Research Articles

The production of biochar through pyrolysis of biomass is expected to reduce dependence on traditional energy sources and mitigate global warming. However, current predictive models for biochar yield and composition are computationally intensive, complex, and lack accuracy for extrapolative scenarios. This study utilized machine learning to develop predictive models for biochar yield and carbon content based on pyrolysis data from lignocellulosic biomass. Assessing the importance of input features revealed their significant role in predicting biochar properties. The findings indicate that eXtreme Gradient Boosting (XGBoost) algorithms can accurately forecast biochar yield and carbon content based on biomass characteristics and pyrolysis conditions. This research contributes new insights into understanding biomass pyrolysis and enhancing biochar production efficiency.

Particleboards find extensive application in both civil construction and the furniture industry. Nevertheless, concerns about the interaction of panels with humidity require the exploration of alternative sources to develop a product that meets the requirements for use. This work aims to produce single-layer particleboards with coconut fiber (Cocos nucifera) as substrate, bonded with 10% by mass castor oil-based polyurethane resin (CPUR). Two groups of mixtures were proposed, different from each other in the initial moisture content of the Cocos nucifera particles, ranging from 0 to 2% and from 4% to 6%. For this purpose, density (D), thickness swelling after 24 h (TS), moisture content (MC), and water absorption (WA) were evaluated. The Tukey mean contrast test, at a 5% significance level, was used to verify the influence of the initial moisture content of the particles on the physical properties of the particleboards. The microstructure of the composites was assessed through the utilization of scanning electron microscopy (SEM) technique. The results indicated better compaction of the C. nucifera particles, resulting in fewer voids, contributing to the densification of the panels and, with this, the reduction of water absorption by 15.1%.

Wood specimens were dyed by boiling them in the presence of walnut shells and dye to penetrate the dyestuff into the sample. Specimens prepared from Scots pine, oak, and beech woods were boiled separately in walnut shell, water, and NaOH environment, and the penetration of the dyestuff into the samples was ensured. Sodium hydroxide solution was preferred because it facilitates the dissolution of the hemicelluloses in the wood and the dyestuffs in the walnut shell. Alum was added in other samples to reveal the mordant effect on the adhesion of dyestuffs to wood. Thermogravimetric (TG) analysis revealed that wood degradation primarily occurs due to evaporation of free water at 50 to 120 °C, followed by lignin and cellulose breakdown across a wide temperature range of 160 to 600 °C. Treatment with NaOH and NaOH+alum notably reduced the peak temperatures in differential-thermogravimetric analysis by indicating an effect on lignin. This was supported by Fourier transform infrared analysis, particularly in the disappearance of carboxyl groups at 1710 cm^–¹ and significant decreases in peak intensities at 1027, 1247, 1315, and 1501 cm^–¹. Based on the findings, it was concluded that the dyed parts obtained can be used in the wooden toy industry.

This study investigated the mechanical performance of hybrid tubes made via roll-wrapping and enhanced with an aluminum mesh and epoxy matrix (AL-DMEM). The specimens included Basalt + Jute (BJAJB), Basalt + Bamboo (BBmABmB), Basalt + Banana (BBaABaB), Basalt + Hemp (BHAHB), and Basalt (BAB). The BBmABmB specimen showed the best mechanical properties with the highest peak crushing force, specific energy absorption, mean crushing force, and total energy absorption. The AL-DMEM integration improved load-bearing capacity and energy absorption, reducing matrix cracking and fiber breakage. Scanning electron microscopy and energy-dispersive X-ray analysis highlighted BBmABmB’s robust reinforcement. Its superior structural integrity and aluminum content make it suitable for applications requiring high structural integrity, such as micromobility vehicles, highlighting the potential of AL-DMEM-reinforced composites in advanced engineering applications.

Substituting the use of non-renewable materials with wood-based products in the furniture industry is expected to reduce greenhouse gas (GHG) emissions. This substitution effect can be quantified by estimating the displacement factor (DF) of wood products. However, the lack of a standardized DF calculation method limits a reliable estimation of DFs for wood substitution in the furniture industry. Herein, DF values were determined for wood substitution in office furniture in Korea using three DF calculation methods, single DF, replacement rate-based DF, and more/less wood-intensive DF. The results indicated that substituting non-wood furniture with wood-based furniture can help reduce GHG emissions, with the most positive DF values observed. The negative DF values generated using the replacement rate-based DF method highlighted the importance of weight calculation when considering wood products. However, the difference in DF calculation methods between studies and the lack of life cycle assessment (LCA) data in Korea must be addressed. In conclusion, these results emphasize the need for a standardized DF calculation method and LCA data to improve the accuracy and applicability of the DF of wood-based furniture products. The present results provide insights into the environmental benefits of replacing non-wood products with wood products in the furniture industry.

The use of wood in the construction sector to reduce greenhouse gas (GHG) emissions is garnering global interest. In South Korea, the wood usage in public buildings is limited, being influenced by factors such as the high price of wood products and their limited use in large structures. In this work the future wood consumption in South Korea is predicted based on its potential use in current public buildings. The structural wood products required for the buildings were quantified based on the available statistical data. Items investigated were the (1) number of buildings started, (2) ratio of public buildings, (3) ratio of wooden structures, (4) average floor area of wooden buildings, (5) material cost per floor, and (6) wood prices. Assuming that the buildings contain reinforced-concrete and wooden structures, the wood consumption was estimated based on the replacement ratio. The results indicated that the prices of wood products were relatively higher than those of raw timber. The number of buildings is expected to decrease in line with the expected population decline, resulting in the decrease of wood amount required for public buildings. To achieve long-term GHG-reduction goals, it is important to replace the existing public buildings in Korea with wooden structures.

The mortise and loose tenon (M&LT) joint is a form between mortise-and-tenon (M&T) joint and dowel. It combines the advantages of easy processing and high bonding strength and has no requirement for the shape of the tenon shoulder. However, there is a lack of research conducted separately on the parallel-to-grain part of M&LT joint. This study explored the withdrawal capacity of the equivalence I-type specimen to focus on the strength of the parallel-to-grain part of M&LT joint by conducting mechanical experiments and establishing finite element model. The results indicated that (1) The largest average pull-out load occurred at the group of 0.1 mm interference fit with the value of 16000 N, most of the joints underwent shear damage of material parallel-to-grain; (2) The maximum load of FEM is 14300 N with an error of 10.5%, so finite element model is a rational approach to predict the withdrawal strength of parallel-to-grain connection of M&LT joint.

This paper reports the first study of phyco-remediation of cyantraniliprole, a second-generation diamide insecticide with high toxicity and persistence in aquatic environments, using the green microalga Chlamydomonas reinhardtii. Cultures of C. reinhardtii were treated with four concentrations of cyantraniliprole (0, 25, 50, and 100 ppm). The removal efficiency, antioxidant responses, and biomass composition of the microalga were measured after 1 h and one week of exposures. C. reinhardtii was able to remove cyantraniliprole from the medium by biodegradation, biotransformation, bioaccumulation, and bio-adsorption mechanisms, achieving up to 87.0% removal within 1 h and 84.5% after one week. The microalga also maintained acceptable levels of enzymatic and non-enzymatic antioxidants, indicating its tolerance to cyantraniliprole stress. Moreover, some treated cultures (especially those with 25 and 50 ppm cyantraniliprole) showed enhanced specific growth rate, and biomass productivity compared to control cultures. In addition, those with 50 and 100 ppm cyantraniliprole showed enhanced carbohydrate and lipid concentrations compared to the control cultures. These results suggest that C. reinhardtii is a promising candidate for bioremediation of cyantraniliprole-contaminated water and biofuel production.

Green routes for the bio-designing of bicomponent nanocomposites and their utilizations have attracted many investigators. Bio-designing of CuO@ZnO nanocomposites was performed using spent mushroom substrate (SMS). Ultraviolet-spectrophotometry, transmission electron microscopy, Fourier transform infrared (FT-IR), and energy dispersive X-ray (EDX), besides X-ray diffraction (XRD) were exploited to characterize the synthesized CuO@ZnO. The dimensions of CuO@ZnO nanocomposites ranged from 31.4 and 95.9 nm. Both FT-IR and EDX analyses displayed the presence of some organic constituents from the SMS that joined to the surface of the fabricated CuO@ZnO nanocomposite. CuO@ZnO nanocomposite succeeded in inhibiting Candida albicans with an inhibition zone of 33.5 ± 2 mm. C. albicans biofilm was affected by CuO@ZnO nanocomposite with biofilm inhibition of 25.08, 68.70, and 88.56% at 25, 50, and 75% of minimum inhibitory concentration, respectively. Molecular docking studies showed substantial binding affinities, as well as common hydrogen bonds. Optimum binding sites for CuO and ZnO nanoparticles were found to have binding affinities of interactions with 4YDE, 3DRA, and 1EAG proteins of C. albicans, resulting in, respectively, -2.7942, -3.30097, and -2.52129 kcal/mol, and -3.78244, -4.6029, and -4.1352 kcal/mol values. The findings suggest that CuO@ZnO nanocomposite can effectively suppress C. albicans growth.

Catastrophe theory was used to establish a safety assessment model to reduce the reliance on subjective judgments in evaluation of timber-framed heritage buildings. This study was conducted in three phases. Initially, a comprehensive evaluation index system was established from the perspective of foundation. It consisted of eight aspects and 25 safety evaluation indicators using superstructure load-bearing elements, maintenance structures, and their interconnections in timber-framed heritage buildings. The 25 safety evaluation indicators included foundation, base, stone piers, columns, beams, lintels (beams, pads, and other bending components), bracket sets, arches, maintenance walls, beam-brace connections, and roof structures. The bottom-level indicators in the index system were dimensionless. The second phase employed typical catastrophe models (cusp, swallowtail, and butterfly) for normalization, resulting in calculated catastrophe scales and evaluation levels. The case study of the Buddha Hall of Zhihua Temple, Beijing, was applied in the final phase. It was found that the catastrophe scales method solved the subjectivity issues in determining weights. Additionally, the calculations were found to be concise and reliable, providing accurate results. The model can be used as a theoretical reference for the future safety assessment of timber-framed heritage buildings.