جستجوی مقالات مرتبط با کلیدواژه "non" در نشریات گروه "صنایع چوب و کاغذ"

Using non-destructive methods to study forest productivity and wood quality as well as annual growth variations deserve special importance. In this regard annual growth changes of Pinus eldarica include width of the spring and summer rings and percentage of tissue structure was determined using X-ray method. Spring wood accounts as the effective factor for growth ring width in pine wood. The annual rings of the tree are thicker in the spring than in the summer time. Pine tree growth rate decreases with age and as the tree age rises, width of the ring as well as spring and summer wood width is lowered.

The possibility of estimating some acoustical properties of particleboard panels such as "Acoustical coefficient" and "Acoustical Converting efficiency" using vibrational non-destructive techniques was investigated. Particleboard plates with the dimensions of 50×50, 100×50 and 150×50 were used. For each plate, three replicated samples were prepared and after conditioning and the measurement of weight and dimensions, the flexural vibration test was performed on plate free-free test. In order to be ensured of the accuracy of the test, panels were converted to beams with the dimensions of 500×50×16 mm and then the same test was repeated on these samples. The results obtained from flexural vibration test of plates and beams were compared. The results indicated that it is possible to evaluate the Acoustic Coefficient and Acoustical Converting Efficiency factors with adequate accuracy using the testing method used in this study.

A fundamental study was carried out to explore the canola stalks properties in order to increase the use of abundant agricultural residuals in pulp and paper production. In this study, the morphological, chemical composition and soda pulping properties of Canola stalks were investigated. The results showed that except the thicker cell wall, the morphological properties of Canola stalks fibers were comparable to those of nonwoods and hardwoods fibers. Chemical analysis indicated that Canola stalks contains lower amount of cellulose (44%), while the lignin, hemicelluloses and ash content of Canola stalks are comparable to other non-woods. In comparison with most of non wood fiber resources, soda pulping of Canola stalks required higher chemical charge and pulping time. Soda pulping of Canola stalks in 22% active alkaline and 100 min in max temperature produced pulp with 82.6% ISO of brightness The strength properties of bleached Canola stalks soda pulp include tensile index (Nm/g), burst index (kpam2/g) & tear index (mNm2/g) showed respectively 63.6, 2.22 & 4.9.