جستجوی مقالات مرتبط با کلیدواژه « متناوب » در نشریات گروه « میان رشته ای »

Investigating changes in biometrics and anatomy of wood species in different parts of tree stems is one of the issues that have been of long interest to researchers in the wood and paper industry. In this study, a comparison of the anatomical and biometrical characteristics of heartwood and sapwood Elaeagnus angustifolia was made. For this purpose, a completely healthy tree native to Khorasan Province, Iran was selected and cut. Test specimens with dimensions of 2 × 2 cm and a length of 3 cm sequentially taken from near the pith (heartwood) to near bark (sapwood) were prepared for biometric and anatomical experiments. Biometric characteristics including fiber length, fiber lumen diameter, fiber diameter and cell wall thickness were evaluated. The results showed that the effect of different parts of the stem on the biometric characteristics of the fibers at the upper level was significant, so that biometric properties had an increasing trend as they moved away from the pith area and neared the bark area. Microscopic studies of wood close to the bark of the elaeagnus angustifolia showed that this species is of the ring porous hardwood species, with distinct growth ring, simple perforation plates and scalariform, alternate intervessel pits and presence of Tyloses.

In this research study, the biometric properties of fibers and microscopy of fraxinus wood were investigated. For this purpose, a perfectly healthy stem of the fraxinus tree native to Chamestan area was selected and one disc of 5 cm thickness was prepared at breast height. In transverse direction, the test specimens were cut 2 × 2 cm to 3 cm from the pith to the bark sequentially and examined. Then, the biometric properties of the fibers including fiber length, fiber lumen diameter, cell wall thickness and fiber diameter were measured.  The results showed that all the dimensional properties of the fibers from the brain to the skin were increasing. In order to microscopically study fraxinus tree wood, microscopic sections of three transverse, tangential and radial surfaces of wood close to the bark of the fraxinus tree were prepared and evaluated by a light microscope. Results of the anatomical study indicated that the fraxinus tree is a ring porous hardwood species with distinct growth, simple perforation plates and scalariform, alternate intervessel pits and without tyloses.