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Finger joints are one of the most important and widely used joints in the wood and wood products industry. The design, type of construction, and the type of glue used, etc., are the most important things in this joint that determine its final quality. In this research, the effect of cellulose nanofiber and nanoclay in polyvinyl acetate (PVA) glue at levels of 0, 0.4, and 1.5% in finger joints with lengths of two fingers of 5 and 10 mm was investigated by the free vibration in free-free beam method. In joints without nanoparticles, finger joints with a finger length of 10 mm had better acoustic properties than joints with a finger length of 5 mm, except for the acoustic conversion efficiency factor. The results showed that by adding cellulose nanofiber (CNF) and nanoclay in both finger lengths of 5 and 10 mm at both 0.4% and 1.5% levels, the dynamic modulus of elasticity, elastic stiffness, acoustic coefficient, and acoustic conversion efficiency increased significantly, while the damping factor values showed a significant decrease. In general, the effect of CNF on the acoustic properties of both types of joints was better than that of nanoclay. [ABSTRACT FROM AUTHOR]

Background and objectives: Due to the limitations of determining the remaining useful life in the components of the wooden structures at the conditions of use with destructive methods is the impossibility of calculating the modulus of elasticity due to the impossibility of removing the part from the structure. Therefore, most of the classifications during use in the components of structures such as historical buildings are based on measuring the speed of sound. In this research, to calculate the local and global density و the method of pin penetration rate in wooden tie was used to calculate the amount of the remaining useful life. Pin penetration rate was combined with stress wave and free longitudinal vibration methods. Methodology: The three beech wood (Fagus orientalis) impregnated wooden tie from Iran Railway Company with the dimensions of 15x25x260 cm, were selected and the density was measured by pin penetration method at 5 points of each wooden tie (50 cm distance between each point) and the average results of 5 points were compared with the results of ISO 13910 standard method. The stress wave test was carried out at the same 5 points of density determination by pin penetration rate method to determine the local modulus of elasticity and the results of each point were compared with the global modulus of elasticity of the beam. Longitudinal vibration test was also performed to calculate the damping factor values of the samples. Results: The results showed that there was no significant difference at the 95% level between the values calculated with both the ISO 13910 standard methods and the pin penetration rate method, and there was a favorable linear correlation between the results of the two methods. According to the results, there was no significant difference between the global sound speed of the beams and their local sound speed in any of the five measured points at the 95% level and there was a linear correlation between the values of the global sound speed and each of the five local points. There was no significant difference at the 95% level between the values of the global modulus of elasticity and the values of the local modulus of elasticity calculated in each of the five points. Also, there was a linear correlation between the values of the global modulus of elasticity and the results of the local modulus of elasticity in each of the five points. There was an exponential correlation between the values obtained from the global modulus of elasticity and the damping factor of each of the wooden tie. Conclusion: The equality of density according to the ISO 13910 standard method and the nail penetration method, as well as the equality of the modulus of elasticity calculated by the stress wave method and the free longitudinal vibration method, make it possible to obtain all the data required for required calculations without removing the part from the structure. The remaining strength of wooden components should be provided according to EN338 standard. [ABSTRACT FROM AUTHOR]

The effect of fiber characteristics from old corrugated container (OCC) paper on the strength properties of OCC/polypropylene composites was evaluated. Fibers with different contents of lignin (2.8%, 3.8%, 5.3%, and 7%) were produced using soda pulping. Wettability, tear, and tensile strength of the fibers were measured as the indication factors to assess the strength of reinforcing component in the composites. The weight portions of the OCC fibers, polypropylene, and maleic anhydride-grafted polypropylene (MAPP) were selected at 20%, 77%, and 3% of the total weight of the composite, respectively. The composite compounds were formed using a counter-rotating twin screw extruder, and the specimens were made in an injection molding machine. The interaction of fiber characteristics and fiber lignin content on the mechanical properties of composite was investigated. The results revealed that with lower fiber lignin content, both flexural and tensile properties were increased. Consequently, by forming better fiber dispersion and by reducing stress regions in the composite, impact strength was also improved. Lower lignin content resulted in better mechanical properties than fiber characteristics.

The relationship between the sustainable supply chain practice and firm performance has attracted interest from scholars and industry owners in recent years. On this basis, a model for sustainable supply chain management (SCM) in Iranian Wood Furniture Industry was developed and used to improve the performance of home and office furniture manufacturing companies. The statistical population of the qualitative part consisted of experts and specialists of sustainable SCM, and purposive non-random sampling was used. A structural equation modeling was used in the inferential and quantitative part through Lisrel-v8.8 software. The study identified economic, environmental, and social factors as underlying dimensions of SSCM. It also identified the components of customer satisfaction, financial and market performance as performance components. The results revealed that the path coefficient of SSCM to performance was 0.90. As the t-statistic was 18.07, it was confirmed at 99% level. So, in Iranian wood furniture industry, SSCM has a statistically significant impact on firm performance. Several factors such as strategies, backgrounds, and intervening factors were considered in the final model. The study has significant practical implications for industrial managers and government policy makers in the furniture industry. [ABSTRACT FROM AUTHOR]

Despite the progress in synthetic polymer industries, wood is one of the main materials in making musical instruments because of its unique characteristics. Many instrument makers try to improve the acoustic properties of wood by traditional treatments. In this study, the changes in the acoustic properties of walnut wood during the processes of fermentation pretreatment, water washing, and organic solvent washings were evaluated. For this, the samples were divided into two groups of 20. For the first group, de-extraction was started with fermentation pretreatment, while the second group samples directly underwent stepwise extraction, using hot water and ethanol-acetone solvents. The results showed a decrease in density, dynamic modulus of elasticity, and damping factor due to the soaking process. But the elastic stiffness did not change. The values of the acoustic coefficient and the acoustic conversion efficiency increased due to the soaking process. The values of density, dynamic modulus of elasticity, elastic stiffness, and damping factor decreased due to ethanol-acetone washing, while the acoustic coefficient and acoustic conversion efficiency showed a significant increase. In general, soaking process and ethanol-acetone washing with fermentation pretreatment improved the acoustic properties of walnut wood. [ABSTRACT FROM AUTHOR]

Factors of manufacturing sustainability in the papermaking industry were identified and ranked using qualitative analysis and nonparametric tests. Based on a review of the literature on sustainable development and production, seven main factors of economic, environmental, technological, social, human, material and product, and regulations were identified to underpin the manufacturing sustainability in the papermaking industry, as well as some sub-factors. Then, a self-designed questionnaire was developed to take a poll among papermaking managers and experts regarding the effectiveness of the factors and sub-factors in manufacturing sustainability and their status. The factors affecting manufacturing sustainability in the papermaking industry were confirmed by the standard and significance coefficients in the structural equations and the predictive criterion. The cross-validated redundancy index showed that the data were valid enough for prediction. The research factors were ranked by the ordinal average affecting sustainability, current status, and distance to sustainability. The materials and product, environmental, technological, and economic factors had the greatest influence on manufacturing sustainability, and the regulation and human factors had the highest distance to sustainability. To achieve manufacturing sustainability in the papermaking industry, regulations and human factors need to be further studied. Their improvement has potential to achieve manufacturing sustainability. [ABSTRACT FROM AUTHOR]

This study addressed the urgent need for biofuels even in countries such as Iran, which has fairly good fossil fuel resources. The problems, necessities of the present, and future demand for biofuels are discussed. As the transportation sector is one of the largest sources of air pollution, this study has focused on this sector. This issue was examined from a global perspective, and then within the context of domestic bioethanol production using agricultural residues and proposing different scenarios. The first step in implementing this policy is the accurate forecast of the demand for second-generation bioethanol in the coming years. A nonlinear auto regressive neural network was applied to predict gasoline demand based on Mackey-Glass chaotic time series. Gasoline demand is forecasted by 2030, based on projected volumes of gasoline in different bioethanol mixture scenarios. Results revealed that using scenarios E10, E15, E25, the volume of bioethanol needed by 2030 will amount to 10.12, 15.16 and 25.31 million L per day which can be produced using agricultural products wastes. [ABSTRACT FROM AUTHOR]

The goal of this work was to evaluate the technical feasibility of walnut shell flour (WSF) as substitute for wood in walnut shell flour/thermoplastic starch (WSF/TPS) composites. The effects of walnut shell flour (WSF), thermoplastic starch (TPS), and nanoclay on the physical and mechanical properties of WSF/TPS composites were investigated. The composite samples were formed in a Colin extruder with four-chamber heat with temperatures. Then, test samples were made using injection molding. The addition of up to 40% WSF greatly improved the tensile strength, flexural strength, and elasticity modulus of the composite. Also, the composites made with higher WSF contents had increased thickness swelling and water absorption. The incorporation of nanoclay (0% to 5%), greatly improved the tensile properties. Soil burial degradation experiments showed that biodegradation was accelerated by the increase of starch in the composite mixtures. The study showed that WSF can be successfully utilized for the manufacture of composites with useful physical and mechanical properties. [ABSTRACT FROM AUTHOR]