Research Paper
Nooshin Toghraie; Abdolrahman Hosseinzadeh; Davood Parsapazhoh; Fardad Golbabaei
Abstract
Peroxidases are enzymes which catalyse two final steps in the wood lignin biosynthesis. The connection between xylem peroxidase activities and wood xylem lignifications was examined by determining peroxidase activities in the stems of eucalypt (Eucalyptus camaldulensis Dehn.) trees during two seasons ...
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Peroxidases are enzymes which catalyse two final steps in the wood lignin biosynthesis. The connection between xylem peroxidase activities and wood xylem lignifications was examined by determining peroxidase activities in the stems of eucalypt (Eucalyptus camaldulensis Dehn.) trees during two seasons in 1999over the period of annual growth. In addition, samples from the same trees were examined for lignin content. This study clarifies the possible roles of this enzyme in lignin biqsynthesis and forms a background for further work on the last steps in lignin polymerisation. The peroxidase activity of some samples was lower in Autumn. But in the others there was a great increase in Autumn vs. Winter. Though in Autumn there were more isoenzyme. The results show a relation between lignifications and Peroxidase enzyme zones. In Eucalyptus camaldulensis Dehn. in khozestan.
Research Paper
Abolfazl Kargarfard; Abdolrahman Hosseinzadeh; Amir Nourbakhsh; Fardad Golbabaei; Reza Hajihassani
Abstract
In order to investigate the influence of processing variables such as particle drying temperature, press temperature and hardner consumption on wood acidity and bonding performance of UF resin, experimental boards were produced using beech wood particle, drying temperature varied at 80, 110 and 140°C, ...
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In order to investigate the influence of processing variables such as particle drying temperature, press temperature and hardner consumption on wood acidity and bonding performance of UF resin, experimental boards were produced using beech wood particle, drying temperature varied at 80, 110 and 140°C, press temperature at 150, 165 and 180°C and hardner consumption at 1, 1.5 and 2% (based on solid content of UP resin). Eighty one sample boards were produced and tested. The results of physical and mechanical properties measurements were as follows: Modulus of rupture and modulus of elasticity of boards produced with particles dried at 80°C were higher than 110 and 140°C. Application of 2% hardener with increasing press temperature decreased MOR and MOE. Internal bonding of boards were measured and the results indicated that drying temperature had significantly effected the IB and boards produced with particles dried at 80 and 140°C, produced highest IE and lowest IE was belong to 110°C. The effect of hardner consumption was statistically significant and the highest IB was belonging to 2% hardner consumption. The results of thickness swelling measurement after 2 hr. soaking in water indicated that T.S2 of boards produced with particles dried at 140°C were the lowest. The combined effect of press temperature and hardner consumption on T.S2 was statistically significant and at 2% hardner consumption with increasing press temperature, increased thickness swelling.
Research Paper
Ali Reza nezhad; Habib alah Arab tabar firoz jaei; Abdolrahman Hosseinzadeh
Abstract
Samples of 3 wood species including: Beech (Fagus orientalis), Oak (Quercus castaneafolia) and Hornbeam (Carpinus betulus) were treated with creosote and celcure. The dimension of samples were 200 x 7 x 20 mm. Both treated and untreated samples were placed in sea water (Boshehr in Persian Gulf) according ...
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Samples of 3 wood species including: Beech (Fagus orientalis), Oak (Quercus castaneafolia) and Hornbeam (Carpinus betulus) were treated with creosote and celcure. The dimension of samples were 200 x 7 x 20 mm. Both treated and untreated samples were placed in sea water (Boshehr in Persian Gulf) according to IRG/WP-4432(l985). After 5, 9, 15, 24, 29 and 38 months, the samples were inspected according to recommendation of ASTM D 248. The control samples (untreated wood) of Beech, Hornbeam after 9 months, the samples of Oak after 14 months, seriously attacked. Treated samples of Beech, Oak and Hornbeam with celcure, after 14 months, were seriously attacked. Creosote, treated samples of Beech, after 29 months, Oak and Hornbeam after 38 months were seriously attacked. It can be concluded that treatment with creosote using full cell process (Bethell) increased resistance of investigated wood species against marine borers.
Research Paper
Composite wood products
masoudreza habibi; Abdolrahman Hosseinzadeh; Hossein Hosseinkhani; Saeed Mahdavi
Abstract
In this study the effect of two variables, (resin content and press time) on properties of MDF was investigated. Levels of each variable was as follow: Resin content (8, 9.5, 11 percent) Press time (4, 5, 6 minutes). The statistical analysis proved that the effect of press time on MOE and MOR was significant. ...
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In this study the effect of two variables, (resin content and press time) on properties of MDF was investigated. Levels of each variable was as follow: Resin content (8, 9.5, 11 percent) Press time (4, 5, 6 minutes). The statistical analysis proved that the effect of press time on MOE and MOR was significant. MOE and MOR were the highest at press time of 6 minutes. According to Duncan's test, there aren’t any significant differences between MOE at press time of 5 and 6 minutes. Also the effect of resin content on MOE had significant differences. MOE was the highest at resin content of 11%. There aren’t any significant differences between MOE on resin content at 9.5% and 11% levels. The results showed that effects of press time and resin content had significant differences on IB. IB was the highest at press time of 6 minutes and resin content of 11%. There aren’t any significant differences between IB on resin content at 9.5% and 11%. The effects of press time and resin content had significant differences on thickness swelling after 2 hours. Thickness swelling was the lowest at press time of 6 minutes and resin content of 11%. According to the results of this study optimum combination for MDF production from baggasse includes resin content and press time of 9.5% and 5 minutes respectively.
Research Paper
Physics and anatomy
Nooshin Toghraie; Abdolrahman Hosseinzadeh; Davood Parsapazhoh; Fardad Golbabaei
Abstract
To study saxaul wood properties in the various ecological regions of Iran twelve 10-22 years old sample trees (4 trees from each species) were selected and cut from three different areas around kerman. Physical, chemical and anatomical characteristics of wood samples were investigated. The results of ...
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To study saxaul wood properties in the various ecological regions of Iran twelve 10-22 years old sample trees (4 trees from each species) were selected and cut from three different areas around kerman. Physical, chemical and anatomical characteristics of wood samples were investigated. The results of this investigation revealed that the initial moisture content before felling was 38.6% and the mean specific gravity based on oven dry weight and oven dry volume (WOD/VOD), oven dry and saturated weight Saxaul saturated volume (WOD/Vs ,WS/VS ), were studied for yellow, white and black and respectively. It is concluded that saxaul wood of Kerman province is heavy. The average longitudinal, radial and tangential shrinkage were surveyed. Wood periodicity of growth was determined to be 3-4 rings per year. Anatomical features were investigated by light microscopy and papermaking factors were determined. Fiber length, fiber diameter and lumen diameter were determined. These values lead to species with short and thick fibers. Chemical composition including percentage of cellulose, lignin, extractives and ash were revealed too.
Research Paper
Physics and anatomy
Hossein Familian; Abdolrahman Hosseinzadeh; Mohammad hassan Asareh; Saeed Mahdavi; Sayed mosa Sadeghi; Kamyar Salehi
Abstract
Ziziphus lotus of the family Rhamnaceae is distributed in the southern region of Iran and considered as one of drought - resistant tree species of the country. This investigation is the first attempt to study wood properties of this species, in order to contribute to a better understanding of it. The ...
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Ziziphus lotus of the family Rhamnaceae is distributed in the southern region of Iran and considered as one of drought - resistant tree species of the country. This investigation is the first attempt to study wood properties of this species, in order to contribute to a better understanding of it. The results of this study revealed that Ziziphus lotus is a diffuse – porous with basic specific gravity medium and medium - textured wood. The length of vessel elements are medium, the diameter of vessel elements is small, porous with pores round to oval, intervessel pilting, opposite and intermediate, 20 vessels per square millimeter, simple perforation plates, vessel - ray pits similar to intervessel pits in size and shape and half bordered; Vascular tracheids present, there are rarely tyloses and Gums in vessels. Fibers with simple to minutely bordered pits, thin - to thick – walled and fiber lengths short; Parenchyma scanty paratracheal, vasicentric and rarely aliform; Ray uniseriate and sometimes biseriate, ray height is short, rays with procumbent, Square and upright cells mixed throughout the ray and one Prismatic crystals in chambered upright and square ray cells, rays 12 per mm, silica bodies in ray cells; There are 7-10 Schizogenous canals in pith.In this species also percentages of cellulose are high but ash and extractive soluble in acetone content was found to be low.
