Physics and anatomy
Farshid Basiji; Vahid reza Safdari; Ahmad Jahan latibari; Amir Nourbakhsh
Abstract
The objective of adding reinforcing fillers, such as natural fibers to plastics is to increase the strength compared with neat plastic and wood. In this research the effect of wood pulp fiber length (short, medium and long), aspect ratio and fiber content (27%, 37%, 47% and 0% (non-reinforced PP)) with ...
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The objective of adding reinforcing fillers, such as natural fibers to plastics is to increase the strength compared with neat plastic and wood. In this research the effect of wood pulp fiber length (short, medium and long), aspect ratio and fiber content (27%, 37%, 47% and 0% (non-reinforced PP)) with 3% maleic anhydride grafted polypropylene on wood plastic composites (WPCs) has been studied. Results showed that increased fiber length or aspect ratio and fiber content increases mechanical properties (tensile strength, tensile modulus and MOE). Impact strength had an inverse correlation with fiber content and fiber length, but fiber content was a much more important factor than fiber length for impact strength. The impact strength of composite of softwood pulps was much higher than wood floor composite plastic. The significant interaction between fiber length and fiber content, and the lack of a specific trend in the treatments made assessment of the effect of fiber properties on MOR difficult.
َAbdolah Shakeri; Vahid Reza Safdari; Mehran Rohnia; Amir Nourbakhsh
Abstract
Coupling agents in wood fiber reinforced plastic composites play an important role inimproving compatibility and adhesion between polar wood fiber and non-polar polymermatrices by forming bridges of chemical bonds between the fiber and the matrix. Maleatedpolyethylene (MAPE) and diisocyanate (HMDI) are ...
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Coupling agents in wood fiber reinforced plastic composites play an important role inimproving compatibility and adhesion between polar wood fiber and non-polar polymermatrices by forming bridges of chemical bonds between the fiber and the matrix. Maleatedpolyethylene (MAPE) and diisocyanate (HMDI) are two most common coupling agents whichare subject to evaluation, singly and in mixture. Polypropylene and wood fibers werecompounded with Maleated polyethylene (MAPE) and diisocyanate (HMDI) in concentration of2% and 4% in solitary form and mixture form (HMDI %2 + MAPE %2) into pellets using acounter-rotating twin-screw extruder and mechanical test specimens were prepared by injectionmolding. The result showed that adding 4% MAPE and 2% HMDI individually lead to increasein flexural and tensile strength of the composites. Also adding (%2HMDI + %2MAPE) causedan increase of flexural, tensile and in particular the impact strength.
Seyyed Khalil Hosseinihashemi; Ali Bagheri; Vahidreza Safdari; Hassan Sadeghifar
Abstract
Black locust wood is durable against microorganisms. The species is planted as a nitrogen fixing specie in many arid and semiarid areas of Iran. Extraction procedures included soaking wood samples in hexane solvent for 15 days were applied. Average percentage of black locust heartwood extractives was ...
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Black locust wood is durable against microorganisms. The species is planted as a nitrogen fixing specie in many arid and semiarid areas of Iran. Extraction procedures included soaking wood samples in hexane solvent for 15 days were applied. Average percentage of black locust heartwood extractives was determined as 8.4 percent. Identification of chemical compounds in the extractives was performed on a GC/MS device. Generally, 25 compounds were identified with different percentage in heartwood. The most abundant compound within the hexane heartwood extract of black locust samples was hexadecanoic acid as a trimethylsilyl ester, amounting to 13.39% saturated fatty acids group. The most important identified unsaturated fatty acids in the heartwood of the species 9, 12-octadecadienoic acid (Z, Z) - (10.10%). Tetradecane (6.88%) and hexadecane (6.15%) were the most important identified alkenes in the heartwood of the species. Also squalene as pure and mineral hydrocarbon oil was identified amounting to 1.17%. Squalene Vaccine manufacturers has proved that the squalene is effective against virus diseases of animals
Physics and anatomy
Mohammad reza Nicsresht sigharodi; Vahid reza Safdari; Mohammad javad Sepideh dam; sayed Khalil Hosseini hashemi
Abstract
Paper’s components identification is important for pulp and paper mills and many organizations. In the present study we tried to identify paper fibers and introduce the most important anatomical characteristics which are effective in identification. First anatomical characteristics of wood and ...
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Paper’s components identification is important for pulp and paper mills and many organizations. In the present study we tried to identify paper fibers and introduce the most important anatomical characteristics which are effective in identification. First anatomical characteristics of wood and non-wood species which are important in pulp and paper industry were investigated. Then the papers of 3 important paper mills in Iran (totally 5 different papers) which their raw material include forest species, imported pulp and waste paper were sampled and examined. Many slides have been prepared according to ISO 9184-1 (ISO 1990) standard and valuable Atlases useful for identification of exotic species were reviewed. At the end important anatomical characteristics were recorded. Results showed that the fiber identification of papers is feasible. For softwoods identification, cross-field pits and for hardwoods, vessel shape, including, spiral thickening, perforation plate, inter-vessel pits and especially ray- vessels pits are the most crucial features for identification. Parenchyma, fiber biometric properties and fiber shape, in most species were similar and least effective in identification process. Epidermal cells, parenchyma and vessels were the most important anatomical feature for identification of non-woods.
Physics and anatomy
Vahid reza Safdari; Meisam Golchinfar
Abstract
In this investigation, anatomical characteristics of Iranian native woods from Ulmaceaefamily: Ulmus glabra, Ulmus carpinifolia,Zelkova carpinifolia,Celtis australis have been compared. These 4 woods are similar and have been used in Iranian historical buildings and their identification would be important.Among ...
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In this investigation, anatomical characteristics of Iranian native woods from Ulmaceaefamily: Ulmus glabra, Ulmus carpinifolia,Zelkova carpinifolia,Celtis australis have been compared. These 4 woods are similar and have been used in Iranian historical buildings and their identification would be important.Among 4 species, Zelkova carpinifolia is somehow similar to Celtis australis while, Ulmus glabrar is close to Ulmus carpinifolia. Boundary cells of rays in Zelkova carpinifolia and Celtis australis are bigger than inside cells of rays. The difference between Zelkova carpinifolia and Celtis australis are in ray width. Ray width of Celtis australis is 7-8 cells, whereas Zelkova carpinifolia 5- 6 cells. The color of soluble (Glycerin + water)which have been used for softening of wood samples(2× 2 cm)for Zelkova carpinifolia got golden color but others grey. The difference between Ulmus glabra and Ulmus carpinifolia are in appearance of rays. The appearance of Ulmus carpinifolia’s ray is short and wide while ray of Ulmus glabrar is tall and slender. Meanwhile the frequency of rays in cross section of Ulmus carpinifolia is 6-8 per millimeter but in the case of Ulmus glabrar the figure is 4-5.
Management and Economics wood
Mehdi Modirzarea; Sayed khalil Hosseini hashemi; Amir Nourbakhsh; Vahid Safdari
Abstract
In this study the effect of white and brown-rot fungi on durability and hardness characteristics of Bagasse/Polypropylene composite was evaluated. The test specimens were prepared using Bagasse fibers (38%), Polypropylene (60%), and maleic anhydride (2%) according to respective standard and by hot press ...
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In this study the effect of white and brown-rot fungi on durability and hardness characteristics of Bagasse/Polypropylene composite was evaluated. The test specimens were prepared using Bagasse fibers (38%), Polypropylene (60%), and maleic anhydride (2%) according to respective standard and by hot press method. Then specimens were exposed to white (Coriolus versicolor) and brown-rot (Coniophora puteana) fungi according to BS 838:1961 standard and Kollescale method at 8, 12 and 16 weeks. After that, superficial damage, weight loss, and hardness strength of samples were determined. The results showed that superficial damage of brown-rot fungus was lower than white-rot fungus. The weight loss of white-rotted samples were significantly (P<0.05) higher than brown-rotted one, but the hardness of white-rotted samples was a little higher than brown-rotted one. Totally by increasing of time the severity of decay increased.
