Number 6, 2016
Ergün Güntekin and Tuğba Yilmaz Aydin

Prediction of bending properties for some softwood species grown in Turkey using ultrasound

Ultrasound has been used in prediction of bending properties for some important wood species grown in Turkey including Calabrian pine, Anatolian black pine, Cedar and Oriental Spruce. Sound velocities of small clear wood specimens were determined using EPOCH 650 ultrasonic flaw detector with 2.25 MHz contact longitudinal transducers at constant moisture content. Following non-destructive measurements, specimens were subjected to three point bending tests. The measured average sound velocities for species tested in L directions were ranged from 4510 to 5254 m∙s-1. Although spruce had the lowest density (425 kg∙m-3), it had the highest sound velocity. The predicted average dynamic modulus of elasticity (Edyn) values for the species tested varied from 10137 to 12856 N∙mm-2. The correlation coefficients between Edyn values and MOE values were higher than those between Edyn and MOR. Edyn values are higher than calculated MOE values. The correlation coefficient between predicted Edyn and calculated MOE values ranged from 0.81 to 0.89. The correlation coefficient between Edyn and MOR varied from 0.78 to 0.88 for the species tested. Results indicated that there was no certain relationship between the density and wave velocity except Calabrian pine which showed negative weak correlation. MOE is better indicator of MOR than Edyn as expected.