Volume 20 Issue 2

Particleboards constitute an important solution addressing two current demands: Improving the use of exploited resources and implementing adequate waste management. In this study, panels were produced from recycled polyethylene terephthalate (PET), rosin (adhesive derived from natural pine resin or colophony), and particles of Pinus sp. wood (pinewood). Rosin resin was used at a 20% ratio for all panels, and recycled PET was incorporated at varying proportions (75%, 50%, and 25%) as a wood substitute. Physical tests assessed included density (D), moisture content (MC), 24 h thickness swelling after 24 h (TS-24h), and water absorption after 24 h (WA-24h). All tests were carried out in accordance with NBR 14810-2 (ABNT 2018). The findings revealed commendable physical performance across all mixtures, with mixture M4 demonstrating the most favorable results among the four evaluated. Although further investigation is warranted, the integration of wood, rosin resin, and PET in particleboard production represents a sustainable and efficient alternative.

This study analyzed the antibacterial potential of Dactylicapnos scandens extract (DSE) against Mycoplasma pneumoniae (MP)-induced pneumonia in mice. The DSE was tested for in-vitro antibacterial activity against MP and pharmacological activity in MP-induced pneumonia in mice. DSE showed significant in-vitro antibacterial activity against MP. It improved the level of nitric oxide, and myeloperoxidase, including the lung weight index near to control in a dose-dependent manner in experimental animals. The levels of glutathione and superoxide dismutase were found significantly increased in DSE treated rats with a reduction in malondialdehyde activity as compared to pneumonia-induced mice in a dose dependent manner. The level of pro-inflammatory cytokines, such as interleukin-6, Interleukin-1 beta, and tumour necrosis factor alpha, and total cells and DNA content were also found reduced in DSE treated group as compared to disease control mice. This study demonstrated potent antibacterial activity of Dactylicapnos scandens extract against Mycoplasma pneumoniae infection.

Wood, as a renewable and highly abundant material, has been receiving increasing attention for use in high-performance applications, such as a structural element subjected to high temperatures. For its successful implementation in the construction or timber industry sector, it is crucial to understand its behavior during and after exposure to high temperatures. In this study, the red angelim wood, Dinizia excelsa, was subjected to high temperatures, up to a temperature of 508 K, using the dynamic excitation wave propagation test. Samples tested in the furnace were dimensioned in six distinct directions: three main ones (radial, tangential, and longitudinal) and three intermediate ones at 45º (longitudinal-radial, longitudinal-tangential, and radial-tangential). The static test used only the main directions of wood orientation. The values of elasticity modulus exhibited a reduction after the heat treatment, resulting in significant decreases of up to 45%. Results demonstrated that the excitation wave propagation method was effective in estimating the elasticity modulus at room temperature up to 508 K. Therefore, this study contributed to the construction of a database that can be expanded by future research focused on Brazilian woods.

The design of Chinese-style furniture (CSF) strives to preserve cultural symbols and aesthetic features while enhancing user experience and emotional resonance. This paper explored how to optimize the design of CSF by analyzing the relationships between affective vocabulary, cultural symbols, and user perception, aiming to narrow the gap between designer intent and user perception, thereby enhancing emotional resonance and user satisfaction. An Affinity Diagram was employed to collect and organize affective vocabulary related to furniture design. Subjective weights of the affective vocabulary were calculated using the Analytic Hierarchy Process (AHP), and objective weights were determined through the Entropy Weight (EW) Method. The Coupling Coordination Degree (CCD) Method was applied to identify the core affective vocabulary. The artifact shapes and patterns from the Haihunhou tomb site were analyzed to extract representative design elements. Finally, the Quality Function Deployment (QFD) Method was utilized to examine the mapping relationships between core affective vocabulary and the artifact shapes and patterns, ranking the characteristics of these elements. The optimized design elements were integrated into the design of a Chinese-style chair. The incorporation of cultural symbols and affective vocabulary into Chinese-style chair design enhanced user experience and emotional identification, providing a viable path for innovation in CSF design.

The permeability, hydrophobicity, glass transition temperature, crystallinity and chemical composition of bamboo subjected to wax-scalding heat treatment were detected using depth-of-field microscopy, contact angle measurement, thermogravimetric analysis, X-ray diffractometry, and infrared spectrometry. Effects of wax scalding technology and formula on bamboo properties were studied from three aspects: temperature, time, and wax species. The improved wax scalding technology was found to have a good penetration effect and to achieve hydrophobic and mildew-proof effects. At the heat treatment temperature of 180 °C, a good permeation effect was achieved and the hydrophobicity of bamboo was increased. The penetration depth of wax in bamboo within 2 min decreased with the shortening of wax scalding time. However, the infiltration effect was not obvious with the prolonging of time, and increasing preheating treatment will obviously improve the permeability. The effect was the best after preheating and wax scalding at 180 °C for 2 min. Mixed experiments of various waxes showed that the wax had the best penetration effect into bamboo when the ratio of paraffin wax to white wax was 5:4:2, the wax scalding temperature was 180 °C (above which the wax begins to sublimate), and the wax scalding time was 2 min.

This study aimed to investigate the effects of wood species and lumber quality grades on the mechanical properties and costs of cross-laminated timber (CLT) panels. Various combinations of lumber with different quality grades were utilized in the layers to identify the optimal configurations for producing CLT panels with high mechanical performance and low costs. In the study, spruce and Scots pine lumber of three different quality grades (Grades 1, 2, and 3), classified according to TS 1265 standards, were used. Some mechanical properties of the CLT panels produced from lumber of varying quality grades were determined following the TS EN 408 standard. Additionally, cost analyses of the CLT panels were conducted based on the calculation of raw material costs. The results show that while higher-grade lumber improves mechanical performance, lower-grade combinations still can meet structural needs at lower costs. Mixed-grade configurations offer a balance between strength and affordability. These findings can help CLT producers optimize material selection and reduce costs while maintaining structural integrity. Using lower-grade lumber can address shortages and reduce reliance on expensive timber. Policymakers can promote sustainable forestry and lower production costs, making mass timber construction more viable and environmentally sustainable.

Exploiting stimuli-responsive Pickering interfacial catalysts is crucial to the development of organic reactions in water and green chemistry. Herein, amphiphilic carboxylated cellulose nanocrystals were synthesized by surface modification of hydrophilic carboxylated cellulose nanocrystals. The obtained amphiphilic carboxylated cellulose nanocrystals showed great toluene-in-water Pickering emulsion stabilization capacity and pH-responsive property. Emulsification and rapid demulsification behaviours were observed by simple pH adjustment. Palladium nanoparticles supported on the amphiphilic carboxylated cellulose nanocrystals exhibited high activity in the hydrogenation reaction of nitrobenzene in aqueous media because of the improved mass transfer between hydrophobic substrate and hydrophilic solvent. Moreover, the pH-responsiveness of amphiphilic carboxylated cellulose nanocrystals could promote the recovery of both products and the Pickering interfacial catalyst. Therefore, palladium nanoparticles loaded bio-derived carboxylated cellulose nanocrystals for efficient pH-switched Pickering emulsion catalytic hydrogenation was successfully prepared. Outstanding activity and reusability were achieved.

Saw wood cracks are defects that affect the appearance and mechanical strength of sawn wood. Crack defects in the surface of sawn wood can be readily detected. Decisions regarding the presence and severity of such defects can affect the utilization rate of sawn timber. Due to the heavy workload, low efficiency, and low accuracy of manual inspection, traditional machine learning methods have strong specialization, complex methods, and high costs. By studying the semantic segmentation model of surface crack defects in sawn timber based on deep learning, the optimal model for segmentation and detection of surface cracks in sawn timber was established. The improved Attention U-Net model encoding stage was introduced into CBAM, and AdamW optimization was used instead of SGD and Adam to achieve better crack semantic segmentation results. The ECA module was introduced in the skip connection part, and the weighted fusion multi loss function was used instead of the original cross entropy loss function. The positions of the two modules were replaced to improve the accuracy of semantic segmentation of surface cracks in sawn timber. Through comparative experiments, the improved model also achieved higher scores in semantic segmentation indicators for surface cracks in sawn timber compared to other models.

Sage oil plays a vital role in various fields, including health and food. The effects of UV radiation (UVR) can increase the bioactive content of medicinal plants, but there has been little research on how this affects sage oil. Therefore, this study aimed to evaluate the impact of UVR on the sage oil phytoconstituents and its biological activity. GC-MS analysis detected 20, 23, and 25 different compounds in sage un-exposed and exposed to UVR for 30 and 60 min, respectively. Candida albicans, C. tropicalis, and C. glabrata were suppressed with inhibition zones 21.62 ± 1.22, 16.20 ± 1.23, and 8.20 ± 0.66 mm by sage oil, while the exposed sage oil to UVR for 60 min exhibited 26.50 ± 1.33, 21.43 ± 2.12, and 20.25 ± 0.50 mm inhibition zone, respectively. The required IC₅₀ to inhibit butyrylcholinesterase, α-amylase, and protein denaturation was 95.3, 14.9, and 10.7 µg/mL in sage oil that was not exposed to UVR, and 35.1, 7.1, and 7.1 µg/mL in exposed sage oil to UVR for 60 min, respectively. There were negligible effects between the unexposed and exposed sage oil to UVR for 30 and 60 min against Hela cells with IC₅₀ 193.19 ± 0.98, 149.71 ± 0.18, and 148.19 ± 0.66 µg/mL, respectively.

Self-tapping screws and round steel nails were driven into Pinus massoniana and Cunninghamia lanceolata dimension lumber pieces to explore the influence of intersection angle on nail-holding performance, expecting to provide a more complete scientific basis for the connection of wood structures. The results showed that (1) as the intersection angle declined, the nail-holding strength of self-tapping screws for both P. massoniana and C. lanceolata dimension lumber gradually decreased. At the intersection angle of 90°, nail-holding strength was the maximum, being 79.8 and 80.5 N/mm, respectively; (2) With the reduction of the intersection angle, the nail-holding strength of round steel nails for both dimension lumber initially increased and then gradually declined. The maximum nail-holding strength (21.0 N/mm) of P. massoniana appeared at the intersection angle of 45° while that (22.3 N/mm) of C. lanceolata appeared at 60°; (3) No matter for self-tapping screws or round steel nails, the rigidity at the connection point was the greatest at the intersection angles of 90° and 0° (cross-section). If diagonally nailed into lumber, both self-tapping screws and round steel nails can enhance the ductility of connection joints, where the former exerts a more evident effect.