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Karim M.,Guilan University | Daryaei M.G.,Guilan University | Torkaman J.,Guilan University | Oladi R.,University of Tehran | And 2 more authors.
International Biodeterioration and Biodegradation | Year: 2016

Decayed wood samples were collected from naturally infected oak (Quercus castaneifolia C.A.M.). Fruiting bodies of the basidiomycete white-rot fungus Pleurotus ostreatus were identified morphologically and confirmed with rDNA ITS sequencing. Cellulose and lignin compositions were determined and FT-IR spectroscopy was used to collect spectra from decayed and un-decayed wood samples. Histological aspects of decay were monitored by light microscopy. The results of the chemical analysis indicated that P. ostreatus decayed both cellulose and lignin in similar quantities. FT-IR analysis and microscopic images demonstrated that P. ostreatus exhibited simultaneous white-rot in naturally infected oak samples. © 2015 Elsevier Ltd.


Bari E.,Sari Agriculture and Natural Resources University | Taghiyari H.R.,Shahid Rajaee Teacher Training University | Mohebby B.,Tarbiat Modares University | Clausen C.A.,U.S. Department of Agriculture | And 3 more authors.
Holzforschung | Year: 2015

The effects of exposing specimens of Oriental beech [Fagus sylvatica subsp. orientalis (Lipsky) Greuter and Burdet] to the white-rot fungi Pleurotus ostreatus (Jacq.: Fr.) Kummer and Trametes versicolor (L.: Fr.) Pilat strain 325 have been studied concerning the mechanical properties and chemical composition in terms of carbohydrates, cellulose, and lignin. Biological decay tests were carried out in accordance with the EN 113 standard specifications for 30 and 120 days. P. ostreatus had nearly the same deteriorating effects on the mechanical properties and chemical composition as that caused by T. versicolor. High and significant correlations were found between some mechanical properties with chemical components; for instance, the correlation coefficient (R2) between impact bending and carbohydrate content was about 0.96. The changes of components influence the various mechanical properties to a different degree. Incipient fungal decay caused severe changes for impact bending and carbohydrate loss. Several other properties declined at 120-day exposure time, such as the hardness, compression strength parallel to grain, and cellulose and lignin losses. © 2015 by De Gruyter.


Taghiyari H.R.,Shahid Rajaee Teacher Training University | Bari E.,Sari Agriculture and Natural Resources University | Schmidt O.,University of Hamburg | Tajick Ghanbary M.A.,Sari Agriculture and Natural Resources University | And 3 more authors.
International Biodeterioration and Biodegradation | Year: 2014

The effect of wollastonite nanofibers (NW) on biological resistance of particleboard, made from wood chips and chicken-feather fibers (CF), against Antrodia vaillantii was studied. 10% of NW, as well as 5 and 10% of CF, were applied to the particleboard-matrix based on the dry weight of wood chips. Then, as a complimentary study, 10% wood fibers were also added to the wood chips; totaling, 10 mixing treatments. Specimens were prepared and mass loss (ML) values were measured in accordance with the EN 113 specifications. Results indicated that the highest ML (37%) occurred in the control treatment without NW- or CF-content; the lowest ML was seen in panels with 10% of NW, CF, and wood fibers (2.5%). NW substantially decreased ML in all mixing ratios. CF also showed a significant decreasing effect on ML. No significant correlation was found between ML values with any of physical and mechanical properties; however, high significant correlations were found between most of the mechanical properties. It is concluded that NW may be considered an effective filler in wood-composite industry to increase the durability against fungal attack; however, more studies should first be conducted on different fungi and wood and wood-composite materials to finalize this conclusion. © 2014 Elsevier Ltd.


Bari E.,Sari Agriculture and Natural Resources University | Schmidt O.,University of Hamburg | Oladi R.,University of Tehran
Forest Pathology | Year: 2015

Chemical, light and electron microscopic studies were carried out on wood of Oriental beech (Fagus orientalis Lipsky) decayed by the white-rot fungi Pleurotus ostreatus and Trametes versicolor for 30, 60 and 120 days according to the modified European standard EN 113. Mass loss as well as lignin, cellulose and carbohydrate content were determined before and after fungal attack. There were no significant differences of wood mass loss and chemical composition between both fungi at the end of incubation. After each incubation period, small specimens were stained for microscopic studies. The micromorphology of fungal cell wall degradation was rather similar for both fungi. Both decreased the cell wall thickness to the same extent. The accumulation of hyphae as well as the rupture of cell walls was also similar. The occurrence of hyphae, cavities in the pits and vessel walls followed nearly the same patterns. The parenchyma cells were completely destroyed. Altogether, both fungi produced a simultaneous white rot in Oriental beech wood. © 2015 Blackwell Verlag GmbH.


Reza Jalali M.,Sari Agriculture and Natural Resources University | Ziatabar Ahmadi M.K.,Sari Agriculture and Natural Resources University | Aghajani G.,Sari Agriculture and Natural Resources University | Shahnazari A.,Sari Agriculture and Natural Resources University | Ahmadi M.,Bu - Ali Sina University
12th International Multidisciplinary Scientific GeoConference and EXPO - Modern Management of Mine Producing, Geology and Environmental Protection, SGEM 2012 | Year: 2012

Sediment accumulation is one of the major problems in drainage systems. This problem usually leads to clogging of the drains and has effects on the efficiency of water disposal system. This problem occurs in cohesion-less soils, such as fine gravels and silts. The present study attempts to investigate the flow-net behavior when a part of drainage system is clogged. For this purpose, the field modeling of clogging was performed. The experiments and observation were carried out in a sample farm. Therefore, three drain laterals were designed and installed. The upper part of the central one was clogged. Each lateral was 100 meter long and four inches in diameter, the distance between the laterals was 20 meters. The mean longitudinal slop of each lateral was about 0.001 m/m, the distance between the drain and trench was about 10 centimeters from each side which was filled by filter materials. Through analyzing the results obtained from the situ tests,the hydraulic conductivity of soil was assessed to be 0.5 meters per day. In this drainage system a main collector was considered at the end of laterals and proper observation wells were drilled for underground water table exploration and monitoring. After 6 months of observing and recording the data for the underground water table, Laplace equation was reformulated for the upper clogged drains to draw the flow-net. The assumptions made and the conclusions are included. © SGEM2012 All Rights Reserved by the International Multidisciplinary Scientific GeoConference SGEM Published by STEF92 Technology Ltd.


Taghiyari H.R.,Shahid Rajaee Teacher Training University | Bari E.,Sari Agriculture and Natural Resources University | Schmidt O.,University of Hamburg
European Journal of Wood and Wood Products | Year: 2014

The effect of wollastonite nanofibers (NW) on biological resistance of medium-density fiberboards (MDF) made from wood and chicken-feather fibers (CF) against Antrodia vaillantii was studied. NW content of 10 % and CF content of 5 and 10 %, based on the dry weight of wood fibers, were applied to the MDF matrix, giving a total of six different MDF mixing treatments. Mass loss values were measured roughly following the EN 113 specifications. The results showed that NW significantly decreased mass loss to a considerable extent in all mixing ratios, proving its potential to be used as a suitable preservative in wood-composite materials without environmental hazards. A CF content of 5 % showed improving effects on biological resistance, while CF of 10 % was too high and resulted in a weak MDF-matrix; eventually the biological resistance did not improve properly. NW ameliorated part of the undesirable effect of adding chicken feather fibers to the MDF-matrix. A significantly high correlation was found between mass loss versus water absorption (R 2 of 81 %), implying that the penetration of water and fungal hyphae can have rather similar patterns. It can be concluded that NW not only can be used to improve the biological resistance in wood-composite materials against fungi attack, but it can also reduce some of the undesirable properties of chicken feathers, thus providing a reliable and renewable resource for natural fibers to be used in the MDF manufacturing industry. © 2014 Springer-Verlag Berlin Heidelberg.


Moradi Malek B.,Sari Agriculture and Natural Resources University | Ghorbani Kookande M.,Sari University of Agricultural Sciences and Natural Resources | Taghiyari H.R.,Shahid Rajaee Teacher Training University | Mirshokraie S.A.,Payame Noor University
European Journal of Wood and Wood Products | Year: 2013

Effects of silver nanoparticles and fungal degradation on the weight loss and chemical composition of heat-treated poplar wood were studied. Wood blocks were impregnated with a 400 ppm nanosilver suspension under 3 bar pressure for 20 min using Lowry process (edited empty cell). Heat-treatment was carried out at 135, 160 and 185 C. Specimens were divided into 4 groups; control, nanosilver impregnated, heat-treated and impregnated- heat treated specimens (135, 160 and 185 C). All samples from the internal and superficial parts of the blocks were exposed to the white rot fungus Trametes versicolor. The results of heat-treated samples indicated higher amount of Klason lignin and extractives, but lower holocellulose and cellulose content. Furthermore, heat-treatment illustrated an increasing effect on the fungal resistance. For all the properties, significant difference was found between the internal and superficial test specimens. Nanosilver impregnation had an intensifying effect on the results of the heat-treatment. © 2013 Springer-Verlag Berlin Heidelberg.


Gharaei-Fathabad E.,Mazandaran University of Medical Sciences | Tajick-Ghanbary M.A.,Sari Agriculture and Natural Resources University | Shahrokhi N.,Mazandaran University of Medical Sciences
Research Journal of Toxins | Year: 2014

As a part of a research program that aimed to identify antibacterial and antifungal substances from fungus specimen of North Iranian soil samples, four penicillium species were identified as a source of secondary metabolites possessing antibiotic activities. These microorganisms were cultured in a liquid medium for 10 days. The antimicrobial disc assay activity of these extracts towards Candida albicans, Bacillus subtillis, Staphylococcus aureus, Salmonella typhi and Escherichia coli was performed. Supernatants and cell extracts of P. viridicatum Westling, P. citrinum Thom., P. auraniiogriseum Dierckx and P. waksmanii Zaleski showed distinguished antimicrobial activities. TLC assay of supernatants and cell extracts showed production of citrinin by P. citrinum and P. auraniiogriseum and penicillic acid by P. viridicatum and P. auraniiogriseum; while two unknown metabolites from P. waksmanii needed more examinations. These mycotoxins could be examined for other biological activities such as antineoplastic property. © 2014 Academic Journals Inc.


Taghiyari H.R.,Shahid Rajaee Teacher Training University | Moradi Malek B.,Sari Agriculture and Natural Resources University
Heat and Mass Transfer/Waerme- und Stoffuebertragung | Year: 2014

Effects of heat-treatment on longitudinal permeability of circular and square wood specimens were studied here. Specimens were heated to 50, 75, 100, 125, 150, and 185 °C. Results showed that permeability increased at the lowest temperature due to shrinkage; then, it decreased due to irreversible hydrogen bonding and stiffness. The highest temperature increased permeability due to micro-cracks. The higher perimeter in the square specimens aggravated the effects of heat treatment. © 2014 Springer-Verlag Berlin Heidelberg.


Khoshkroudi S.S.,Sari Agriculture and Natural Resources University | Sefidkouhi M.A.G.,Sari Agriculture and Natural Resources University | Ahmadi M.Z.,Sari Agriculture and Natural Resources University | Ramezani M.,Sari Agriculture and Natural Resources University
Archives of Agronomy and Soil Science | Year: 2014

The measurement of saturated water content (SWC) is necessary in the estimation of soil water retention and unsaturated hydraulic conductivity curves. In several studies, pedotransfer functions (PTFs) were developed to predict SWC. Among them, evolutionary polynomial regression (EPR) is one that can operate on large quantities of data in order to capture nonlinear and complex interactions between the variables of the system. In this study, the evolutionary data-mining technique was used to derive new PTFs and different methods were evaluated, such as the soil porosity method, Rosetta method, and others, for the estimation of SWC. For this purpose, 270 soil samples (3:1 ratio for development and validation) from three data sets were used. Among 190 PTFs provided by EPR, one equation with the highest accuracy and the least number of inputs was selected. The EPR predictions were compared with the experimental results as well as the PTFs proposed in previous studies. Comparison of the statistical indicators showed that the 'proposed PTF' and 'porosity method' are the best and worst methods for the prediction of SWC, respectively. Also, good predictions were achieved from the proposed approaches by the groups of Scheinost, Vereecken, and Williams. © 2013 © 2013 Taylor & Francis.

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