Variations in average tracheid dimensions (such as length, diameter, lumen diameter, and wall thickness) and its biometrical ratios including slenderness ratio, flexibility ratio, and Runkell ratio, oven-dry and basic density, longitudinal, radial, tangential, and volume shrinkage, maximum moisture content, and porosity of cypress trees wood (Cupressus sempervirens L.var. horizontalis), which was cultivated in the north of Iran, were studied from the pith to bark (radial position), and along the stem from the base upwards. To measure the mentioned traits, the test specimens were prepared from three stands and 9 discs at different height levels (5, 25, and 50% of the total tree height) based on ASTM-D143 standard. Results indicated that the tracheid length, tracheid cross-sectional dimensions, and its biometrical ratios irregularly varied at each height level, along the stem from the bottom to top, but within the discs, at the same height level biometrical traits in the radial position regularly increased from the pith to bark. Within the tree, wood oven-dry and basic density, longitudinal, radial, tangential, and volume shrinkage varied at each height level, decreasing along the stem from the base upwards. Within the discs, at the same height level, wood density and shrinkage, except for longitudinal shrinkage in the radial position, increased from the pith to bark. The maximum moisture content and porosity varied at each height level, increasing along the stem from the bottom to the top of the tree. Moreover, within the discs, at the same height level in the radial direction porosity decreased and maximum moisture content increased except for at 5% of height level from the pith to bark.
Pengaruh variasi kecepatan udara dan massa bahan terhadap waktu pengeringan jagung pada alat fluidized bed
