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.
Composite wood products
Saeid Ismaeilimoghadam; Afsaneh Shahraki; Fatemeh Dehdast; Samaneh Pourkarami
Abstract
The objective of this study was the evaluation of the addition of silica particles in composite on natural resistance and morphology of wood plastic composite against of white rot fungi (Trametes Versicolor). Wood flour at the ratio of 60% (w/w), polypropylene and 2 per hundred compound (phc) MAPP was ...
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The objective of this study was the evaluation of the addition of silica particles in composite on natural resistance and morphology of wood plastic composite against of white rot fungi (Trametes Versicolor). Wood flour at the ratio of 60% (w/w), polypropylene and 2 per hundred compound (phc) MAPP was mixed. Nano and micro silica at 0, 1, 3 and 5 (phc) were added as filler. The mixing process in internal mixer (HAAKE) was done and test specimens were prepared using injection molding. The test specimens were exposed to Trametes Versicolor fungi for 8, 12 and 16 weeks at 25 oC and 75% humidity according to BS 838:1961. Then the mass loss, long-term water absorption and humidity coefficient diffusion of the samples were measured. The formation of hydrogen bonds between silica and wood flour was determined by Fourier Transform Infrared (FTIR) spectroscopy and the morphology of composite was stydied using scanning electron microscopy (SEM). The result showed that with increasing period of samples exposure to fungi, the mass loss, long-term water absorption and humidity coefficient diffusion in wood plastic composite increased. However at higher silica, decay in the samples was decreased. The effect of silica nanoparticles on natural resistance of wood plastic composite was higher than sample containing silica micro particles. Infrared spectroscopy showed hydrogen bonds between wood flour and silica. The result of scanning electron microscopy showed that with increasing of exposure time to fungi, small and large cracks in composite were created. However increasing silica addition, these cracks were decreased.
Management and Economics wood
Arash Hassan poor; Behzad Bazyar; Habib alah Khademi eslam; Amir Hooman Hamasi
Abstract
Wood polymer composites (wpc) have been extracting used for building Products, Automotive, Packaging materials and another applications. Wpc is subject to fungal attack due to wood components. Early detection of wood decay is critical because decay fungi can cause mass loss and rapid structure failure. ...
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Wood polymer composites (wpc) have been extracting used for building Products, Automotive, Packaging materials and another applications. Wpc is subject to fungal attack due to wood components. Early detection of wood decay is critical because decay fungi can cause mass loss and rapid structure failure. The objective of this study was to compare the effects of two fungi Trametes versicolorand Coniophora puteana on the mass loss of wood plastic composites. Specimens as four various treatments: contain 40,50,60,70 percent of wood flour in composition, were exposed to brown rot and white rot for 4, 8, 12, 16 week. After each of mentioned time Mass loss was measured and its amount increased for each of treatments. As seen, most amount of mass loss occurred on 16th week after contamination and in samples with 70% wood flour about two fungi .Results shown that contamination time and wood flour percent in composition have direct correlation with composites mass loss. Also at same treatments and contamination times white rot has more severe effects on mass loss factor than brown rot.
Sayed mahmood Kazemi; Aliakbar Enayati; Heshmatalah Rahymian
Abstract
The durability of following five wood species: Zelkova carpinifolia, Ulmus glabra, Pterocarya fraxinifolia, Carpinus betulus and Acer laetum were studied. Wood blocks exposed to Trametes versicolor(a white rot fungus) under laboratory conditions according to DIN52176 standard. After 16 weeks incubation ...
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The durability of following five wood species: Zelkova carpinifolia, Ulmus glabra, Pterocarya fraxinifolia, Carpinus betulus and Acer laetum were studied. Wood blocks exposed to Trametes versicolor(a white rot fungus) under laboratory conditions according to DIN52176 standard. After 16 weeks incubation the heart wood of Z. carpinifolia showed 2.19% reduction in weight loss, while U glabra with 41.69%, C. betulus with 45.64%, A. laetum with 53.03% and P. Fraxinifolia with 43.08% weight losses were very decayed. For finding relationship between amount of wood decay and wood extractives a regression was carried out. The percentages of extractive materials by using T20403 standard were 13.84% in Z. carpinifolia, 4.51% in U. glabra, 2.74% in C. betulus, 3.88% in A. laetum, and 4.11% in P. fraxinifolia. Finally there was a negative correlation between rate of decay and amount of wood there was expect P. fraxinifolia. for all wood species extractives.
