Research Articles

Long-term anthropometric changes (1980 to 2025) of young adults (aged 18 to 25) were evaluated in the Czech Republic and Slovakia to inform the design of wooden beds. Both populations exhibited identical anthropometric parameters and secular trends: mean body mass increased by 6.2 kg (~1.4 kg/decade) in men and 7.1 kg (~1.6 kg/decade) in women. To address these changes, updated single-bed dimensions are proposed, extending the bed length from 200 cm to a minimum of 220 cm (recommended: 240 cm) and increasing the width from 90 cm to a minimum of 100 cm (recommended: 141 cm). A 3D finite-element (FE) model evaluated structural performance under a design load of 250 kg, which surpasses the reference single-user body mass (~110 kg) specified in EN 1725:2023. The analysis identified the side rails as the most critical structural components. Stiffness was verified against the Eurocode 5 (EN 1995-1-1) L/300 criterion (an 8.0 mm limit for a 2400 mm span). Maximum vertical deflections (6.2 mm for oak and 8.2 mm for spruce) and lateral deflections (5.2 mm and 6.8 mm, respectively) demonstrated that oak satisfies the stiffness requirements, whereas spruce marginally exceeds the allowable deformation limit. The findings confirm that current furniture design standards fail to align with the anthropometric realities and require updates.

Root biomechanical properties, including tensile strength, tensile force, and Young’s modulus, are fundamental parameters governing vegetation-induced soil reinforcement. However, the effects of sample preservation and loading rate on these properties remain insufficiently understood, limiting the reliability and comparability of root biomechanical data. This study investigated the influence of loading rate and freezing preservation on the mechanical properties of roots from four dominant Hyrcanian forest tree species. Fresh roots were tested at two loading rates, and an additional experiment evaluated the effect of one month of frozen storage before tensile testing. Freezing significantly increased tensile force, tensile strength, and Young’s modulus, while also improving the consistency of diameter–property relationships. These increases most likely resulted from structural and moisture-related changes induced by freezing rather than reflecting the natural mechanical behavior of roots, indicating that frozen samples may overestimate root reinforcement capacity. In contrast, loading-rate effects were generally limited and species-dependent. Root diameter increased tensile force but was generally associated with lower tensile strength and Young’s modulus. These findings highlight the importance of standardized testing protocols to improve the reliability of root biomechanical data and the accuracy of soil bioengineering applications.

Cross-laminated timber (CLT) slabs and steel beams can be combined to form hybrid floor systems for long spans and heavy loads. The performance of these systems depends greatly on the shear connections between the CLT slabs and steel beams. In this study, push-out tests were conducted on CLT–steel joints connected with bolts or lag screws. The tests followed the loading procedure specified in EN 26891. Six specimen types were prepared by varying the fastener type, lag screw diameter and length, and reinforcement condition. Carbon fiber reinforced polymer (CFRP) plates were fabricated by laminating pultruded CFRP sheets with epoxy resin, whereas GF plates were fabricated by bonding woven glass-fiber cloth layers with phenol–resorcinol–formaldehyde adhesive. Both types of plates were bonded to the CLT with epoxy resin. CFRP reinforcement increased the strength and stiffness of the joints but resulted in brittle screw fracture. GF reinforcement produced smaller strength gains but showed a more gradual post-peak response. A modified Ramberg–Osgood model was used to describe the nonlinear load–slip behavior. The analytical curves agreed well with the test results (R² > 0.99). The model parameters reflected differences in fastener geometry and reinforcement condition. The results provide useful data for the design and numerical analysis of CLT–steel composite floor systems.

The flatbed die-cutting principles used to convert sustainable dispersion-coated paperboards for food packaging have remained largely unchanged for decades, despite persistent issues with coated-surface integrity after creasing. To improve the convertibility of such materials, this study developed novel die incorporating low-friction plastic creasing rules for industrial die cutters. The die comprised conventional uncoated steel creasing rules as the control condition and interchangeable creasing-rule inserts machined from polytetrafluoroethylene (PTFE) or polyoxy-methylene (POM). The rule contours were surrounded by conventional steel knives to produce standard folding-carton blanks from three dispersion-coated paperboards. The coated surface integrity of the materials was evaluated by measuring the oil and grease resistance (OGR) and performing scanning electron microscopy before and after conversion. The results indicated that the highest OGR was obtained for two paperboards creased with PTFE rules. Die cutting with POM rules improved creasability at specific test points; however, the average performance was comparable to that of steel rules. The third paperboard was particularly prone to damage, precluding a comparison across rules. As the PTFE-based toolset demonstrated superior performance on an industrial die cutter, future research should examine whether die design can be simplified by applying a low-friction PTFE coating to conventional steel creasing rules.

A composite material was fabricated using a hand lay-up technique, incorporating layers of woven kenaf, cotton, and polyester fiber fabrics as reinforcement in a polyester resin matrix, arranged in a specific stacking sequence to enhance its properties performance. The composite material was compressed after the polyester resin was applied in the stacking sequence. Four stacking sequences were designed, and their influence on density, water absorption, moisture content, thickness swelling, tensile strength, flexural strength, and thermal stability was assessed. The PKCCKP sample also exhibited the lowest water absorption (1.99%), moisture content (1.42%), and thickness swelling (0.6%). Tensile and flexural strength attributes were enhanced when all three reinforcement materials were used together.  The optimal stacking sequence for tensile, and flexural strength and modulus was with PKCCKP (52.1 MPa and 133.4 MPa). This improvement can be attributed to the excellent fabric adherence, with polyester fabric playing a significant role in the outside layer compared to the inside layer. All hybrid composite stacking sequences demonstrated good thermal stability, indicating their suitability for various eco-friendly applications. The choice of outer layers affected the durability and mechanical performance of composites for use in automotive, household, and structural applications.

Old ship timber is a wood resource that combines reuse potential, cultural significance, and distinctive aesthetic characteristics. By extending the material life cycle and promoting resource circularity, it provides potential value for sustainable furniture design. However, wood furniture design remains limited by insufficient requirement identification, experience-driven decisions, and inadequate integration of cultural values with contemporary functional needs. To address these challenges, this study focused on Chinese old ship timber furniture and proposes a sustainable design decision-making framework integrating Grounded Theory (GT), Kano model, the Analytic Hierarchy Process (AHP), Quality Function Deployment (QFD), and VIKOR. Semi-structured interviews were conducted with 15 participants to capture users’ perceptions, and GT identified five categories of user requirements—functional, visual, cultural, material, and market-related—comprising 15 elements. Kano classified these requirements, while AHP quantified their relative importance, identifying material expressiveness, ergonomic performance, and style compatibility as the highest-priority requirements. QFD translated these priorities into nine technical characteristics, and VIKOR evaluated four design schemes. Results indicate that Scheme 2, emphasizing the integration of reclaimed ship timber with contemporary living environments, achieved the highest overall evaluation score. The findings suggest that the framework supports requirement identification, technical translation, and alternative selection for sustainable furniture design.

Agro-industrial residues from the olive oil industry present considerable environmental challenges due to their high organic load and phytotoxic phenolic content. This study explored the valorization of olive pomace by developing pectin, pectin gel, and a biochar–pectin gel composite (BPGC) for sustainable agricultural applications. The materials were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, and Brunauer–Emmett–Teller analysis, confirming successful composite formation and revealing the predominantly mesoporous characteristics of the olive pomace-derived biochar. Swelling analysis showed that pectin reached 121% within 10 min and 195% after 2 h, while BPGC exhibited superior moisture retention (60%) and water-holding capacity (97.9%). Germination studies demonstrated high seed viability (96% to 98%) across treatments, with BPGC producing the highest seedling-growth responses, including shoot length of 8.31 cm, root length of 4.03 cm, and a seedling vigor index of 1210. Enzymatic activity was also improved, with protease and lipase reaching 186 and 201 U/g FW, respectively, in BPGC-treated samples. No detectable phytotoxic effects were observed under the tested conditions. These findings indicate that BPGC is a promising bio-based water-retaining soil amendment for improving soil moisture management and early plant growth, particularly in arid and semi-arid agricultural systems.

Enzyme instability and recovery may limit the practical use of ligninolytic enzymes that originate from white-rot fungus for the management of colored industrial effluents. This study examined the use of a crude cellulose synthesis enzyme preparation from Trametes versicolor in conjunction with a charcoal-based support to treat wastewater from food processing. Spectrophotometric analysis was utilized to assess the conditions of mushroom biomass extraction and charcoal treatment, while FTIR, XRD, SEM, and dynamic light scattering were employed to investigate changes in the charcoal material after modification. The improved charcoal preparation showed alterations in its surface functional groups, scattering profile, shape, and hydrodynamic size distribution; the optimal extraction temperature examined was 30 °C. Shezan International Limited in Lahore provided food-processing wastewater, which was first physically pretreated before being treated with an enzyme preparation and charcoal-based substance. Following treatment, a decrease in UV-Vis absorbance was noted, suggesting color removal. The decrease in absorbance cannot be taken as proof of enzymatic dye degradation because hydrogen peroxide can contribute to chemical oxidation and charcoal can independently absorb color-causing chemicals. The results underline the necessity for quantifiable immobilization, adsorption, stability, and degradation-product studies while supporting the potential of the charcoal-supported ligninolytic enzyme system for additional research.

Plant-biochar remediation is a promising strategy for heavy metal-contaminated farmland, but its practical value should be evaluated by considering both residual soil risk and the response of subsequently planted crops. In this study, waste-derived Pteroceltis tatarinowii Maxim. (PTM) biochar was combined with the non-food accumulator Chlorophytum comosum (C. comosum) to remediate field-collected Cu-Pb-contaminated soil. Lactuca sativa (L. sativa) was subsequently planted as a sensitive indicator crop. Among the treatments, the combined application of 5% PTM biochar and C. comosum (BC5) produced the strongest overall remediation effect. BC5 improved the growth of L. sativa, increased leaf chlorophyll content, decreased malondialdehyde content and antioxidant-enzyme activities, and reduced Cu and Pb uptake and translocation (P < 0.05). BC5 also reduced the bioavailable fractions of Cu and Pb in soil and was associated with shifts in bacterial community structure, increased relative abundances of Bryobacter and Vibrionimonas, and changes in predicted metabolic pathways related to nutrient cycling and stress regulation. These microbial responses may help explain the improvement in soil ecological function and the reduced metal stress in L. sativa, although further functional validation is needed. Overall, sequential remediation using PTM biochar and C. comosum provides a potential low-cost and eco-friendly approach for reducing residual phytotoxicity and crop metal-uptake risk in Cu-Pb-contaminated farmland.

To investigate Generation Z’s design preferences for solid wood smart home products and the factors influencing their choice of design solutions, the AHP-CRITIC-TOPSIS integrated evaluation model was applied. The KJ method was used to screen nine design proposals, and 14 evaluation criteria were established based on material appearance, material–technology integration, and emotional needs. The model combined subjective weights from AHP, objective weights from CRITIC derived from 159 questionnaires, and TOPSIS rankings. The results indicated that embedded-structure rationality, aesthetic harmony, maintenance convenience, and perceived rationality of heat-source layout were key indicators, with the S6 design ranking highest among the nine evaluated alternatives. This study provides a quantitative reference for sustainable innovation in solid wood smart home products.