Volume 20 Issue 4

The structural performance of timber buildings is significantly affected by the behavior of connections. This study investigated the structural behavior of bolted glulam beam-to-column connections with external steel plates. Data were obtained for the structural behavior of two types of connections. The glulam was manufactured from Red Meranti (Shorea spp.). The load-carrying capacity, moment capacity, rotational stiffness, initial stiffness, post-elastic stiffness, and ductility ratio of the connections were evaluated and discussed. The results indicate that the type 1 connection was in the partial ductility capacity category (μ = 2.60), while the type 2 connection was in the limited ductility (μ = 1,27). The average moment capacities of type 1 and type 2 connections were 4.56 kN.m and 21.2 kN.m, respectively. The moment and rotation relationships models of the glulam beam-column were approximately bilinear with initial stiffness 9 times and 2.4 times for type 1 and type 2 connections, respectively, compared to corresponding post-elastic stiffness. Steel plates helped improve ductility ratio, as shown by splitting failures near the column bolt rows. This stiffness model can then be used as input data for spring properties of similar connections in the analysis of multi-story building structures.

Tibetan furniture faces the dual challenge of maintaining the authenticity of cultural heritage while meeting the functional needs of modern living. The Tibetan-style seating bed is used in religious rituals and for daily purposes. A hybrid model integrating the Triangular Fuzzy Analytic Hierarchy Process (TFAHP), Quality Function Deployment (QFD), and VIseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) was constructed, aiming to resolve the conflict between cultural heritage revival and modern functional requirements in Tibetan furniture design. Through the grounded theory, 16 design elements were identified. TFAHP was employed for quantitative analysis, and the results showed that the cultural dimension of Tibetan furniture has a higher weight than the functional, apparent, and technological dimensions. Cultural recognition and Buddhist culture are the core driving forces behind this design. After mapping user needs via QFD, technical features such as modular design and integrated seating/storage designs were identified. Finally, VIKOR was used to conduct multi-objective optimization on three design schemes, and the optimal one is selected. The hybrid model proposed in this study provides a scientific framework for balancing cultural authenticity and user experience and offers a replicable design paradigm for the modern transformation of ethnic cultural heritage.

The mechanical and thermal properties of epoxy hybrid composites reinforced with natural fibers were studied, addressing the growing demand for eco-friendly materials. Fibers from chicken feathers (CF) and Sesbania grandiflora (SG) were used together with epoxy resin in composites, which were fabricated using the compression molding technique. Both the CF and SG fiber ratios ranged from 1:2 to 2:1, while fiber-to-resin weight proportions were set at 30:70 and 40:60. The composites were evaluated for mechanical and thermal characteristics in adherence to ASTM standards, with thermal properties assessed using thermogravimetric analysis (TGA). Surface morphology was examined using scanning electron microscopy (SEM). Process parameters were optimized using mathematical modeling, employing Analysis of Variance (ANOVA) and Response Surface Methodology (RSM). The hybrid composite with a 30:70 fiber/matrix ratio and a 2:1 CF/SG fiber combination demonstrated superior mechanical and thermal properties while showing reduced water absorption. A 30% fiber loading with a 2:1 CF/SG fiber ratio considerably enhanced the composite’s overall performance. The optimal blending ratio for hybrid composites was a 2:1 weight proportion of CF to SG fibers, offering a promising approach to developing sustainable materials with improved characteristics. This research highlights the potential of natural fibers in creating environmentally friendly composites.

Consumers tend to purchase and use furniture products that fulfill their emotional needs. However, existing bamboo furniture design departments lack a systematic and scientific approach to morphological design, and their innovation capabilities remain insufficient. This study proposes a generative design method for bamboo furniture that integrates Game Theory (GT) with AI-Generated Content (AIGC), grounded in Kansei Engineering. This approach aims to assist design departments in developing creative products that align with consumers’ emotional needs, thereby fostering sustainable consumption and advancing the bamboo furniture industry. First, consumer-driven Kansei words were collected and categorized. Then, subjective and objective weight values of consumer requirements were calculated using Grey Relational Analysis (GRA) and entropy, respectively. Based on GT, a comprehensive weight value was determined to accurately identify key consumer requirements. Next, Diffusion Models in AIGC technology were employed to generate new furniture images, followed by morphological deconstruction. Finally, a House of Quality based on Fuzzy Quality Function Deployment was constructed to establish the mapping relationship between key consumer requirements and new morphological elements, determining the optimal furniture design parameters. The proposed method integrates the strengths of both subjective and objective approaches, enhancing the accuracy and scientific rigor of design decision-making.

The structural safety of a natural monument tree was evaluated using the finite element method (FEM), assuming the tree’s material properties to be isotropic. This research involved quantifying external forces, gravity, snow, and wind loads, and analyzing the resulting stress and displacement of the tree. The effectiveness of support structures in improving the tree’s overall structural stability was also investigated. The results show that the greatest displacement and stress occur under snow load conditions. The highest stress was observed in branch D (13.63 MPa) under snow load without any support structure. When this stress was compared with the bending strength of the Zelkova tree’s branches (69.7 MPa), it was found that the tree has a safety margin of 56.1 MPa. Furthermore, when the current support structure positions were considered, branch F, which is supported, exhibited a significant reduction in displacement (by 30% to 42%) and stress (by 84% to 92%) compared to conditions without support. Conversely, branch D, which lacks a support structure, showed no reduction in displacement or stress. These results show that FEM simulation can contribute to the review of reinforcement facility installation to ensure the stability of large old trees.

Amid growing concerns about antibiotic resistance in livestock systems, there is a global shift toward identifying plant-based alternatives to conventional synthetic feed additives. This study explored the physicochemical characteristics of raw Napier grass (Pennisetum purpureum) and assessed its viability as a low-cost, functional feed additive for colored broiler chicken diets. Comprehensive characterization was conducted on the raw grass, revealing structural features and functional groups characteristic of bioactive, fibrous biomass. A subsequent feeding trial was conducted with 216 Sasso broiler chicks divided among six dietary regimens: a negative control (basal diet), a positive control (100 mg/kg oxytetracycline), and four supplementation levels of P. purpureum grass meal (1.25 to 5.00 g/kg). The highest supplementation level (5.00 g/kg) significantly enhanced growth performance (p < 0.05), reducing feed conversion ratio (FCR) while maintaining low feed intake. Economic analyses demonstrated that this treatment yielded the greatest profitability, exhibiting superior net profit margin, break-even efficiency, and margin of safety. These findings indicated P. purpureum as a promising phytogenic feed additive with dual benefits of enhancing production efficiency and promoting sustainable poultry farming.

The mechanical, moisture absorption, and chemical bonding properties were studied for hybrid polyester composites reinforced with snake grass (SG) fiber and Sal wood (S) and Babool (B) sawdust fillers. Composites were fabricated via compression molding with 60% polyester resin and varying filler-fiber ratios. Mechanical tests showed tensile strength increasing from 38 MPa (S1) to 56 MPa (S4), flexural strength peaking at 85 MPa (S4), and maximum hardness of 84 Shore D (S4). Impact strength reached 6.98 J (S4). Water absorption decreased with higher filler content, with S4 absorbing only 21%. Scanning Electron Microscopy (SEM) revealed improved interfacial bonding in S3 and S4, while S1 showed voids and fiber pull-out. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed enhanced chemical interactions in samples with optimized filler-fiber ratios, particularly in S4, contributing to its superior performance. The filler-fiber composition was optimized to maximize mechanical strength, moisture resistance, and chemical bonding, demonstrating the potential of these sustainable composites for durable, eco-friendly applications.

Over the past decade, advances in bioenergy technology have enabled the expansion of renewable energy consumption. Projections indicate that roughly 30% of the anticipated increase in renewable energy utilization will stem from modern bioenergy in its solid, liquid, and gaseous fuel manifestations, owing to its substantial role in heat and transportation sectors. At present, fossil fuels account for 60% of global electricity generation, while renewables contribute 30%. Notably, Turkey surpasses this global average, with renewables constituting 36% of its electricity production. In 2002, Turkey’s electricity output from renewable sources stood at 34 billion kWh; by 2023, it had surged by 300% to reach 200 billion kWh. Likewise, the installed renewable energy capacity, which was about 12,300 MW in 2002, has more than tripled, exceeding 82,700 MW in 2023. This research delves into biomass, a key pillar of renewable energy, analyzing its potential, technological advancements, significance, and current status in Turkey. Furthermore, it aligns with one of Turkey’s foremost energy strategies that focuses on enhancing domestic and renewable energy production.

The combined effects of temperature, Fe (III) contents, NH₄⁺-N contents, and soil-liquid ratio were evaluated relative to the loss of NH₄⁺-N in soils using a response surface methodology (RSM). The microbial mechanisms were explored for nitrogen transformation by quantifying functional genes related to nitrification and denitrification. According to parameter optimization analysis for prediction equation, the maximum NH₄⁺-N loss was 86.1% under the conditions of 17.0 °C, 0.772 g·kg^-1 Fe (III), 21.9 mg·kg⁻¹ NH₄⁺-N, and soil: liquid ratio of 1:1. The prediction result was similar to experimental data in the current study, which the NH₄⁺-N loss was 83.2% under the condition of 25 °C, 0.723 g·kg^-1 Fe (III), 20 mg·kg⁻¹ NH₄⁺-N, and soil-liquid ratio of 1:1. While the N₂O flux reached its minimum value of 8.35 μg·m⁻²·h^–¹ under the experimental conditions, correlating with gene copy numbers for ammonia-oxidizing bacteria ammonia monooxygenase subunit A gene (AOB-amoA), and nitrite reductase genes (nirK) were maximum values of 4.5×10⁵ and 4.8×10⁵ copies·g^-1, respectively. NH₄⁺-N loss resulted from multiple interacting processes beyond ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) mediated oxidation. The research findings can provide insights for reducing nitrogen application to avoid NH₄⁺ toxicity and increasing soil planting suitability.

Environmentally friendly and biodegradable polyvinyl alcohol (PVOH) film combined with Phellodendron amurense extract was used to prepare an anti-UV composite film through thermal flow molding technology. The prepared PVOH composite film containing Phellodendron amurense extract exhibited UV-resistant properties, with the composite film made from leaf extract showing the highest UV resistance. Additionally, the tensile strength and toughness of the PVOH composite film with added Phellodendron amurense extract significantly increased compared to pure PVOH film. Studies on film-forming and UV-resistant mechanisms have revealed that extract particles can act as nucleating agents to promote the local ordered arrangement of PVOH molecular chains, forming microcrystalline regions. This enhances the tensile strength of composite films while maintaining their toughness. During the film-forming process, the extract forms hydrogen bonds with PVOH, and the benzene ring conjugated double bonds in the extract can absorb ultraviolet light, contributing to the UV resistance of the PVOH composite film. The composite film prepared from Phellodendron amurense extract and PVOH with UV resistance and high strength can be applied in fields such as packaging, food, and sunscreen products, which is of great significance for promoting the efficient development and utilization of biomass resources.