Volume 19 Issue 4

The biological durability of oil palm trunk modified with 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) was tested after subsequent curing at elevated temperatures. The resistance against mold, decay fungi, and subterranean termites was examined. Dimethylol dihydroxyethyleneurea-modified OPT demonstrated improved resistance against mold and decay fungi; however, the effect was lesser on subterranean termite attacks. Oil palm trunk modified with 34% DMDHEU and cured at 160 °C exhibited the most effective reduction in mass loss due to biological degradation compared to the untreated controls. High curing temperature (> 180 °C) caused cracks and ruptured the cell walls, exposing the untreated zone of the OPT to biological attack. As a non-biocidal wood modification, homogeneous dispersion of DMDHEU with adequate concentration and curing temperature is important to fully prevent OPT degradation by wood-destroying fungi and termites. These results provide valuable information for technologists to enhance or streamline the experimental design of combined modification with DMDHEU and thermal treatment, supporting their practical goals. It is recommended to continue research on the leaching of DMDHEU-modified OPT to understand the prevailing effect of DMDHEU on the biological durability of OPT, whether it is due to cross-linking or filler dispersion.

The application of copper azole (CA) preservative on glulam can improve the durability of the material. The effect of CA preservative was evaluated relative to the surface bonding quality of laminates with different surface conditions. The surface morphology and wettability of CA preservative-treated laminates were analyzed. A comparison was made on the interlaminar shear strength of preservative-treated glulam under varying environmental conditions. The atomic force microscope (AFM) diagrams showed that CA preservative adhered to the wood fibers’ surface and filled some wood cell cavities, thus reducing the water permeability of the treated laminate. Planing effectively enhanced the surface wettability of the preservative-treated laminate. The tiny particles of CA preservative on the planed laminate surface were distributed relatively uniformly, with a proportion smaller than that of the unplaned laminate. Furthermore, the interlaminar shear strength of preservative-treated glulam using planed laminates was at least 15% higher than that of unplaned laminates. In both hot and humid environments and natural aging tests, preservative-treated glulam bonded with resorcinol formaldehyde (RF) adhesive outperformed those bonded with polyurethane (PUR) adhesive. To ensure reliable quality of preservative-treated glulam, it is recommended to plane the laminate by 0.6 mm and use RF adhesive.

The potential of decayed wood was investigated as a raw material to produce activated carbon. Both sound and decayed beech wood specimens were subjected to chemical activation with ZnCl2 at a carbonization temperature of 400 °C and 75% impregnation ratio to produce activated carbon. The produced activated carbon was tested using Brunauer–Emmett–Teller, Fourier transform infrared, scanning electron microscopy, and thermogravimetric analyses to investigate its properties. The activated carbon was used to adsorb rhodamine B dye in an aqueous solution. Additionally, to investigate the impact of activated carbon surface modification on the adsorption of rhodamine B dye, both kinds of activated carbon underwent surface modification using dielectric-barrier discharge (DBD) plasma at a high frequency of 20 kHz in the air atmosphere for 20 min at a voltage level of 10 kV. The modification of the activated carbon substantially improved its characteristics, resulting in a 20% increase in rhodamine B removal for the activated carbon derived from sound wood and a 12% increase for the activated carbon derived from decayed wood. The utilization of DBD air plasma in this method is suitable because of its simplicity, cost-effectiveness, and improved adsorption capacity in activated carbon.

The use of wheat straw as a renewable energy source is essential from both energy production and environmental points of view. It has a great energy potential that can be generated either by combustion or anaerobic digestion. However, there are some limitations during its conversion to energy in both techniques. Therefore, the current study investigated the effect of physical and chemical treatments on the characteristics of wheat straw as fuel for energy applications. Water washing of wheat straw and mixing with KOH solution were applied for physical and chemical treatments. Physical, chemical, and thermal characteristics of wheat straw were investigated before and after the treatments. It was found that the wheat straw has high carbon (44.8%) and volatile contents (87.1%), making it an excellent source for energy production. The physical treatment showed a positive impact on reducing the ash content (by 14.9%) and undesirable compounds, such as K and Cl, which were reduced by 46.4% and 57.0%, respectively. Moreover, it reduced sintering formation through combustion. In contrast, the chemical treatment resulted in 9.3% lignin removal and destroyed the complex lignocellulosic structure, thereby increasing the cellulose accessibility and enhancing the anaerobic digestion process. Therefore, the applied treatments showed attractive options to solve problems related to straw energy generation.

The production of nanoparticles in the presence of biomaterials has become a promising substitute to traditional chemical and physical manufacturing procedures. Zinc oxide nanoparticles (ZnO-NPs) were prepared using Phyla nodiflora leaf extracts as a natural reducing agent, along with distilled water. The nanoparticles were analysed using various methods such as transmission electron microscopy, Fourier transformed infrared spectroscopy, UV-visible spectroscopy, energy dispersive X-ray, X-ray diffraction, dynamic light scattering, and zeta potential to examine their synthesis, structural morphology, chemical bonding, elemental composition, and crystalline structure. ZnO-NPs were orally provided for three weeks instead of usual drinking water to assess their therapeutic efficacy. Blood biochemical examinations were performed, including liver and kidney function tests, lipid profiles, and complete blood counts. The study exhibited a notable reduction in blood urea, creatinine, and uric acid levels, substantially alleviating hyperuricemia and gouty arthritis. A slight increase in liver enzymes, alkaline phosphatase (ALP), aspartate transaminase (AST), and alanine transaminase (ALT) was detected in the study groups, with no negative changes histopathologically found in the liver, muscle, or kidney tissues. The results indicate that ZnO-NPs have the potential to be an effective alternative to current pharmaceutical treatments for hyperuricemia and gouty arthritis.

Scots pine (Pinus sylvestris L.), a keystone species in Eurasian forests, supports diverse fungal communities and thus contributes to forest health and ecosystem functions. The southern marginal populations of P. sylvestris in Türkiye, situated in more arid and warm conditions, offer a unique environment to explore fungal biodiversity. In this study, the authors investigated the fungal assemblages in living (green) and dead (senescent, fallen, and litter) Scots pine needles in Türkiye. Using a culture-based approach coupled with DNA sequencing, distinct fungal communities were identified across different needle types. Frequent isolates included well-known P. sylvestris associates, including Lophodermium pinastri, Sydowia polyspora, and Cyclaneusma minus. Novel findings, such as unidentified Eurotiomycete and Basidiomycete taxa, suggest potentially new species and hidden fungal diversity in this biogeographically important region. Additionally, this study reports the first records of Desmazierella acicola and Phacidium lacerum in Türkiye, further underscoring the region’s underexplored fungal biodiversity. Moreover, the biodiversity and community structure analysis revealed the intricate and complex nature of fungal colonization and succession, with significant variations between green, senescent, freshly fallen, and litter needles sampled concurrently. These findings provide new insights into the fungal communities of marginal, understudied Scots pine populations.

This study evaluated the impact of night frost incidents on the biochemical, physiological, and reproductive functions of the olive varieties Manzanillo, Coratina, Koroneiki, and Picual. Certain cultivars were more suited to moderate cold night stress than others, based on the changes in the performance of the stressed plants, including vegetative growth, tree yield, fruit physical characteristics, and fruit chemical characteristics. Compared to other tested cultivars, the biochemical responses of the plants in terms of photosynthetic pigments, relative water content (RWC), total phenolic compounds, total flavonoid, and antioxidant enzyme accumulation demonstrated that some cultivars could withstand the applied stress. The conclusion that some cultivars responded differently to cold stress than others was supported by the plant phenology. This research could be a game-changer for farmers. By understanding how olive trees adapt to cold snaps, a common stressor in open fields, they can make informed decisions about breeding and choosing the best cultivars, ultimately leading to more resilient crops. The results showed that all tested olive tree cultivars differ significantly regarding cold stress conditions. Coratina and Koroneiki were the most resistant tested cultivars in terms of biochemical, physiological, and reproductive functions, followed in ascending order by Manzanello and Picual.

Due to wood’s susceptibility to fire, it is crucial to treat wood-based materials with flame retardants, especially in construction applications. This study investigated the effectiveness of various grooving types, including transverse, longitudinal, both transverse and longitudinal, and surface grooving, in enhancing the vacuum pressure impregnation of larch wood. The results revealed that transverse grooving provided a slightly greater impregnation advantage than longitudinal grooving. Moreover, exceptional impregnation performance was observed in larch samples subjected to threefold longitudinal, transverse, and surface grooving, exhibiting a remarkable improvement of 215% compared to untreated larch. However, a limitation of this study is that only one wood species and one flame retardant formulation were used. While it is meaningful as a preliminary investigation into the vacuum pressure impregnation performance of flame-retardant wood based on groove processing, further studies using various wood species and flame retardants.

To enhance the design and research work on dynamic characteristics of high-rise laminated timber buildings, this paper carried out a modal analysis study on one of the largest laminated timber buildings in China. The finite element calculating modal analysis was carried out using SAP2000 software, and the experimental modal analysis of the building was carried out via environmental excitation. The calculating modal results and the experimental modal results showed good agreement. The calculating modal frequency values were generally lower than the experimental modal frequency values. The natural frequencies obtained by the two methods appeared in the Y-direction first-order bending mode and had values of 2.03 and 2.5 Hz, respectively. The corresponding frequencies of the first-order torsional mode were 2.82 and 3.25 Hz, respectively. The distribution of the CLT core tube along the length direction of the building has an impact on the vibration mode. The six-story part shows the second-order bending form, while the four-story section only shows the first-order bending form. The above work provides a case study and reference for the simulation and modal analysis of high-rise laminated timber buildings, demonstrating the critical role of the core tube structure in such wooden buildings. This insight contributes to a better understanding of structural performance and design considerations in similar projects.

Petroleum-based plastic coatings are used to create moisture barriers and heat-sealable layers on paperboard. Despite their good convertibility and barrier properties, the use of sustainable biobased polymer coatings as alternatives has attracted interest due to environmental concerns. In this study, the convertibility and water resistance of bio-based multilayered coating composed of biowax and polylactic acid (PLA) were investigated. Convertibility of the coatings was studied through heat-sealing experiments and by evaluating their durability when they were subjected to high stresses during creasing and folding. Surface imaging was performed to evaluate film formation and coating integrity. The wettability and water absorption properties of the coatings were also investigated. Different coating compositions resulted in different film formation processes, surface appearances, and water absorption. The presence of wax in a coating increased its hydrophobicity and reduced its water absorption already with the smallest addition in the coating. However, a high wax content in the coating caused defects in the coating layer, whereas the addition of PLA increased the convertibility of the coated material. This indicates that water resistance, heat sealability, and convertibility can be simultaneously achieved by optimizing the composition of wax and PLA coatings.