Management and Economics wood
Reza Jazayeri; Reza Hajihassani; Sedighe Nazari
Abstract
The main purpose of this study was to evaluate the effect of hydrothermal treatment with boric acid impregnation on some physical and mechanical characteristics and fire resistance of poplar (Populus nigra) and radiata pine (Pinus radiata) wood. In this study, two times of 60 and 90 minutes with two ...
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The main purpose of this study was to evaluate the effect of hydrothermal treatment with boric acid impregnation on some physical and mechanical characteristics and fire resistance of poplar (Populus nigra) and radiata pine (Pinus radiata) wood. In this study, two times of 60 and 90 minutes with two temperatures of 150○C and 180○C were used for the hydrothermal treatment, and boric acid with concentrations of 1, 3 and 5% dissolved in water used for the impregnation treatment. The measurement of the characteristics, including bending strength, impact resistance, volumetric swilling and fire resistance (weight loss due to fire) were done by ASTM-D143, ASTM-D256, ASTM 4446-2002 and ISO 11925 standards, respectively. About fire resistance, 5% boric acid treatment showed the least weight loss due to burning in the wood of two species. As a result of the hydrothermal treatment alone, the fire resistance was even lower than the control. In this regard, the combination of hydrothermal treatment with boric acid treatment resulted in results close to those of hydrothermal with boric acid treatment. Positive effect of hydrothermal treatment on the improvement of dimensional stability, is considered as one of the results of the present study. The temperature of 180○C with a time of 90 minutes reduced the swelling of poplar and radiata pine by about 36.8 and 42%, respectively. Regarding impact resistance, the effect of hydrothermal treatment on the wood of both species and the effect of boric acid treatment on radiata pine wood were negative. Hydrothermal treatment at a temperature of 180○C and with a time of 90 minutes decreased the impact resistance by 28.2% in the wood of both species, and 5% boric acid treatment caused a 13.3% decrease in this property in radiata pine wood.
Management and Economics wood
Seyed Mahmoud Miri Tari; asghar tarmian; Mohammad Azadfallah; Abdolkhani Ali; Davood Efhamisisi
Abstract
DOR:98.1000/1735-0913.1398.34.45.66.1.1575.1575 Mold growth resistance of Polyurethane and Diotrol coatings containing natural (Thyme essential oil) and synthetic (IPBC) fungicides in both free and microencapsulated forms was studied. Polymethyl methacrylate (PMMA) microcapsules were prepared using solvent ...
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DOR:98.1000/1735-0913.1398.34.45.66.1.1575.1575 Mold growth resistance of Polyurethane and Diotrol coatings containing natural (Thyme essential oil) and synthetic (IPBC) fungicides in both free and microencapsulated forms was studied. Polymethyl methacrylate (PMMA) microcapsules were prepared using solvent evaporation method by means of oil emulsion formation in water. Mold growth resistance against Aspergillus niger was determined by Filter Paper Disc method before and after aging process according to ASTM D 5590 Standard. Adhesion strength and surface roughness of coated samples were also measured. Results revealed that biocide-free coatings cannot provide adequate protection against mold growth, and addition of biocides, especially IPBC, significantly improved the mold growth resistance. Even after the aging process, microencapsulated biocides were able to provide better protection against mold growth due to controlled-release mechanism and shielding-effect of polymeric shell. Although the surface roughness of polyurethane coating was increased by using of biocides in both forms, especially microencapsulated ones, its adhesion strength reduced.
Management and Economics wood
Aisona Talaei
Abstract
The present study was carried out with the aim of thermal analysis of furfurylated wood produced from beech (Fagus orientalis) and fir (Abies alba). In this regard, the specimens were saturated with two different levels of furfurylation in the form of low levels (14% fir and 20% beech) and high levels ...
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The present study was carried out with the aim of thermal analysis of furfurylated wood produced from beech (Fagus orientalis) and fir (Abies alba). In this regard, the specimens were saturated with two different levels of furfurylation in the form of low levels (14% fir and 20% beech) and high levels (38% fir and 65% beech), and compared with control samples. The results showed that changes in the TGA and DTA thermograms occur with an increase in the furfurylation level. In the first section of TGA graphs, thermal stability of the wood increased with furfurylation and its level change due to decreased water absorption and evaporation of gases during the process of furfurylation. But in the second and third regions, because of the replacement of furfuryl alcohol with lower thermal stability and flammability in the structure of wood and changes in the chemical structure of the wood, the thermal stability of wood polymers in both species decreased. The results of the analysis of DTA thermograms, in addition to confirming the findings from the TGA analysis, made clear the results of the impact of wood species on the thermal stability of wood polymers. Due to the difference in cellulose and hemicellulose and lignin in the structure of softwoods and hardwoods, the hemi-cellulose type in two species and the thermal stability difference of different implementation, wood polymers from two beech and fir are different in the variation of the surface under the curve of the DTA thermograms, the initial temperatures and peak temperatures.
Management and Economics wood
anooshe fazeli; mohammad ghofrani; fatemeh Hassani khorshidi
Abstract
The present study was conducted to inverstigate the effect of moisture content on adhesion strength of sealer half-polyester and sealer polyurethane on beech (Fagus orientalis) and hornbeam (Carpinus betulus) wood types of northern regions of Iran. PH values of beech and hornbeam was 5.51 and 5.19, respectively. ...
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The present study was conducted to inverstigate the effect of moisture content on adhesion strength of sealer half-polyester and sealer polyurethane on beech (Fagus orientalis) and hornbeam (Carpinus betulus) wood types of northern regions of Iran. PH values of beech and hornbeam was 5.51 and 5.19, respectively. Dried specimens were put in a climatization room to reach moisture contents of 7%, 11% and 15%. After the preparation stage, two layers of sealer were placed on the specimens using a spray. Next, polyurethane and half-polyester were applied to the specimens. The pull-off test was performed on the specimens according to the ASTM D 4541 Standard. The results showed that the most adhesion strength was that of the sealer polyurethane used on the beech wood type with the moisture content of 7 percent and the least adhesion strength belonged to the sealer half-polyester used on the hornbeam wood type with the moisture content of 15 percent. It was also observed that increasing moisture content caused a decrease in adhesion strength of both wood types.
Management and Economics wood
Habib alah Arab tabar firoz jaei; Ali Reza nezhad; Abdolrahman Hosseinzadeh
Abstract
Wood samples of seven Iranian hardwood species including: Beech (Fagus orientalis), Oak (Quercus castaneaefolia), Hombeam (Carpinus betulus), Alder (Alnus subcordata), Oriental plane (Platanus orientalis), Eucalyptus camaldulensis and Babul (Acacia arabica) were treated with Creosote and Celcure. Then ...
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Wood samples of seven Iranian hardwood species including: Beech (Fagus orientalis), Oak (Quercus castaneaefolia), Hombeam (Carpinus betulus), Alder (Alnus subcordata), Oriental plane (Platanus orientalis), Eucalyptus camaldulensis and Babul (Acacia arabica) were treated with Creosote and Celcure. Then the samples were installed in the sea water of Bandar Abbas coast (Persian Gulf) for a period of 36 months. During 9, 12, 18 and 36 months, the samples were inspected according with recommendation of IRG/WP/4432(l985).The results showed that, untreated samples of all species were not resisted to the marine borers. The samples treated with creosote using full cell process increased durability of all species expect Hombeam and Babul. Treated samples with celcure were not resisted very well and after 15 months were destroyed.
Management and Economics wood
Ebrahim Farashiani; Hossein Hosseinkhani; Satar Zinali
Abstract
Sart long horn beetle (Aeolesthes sarta) is one of the most important pests of elm, walnut, poplar, sycamore and... in Iran. The wood of these trees is valuable and they can be attacked by A. sarta. For the first time in the world, during 1997 -2001, quality and quantity of damage of A. sarta on host ...
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Sart long horn beetle (Aeolesthes sarta) is one of the most important pests of elm, walnut, poplar, sycamore and... in Iran. The wood of these trees is valuable and they can be attacked by A. sarta. For the first time in the world, during 1997 -2001, quality and quantity of damage of A. sarta on host trees was investigated. To evaluate damage amount and reduction of wood production, the number and volume per cubic meter of galleries, and quantity of wood fed by the larvae were evaluated.Also for evaluation of quality damage, nonaffected wood as well as infected wood were compared in terms of economical and industrial values. The results indicated that the quantity damage on the wood of trees was considered as high and larvae fed about 20% of wood. In the mean time, because of dying of the trees, production of wood stopped completely.Sometimes, heartwood particularly pith of the trees was fed and about 50% Of trunk become hollow. Because of damages and existence of numerous galleries, the quality of wood has lowered and so wood has no industrial use and some of tree:species such as walnut and alder lost their economical value up to 90%.
Management and Economics wood
Eiraj Mansoryar; Alinaghi Karimi; Ghanbar Ebrahimi; Ahmad Mirshokraei; Sohrab Rahimi
Abstract
The water repellency and dimensional stabilization of wood species are important for outdoor uses. In this study, the water absorption and water repelling of poplar wood (Populus Alba) by emulsion of paraffin, Quaternary ammonium and starch, were investigated. Paraffin in three levels of 0%, 3%, 5%, ...
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The water repellency and dimensional stabilization of wood species are important for outdoor uses. In this study, the water absorption and water repelling of poplar wood (Populus Alba) by emulsion of paraffin, Quaternary ammonium and starch, were investigated. Paraffin in three levels of 0%, 3%, 5%, Quaternary ammonium in three levels of 0%, 1.5%, 2.5% and also starch in three levels of 0%, 1% and 2%(by weight) were selected as variables. A set of matched specimens were set aside as control, for making comparison. Results showed that the amount of paraffin had a positive significant effect on water absorption and water repellency that is increasing paraffin would improve these properties. Furthermore, specimens treated with paraffin had better water repellency than control samples. Based on the results, it is claimed that the treatment of 5% paraffin, 0-1.5% Quaternary ammonium and 0-1% starch will bring about water absorption and water repellency in treated specimens to a desired level, without causing any damage to other physical properties of them.
Management and Economics wood
asghar tarmian; Amir Sepehr
Abstract
The heat transfer through three orthotropic directions and the evolution of temperature gradient in beech (Fagus orientalis) and spruce (Picea abies) during drying were investigated. Thus, due to low capacity of dryer, small flat-sawn boards with dimensions of 80 × 25 × 40 mm (L×R×T) ...
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The heat transfer through three orthotropic directions and the evolution of temperature gradient in beech (Fagus orientalis) and spruce (Picea abies) during drying were investigated. Thus, due to low capacity of dryer, small flat-sawn boards with dimensions of 80 × 25 × 40 mm (L×R×T) were used. Then, the boards were dried at the dry-bulb temperature of 60 °C and relative humidity of 50 %. Four surfaces of the boards were coated by polyurethane-coated aluminum foil to confine the heat flux along one direction. Then, the boards were thermally insulated by 50 mm-thick Styrofoam. Some holes with 1mm in diameter were made on the board specific distances to measure the temperature using thermocouple. The results showed that the temperature of each wood increased as heating up progressed until it reached to the wet-bulb temperature. Then, it remained at an almost constant value as the wet bulb temperature until the wood moisture content reached the hygroscopic range. Furthermore, the pattern of the temperature profile for both wood species was almost identical. The surface temperature of the boards increased until it reached the dry-bulb temperature of 60 °C, while the core temperate remained as the wet-bulb temperature (48-52 °C) throughout the rest of drying period.
Management and Economics wood
Afshin Kshn dehghan; Habibalah Khademi eslam; Behzad Bazyar
Abstract
In this study, the influence of the fungus (Coriolus versicolor) on the durability of Horn beam (carpinus betulus) in natural state and treated with CCA (Copper/Chromium/Arsenic) was evaluated. CCA is a kind of water borne preservatives that was used to treat specimens under vacuum and pressure ...
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In this study, the influence of the fungus (Coriolus versicolor) on the durability of Horn beam (carpinus betulus) in natural state and treated with CCA (Copper/Chromium/Arsenic) was evaluated. CCA is a kind of water borne preservatives that was used to treat specimens under vacuum and pressure (Bethel procedure) with amount of 3.5 & 1.5 percent on the basis of oven dry wood. Specimens were contaminated with cultured fungus for eight weeks in incubator. After this period, weight reduction, compressive strength (parallel to grain) and hardness of specimens were measured. Weight reduction of treated samples with 3.5 & 1.5 percent CCA were 1.68 and 1.73 percent respectively. Weight reduction of control samples were much higher (22.87 percent) than treated ones. There was no significant difference between the Compressive strength (parallel to grain) of treated and control samples without effect of fungus but the samples with effect of fungus have significant difference. Compressive strength (parallel to grain) of treated samples with 3.5 & 1.5 percent of CCA were 64.33 and 60.10 (Mpa) respectively but Compressive strength (parallel to grain) of control samples were much lower (38.44 Mpa) than treated samples. There was no significant difference between the hardness of treated and control samples without effect of fungus. On the other hand, the hardness of treated samples was more than control samples slightly, but this difference was not significant in 5 percent level. The hardness of treated and control samples with effect of fungus have significant difference. Hardness of treated samples with 3.5 & 1.5 percent of CCA were 5788(N) and 5799(N) respectively. However the hardness of control samples were much lower (3139N) than treated samples. Eventually CCA (Tanalith c) increased the durability of Horn beam (Carpinus betulus) from nondurable level to durable level.
Asghar Tarmian; Marjan Ebrahimi; Reza Oladi
Abstract
In this research, the effects of vessel features, including vessel diameter, density and porosity on drying rate and casehardening of beech (Fagus Orientalis) and oak (Quercus castaneifolia) was investigated. For this purpose, flat-sawn boards with dimensions of 170×50×80 mm (L×T×R) ...
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In this research, the effects of vessel features, including vessel diameter, density and porosity on drying rate and casehardening of beech (Fagus Orientalis) and oak (Quercus castaneifolia) was investigated. For this purpose, flat-sawn boards with dimensions of 170×50×80 mm (L×T×R) were cut from the sapwood and were then dried in laboratory kiln at 50˚C and 50 % relative humidity to final moisture content of 8%. After drying, the severity of casehardening of dried boards was measured using prong test. For anatomical studies and measuring vessel features, white chalk and black marker method was used and scanned sections were analyzed using ImageJ. Pearson correlation was applied between vessel features and drying properties using SPSS software. Results showed that vessel proportion and porosity have more pronounced effect on the drying rate than vessel diameter and the latter feature can be ignored; as drying rate in the free-water domain was lower for oak having larger but fewer vessels than beech. Results also showed that correlation between casehardening and vessel diameter was significantly positive; however, a negative correlation was observed between porosity and casehardening.
Management and Economics wood
Meraj Sharari; Ahmad Jahan latibari; Gholamreza Rafiei; Ahmad Mirshokraei
Abstract
In the course of enhanced bioremediation, addition of nutrients such as carbon, nitrogen, phosphorous, etc, substrates, electron acceptors as well as vitamins (Thiamin, etc) and veratryl alcohol, increased metabolic activities, will influence the production of enzymes and enhances the deterioration of ...
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In the course of enhanced bioremediation, addition of nutrients such as carbon, nitrogen, phosphorous, etc, substrates, electron acceptors as well as vitamins (Thiamin, etc) and veratryl alcohol, increased metabolic activities, will influence the production of enzymes and enhances the deterioration of pollutants. In this study, the effect of 1% (V/V) of nutrients containing various mineral salts, carbon (glucose and malt), nitrogen (casein peptone yeast extract) and some enzyme inducer, such as veratryl alcohol and thiamin hydrochloride on production of laccase, peroxidase and xylanase enzymes by Phanerochaete chrysosporium in bagasse preparation effluent is investigated. The results showed that MSB+MCTV is the most effective additive which causes the highest lignolitic activity of this fungus after 5 to 7 days in case of laccase and peroxidase and 3 days for xylanase, and maximizes the production of the enzymes. The production of these enzymes is measured at 78, 193 and 60 U/l respectively. However, in conditions without additives, the relevant values are 26, 54 and 16 U/l respectively. The relation between different stages of fungus growth and enzyme production and changes in lignin and carbohydrate of effluent after the period of nine days is also investigated.
Management and Economics wood
Saeed Khojasteh Khosro; Masoud Taghipour Javy
Abstract
The main objective of the current study was the investigation of the effect of adding the wollastonite nanoparticles (casio3) to the water based acrylic coating onto the fire resistance capability and adhesion strength of coating. The nano wollastonites with the concentrations of 0.5, 1.50, and 2.5 wt% ...
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The main objective of the current study was the investigation of the effect of adding the wollastonite nanoparticles (casio3) to the water based acrylic coating onto the fire resistance capability and adhesion strength of coating. The nano wollastonites with the concentrations of 0.5, 1.50, and 2.5 wt% were dispersed into the coating. Ultrasonic device was used to stabilize the nanoparticles into the substrates. The coating process was carried out with and without application of the nanoparticles on the surfaces of spruce and sycamore samples and their properties comprising the fire resistance and the adhesion strength were investigated. The obtained results showed that adding of nano wollastonite to the acrylic coating with the waight percent of 2.5% (w/w) had the significance effect onto the resistance of the samples to fire. In particluar, these effects was observed in cas of the retard time of ignition of the spruce and sycamore samples with the improvement values of 258 and 184 % compared with the control samples, respectively. Furthermore, the investigation of adhesion properties of coatings to the sample surface indicated that the applied nano wollastonites improved these properties of coatings. In case of the adhesion properties, however, the highest value of this properties was observed in the highest content of wollastonite nanoparticles. It should be noted that the performance of nanocomposite coating containing of the 1.5 wt% of nano onto investigated properties was also acceptable.
Management and Economics wood
Mehrab Madhoushi; Vajihe Mojerian Galogahi; Mohammadreza Masteri Farahani
Abstract
Radiography is a method of non-destructive for evaluating the quality of wood construction machinery in order to detect the defects due to natural degradation. The objective of this study was to investigate the assessment of Poplar (Populus deltoides) and beech (Fagus orientalis) wood defects arising ...
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Radiography is a method of non-destructive for evaluating the quality of wood construction machinery in order to detect the defects due to natural degradation. The objective of this study was to investigate the assessment of Poplar (Populus deltoides) and beech (Fagus orientalis) wood defects arising from the decaying by using x-ray non-destructive method. In this study, for each of species, uncolored (no coating) and colored samples by acid catalyzed lacquers and nitrocellulose lacquers were used. Decay resistance test based on modified ASTM D1413 standard was performed. The decay process was done in the periods of 1, 2 and 3 months with use of Coriolus versicolor fungus at laboratory condition. After each of these periods, for the decay of the samples, x-ray imaging by using an imaging at the lateral, tangential and radial direction was done. Results of weight loss confirmed the presence of decay in the radiographic images. The results showed that after 1, 2 and 3 months of exposure to fungus, fungal degradation leads to weight loss in the painted and unpainted samples. So that, the weight loss caused by decay in beech was less than poplar samples. As well, the weight loss of unpainted was less than painted samples, which was also statistically significant. The x-ray results of unpainted and painted samples at the cross, tangential and radial directions indicate that decay has a more impact on beech in comparison to poplar wood structure. The study as well showed that the protective layer has partly a barrier for decay destruction in these samples.
Management and Economics wood
Foroogh Dastoorian; Faezeh Farhadi; Fahimeh Hoseinzadeh; majid zabihzadeh
Abstract
The present study was done with the aim of investigation of the effect of heat treatment on chemical and physical properties of Iranian beech and Velvet maple. Results of spectroscopy showed that heat treatment led to decrease of hydroxyl groups which became more sensible with increasing temperature ...
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The present study was done with the aim of investigation of the effect of heat treatment on chemical and physical properties of Iranian beech and Velvet maple. Results of spectroscopy showed that heat treatment led to decrease of hydroxyl groups which became more sensible with increasing temperature up to 175oC. Treatment at 190oC led to an increase of hydroxyl group comparing to the control ones. Increasing cellulose crystallinity, decreasing the hemicellulose content, increasing the lignin ratio, degradation of syringyl lignin and increase the condensation reaction of lignin was also obtained from spectroscopy. Results of water absorption tests also showed that heat treatment caused decreasing of water absorption. The water repellent and anti-swelling efficiency for both species showed that heat treatment at 160oC didn’t improve the water repellency and dimensional stability however treatment at 190oC led to decrease of water absorbance specially in beech. In total, the effect of heat treatment on anti-swelling efficiency in beech was more considerable comparing to acer, which can be explained by higher weight loss after heat treatment.
Mehrabi Madhoshi; Maliheh Alizadeh
Abstract
In order to establish a kiln drying schedule for Iranian Beech (Fagus orientalis) lumbers of 5.5 cm thickness, commercially cut from Shast Kola region , 5 km distance from Gorgan. They were then dried under the program based on diffusion theory (from Malmquist's relations) were adopted to dry the lumbers ...
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In order to establish a kiln drying schedule for Iranian Beech (Fagus orientalis) lumbers of 5.5 cm thickness, commercially cut from Shast Kola region , 5 km distance from Gorgan. They were then dried under the program based on diffusion theory (from Malmquist's relations) were adopted to dry the lumbers to the final moisture content of 12±2 %. This program for three separate kiln charges and initial moisture content 66.6, 58 and 45 percent was developed. Initial drying bulb temperature (first step) 46 °C and wet-bulb temperature 45 °C was calculated and in three schedules were same. The severity of surface, end checks and warp (bowing, crooking, twisting) in the lumbers were measured before and after the drying process and quality control methods were used to analyze the wood defects. Results indicated that drying of beech lumber using this new schedule was satisfactory. Also intensity changes of defect in all three repeats were about acceptable quality and quantity. Superior characteristics of this program was no surface checks in samples because the moisture content was reduced slowly.
Management and Economics wood
Mysam Khalilian Shalamzari; Mahammad ali Sadat nia; Hamid reza Pirayesh
Abstract
The aim of this study was to investigate the effects of natural weathering induced by critical climate conditions on quality of sugarcane bagasse lignocellulosic material in Pars factory. The experimental samples selected from fresh and also stored bagasse for durations of 6 months, 1, 2 and 5 years, ...
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The aim of this study was to investigate the effects of natural weathering induced by critical climate conditions on quality of sugarcane bagasse lignocellulosic material in Pars factory. The experimental samples selected from fresh and also stored bagasse for durations of 6 months, 1, 2 and 5 years, were used. The mechanical and the chemical properties as well the color variations were measured on taken samples. The results showed that the long storage durations of bagasse significantly decreased the quality of row materials observed in hand sheet tensile and fold strengths. The results illustrated that the amount of Lignin and extractives increased (44 % in lignin and 32% in extractives amount respectively) and also decrease in amount of cellulose and hemicellulose was found (10% for cellulose and 43% for hemicellulose) during 5 years storage in yard. According to the results, there was an obvious difference in L and a color index of 5 years old bagasse in comparing with those of fresh bagasse. Finally it can be drawn that the use of discorded and weathered bagasse could cause the loss in the final products quality which means more chemical treatment for bleaching and more using long fiber in paper making process.
Management and Economics wood
Hadi gholamian; Asghar Tarmian; Ali Abdulkhani
Abstract
In present study, the adhesion strength of polyurethane and alkyd coatings on the poplar wood (Populus nigra) was improved by nano-silane coating using sol-gel method for outdoor application. For this purpose, the boards with dimensions of 15 × 10 × 2 mm were prepared according to EN 927-5. ...
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In present study, the adhesion strength of polyurethane and alkyd coatings on the poplar wood (Populus nigra) was improved by nano-silane coating using sol-gel method for outdoor application. For this purpose, the boards with dimensions of 15 × 10 × 2 mm were prepared according to EN 927-5. The surfaces of wood specimens were modified with Tetraethoxysilane (T) sol-gel material and then, solvent-borne alkyd (AS) and solvent-borne polyurethane (PS) coatings were applied. The coated samples were placed outdoor on a platform with a slope close to Karaj latitude (36̊) for 8 months according to ISO 877 standard. In order to characterize the quality of the coatings, colorimetric, tensile adhesion (Pull off), scratch adhesion (Cross cut) and ATR-FTIR tests were performed before and after weathering. The ATR-FTIR analysis demonstrated that the wood surface was covered with silicon oxides (SiO2) attached to hydrocarbon chains. As a result of surface wood modification by sol-gel, the color and adhesion strength of polyurethane and alkyd coatings were less affected by weathering. The highest tensile and scratch adhesions were found for the combined sol-gel and polyurethane coatings.
Management and Economics wood
mahboob abdolalizadeh; mehrnaz azadi boyaghchi; mohammad mohammadypour; mohsen mohammadi achachluei
Abstract
Paper works are more attacked by biological agents such as fungi, bacteria and insects due to its organic nature. In archives, most of the biological destruction of paper is related to fungi. The importance of paper works conservation has led to applying different methods to fungus removal. ...
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Paper works are more attacked by biological agents such as fungi, bacteria and insects due to its organic nature. In archives, most of the biological destruction of paper is related to fungi. The importance of paper works conservation has led to applying different methods to fungus removal. The chemical disinfection is of of the most common disinfection methods. In this research, the application of Thiophanate methyl in paper destructive fungi has been studied. Laboratory studies to evaluate the effects of Thiophanate methyl on paper and fungus include accelerated ageing, the evaluation of effectiveness of antifungal Thiophanate methyl on fungi such as Aspergillusniger, Aspergillusflavus and Penicilliurnsp and determination of antifungal stability after accelerated ageing. Examination shows that Thiophanate methyl has successfully prevented spread of fungus in all density of 10, 50, 100,200 and 500 ppm. Aspergillus flavus fungus had a slight growth at 10 ppm, but no growth were observed in other density. Aspergillusniger fungus had no growth capacity in density more than 100 ppm. According to the results, treated papers are still able to control fungus growth after being in accelerated ageing condition. In general, the results obtained by fungus growth halo and non-growth halo indicate that all fungi are controllable in density of 200 ppm.
Management and Economics wood
Latif Nazari; Seyyed Khalil Hosseinihashemi
Abstract
In this research, the individual and interaction effects of three organic biocides (propiconazole, tebuconazole, and chlorothalonile) with the metal chelator EDTA and the antioxidant BHT at different concentrations (50, 150, 250, 350, and 450 ppm) against the white-rot fungus, Trametes versicolor was ...
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In this research, the individual and interaction effects of three organic biocides (propiconazole, tebuconazole, and chlorothalonile) with the metal chelator EDTA and the antioxidant BHT at different concentrations (50, 150, 250, 350, and 450 ppm) against the white-rot fungus, Trametes versicolor was investigated. In under laminar sterile hood, about 25 mL of the media was poured into the Petri plates. Three antibiogram discs (with triangular position) put on the media. By micro-sampler about 20 μL of steriled preservative solutions was poured on every disc, separately. Then, about 5 mm of mycelium plug of intended fungus that was inoculated previously was put in the center of plates. The plates were incubated and daily for one week, the mycelium growth of fungus and inhibition effects of different preservative solutions against fungus was measured. The results of this research demonstrated that chlorothalonil biocide by itself have not any inhibition effect on growth of fungus, whilst propiconazole and tebuconazole biocides by itself have significant effect at different concentrations on growth of fungus. In consider of synergistic effect of propiconazole, tebuconazole, and chlorothalonil biocides with non-biocides additives of EDTA and BHT, it has been found that there is synergistic effect between propiconazole biocide and the metal chelator EDTA at high concentration such as 450 ppm, but in combination with other solutions synergistic effect has not been found. Also, any synergistic effect has not found between tebuconazole and chlorothalonil biocides with other preservative solutions.
Management and Economics wood
Mohammad Hadi Rezvani; Aisona Talaei; Hosseinali Rajabi Cham Heidari
Abstract
One of the main strategies to develop the extent of wood modification is using active functional groups in wood structure or the so-called impregnation with modified N-methylol compound. The aim of this study was to evaluate the physical properties of paulownia wood after modify with Polycrease ECR Cell ...
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One of the main strategies to develop the extent of wood modification is using active functional groups in wood structure or the so-called impregnation with modified N-methylol compound. The aim of this study was to evaluate the physical properties of paulownia wood after modify with Polycrease ECR Cell wall resin, to name modified dimethylol-dihydroxyethyleneurea (mDMDHEU). Physical test samples were prepared according to ASTM and EN standard and treated with pressure vessel method at two concentration levels; 15 and 25 percent of soluble resin. For polymerization, treated samples were heated in oven for 24-hour periods at 145 and 155 ºC respectively. Weight percent gain (WPG), bulking, water soaking, swelling, anti-swelling efficiency (ASE), leaching and contact angle were determined. High mDMDHEU concentration increased the weight gain and cell wall bulking. Highest weight percent gain (10.70%) and bulking efficiency (6.85%) in to levels of 25% were determined at 155 ˚C. In comparison with the unmodified wood, the mDMDHEU modified wood due to absorbed polymer enhancement exhibited improved dimensional stability and reduced water uptake, and maximum dimensional stability were determined in samples modified using to level 25% mDMDHEU containing solutions and curing temperature 155 ºC. Moreover, mDMDHEU treatment was resistant to leaching. Contact angle measurement further confirmed the improved hydrophobicity of wood after modification. Modification with mDMDHEU improved significantly the physical properties. The improve of the resistance of chemically modified wood exposed to can be attributed to the reduction of wood moisture, bulking of cell walls and cell cavities blocking affect to dominant reactivity mDMDHEU with cell wall wood polymer.
Management and Economics wood
Fatemeh Hasani Khorshidi; Mehdi Emadi
Abstract
In this study, effect of accelerated aging on adhesion strength of half-polyester and polyurethane transparent coatings were evaluated in maple and pine species. For this purpose, dried specimens with 12×110×550 millimeters were used. Sealer as substrate, and half-polyester and binary polyurethane ...
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In this study, effect of accelerated aging on adhesion strength of half-polyester and polyurethane transparent coatings were evaluated in maple and pine species. For this purpose, dried specimens with 12×110×550 millimeters were used. Sealer as substrate, and half-polyester and binary polyurethane as coatings were applied on wood. Coatings were implemented thereby film applicator and gun methods, and accelerated aging test of wood specimens was carried out according to ASTM D1037. Results indicated that maximum value of adhesion strength is belong to binary polyurethane in maple applied by film applicator and minimum for half-polyester in pine applied by gun method, in opposite. Due to thin film, velocity variations in gun method by painter person, and consequent rapid evaporation of thinner, adhesion decreased in comparison with film applicator method. Also it's found that accelerated aging diminished adhesion strength of coatings in both maple and pine species. It can be concluded during the accelerated aging test, the steam causes moisture absorption and swelling of the fibers near the surface and thus reduce the resistance of the coating adhesion.Long-term effect of humidity and aging makes Ecowool quickly lose their stickiness.And the effect of floating in the water samples, lignin degradation products in the process of steaming and freezing and heating washed by water And cause the loosening of the cellulosic fibers in the wood, resulting in wood adhesive strength is significantly reduced due to the accelerated aging test.
Management and Economics wood
Azar Haghighi Poshtiri; Mehdi Jonoobi; Ali Naghi Karimi
Abstract
Cellulose nanocrystals (CNC) are new class of cellulose materials that find wide applications in various research areas over the past two decades. These nanoparticles are usually made by acid hydrolysis of cellulose substances such as wood, cotton, Starch etc. The main aim of this study is to find the ...
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Cellulose nanocrystals (CNC) are new class of cellulose materials that find wide applications in various research areas over the past two decades. These nanoparticles are usually made by acid hydrolysis of cellulose substances such as wood, cotton, Starch etc. The main aim of this study is to find the optimal conditions for obtaining an aqueous stable colloid suspension of cellulose nanocrystal (CNC) from α-cellulose with a high-yield procedure. Therefore various conditions of acid hydrolysis were evaluated as reaction temperature and reaction time. The percentage of yield was calculated for all suspensions. The morphology of the prepared CNC was characterized by Transmission Electron Microscopy (TEM), Environmental Scanning Electron Microscopy (ESEM) and the crystallinity was measured by X-ray diffraction (XRD). The results showed that highest yield of CNC (88%), was achieved from the reaction condition of 60 minutes at 60 °C. Generally, rod-like shape crystals achieved from α-cellulose with an average size of 35-50 nm and high crystallinity (92%) can be make it to a convenient and competitive source for the production of cellulose nanocrystal for various industries.
Management and Economics wood
Reza Hajihassani; Behbood Mohebi; Saeid Kazemi Najafi; Parviz Navi
Abstract
Abstract The present research work has investigated the physical and mechanical properties of hygro-thermally modified poplar (Populus deltoides) wood. The poplar wood blocks were treated hygrothermally at temperatures of 130, 150 and 170°C and for 20, 40 minutes as holding time. The physical and ...
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Abstract The present research work has investigated the physical and mechanical properties of hygro-thermally modified poplar (Populus deltoides) wood. The poplar wood blocks were treated hygrothermally at temperatures of 130, 150 and 170°C and for 20, 40 minutes as holding time. The physical and mechanical properties were determined for both treated and untreated wood. The properties; mass loss, collapse, specific gravity changes, dimensional stability, surface roughness, bending strength and modulus of elasticity, were determined prior to and after the treatment in all wood blocks. As expected, the hygrothermal treatment significantly improved the dimensional stability of the samples. It was also found that the hygrothermal treatment could increase collapse, surface roughness and modulus of elasticity due to the treatment. However, there were decreases in wood mass, specific gravity and bending strength of the treated poplar wood. It was revealed that the mass loss, decrease in the density as well as collapse in woos is correlated with treatment temperature as well as the holding time. While, raise of the treatment temperature as the holding time caused increase of the dimensional stability.
Management and Economics wood
Aisona Talaei; Mohammad Hadi Rezvani
Abstract
In this research the effect of chemical modification with Polycrease ECR on the functional performance of poplar wood to use as wood polymer were investigated. Polycrease ECR the modified dimethyloldihydroxy-ethyleneurea (DMDHEU) was used for chemical modification of wood by impregnation method. Specimens ...
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In this research the effect of chemical modification with Polycrease ECR on the functional performance of poplar wood to use as wood polymer were investigated. Polycrease ECR the modified dimethyloldihydroxy-ethyleneurea (DMDHEU) was used for chemical modification of wood by impregnation method. Specimens prepared according to the ASTM standard and treated in two levels of 30 and 50%. Modification process of specimens were performed at 24 hours in temperature of 120°C. Functional performance including Weight percent gain (WPG), bulking, long term water absorption and volumetric swelling in 8 weeks, bending strength (MOR) and modulus of elasticity (MOE), compression strength parallel to the grain, shear strength and withdrawal resistance of screw parallel to the grain was measured. Two-way analysis of variance (ANOVA) was used for statistical analysis. Obtained results of modified specimens were compared with untreated control. Results showed that modification with Polycrease ECR had significant effects on physical and mechanical properties in treated specimens. Chemical modification in 30% level, lead to reduce long term water absorption and volumetric swelling. Reduction in mechanical properties were not considerable. Chemical modification with Polycrease ECR in 30 % level compared to 50 % level, showed better physical and mechanical properties. Generally, influence of chemical modification on the physical properties (long term water absorption and volumetric swelling) were dominant.
Management and Economics wood
Elham Hatamzadeh Arabi; Maryam Ghorbani; Prya Biparva
Abstract
The current research work was planned to investigate the possibility of zinc oxide nanoparticles synthesis using hydrothermal method in wood structure and its effect on mechanical and biological properties of wood-polymer composite. Test samples were divided to control and treated with styrene, zinc ...
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The current research work was planned to investigate the possibility of zinc oxide nanoparticles synthesis using hydrothermal method in wood structure and its effect on mechanical and biological properties of wood-polymer composite. Test samples were divided to control and treated with styrene, zinc oxide nanoparticles, nanocomposite and nano/Styrene. Mechanical and biological tests samples according toASTM-D143 and EN113 respectively were treated by vacuum- pressure method using cylinder experimental. The mechanical tests were considered for each level 5 repeat and for biological test for each level 10 repeat. The presence of zinc oxide nanoparticles on cell wall and styrene in the cell cavities were confirmed by Scanning electron microscopy. According to the results, bending strength, bending modulus, hardness and pressure parallel to grain for nano/styrene samples with highest improvement were increased 36.74, 40.23, 60.58 and 25.07 in comparison with control respectively. Also, decay resistance of treated samples increased, so that maximum and least weight loss were recorded for control and nano/styrene samples with 25.81 and 3.37% weight loss.
