The intention of this exploratory study was to determine whether nearinfrared spectroscopy, combined with multivariate statistical modeling, could become a swift and accurate tool for identifying sub-alpine fir within a typical spruce-pine-fir (SPF) lumber mix in the green chain of a sawmill. This need arises from the difficulty encountered in the drying sub-alpine fir. Its identification and removal from the SPF mix before kiln drying may be quite beneficial for producing high quality lumber. Near-infrared spectra were obtained from scanning of small specimens that were prepared from freshly cut trees. The results of the initial principal component analysis indicated that all four components could be used for species differentiation with the help of partial least squares discriminant analysis. All specimens in the training set were fitted into the correct sub-group of either fir or spruce-pine groups. The test set was validated and it revealed that all specimens were correctly classified. The outcome also confirmed that near-infrared spectroscopy combined with multivariate statistical modeling could be a suitable prediction model for separation of sub-alpine fir from the SPF mix.
Pinewood nematode (Bursaphelenchus xylophilus) mortality was investigated after ultrasonic treatment at 20 and 40 kHz frequency. Experiments were conducted with infected small wood specimens that were ultrasonically treated for 1, 3, 5 and 7 hours and two variable temperature conditions, namely, a gradually increasing from ambient to a maximum of 70 o C and a decreasing from ambient to a minimum of 5 o C. The results revealed that the ultrasonic treatment itself had no significant effect on the nematode mortality at the 5 o C level, while at the 70 o C level, considerable nematode mortality was observed in short time periods and at 7 hours of sonic exposure it reached 100%. Therefore, certain combinations of timing and frequency of ultrasonic waves and produced heat can be effective in killing pinewood nematodes thus resulting in phytosanitized wood.
The aim of this paper is to determine the effect of hole diameter (LR Direction) on acoustic performance indicators such as acoustic coefficient and acoustic conversion efficiency of wooden beams using flexural vibration of a free-free bar test.The drilling from 0 to 8 millimetres diameter was made exactly at the middle of the bar, on the node of the second mode of vibration. The results revealed that holes of diameter from 0 to 8 millimeters didn’t cause any sever change on acoustic coefficient and acoustic conversion efficiency when the beam was impacted on both radial and tangential surfaces. Nevertheless, these acoustic properties changed a bit when the beam was impacted on the tangential surface. Thus, the changes of the acoustic coefficient and acoustic conversion efficiency for both radial and tangential impacts were not significant, even with an 8 mm hole. Therefore, hole diameter not only didn’t cause any severe effect on acoustic coefficient and acoustic conversion efficiency but also somewhat increased their values. So, a hole having a relatively small diameter may cause improved acoustical performance of a wooden beam.
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