In this study particleboards were manufactured from mixtures of corn stalks (Zea mays indurate Sturt.) and industrial woodchips at several ratios. The corn stalks and industrial wood particles were mixed at ratios 0, 25, 50, 75 and 100 % respectively. The suitability of corn stalks chips for particleboard production was examined. Urea formaldehyde resin was used as a binder in 3-layers particleboards. Produced panels were tested for certain mechanical and physical properties. The manufactured boards were tested according to EN standards. In addition, the chemical properties of corn stalks were evaluated. Experimental results indicated that increase in corn stalk chips in the mixture generally diminished the mechanical and physical properties.
This study was conducted to investigate the properties of Persian oak (Quercus brantii Lindl.) wood, the most abundant tree species, harvested in the west and southwest regions of Iran. To the best our knowledge, there were no reported studies investigating the physical, chemical and biometrical features of Persian oak wood. For this purpose, 12 healthy trees in three diameter classes including 10-20, 20-30 and 30-40 cm were selected randomly and a disk was cut from each one at breast height. Results indicated that the highest basic densities are related to the diameter class 20-30cm (0.98 g.cm-3) and the lowest one at diameter class 10-20 cm (0.88 g.cm-3). The highest shrinkage was determined at oak wood samples from the diameter classes 10-20 cm (14.15%). Fiber length varied between 0.82 g.cm-3 (Dia. Class 10-20 cm, middle part) to 1.01 (Dia. Class 20-30 cm, bark). With increasing diameter, the cellulose content increased and the lignin content decreased while ash and extractive content was quite constant.
A new mutant E. ulmoides with red xylem is found, and this red color will gradually metabolize over time. Comparisons of chemical properties and metabolites of xylem between the mutant and wild type were analyzed in this study in order to discover the cause of the red mutation. The results showed that the acid-insoluble lignin content of mutant type was about 13.83% higher than that of wild type, but the crude protein of wild type was almost 2 times of mutant type. Meanwhile, 6 most important amino acids and amino acid derivatives were detected, which had significant correlation with crude protein. Additionally, the contents of organic acids, polyphenols and alkaloids in the mutant type were 243%, 316% and 281% of those in the wild type, respectively, while the contents of flavonoids and phenolamines contents were 78.8% and 27.3% of those in the wild type, respectively. These results will provide an important reference for understanding the wood color variation during growing.