Research Articles

Azelaic acid (AzA) impregnation is an effective method for improving the dimensional stability of wood; however, the related microstructural and mechanical changes in lignocellulose remain unclear. In this study, the microstructure and deformation behavior of AzA-esterified wood were investigated using an integrated approach combining thermal analysis, attenuated total reflection infrared (ATR-IR) spectroscopy, wide-angle X-ray diffraction (XRD), and compression testing. When heated below the melting point of AzA, unreacted AzA was observed on the wood surface and within the lumen. In contrast, heating above the melting point promoted diffusion of AzA into the cell wall and induced esterification, which progressed with increasing temperature. The maximum ester content was 1.08 mmol/g dry wood. Heat treatment at 120 °C or higher suggested the formation of cross-links between molecular chains. The relationship between nominal compressive stress (σ) and compression ratio (C) exhibited an inflection point at approximately 10 MPa, suggesting sliding behavior in the intercellular layer under low compressive loads. Furthermore, esterification-dependent differences in cellulose-derived molecular mobility and thermal decomposition behavior were observed.

Effects of pilot-hole application and screw insertion surface were studied relative to the maximum screw withdrawal force and full-field strain distributions in beech (Fagus orientalis) and oak (Quercus petraea) wood using two-dimensional Digital Image Correlation (2D DIC). A total of 80 specimens were evaluated in a 2 × 2 × 2 factorial experimental design, including two wood species, two anatomical surfaces (transverse and tangential), and two pilot-hole conditions (with and without pilot holes). Pilot-hole application increased the mean withdrawal force on transverse surfaces by approximately 30.0% in beech and 7.0% in oak. Conversely, it decreased the mean withdrawal force on tangential surfaces by approximately 15.7% in beech and 30.4% in oak. The factorial ANOVA indicated significant effects of anatomical surface and pilot-hole application, together with significant two-way interactions among the experimental factors. The DIC strain maps revealed spatial variations in normal and shear strain distributions around the screw withdrawal region. However, comparisons between experimental groups were interpreted qualitatively because the strain maps were obtained at different maximum load levels. The findings demonstrate that the influence of pilot-hole application depends on the anatomical surface and wood species, highlighting the importance of considering their interactions when evaluating screw withdrawal performance.

Activated banana peel carbon (BPAC) was prepared and evaluated as an adsorbent for Reactive Yellow 145 (RY 145) dye from aqueous solution. BPAC was prepared from Musa x paradisiaca peels via carbonization at 400 °C followed by KOH activation at 650 °C. Structural analysis affirmed the formation of a highly porous, predominantly amorphous carbon having abundant oxygen-containing functional groups suitable for dye adsorption. Batch adsorption studies established that the efficiency was strongly influenced by solution pH (pH 2), adsorbent dosage (25 mg), contact time (90 min.), and initial dye concentration (200 mg L^-1). The Langmuir isotherm showed better representation of the equilibrium data with R² = 0.976, which was higher than the Freundlich model (R² = 0.923), suggesting monolayer adsorption on a relatively homogeneous surface with a maximum adsorption capacity of 159.0 mg g^-1. Thermodynamic data revealed that the uptake process was spontaneous (ΔG° = −1.187 kJ mol⁻¹ at 323 K), endothermic (ΔH° = 7.211 kJ mol⁻¹), and accompanied by a slight increase in interfacial randomness (ΔS° = 26 J mol⁻¹ K⁻¹). Generally, the BPAC displayed good adsorption performance and represents a promising biomass-derived adsorbent for the treatment of dye-contaminated wastewater.

Wood structures used in stilt houses are exposed to environmental conditions in the Amazon that favor degradation processes. Such degradation may compromise durability, performance, and safety. This study evaluated pathological manifestations in the wood structures of stilt houses located in the Jardim das Araras neighborhood in Itaituba, Pará state, Brazil, to analyze the maintenance conditions and practices adopted by residents. The research was designed as a qualitative, descriptive case study based on in situ visual inspection of 10 stilt houses, photographic records, structured interviews with housing users, and prioritization using the GUT Matrix (Gravity, Urgency, and Trend). Eleven pathological manifestations were identified, including mold fungi, degradation at the bases and tops of pillars, longitudinal cracks, decay fungi, rupture and displacement of structural elements, visible beam deformation, and member instability. The questionnaire results showed the predominance of corrective maintenance, with 70% of residents reporting that they replace components only after visible defects appear. Moisture exposure, biological agents, and insufficient preventive maintenance were associated with the deterioration observed. Periodic inspections and preventive actions were recommended to the users, with priority given to critical support elements.

Secondary fibers obtained from wastepaper have become quite important due to the rapid increase in paper consumption. Despite the numerous advantages obtained from the utilization of wastepaper, problems arise during paper production due to the low drainage of secondary fibers, the presence of foreign matter, and the decrease in their resistance after each recycling. Another source of problems is microorganisms that develop during the production process. Microorganisms cause stains or holes to form on the paper sheet during the production process, unpleasant odors to spread into the environment, corrosion of machine parts, paper tearing and loss of gloss, reduction in the effectiveness of added chemicals, and clogging of conveyor pipes. These problems ultimately lead to low-quality paper production, shortened life of paper machine screens, low production speed, and consequently, high costs such as reduced production. In the study, the foreign matter and moisture content of the wastepaper were determined before it entered the system. The turbidity, density, pH, and conductivity of the pulp sample were determined. Additionally, microorganism content was determined in relation to NaCl, hydrogen peroxide, and biocide addition to the pulp sample. Such treatments have to potential to prevent production disruptions and ensure quality and cost-effectiveness.

Physical and mechanical properties of commercial E1 and E2 grade particleboards produced by different manufacturers in Turkey were compared, and the relationships among these properties were examined. A total of 14 particleboard samples with a thickness of 18 mm, obtained from the domestic market, were evaluated. The moisture content (MC), density, formaldehyde emission, modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond strength (IB) of the panels were determined; the data were analyzed using one-way analysis of variance, Duncan’s test, the independent samples t-test, and Pearson’s correlation analysis. The results showed that there were no significant differences between E1 and E2 panels in terms of MC and MOR (p > 0.05); however, there were significant differences in terms of density, formaldehyde emission, MOE, and IB (p < 0.05). The average formaldehyde emission was determined to be 4.84 mgF/100 g of dry panel for E1 panels and 10.73 mgF/100 g of dry panel for E2 panels. All panels met the minimum performance criteria for Class P2 as specified in the TS EN 312 (2012) standard, and the study revealed that performance differences among commercial particleboard products may exist, depending on the manufacturer and emission class.

Significant advances have been made in understanding the structural performance of cross-laminated timber (CLT) systems under seismic loading, with current design approaches largely focused on structural safety criteria. However, early-stage design decisions are inherently multi-dimensional and increasingly require the integration of structural performance, environmental impacts, and economic feasibility. This study addresses the factors required for a multi-criteria decision framework to support early-stage design of CLT buildings. A methodology was developed which combined a comprehensive literature review, semi-structured interviews with recognized key experts, and the application of the Voting Analytic Hierarchy Process. Based on these analyses, a model was developed comprising three main criteria—structural safety, environmental performance, and economic efficiency—and seven associated sub-criteria. The sub-criteria were subsequently evaluated through a survey involving 27 experts. The results indicate that structural stability and the configuration of lateral force-resisting systems are perceived as the most critical factors. Environmental aspects, particularly carbon reduction strategies, and resource efficiency, also play a significant role. Based on the research undertaken, a proposal for an expert-derived preliminary framework tailored to CLT buildings in seismic regions is developed and presented, contributing to the existing knowledge and bridging the gap between structural engineering and sustainable design.

The volatile composition of the steam-distilled essential oil (EOSD) and the hexane-extractable fraction obtained from the corresponding hydrolate (EOSDH) of Juniperus excelsa subsp. polycarpos were comparatively investigated. Fresh Twigs bearing leaves and cones were collected in early spring (April 2025) in Ab-Barik, Firouzkooh, Tehran Province, Iran. Each sample was subjected to single steam distillation, without independent replicate distillations, using a 400-L distillation unit. The hydrolate was extracted twice with hexane, and both (EOSD) and the EOSDH fractions were analyzed by gas chromatography-mass spectrometry (GC-MS). In the EOSD sample, 29 compounds were identified, accounting for 89.6% of the total chromatographic peak area. Sesquiterpenes were the predominant class (49.0%), followed by monoterpenes (33.3%) and diterpenes (7.2%). The major constituents were α-pinene (27.6%), α-cedrol (19.3%), germacrene B (6.2%), abieta-7,13-diene (5.9%), and δ-cadinene (5.0%). In contrast, 16 compounds were identified in the EOSDH fraction, accounting for 13.1% of the total chromatographic peak area, meaning that most of the chromatographic area remained unidentified. Aliphatic hydrocarbons represented the largest reported chemical class (10.4%), followed by oxygenated monoterpenes (0.75%), and oxygenated sesquiterpenes (0.48%).These findings indicate different recoverable volatile profiles for the steam-distilled essential oil and the analytical condition used.

Traditional auspicious creature symbols often retain solemn and imposing forms when adapted for contemporary cultural and creative products. Such forms can create a sense of distance and may not satisfy younger consumers’ preferences for cute aesthetics and emotional value. Taking the Wenyao fish symbol as a case study, this study proposes a visual translation process for expressing cuteness in wooden cultural and creative products, with the aim of making traditional symbols more approachable. A database of auspicious creature symbols was first established, from which characteristic line drawings were extracted and visual elements were coded. Cuteness-related affective descriptors were organized through affinity diagramming, while order relation analysis was used to assign weights and develop the evaluation criteria. Quality Function Deployment (QFD) was applied to quantify the contribution of each visual element to cuteness, leading to the selection of three key elements. Shape grammar was employed for iterative design generation, producing three wooden cultural and creative product proposals. Finally, 103 participants from the target audience evaluated the proposals using a Likert scale. Integrated evaluation was conducted to compare the differences. Mouth-to-head ratio, eye-to-head ratio, and wing-to-body ratio were found to be the principal factors influencing the Wenyao fish’s capacity to convey cuteness.

Ring-porous hardwoods contain marked anatomical differences between earlywood and latewood that can produce heterogeneous hygroscopic deformation. This exploratory study monitored growth-ring-scale hygroscopic deformation in one elm (Ulmus pumila L.) specimen using stereomicroscope-based two-dimensional digital image correlation (2D-DIC), while time-domain nuclear magnetic resonance (TD-NMR) measurements on four companion specimens were used to estimate moisture content at corresponding adsorption times. Tangential and radial displacement fields evolved progressively and remained spatially heterogeneous during adsorption. Local profiles at an earlywood position and a latewood position showed different responses, but these differences were interpreted as local deformation heterogeneity because the two positions experienced different boundary conditions. After 120 h, mean moisture content reached 25.0%, whereas median tangential and radial Green-Lagrangian swelling strains reached 0.0316 and 0.0169, respectively. In the monitored DIC specimen, tangential strain exceeded radial strain at all investigated time points, while additional strain increments were relatively small from 22 to 120 h, during which the companion specimens continued to absorb moisture. These results demonstrate transverse swelling anisotropy together with growth-ring-scale spatial heterogeneity and provide a material basis for assessing moisture-related dimensional stability and anatomical orientation in elm wood products.