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This study investigates the relationship between laboratory aging, physical and mechanical changes, and the outcomes of non-destructive testing. A total of 45 composite specimens containing 60 % wood fiber, 35 % low-density polyethylene, and 5 % additives were tested. A laboratory aging process, consisting of water immersion at 20 ºC and 50 ºC for a total of 56 days, was applied to the specimens. During the aging process, several batches of specimens were extracted and tested to measure their physical (density) and mechanical properties (bending strength and modulus of elasticity). Non-destructive testing, including ultrasound and stress wave devices, a screw withdrawal resistance meter, and a penetration tester, were employed. Results indicated that temperature had a greater influence on the WPC deterioration than humidity. A decrease in density (2 % - 4 %) and a significant reduction in mechanical properties (20 % - 60 %) were observed. The non-destructive methods used proved to be reliable estimators of composite properties, especially ultrasound wave propagation, confirming previous findings on other materials.

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Several methods are implemented to improve the quality and productivity of Eucalyptus plantations, including genetic improvement and seedling fertilization. These practices, combined with the favorable soil and climate conditions across much of Brazil, have enabled high yield forest production. These plantations supply raw materials for a wide range of industrial uses, notably the manufacture of wood panels. Among them, edge glued panel are produced by joining battens laterally or on their surface using adhesive bonds. This work aimed to evaluate the technological potential of Eucalyptus dunnii (white gum) wood from different fertilization treatments and genetic sources for the production of edge glued panels. The material was collected from a plantation with trees 8,5 years old in Pinhais, Parana, and included 24 trees: 12 from clonal material and 12 from selected seeds. Each genetic source was subjected to two fertilization treatments (conventional and slow-release) and one control, resulting in six treatments. The wood was analyzed for volumetric, chemical and physical properties. After drying, battens were glued and the strength of the adhesive joints was tested. Clonal trees exhibited the highest volume and the lowest basic density. The lowest anisotropic coefficient was found in wood subjected to slow release fertilization. Fertilization also influenced all aspects of chemical composition. Overall, the treatments with clonal trees and slow release fertilization showed the highest suitability for edge glued panel production, justifying the investment in silvicultural practices from the point of view of wood technology.

El objetivo del estudio fue describir las características anatómicas macroscópicas y microscópicas de maderas perteneciente a la familia botánica Fabaceae para distinguir las especies, proporcionando información para evitar la comercialización ilegal en la Amazonía Brasileña. Se recolectaron muestras de madera en las comunidades extractivas "Verde para Siempre" en el Estado de Pará. Se extrajeron discos de la base de los árboles seleccionados y se elaboraron cubos de madera de 2,5 cm x 2,5 cm x 2,5 cm para realizar los análisis. La caracterización anatómica de las maderas siguió las normas de la Asociación Internacional de anatomistas de la madera. La identificación de la estructura anatómica macroscópica y microscópica de las muestras se realizó en las direcciones de corte de la madera: transversal, radial y tangencial. Los datos obtenidos fueron sometidos a un análisis estadístico cuantitativo descriptivo utilizando el software estadístico R. Fue factible establecer diferencias significativas en la estructura anatómica, de los seis géneros estudiados: Hymenolobium, Dipteryx, Ormosia, Enterolobium, Hymenaea y Pseudopiptadenia. Los caracteres anatómicos más relevantes para la separación de especies fueron radios, parénquima axial, fibras y/o tilosis, resina y cristales en serie en las células del parénquima axial y/o radial. Esta información puede utilizarse para identificar especies en las zonas de gestión forestal y controlar la comercialización de la madera después de la tala.

In this study, the bioactive properties of Ganoderma adspersum, a wood-decaying mushroom, were investigated. The study was designed in three steps: an experimental study, optimization of extraction conditions, and determination of bioactive properties of the optimum extracts. The main research problem was to determine the most effective extraction conditions to maximize the bioactive potential of G. adspersum using advanced optimization techniques. The extraction conditions were designed according to the I-optimal design and optimized using both the response surface method and the integration of artificial neural networks–ant lion algorithm. In the third step of the study, the bioactive properties of the two estimated extraction conditions and the extraction condition providing the highest total antioxidant status value obtained from the experimental studies were evaluated. Antioxidant activity, total phenolic and flavonoid content, antimicrobial properties, anticholinesterase activity, and phenolic content of three different optimum extracts were determined. As a result, the optimum extraction conditions suggested by artificial neural networks–ant lion algorithm optimization showed the best overall bioactive activity, highlighting the effectiveness of hybrid artificial intelligence-based models in bioactive compound extraction processes.  

The cost of wood and non-wood lignocellulosic materials continues to escalate yet the demand keeps rising at the face of the climate change problem aggravated by unsustainable tree removal across the world. Lignocellulose waste is unavoidably generated during construction. The viability of producing decorative furniture items from recoverable wood wastes from a construction site was investigated. Ten construction sites were randomly chosen, for on-the-spot assessment to obtain information on characteristics of bio-wastes originating from construction sites. A 6-flat-storey building was selected for an in-depth study. Data were collected on the composition of bio-wastes, Retrievable volume, and exposure and deterioration status. Redundant fragments of wood wastes were retrieved and processed into glue-laminated panels, constituting intermediate raw material that was used for manufacturing three decorative furniture items. Although a wide range of bio-wastes was generated at the construction sites, wood, bamboo, and medium density fibreboard, wastes were generated more substantially and in decline order, respectively. Most of the bio-wastes had largely deteriorated, but about 60 % of the wood wastes can still be recovered for re-use. Re-using recovered wood for decorative furniture items may save as much as 73 % of the actual cost of wood needed for production, with a negligible increase in labour cost. Glued-laminated panels were used to manufacture shelves installed for office use. The study suggested that more values may be obtained from bio-waste reuse if retrieved without delay.  

In this study, the purpose was to improve outdoor performance of cement bonded wood composite due to their biodegradation and sensitivity to moisture especially in warm and humid climates. Cement bonded wood composites were treated with different concentrations (10 %, 25 %, 50 %, 75 % and 100 %) of water repellent. Water repellent used was an organo-silicon based, nano-sized, eco-friendly, water-based agents. Dipping and pressure systems were applied for composite treatment. Water absorption, thickness swelling, accelerated weathering, color changes and mechanical properties after accelerated weathering were determined for treated and untreated cement-bonded composites. Results showed that treatment of composites with water repellent provided a transparent layer on composite surface. Thus, lower water absorption and thickness swelling results in the beginning of immersion in water. Treated and untreated composites were exposed to an accelerated weathering test for 350 h. Their mechanical strength including modulus of rupture, modulus of elasticity and internal bonding properties were decreased after 350 h of weathering. However, overall results after weathering test showed that all panels’ mechanical properties provided minimum modulus of rupture, modulus of elasticity and internal bonding requirements of the EN standards.

This study investigated the vertical and radial variability of wood acoustical and physical properties in Ailanthus altissima (ailanthus tree), a species with potential applications in musical instrument construction. However, there is limited information about the variation within the stem in these properties, which is essential for assessing its suitability in acoustically demanding applications. In this context, wood density, dynamic modulus of elasticity, damping coefficient, acoustic conversion efficiency, and tangential and radial shrinkage were analyzed across three stem heights and three radial positions. Results revealed significant variation within the stem, with density and dynamic modulus of elasticity increasing from the base to the middle before declining at the top, while acoustic conversion efficiency showed an inverse trend. Radially, acoustic conversion efficiency was highest near the pith and decreased significantly toward the middle and outer parts of the stem, with no significant difference between these outer zones.  The damping coefficient was lowest at the bottom logs, increased significantly at the middle, and slightly decreased at the top. Radially, the damping coefficient was lowest near the pith, increased toward the middle, and reached the highest values near the bark. Shrinkage increased significantly from pith to bark but showed minor axial variation, with similar values at the base and middle, and a significant decrease at the top of the stem.  Importantly, density could be used as an indicator for acoustic conversion efficiency, enabling indirect assessment of acoustic performance. These variations highlight the potential of selecting specific stem regions to balance sound transmission and structural support, suggesting that Ailanthus altissima (ailanthus tree) could replace traditional woods for the backs and sides of stringed instruments.

Shrinkage is a key factor in generating internal stresses and deformations within wood structures, especially due to the anisotropic nature of wood, which causes direction-dependent stress responses and must be considered to accurately predict the mechanical behaviour of cylindrical elements. However, its influence on the stress distribution in cylindrical wood elements remains insufficiently explored. This study addresses this gap by formulating a theoretical model to evaluate the development of internal stresses resulting from the shrinkage of wood specimens. Shrinkage was determined based on the stress–strain relationship of a cylindrical piece of wood, in the absence of external forces, within a cylindrical coordinate system. Due to its radial symmetry, the displacement field is a function of the radius, and the angular displacement is null. Assuming constant longitudinal strains, the strain components can be described as a function of Lekhnitskii’s reduced strain coefficients and the associated coefficient, denoted by k, where the coefficients depend on the material's elastic properties. Thus, the governing equation of the problem becomes a function of the strain coefficients and, consequently, of shrinkage. To demonstrate the effects of shrinkage and to show how stresses in the radial and tangential directions are influenced, the elastic coefficients of the wood species Pinus taeda (loblolly pine) were experimentally obtained, and the coefficient k was determined. Overall, the results emphasise the importance of considering shrinkage and anisotropy when evaluating radial and tangential stresses, as well as radial displacements, in cylindrical wood elements.

Pernambuco wood is the most used material for making professional violin bows. Since the 18th century, it has been known as the best wood for this purpose. However, it is classified as an endangered species. Some researchers looking for alternative woods for bow making have pointed out that ipe wood may have desirable features for making violin bows. Therefore, the objective of this research was to define an evaluation method that could guide selection steps in order to find suitable wood for violin bows testing it in practice. To carry out this research, ipe wood samples were selected from lumber companies and analyzed. Afterward, five violin bows were made and evaluated by professional violinists using a 6-point scale questionnaire. As a result, ipe bows were highly rated by professional violinists, with mean scores spanning 4.21 to 5.10, suggesting a positive level of acceptance. Furthermore, there was a coherence between the scores given by musicians and the estimated potential quality of wood which also had a larger proportion of fibers and lower apparent density, in conformity with other studies. It was concluded that the method adopted worked to find ipe wood suitable for violin bows with characteristics needed to produce professional violin bows even among piles of discarded wood at lumber companies.