Search Results (3,078)

This paper investigates the influence of fire protection systems and insulation materials on the thermal performance of steel columns. An unprotected column and several columns insulated with different fire protection materials were analyzed using the SAFIR^® (2022 version) and ABAQUS simulation (2017 Version). Thermal and mechanical properties of steel were defined according to Eurocode (EC3), and fire exposure was simulated following the ISO-834 standard fire. The following two insulation systems were considered: contour encasement and box encasement. Results show that, for identical material properties and thickness, box encasement significantly slows the temperature rise compared to contour encasement. Vegetable-based fire protection materials such as wood fiber, sheep wool, and expanded cork reduced the steel temperature to 400 °C for up to 80 min and extended fire resistance of steel columns 40 to 310 min. These findings demonstrate that such insulation materials can markedly enhance the fire performance and structural integrity of steel columns, offering a sustainable and effective solution to fire protection. Full article

Specialized poplar plantations are relevant for wood-based panel production. In recent years, the Italian poplar sector has progressively moved towards more sustainable cultivation systems. Breeding programs developed new clones with fast growth and increased disease resistance. Agroforestry (AF) has emerged as a promising alternative to the conventional plantation (C), and its ecosystem services have been widely documented. This exploratory study compares the main physico-mechanical properties of solid wood from five new poplar clones cultivated in conventional and agroforestry plantation models. The peeling yields and the performances of plywood produced with their veneers are also investigated. Wood was obtained by harvesting seven-year-old trees in two experimental plantations located in the Veneto Region. All the clones were found to have a higher basic density than that of the ‘I-214’, the reference in the sector, and were suitable for veneers production. It was possible to obtain top-quality sheets from trees of both systems, with some differences between clones. However, the overall quality of the veneers depended on the type of clone and on the cultivation system, where conventional plantations provided better results. Higher mechanical performances were found in plywood produced from clones with higher density. The results provide knowledge to optimize agroforestry cultivation of poplar, also as a complementary source of timber supply for the concerned industrial sector. Full article

Lignocellulosic bio-based materials, such as wood, biocomposites, and natural fibers, exhibit desirable structural properties. This comprehensive review emphasizes the foundational and latest advancements in bioinspired improvement strategies, such as direct mineralization, biomineralization, lignocellulosic nanomaterials, protein-based treatments, and metal-chelating processes. Significant focus was placed on biomimetics, emulating natural protective mechanisms, with discussions on relevant topics including hierarchical mineral deposition, free-radical formation and quenching, and selective metal ion binding, and relating them to lignocellulosic bio-based material property improvements, particularly against fire and fungi. This review evaluates the effectiveness of different bioinspired processes: mineralized and biomineralized composites improve thermal stability, nanocellulose and lignin nanoparticles provide physical, thermal, and chemical barriers, proteins offer biochemical inhibition and mineral templating, and chelators interfere with fungal oxidative pathways while simultaneously improving fire retardancy through selective binding with metal ions. Synergistic approaches integrating various mechanisms could potentially lead to long-lasting and multifunctional protection. This review also highlights the research gaps, challenges, and potential for future applications. Full article

Utilizing forestry and agricultural byproducts like wood and hemp residues advance sustainable additive manufacturing (AM), while reducing material costs. This study investigated the development and characterization of wood–sodium silicate composites incorporating hemp hurd and hemp fibers for AM applications. Formulations varied by wood fiber type (unsifted, 40 mesh, and pellet), sodium silicate concentration (50–60 wt%), and hemp hurd content (0–15 wt%). Properties evaluated include particle size and bulk density of the constituent materials, rheological behavior, extrusion performance, composite bulk density, and flexural and compressive strengths. Rheology and extrusion were largely influenced by the liquid content. Mixtures with low liquid content (50 wt% sodium silicate) had high motor power and low viscosity. As liquid content increased, motor power decreased, while viscosity increased up to 55 wt% and then decreased at 60 wt%. Mechanical properties correlated with particle size, where finer particles enhanced strength. A cost analysis was conducted using raw material prices to determine the economic feasibility of each formulation. Finally, the formulations were evaluated based on strength-to-cost ratios, extrudability and processability. The formulation with pellet wood fibers, 55 wt% sodium silicate, and 10 wt% hemp hurd achieved a high ratio of 73.0 MPa/$ while maintaining low motor power. This formulation offered additional benefits which are discussed qualitatively. Full article

To address the imbalance between the “ecological advantage” and “economic benefit” of wooden structure buildings, this study examines two structural construction methods utilizing inexpensive and readily available small-diameter round timber as the primary material. It demonstrates the advantages of these two structural systems in terms of material consumption, life cycle carbon emissions, and economic efficiency. Through the research methods and processes of “Preliminary analysis–Proposing the construction system–The feasibility analysis of structural technology–Efficiency assessment”, the sustainable wood structure technical system suitable for the development of China is explored. The main conclusions are as follows: (1) Employing the preliminary analysis method, this paper examines and analyzes construction cases that primarily utilize small-diameter round timber as the main material. It delineates specific construction types based on the characteristics of small-diameter round timber. Additionally, it technically reconstructs the methodology for utilizing small-diameter round timber. (2) Two lattice structural systems are proposed, leveraging the mechanical properties and fundamental morphological characteristics of inexpensive and readily available small-diameter round timber of fast-growing Northeast larch. The technical feasibility of these two small-diameter log structure systems is validated through simulation analysis of their spatial threshold suitability. (3) This study conducted a comprehensive comparison between the two small-diameter round timber structural systems and the conventional grain-parallel glued laminated timber (Cross-Laminated Timber) frame structural systems. The analysis was performed from three perspectives. As the primary structural material, grain-parallel glued laminated timber frame structural systems exhibits significant advantages in terms of timber utilization per unit area of the structural system. From a life cycle carbon emission analysis perspective, compared to grain-parallel glued laminated timber frame structures, small-diameter round timber structures can achieve carbon emission reductions ranging from 79.19% to 97.74%. Additionally, the unit area cost of small-diameter round timber structures is reduced by 21.02% to 40.42% relative to grain-parallel glued laminated timber frame structures. Consequently, it can be concluded that small-diameter round timber structural systems possess technical feasibility and construction advantages for small and medium-sized buildings, offering practical value in optimizing technical systems to meet the objective needs of ecological construction. Full article

This study examines the effects of temperature, relative humidity, moisture content, and density on the dielectric constant (ε′) and dielectric loss tangent (tan δ) of oak wood lamellae within a frequency range of 0.079 MHz to 25.1 MHz. The hypothesis tested was that increased temperature and moisture content enhance both dielectric polarization and loss, while density acts as a dominant structural determinant of dielectric behaviour. Oak lamellas were conditioned above saturated salt solutions at 20 °C and measured using an Agilent 4285A LCR meter according to ASTM D150-22. Multiple linear regression was used to demonstrate the statistically significant influence of temperature, relative humidity, moisture content, and density on the tested electrical properties of the lamellas. The results showed that the dielectric properties increase with higher sample density and higher air humidity. Temperature also had an influence, but it was significantly smaller, though still statistically significant (p < 0.05). Changes in dielectric properties were most pronounced at frequencies below 1 MHz, suggesting that dipolar and interfacial polarization are greater at lower frequencies. The findings in this paper provide a basis for optimizing the high frequency/dielectric heating process for heating before bending of oak and other similar hardwoods. Full article

This study showcases the potential of utilizing LiDAR sensing technologies as an automated, efficient, and rapid method for mapping winter pruning wood across vineyards. It was conducted in 2024 in a commercial vineyard in the region of Attica in Greece in the framework of the “AGROSYS” project. The experimental area was 3.5 ha grown with the Savvatiano variety. Cane weight data were collected manually at pruning, while soil spatial variability and canopy properties were mapped and analyzed. The regression analysis of the three-dimensional point clouds and the manual measurements of pruning weight revealed a strong relationship. This signifies the high potential of accurate mapping of dormant pruning canes across vineyards using rapid and time-efficient digital methods. The analysis also revealed strong relationships with the NDRE and canopy temperature at harvest. Full article

Understanding the influence of tree species and their intrinsic traits on biochar yield and carbon retention is essential for optimizing the conversion of biomass to biochar in carbon-negative systems. While it is well-established that pyrolysis temperature and broad feedstock categories significantly affect biochar properties, the extent of species-level variation within woody biomass under standardized pyrolysis conditions remains insufficiently quantified. Here, we synthesized biochar from seven common subtropical tree species at 600 °C under oxygen-limited smoldering conditions and quantified three key indices: biochar yield (Y), carbon recovery efficiency (ηC), and carbon enrichment factor (EC). We further examined the relationships of these indices with feedstock characteristics (initial carbon content, wood density) and functional group identity (conifer vs. broadleaf). Analysis of variance revealed significant interspecific differences in ηC but weaker effects on Y, indicating that species identity primarily governs carbon retention rather than total mass yield. Broadleaf species (Liquidambar formosana, Castanea mollissima) exhibited consistently higher ηC and EC than conifers (Pinus massoniana, P. elliottii), reflecting higher lignin content and wood density that favor aromatic char formation. Principal component and cluster analyses clearly separated coniferous and broadleaf taxa, accounting for over 80% of total variance in carbon-related traits. Regression models showed that feedstock carbon content, biochar carbon content, and wood density together explained 15.5% of the variance in ηC, with feedstock carbon content exerting a significant negative effect, whereas wood density correlated positively with carbon retention. These findings demonstrate that tree species and their functional traits jointly determine carbon fixation efficiency during smoldering. High initial carbon content alone does not guarantee enhanced carbon recovery; instead, wood density and lignin-derived structural stability dominate retention outcomes. Our results underscore the need for trait-based feedstock selection to improve biochar quality and carbon sequestration potential, and provide a mechanistic framework linking species identity, functional traits, and carbon stabilization in biochar production. Full article

This systematic mapping review and bibliometric analysis examines Scopus-indexed research on computer vision, image processing, and deep learning applied to wood and timber materials and products. A rule-based Scopus search (TITLE-ABS-KEY, 9 December 2025), combining wood and timber terms with imaging and computer vision terminology, followed by duplicate removal and structured exclusions, retained 1019 papers (1983–2026, early access) covering surface inspection, internal imaging, species identification, processing operations (log-yard/sawmill/panels), automation, dimensional metrology, and image-based property/structure characterization. The papers were classified into nine application categories and three methodological classes using improved rule-based classification with weighted scoring and exclusion rules. Paper output continues to accelerate, with 63.7% of papers published since 2016; Wood Surface Quality Control dominates (48.3%), followed by 3D and Internal Wood Imaging (13.6%), Wood Microstructure and Characterization (10.1%), and Wood Species and Origin Identification (10.6%). Methodologically, classical computer vision prevails (73.6%). Deep learning accounts for 26.4% of the corpus overall and 48.8% of papers from 2023–2026 (early access), while classical computer vision remains prevalent (70.1%) across most categories; the dataset totals 11,961 citations (mean: 11.74 per paper). Validation on 97 papers showed 80.41% accuracy for methodological classification and 70.1% for application categories. We quantitatively map method evolution across the nine categories, introducing a tailored taxonomy and tracking the shift from classical vision to deep learning at the category level. The remaining gaps include dimensional measurement automation, warp detection, sawing optimization, and benchmark datasets, with future directions emphasizing Vision Transformers, multi-modal sensing, edge computing, and explainable AI for certification. Full article

The increasing energy crisis demands sustainable functional materials. Wood, with its natural three-dimensional porous structure, offers an ideal renewable template. This study demonstrates that microstructural engineering of wood is a decisive strategy for enhancing magnetothermal conversion. Using eucalyptus wood, we precisely tailored its pore architecture via delignification and synthesized Fe₃O₄ nanoparticles in situ through coprecipitation. We systematically investigated the effects of delignification and precursor immersion time (24, 48, 72 h) on the loading, distribution, and magnetothermal performance of the composites. Delignification drastically increased wood porosity, raising the Fe₃O₄ loading capacity from ~5–6% (in non-delignified wood) to over 14%. Immersion time critically influenced nanoparticle distribution: 48 h achieved optimal deep penetration and uniformity, whereas extended time (72 h) induced minor local agglomeration. The optimized composite (MDW-48) achieved an equilibrium temperature of 51.2 °C under a low alternating magnetic field (0.06 mT, 35 kHz), corresponding to a temperature rise (ΔT) > 24 °C and a Specific Loss Power (SLP) of 1.31W·g⁻¹. This performance surpasses that of the 24 h sample (47 °C, SLP = 1.16 W·g⁻¹) and rivals other bio-based magnetic systems. This work establishes a clear microstructure–property relationship: delignification enables high loading, while controlled impregnation tunes distribution uniformity, both directly governing magnetothermal efficiency. Our findings highlight delignified magnetic wood as a robust, sustainable platform for efficient low-field magnetothermal conversion, with promising potential in low-carbon thermal management. Full article

Norway spruce (Picea abies [L.] Karst.) plays a key role in European forestry as well as in the wood-processing industry. Identifying suitable alternative species has become increasingly important. In this study, we compared several spruce species originating from two sites in the Ore Mountains (Krušné hory, 483–883 m a.s.l.), an area severely affected by an extensive air-pollution disaster (high SO₂ concentrations) during the 1970s and 1980s. Norway spruce, Serbian spruce (Picea omorika [Panč.] Purk.) and blue spruce (Picea pungens Engelm.) were evaluated in terms of production potential, carbon sequestration relevant to climate-change mitigation, and selected physical wood properties (wood density and shrinkage). The greatest stem volume and corresponding carbon sequestration were recorded for P. omorika (0.191 m³; 75.5 kg), followed by P. abies (0.142 m³; 49.0 kg), while P. pungens showed significantly (p < 0,05) lower values (0.069 m³; 30.6 kg). In terms of wood properties, the highest wood-density values were obtained for P. omorika, together with P. abies, at both sites. P. pungens exhibited lower wood densities. In terms of shrinkage, the species displayed similar values. Overall, our results indicate that P. omorika is comparable to P. abies, and its wood could therefore serve as a suitable substitute for certain applications. Full article

Fire-retardant intumescent coatings offer an effective means of enhancing the fire resistance of combustible substrates such as wood. These coatings have a complex chemical composition and, when exposed to temperatures above 200 °C, undergo an intumescent reaction accompanied by the release of non-flammable gases, forming an expanded, charred layer with low thermal conductivity. This provides thermal insulation and acts as a physical barrier against heat, oxygen, and flammable volatiles. In this study, the applicability of several thermoanalytical techniques for evaluating the performance of three different intumescent coatings applied to spruce wood was investigated. Simultaneous thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) showed that coating No. 3 was the most efficient, initiating substrate protection at the lowest temperature and reducing the combustion enthalpy by approximately 50% compared to uncoated wood. DSC-microscopy visualization enabled direct observation of the intumescent expansion, degradation of the carbonized protective layer, and delayed thermal decomposition of coated wood. Furthermore, a comparison between TGA-MS and TGA-IST16-GC-MS demonstrated the superiority of chromatographic separation for identifying evolved gaseous products. While TGA-MS is effective for detecting small gaseous species (e.g., H₂O, CO₂, formaldehyde), TGA-IST16-GC-MS enables the deconvolution of many degradation products evolving simultaneously, allowing for distinction between flame-retardant-related species, polymer backbone fragments, nitrogen-rich heterocycles, and small oxygenated molecules in the most effective coating. Full article

Historic timber buildings rely heavily on naturally aged wood. However, the influence of long-term environmental exposure on the thermal behavior and fire performance of such structural members remains insufficiently understood. This study evaluates the effect of natural aging on heat transfer, charring development, and the phase-change interval of free water in larch wood (Larix decidua). Medium-scale radiant panel tests were conducted on fresh and naturally aged timber beams. Internal temperatures were recorded at multiple depths and analyzed using derivative-based T-history methods. The temperature profiles of aged and fresh larch were highly comparable, exhibiting a strong correlation (R² = 0.89). Aged wood, characterized by a slightly higher density, showed shallower thermal gradients and a marginally lower average charring rate (0.63 mm·min⁻¹) compared with fresh wood (0.65 mm·min⁻¹). In both materials, the charring rate decreased with depth. The phase-change interval of free water differed markedly: fresh wood showed water evaporation between 107.8–142.1 °C, whereas aged wood exhibited an earlier and narrower interval (93.6–116.3 °C), indicating facilitated dehydration due to microstructural degradation. Overall, natural aging did not significantly impair fire-relevant thermal properties, suggesting that aged larch retains charring resistance comparable to that of fresh wood and can reliably perform in passive fire protection applications for heritage structures. Full article

Thermally compressed fast-growing wood exhibits superior mechanical properties, presenting a sustainable and cost-effective alternative to solid wood. However, to prevent structural damage and achieve higher densification during this process, effective pretreatment is essential. This study systematically evaluates the efficacy of hydrothermal and alkaline sulfite pretreatments in modifying Chinese fir (Cunninghamia lanceolata Hook.) and poplar (Populus tomentosa Carr.). The resulting compressed wood was comprehensively characterized in terms of mass loss, mechanical strength, microstructure, chemical composition, and cellulose crystallinity. Results indicate that, under the conditions tested, alkaline sulfite pretreatment was more effective than hydrothermal pretreatment in enhancing the material properties of densified wood, with peak density, compressive strength, and hardness achieved after 5 h for fir and 3 h for poplar, respectively. The results obtained under the present experimental conditions support the fact that alkaline sulfite pretreatment is an effective approach for producing densified wood with enhanced mechanical properties, suggesting its potential suitability for higher-value applications. Full article

Faced with the depletion of fossil resources and the need to promote a circular economy, lignocellulosic biomass represents a solution for energy transition and bioeconomy. However, wood sawdust, which contains bioactive compounds (secondary metabolites), is often burned in the open by many sawmills. This study aims to valorize Framiré wood sawdust by extracting its secondary metabolites through maceration and infusion, then converting the depleted residue into combustible briquettes. The yellowness index of the extracts ranged from 73.490 ± 0.021 (maceration) to 81.720 ± 0.014 (infusion). The total phenolic content varied from 0.097 ± 0.001 to 0.63 ± 0.049 gGAE/100 g dry matter for maceration and infusion, respectively. The extraction of bioactive compounds did not significantly affect the energy or mechanical properties of the fuels. Their higher heating value ranged from 26,153 ± 92 to 26,201 ± 90 kJ/kg for fuels with and without secondary metabolites, respectively. The Shock Resistance Index ranged from 139.33 ± 7.51% (without metabolites) to 153.00 ± 5.20% (with metabolites). A significant difference was observed in the specific consumption of the fuels, decreasing from 1.400 ± 0.100 to 0.861 ± 0.001 kg/L for fuels without and with secondary metabolites, respectively. These results open promising prospects, particularly for the use of Framiré extracts to develop flame-retardant products for wood and its derivatives. Full article