Volume 20 Issue 3

Wind causes significant damage to trees in many parts of the world, affecting tree growth, morphology, and forest ecology. The risk of wind damage is believed to be increasing due to global climate change. In this study, effects of wind exposure on the anatomical traits and stem stand characteristics in stands of Trojan fir trees (Abies nordmanniana subsp. equi-trojani [Asch. and Sint. ex Boiss] Coode and Cullen) were investigated. The study was conducted on Ilgaz Mountain, northwest of Kastamonu City, Türkiye. The wind-damaged and undamaged Trojan fir trees were identified, and their wood anatomical and stand characteristics were compared. Tree-ring width and wood anatomical traits (tracheid length, tracheid lumen area, tracheid wall thickness, and ray width) were higher in undamaged fir trees than in wind-damaged fir trees. It has been suggested that prolonged exposure to wind in Trojan fir trees may result in the development of changes in wood anatomical traits and tree rings such that more wind-exposed trees could produce shorter and thinner tracheid traits, because tracheid cell development processes could be negatively affected by wind exposure. However, wind-damaged Trojan fir trees had greater stem height and diameter, slenderness ratio, and stand basal area than undamaged fir trees. In this study, tall trees tended to be the most vulnerable and least resistant to wind damage.

In this study, the Radiata pine-magnesium-laminated (RML) board was proposed to develop wood materials with flame retardancy. The 45° flammability test, cone calorimeter test, gas toxicity test, single burning item (SBI) test, and Steiner tunnel test were performed to confirm the flame-retardant performance of RML. For RML with 80 to 150 g/m² of flame retardant applied, the carbonized area in the flammability test was 44.3 to 35.0 cm²; in the cone calorimeter test, the total heat release (THR) was 5.4 to 6.2 MJ/m², and the time to stopped behavior of white lab mice was 857s, which surpasses the standard for semi-noncombustible materials in Korea. The RML was Class A2 based on EN 13823 (2020) in the SBI test and Class A based on ASTM E84-21a (2022) in the Steiner tunnel test. In conclusion, RML showed excellent flame-retardant performance. The thin wood veneer absorbs the flame retardant easily, and the magnesium board is a semi-noncombustible material. Accordingly, it was confirmed that an RML board could be a commercial wood-based building material with satisfactory flame retardancy.

Invasive species of Euphorbia peplus and Euphorbia geniculata weeds ‎compete with the crops and act as hosts for ‎other pests, consequently interfering with the livestock. Therefore, a comprehensive allelopathic screening of ‎Euphorbia spp. was implemented via aqueous extracts and decayed ‎residues against Triticum aestivum and their associated weeds.‎ Aqueous and ethyl acetate extracts of E. peplus and E. geniculata were ‎suppressed by the target weeds. The effects were influenced by plant types and ‎concentrations. The Brassica nigra weeds were very susceptible, while ‎T. aestivum was slightly sensitive.‎ The phytotoxicity of Euphorbia spp. decayed residues correlated with the used concentrations and soil properties. Euphorbia spp. extracts were tested against Sclerotina sclerotiorum, Alternaria alternata, and Fusarium oxysporum fungi. E. peplus at 2000 µg/mL decreased fungal growth by 57.1% (S. sclerotiorum), 63.1% (A. alternata), and 63.0% (F. oxysporum), while E. geniculata at 2000 µg/mL decreased fungal growth by 73.0% (S. sclerotiorum), 64.8% (A. alternata), and 72.7% (F. oxysporum). Euphorbia spp. allelochemicals were analysed by HPLC, which indicated the differential in secondary metabolite concentrations between the two species. These substances have a positive potential as natural pesticides that are used in the management of these species.

Wood modification via silicon ingredients was investigated to increase its resistance to biological decay. Surfactant and desiccant features of derived products of silicates are considered the main contributors in wood resistance to decay. The detected fungus from decayed wood sample was identified as Phanerochaete chrysosporium. Inhibitory tests showed that sodium silicate (SS) was more effective than potassium silicate (PS) and copper sulfate (CS) against P. chrysosporium growth. The weight loss of infected wood with P. chrysosporium without treatment was 32.2%, while treatment by SS, PS, and CS reduced weight loss to 4.3%, 11.5%, and 14.3%, respectively, over 40 days. To ducument the effect of SS, PS, and CS on P. chrysosporium, molecular docking was used to evaluate the binding interactions of these compounds with the active site (Lignin peroxidase) of P. chrysosporium (PDB ID: 1QPA). Binding affinities were determined via docking scores, conformational energies, placement energies, and refinement parameters evaluation. SS exhibited the strongest docking scores (S = -6.17 to -5.83) and favorable interactions, including metal coordination and hydrogen bonding. PS and CS showed moderate to weak binding, with distinct interaction patterns. These computational results highlight SS as a potential candidate for further experimental validation in targeting the 1QPA protein.

Composite materials, edge banding, and wooden dowels are being used in inner decorations and the construction of furniture frames. However, there is little information available concerning the withdrawal strength of various fasteners and in particular, dowels in these materials. The aim of this study was to determine the withdrawal strengths of PVC edge bandings with 0.8-, 1-, and 2-mm thicknesses, and dowels produced from six different wood species (ash, black pine, beech, chestnut, oak, and Uludağ fir) bonded parallel to the surfaces of oriented strand board with polyvinyl acetate (PVAc-D4) or polyurethane (PUR-D4). According to TS 4539 standard, the effect of wooden dowel species, thickness of edge banding, and the type of adhesives on the withdrawal strength were determined. Withdrawal strength values of the PUR-D4 adhesive was found to be 26% higher than the strength values of the PVAc-D4 adhesive.  The highest withdrawal strength was obtained for beech dowel bonded using PUR-D4 in the samples with 0.8 mm PVC edge banding (4.782 N/mm²), while the lowest withdrawal strength value was obtained for Uludağ fir dowel with the PVAc-D4 in the samples with 2 mm PVC edge banding (2.529 N/mm²). These values are higher than the predictive statement that allows designers to estimate the withdrawal strengths of dowels.

The degradation of wood in historic structures is influenced by a combination of environmental and biological factors. This study examined the chemical deterioration of wood in historical wooden houses in Rize, Türkiye, with a specific focus on the impact of altitude and facade orientation. Samples were collected from the south-facing facades of six historical buildings situated at varying elevations. Fourier Transform Infrared spectroscopy was employed to assess the chemical changes in the wood, specifically in the cellulose, hemicellulose, and lignin content. A comparison was made between weathered samples and a new control specimen to assess the extent of degradation. The Carbonyl Index (CI) and Lignin Index (LI) were calculated to quantify structural changes. The results revealed substantial degradation in the surface chemistry of aged wood, primarily due to photodegradation and environmental exposure. No systematic correlation was found between altitude and degradation levels, suggesting that local microclimatic factors, rather than elevation alone, predominantly influence chemical deterioration. South-facing facades exhibited greater degradation, likely due to increased exposure to UV radiation. The findings underscore the importance of understanding site-specific environmental influences in heritage conservation, providing a foundation for future restoration efforts. These results emphasized the importance of integrating chemical characterization with environmental monitoring to optimize conservation practices.

The purpose of this work was to create and assess a bio-based head phantom made from bio-based resources for external beam radiotherapy dose planning and delivery in brain cancer. The custom-made head phantom was fabricated using Rhizophora spp. bonded with soy flour and lignin, and its potential as phantom material was evaluated in previous studies. Organs at risk and planning target volume were identified using the treatment planning system, which was guided by computed tomography raw images. Thermoluminescent dosimeters were placed into specific holes positioned throughout the head phantom following individual calibration. Head phantom was imaged, planned and irradiated by linear accelerator. The planned predicted doses by treatment planning system at the targeted volume and the organ at risk regions were obtained and compared with the dosimeter doses. The result revealed that the planning target volume and organ at risks were within the dose range calculated by the treatment planning system, except for lens, optic chiasm and brainstem. Verification of the treatment plans was implemented, and good agreement between measured values and those predicted by the treatment planning system was found. The custom-made, bio-based phantom’s preliminary results have proved to be a valuable tool for the treatment dose verification, demonstrating its prospective as potential phantom material for use in radiotherapy.

To address the challenges posed by complex and variable backgrounds coupled with the small-target characteristics of wood surface defects such as knots and cracks, a novel wood surface defect detection model based on improved You Only Look Once version 8 (YOLOv8) is proposed. The model integrates a multi-head mixed self-attention mechanism into the backbone to improve the representation of fine-grained defect features. A learnable dynamic upsampling module replaces traditional nearest-neighbor interpolation to mitigate feature loss during resolution recovery. Additionally, a structural Re-parameterizable Block is adopted to enhance feature expressiveness during inference, and a small-object detection head is added to enhance the detection of small defects while minimizing both missed and incorrect detections. The experimental results demonstrate that the proposed model effectively enhances detection performance, increasing the mAP of the baseline model from 72.9% to 79.5%. Furthermore, the proposed model surpasses other YOLO variants in mAP across all defect categories. This improvement better meets the quality control requirements of wood processing and manufacturing, ensuring the quality of wood products.

Ultraviolet (UV)-cured coating and water transfer printing (WTP) are popular organic coating techniques offering aesthetic and functional benefits for wood-based panels. This study considered the gloss change of medium density fiberboard (MDF) panels, which were coated with WTP and UV printing processes. Image processing was used before and after being exposed to some domestic cleaning agents. A carbon fiber-patterned organic finish was applied to the surfaces of the prepared sample panels followed by scrub-testing with various domestic cleaning agents in compliance with Turkish Standards (TS) EN ISO 11998. The image processing based scrubbing tester (IPBST) developed in this study was used for the scrubbing process. Digital images of the samples were captured before and after the scrubbing process, and the Red-Green-Blue (RGB) color model was converted to the Hue-Saturation-Intensity (HSI) model for analysis. The I-channel in the HSI system was used to calculate the average gloss values, which were compared to results from the BYK-Gardner Spectro-Guide 45/0 device. Pearson correlation analysis indicated a robust and statistically significant correlation of 0.71. As a result, the image analysis-based gloss evaluation method has been shown to enable a more comprehensive evaluation of surface quality by providing fast, non-contact, and detailed analysis.

A high-performance wood adhesive was successfully developed by incorporating soybean oligopeptides into Camellia oleifera protein through a combination of degradation and epoxy resin crosslinking techniques. The results showed that the presence of oligopeptides boosted the creation of more active functional groups in the degradation liquid system. This process enhanced the adhesive’s initial viscosity and overall stability. As a result, the adhesive’s performance was significantly improved, making the bond more robust and long-lasting. However, a notable drawback was observed: the storage duration of the adhesive was shortened from 10 h to 3.5 h. Despite this limitation, the adhesive exhibited several advantageous properties, including a high curing reaction rate, a relatively low curing temperature, and excellent thermal stability. Additionally, the prepared adhesive demonstrated superior bonding strength and outstanding water resistance, making it a promising alternative for various wood-based applications.