Vahid reza ُSafdari; Nima Eskini; Aghang Tajedini; Valima Bayramzadeh
Abstract
Abstract: Wood anatomy in addition to genetic is affected by environmental factors. One of the environmental factors is soil erosion which affects anatomical properties of roots considerably. Juniperus excelsa is one of Iranin indigenous softwood and has longevity and anatomical properties of its root ...
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Abstract: Wood anatomy in addition to genetic is affected by environmental factors. One of the environmental factors is soil erosion which affects anatomical properties of roots considerably. Juniperus excelsa is one of Iranin indigenous softwood and has longevity and anatomical properties of its root in two conditions: inside of soil and exposed one can reveal effects of soil erosion on wood anatomical properties of root. So many roots and barks of trees in inside of soils and exposed have been sampled and many micro-sections prepared by microtome and anatomical properties were investigated. Results showed that wood roots under soil conform of one row of late-wood and by exposing the lumen area of tracheids in early-wood and late-wood were decreased and the cells appear thicker and late-wood portion increased. The axial parenchyma inclusion of dark resins in exposed roots observed frequently. Meanwhile by exposing of roots the thickness of bark decreased and the thickness of phloem and periderm in exposed root is not as wide as normal roots.
Research Paper
Zinab Frozan; Asghar Taremian; Janin Gerar
Abstract
In this study, the potential use of spectrophotometery and CIELAB technique was evaluated to detect reaction woods, including poplar tension wood and spruce compression wood. Thus, two trees of spruce ( Picea abies) and poplar (Populous nigra) containing reaction wood were cut from a forest belonging ...
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In this study, the potential use of spectrophotometery and CIELAB technique was evaluated to detect reaction woods, including poplar tension wood and spruce compression wood. Thus, two trees of spruce ( Picea abies) and poplar (Populous nigra) containing reaction wood were cut from a forest belonging to ENGREF (the National Engineering School of Forestry close to Nancy in France). Then, the parameters of lightness (L*) and reflectance (R) were measured in the reaction and normal wood regions in the green and dry conditions. The results showed that in the green condition, the spruce compression wood had less lightness than the normal wood and the lightness of compression wood increased as a result of drying. Difference between the lightness and reflectance parameters of two types of reaction woods and those of their corresponding normal woods was significant in the green condition. Consequently, it can be concluded that the macroscopically detection of reaction wood is easier in the green condition than in the dry one.
Research Paper
Vahid reza ُSafdari; Nima Eskini; Ajang Tajdini; Vlima Bayramzadeh
Abstract
Wood anatomy in addition to genetic is affected by environmental factors. One of the environmental factors is soil erosion which affects anatomical properties of roots considerably. Juniperus excelsa is one of Iranin indigenous softwood and has longevity and anatomical properties of its root in two conditions: ...
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Wood anatomy in addition to genetic is affected by environmental factors. One of the environmental factors is soil erosion which affects anatomical properties of roots considerably. Juniperus excelsa is one of Iranin indigenous softwood and has longevity and anatomical properties of its root in two conditions: inside of soil and exposed one can reveal effects of soil erosion on wood anatomical properties of root. So many roots and barks of trees in inside of soils and exposed have been sampled and many micro-sections prepared by microtome and anatomical properties were investigated. Results showed that wood roots under soil conform of one row of late-wood and by exposing the lumen area of tracheids in early-wood and late-wood were decreased and the cells appear thicker and late-wood portion increased. The axial parenchyma inclusion of dark resins in exposed roots observed frequently. Meanwhile by exposing of roots the thickness of bark decreased and the thickness of phloem and periderm in exposed root is not as wide as normal roots.
Research Paper
Roholah Mohebi; Aghang Tajedini; Ahmad Jahan-Latibari; Amir Nourbakhsh
Abstract
The influence of different contents (0, 5 and 10% W/W)of silica and poplar wood powder ( 30 ,40 and 50% W/W of total weight of composite) on strength properties of Polypropylene/Wood powder/Silica composite was evaluated. Various components of composite was melt mixed using two screw counter retating ...
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The influence of different contents (0, 5 and 10% W/W)of silica and poplar wood powder ( 30 ,40 and 50% W/W of total weight of composite) on strength properties of Polypropylene/Wood powder/Silica composite was evaluated. Various components of composite was melt mixed using two screw counter retating extruder, followed by cooling and granulizing. Composite granules were injected into test samples. The results of strength properties measurements revealed that almost all strength values were improved. At higher content of silica, The MOR increased from 47.9 to 53.3 MPa, MOE from 2625 to 4517 MPa and MOE in tensile increased from initial value of 4525MPa (without silica) to 6884MPa (10% silica in composite). Marginal increase in tensile strength and Izod Impact strength was observed, but the hardness of the composite was improved from 66 to73.77 shoreD. At higher silica content, the density of the composite was higher, as expected.
Research Paper
Mohammad Ghofrani; Habib Nori; Hossein Rangavar
Abstract
In this study we have paid to mechanical strength measurement of redy to assemble joints (RTA). Including metallic angular joint and elite and compere them with fixed joints including wooden dowel twist and biscuit joint in two cut load test, siding, in some fiber board factor with medium ...
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In this study we have paid to mechanical strength measurement of redy to assemble joints (RTA). Including metallic angular joint and elite and compere them with fixed joints including wooden dowel twist and biscuit joint in two cut load test, siding, in some fiber board factor with medium density fiber board(MDF ).According to ASTMD1761 standard testing cases with L-from from two pice of MDF with 20cm*20cm dimensions that are mad in L-form and the repetition that have been taken in cansidration for any maintance is 5 sample.The number of 80 sample that are studied in this field are as follow: fixed joint including wooden dowel joint, granulated with drops of 8mm and 10mm covering by Adhesive PVAc, twist joint with 40mm and 50mm length , wooden Biscuitt joint number 10 coverd with( mixed with )PVAc adhesive and ready to assemble joint including Elite joint reinforcement with dowel with 8mm and 10mm diameter, metallic ready to assemble joint with pin and withont pin, reinforcing with dowel to 8mm and 10mm diameter.In fixed joint for studing the coated effect, we have used plates of MDF with coated and without coated (uncoated). The result of study showed ready to assemble joints with pin is more than ready to assemble angular joints without pin, also ready to assemble joints strength of Elite joints with dowel 10mm is more than fixed joint strength of 8mm dowel. fixed joint strength of 5mm twist with MDF uncoated in both tests in more than strength of uncoated 4cm twist. more upper rang of strength 4cm twist. more upper rang of strength in ready to assemble joints are specified in cut load test siding regular spinous and 10mm dowel. In fixed joints there is more strength in 10mm dowel joints. for ready to assemble joints, pin reciprocal effect and dowel diameter is 87 and 30/8 respectfuly.Acocording to obtained resalts between more better care of two group are intraduced in spinous ready to assemble joints with 8mm dowel (191.61 N ) and l0mm dowel joints (135.14N).
Research Paper
Sina Modirrahmati; Ahmad Jahan-Latibari; Mansor Minaei
Abstract
The influence of nanoclay addition on the strength properties of HDPE/ Wheat straw powder Composite was investigated. Composites compounds were produced using 73%HDPE, 25% wheat straw powder and 2% MAPE and three amounts of nanoclay (1, 2, and 3% of composite compound). First, HDPE and nanoclay was melt- ...
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The influence of nanoclay addition on the strength properties of HDPE/ Wheat straw powder Composite was investigated. Composites compounds were produced using 73%HDPE, 25% wheat straw powder and 2% MAPE and three amounts of nanoclay (1, 2, and 3% of composite compound). First, HDPE and nanoclay was melt- mixed and after cooling, the extrudate was milled to fine granules. This granules were then melt compounded with pre-weighted amount of wheat straw powder and MAPE followed by injection moulding to produce test specimens. The flexural, tensile and impact strength were measured. The results showed that the addition of nanoclay to the composite improved flexural strength and modulus, tensile strength and modulus. However the notched Izod strength was reduced.
Research Paper
Kazem Dosthosseini; robab ghafari
Abstract
In this research, the effect of increasing content of urea to urea-formaldehyde adhesive on physical and mechanical properties of poplar wood particleboard was investigated. The content of urea added to the adhesive four levels (zero, 4.1, 8.2 and 16 % based on the solid content of adhesive) and ...
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In this research, the effect of increasing content of urea to urea-formaldehyde adhesive on physical and mechanical properties of poplar wood particleboard was investigated. The content of urea added to the adhesive four levels (zero, 4.1, 8.2 and 16 % based on the solid content of adhesive) and two press temperatures of 170 and 180° C as the variable factors were selected. Boards with density of 0.63 gr/cm3 and 10% of the adhesive dosage were made. Mechanical properties including modulus of rupture (MOR), internal bond (IB) and physical properties including water absorption and thickness swelling were measured. Results showed that urea addition to urea formaldehyde adhesive improved the mechanical strengths of the board especially internal bonding reduced the water absorption and thickness swelling. Also, the impact of press temperature on mechanical and physical properties of boards was noticeable and boards produced applying press temperature of 170° C were superior.
Research Paper
ُSima Sepahvand; Meysam Zahedi; Samaneh vilki; Taghi Tabarsa
Abstract
Tannins are the most desirable natural, renewable phenolic components which obtained from plant resources. The phenolic nature of tannins causes that this materials react with formaldehyde and form tannin-formaldehyde resins. In this study, the raw materials of wheat straw and forest woods were used ...
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Tannins are the most desirable natural, renewable phenolic components which obtained from plant resources. The phenolic nature of tannins causes that this materials react with formaldehyde and form tannin-formaldehyde resins. In this study, the raw materials of wheat straw and forest woods were used for producing of particleboard (with a ratio of about 50 to 50 percent) using phenol formaldehyde based on tannin. Tannin as a powder was added at 10 and 20 percent (based on dry weight of resin solution) to formalin 35% for glue making. Particleboards were made at two range of thickness, 10 and 16 mm and their properties of including bending strength, modulus of elasticity, internal bonding, thickness swelling and water absorption were measured. The results from this investigation showed that the strength properties of the made boards from combined wood chips were lower than those from pure wood chips. Also, increasing of tannin usage into phenol formaldehyde caused to increase internal bonding or adhesion, swelling and water absorption (2 and 24 hours) of the boards.
Research Paper
Mohammad hadi Aryaei monfared; Hossein Tavakoli; Hossein Hosseinkhani
Abstract
One of the lesser known local woody species of the Zirkooh-Qhaen in the east of Iran is Ammodendron persicum with the traditional name of Divdal. In this study three selected logs were used for study of wood properties. For the first time wood of this desert species was studied from different physical ...
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One of the lesser known local woody species of the Zirkooh-Qhaen in the east of Iran is Ammodendron persicum with the traditional name of Divdal. In this study three selected logs were used for study of wood properties. For the first time wood of this desert species was studied from different physical and anatomical aspects. The results showed that Ammodendron ʼs wood is a ring -porous hardwood that all parts of its cross section have long rays that is visible with naked eye. In the study of physical properties of Ammodendron̛ ҆s wood apparent density and dry one respectively was 1.125 and 0.92 g/Cm3 that put this wood to the very dense category.
Research Paper
amir lashgari; Payam Khodayari; Seid Ali Mohammadi
Abstract
In this research the effect of nail′s length on three different values (32,42,48 mm)the nail number (2 and 3)and the kind of of particleboard and MDF on tensile strength and bending moment has been analyzed ,The member dimension of of 10*15*1.6 cm.have been elected for making of L –type ...
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In this research the effect of nail′s length on three different values (32,42,48 mm)the nail number (2 and 3)and the kind of of particleboard and MDF on tensile strength and bending moment has been analyzed ,The member dimension of of 10*15*1.6 cm.have been elected for making of L –type joint. The junction have not used out of any adhesive as an adjuvant. From combination of this variable factors and examination of any strength some 24 samples have created,that due to the 4 iterations,96 specimens of L shaped joints have been coustructed totally.the bending and tensile strength of produced junction has been measured by mechanical test machine.based on captured results the interaction of constituents of,nail penetration length,nails number and members nature on joint strenght weren′t significant in front of tensile and bending.this research indicated that the junctions with the penetration length of 48 mm,the most amount of nail(three nails)on MDF member elements,have the greatest strength against bending strength,and the link with penetration length of 42mm alone with the most amount of nail(3 nails)on MDF have the greatest strength against tensile,as copared with each other.
Research Paper
Mostafa Jafari
Abstract
This paper presents a new approach to forest wood production and stand productivity through dendroecology and analysis of the annual tree rings of forest broadleaves species. Based on this approach, samples were collected from different heights of the trees and the circumferential growth and wood production ...
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This paper presents a new approach to forest wood production and stand productivity through dendroecology and analysis of the annual tree rings of forest broadleaves species. Based on this approach, samples were collected from different heights of the trees and the circumferential growth and wood production under the growth conditions were determined and the impact of probable competition was investigated. The application of tree dendrochronological method is also considered. The results of this study as part of a comprehensive work showed that in the Caspian forest region, this method can be used for such evaluation for more than last five years. A minimum three tree species namely oriental beech (Fagus orientalis Lipsky), oak (Quercus castaneaefolia C. A. Mey.) and hornbeam (Carpinus betulus L.) in three different elevations along the transect line (profile line) from low (400 m), medium (900 m) and high elevation (1250 m) in Astara, Gilan region were selected. Various behaviors of tree species and their responses to climate changes have been recorded in different elevations.
Research Paper
Neda Moradpour; Mohammad reza Mastari frahani; Alireza Shakeri
Abstract
To investigate the effect of acetylation and antioxidant separately and together on discoloration and contact angle wood plastic composite due to weathering , composite s were made using popular wood flour and high density polyethylene . the sample were exposed to natural weathering for 6 ...
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To investigate the effect of acetylation and antioxidant separately and together on discoloration and contact angle wood plastic composite due to weathering , composite s were made using popular wood flour and high density polyethylene . the sample were exposed to natural weathering for 6 months.
The results have shown that acetylation can relatively reduce the discoloration of weathered sample treatment than control sample.the antioxidant does not have any influence on color change but it seems that antioxidant could prevent partly destruction of plastic .
It should be mention acetylating increased the surface contact angle befor weathering. But it could not protect the sample surface after the exposure period. So that was zero after weathering.
Research Paper
Seid Mahmood Kazemi
Abstract
In order to evaluate resistance of commercial wood species of alder and horn beech, logs were cut to lumbers. After caution of reduction moisture content, the lumbers were converted to special marine samples. The wood blocks were impregnated by CCA (Chrome- Cupper-Arsenic) and Betel method. Then treated ...
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In order to evaluate resistance of commercial wood species of alder and horn beech, logs were cut to lumbers. After caution of reduction moisture content, the lumbers were converted to special marine samples. The wood blocks were impregnated by CCA (Chrome- Cupper-Arsenic) and Betel method. Then treated and untreated wood samples were installed in one meter depth of water at seaside of Amirabad port, for 3, 6, 9 and 12 months. The result of observations showed that, the staining fungi and balanus were able to colonized surface of control samples. However, treated specimens were only occupied by balanus and with increasing time (3 to 12 months) balanus presence were major. The numerical result showed that untreated samples of alder were reduced in weight about 3.5% and treated samples not only had no weight losses but also increased in weight to12.21%. In the case of horn beech the result indicated that the weight loss of control was 2.7% and treated samples -7.9%. Also on surfaces of treated samples on both wood species were no sign of staining fungi. Finally could conclude the water of Caspian Sea is safe for using treated woods by many operations.
Research Paper
Sadegh Maleki; Mohammad Mehdei Faezipour; Ghanbar Ebrahimi; mohammad Layeghi
Abstract
The goal of this study was to investigate bending moment resistance of L-shaped screwed corner joints constructed of Plywood members. The thickness of plywood members was nominal 19mm that were compared with medium density fiberboard (MDF) and particleboard with 18mm thicknesses. Effects of thread screws ...
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The goal of this study was to investigate bending moment resistance of L-shaped screwed corner joints constructed of Plywood members. The thickness of plywood members was nominal 19mm that were compared with medium density fiberboard (MDF) and particleboard with 18mm thicknesses. Effects of thread screws (coarse and fine), screw diameter (3.5, 4 and 5 mm), and penetration depth (9, 15 and 28) on bending moment capacity of joints under diagonal tension were investigated. Test results indicated that a screw corner joint becomes stronger as either screw diameter or screw length is increased. Screw length was found to have a greater effect on moment capacity than the diameter. The highest bending moment resistance was observed for joints made with coarse screw which were 5 mm in diameter and 28 mm depth of penetration. The lowest bending moment resistance was observed in joints having fine screw, with 3.5 mm diameter and 9 mm penetrations. Results also showed that bending moment resistance with coarse thread drywall screws was higher than those of the fine thread drywall screws. Bending moment resistance of joints made of plywood was higher than those of joints made of medium density fiberboard (MDF) and particleboard.
