Volume 21 Issue 2

With the intensification of global environmental challenges and the rising environmental awareness among parents, traditional children’s toys face growing criticisms regarding excessive resource consumption, poor recyclability, and inadequate sustainability. Wooden toys, in particular, encounter new obstacles in material innovation, structural optimization, and functional upgrading. To address the conflicting requirements of functionality, safety, and sustainability in wooden toy design, this study proposes a quantitative decision-making framework integrating the Kano model, Analytic Hierarchy Process (AHP), and VIKOR method. Unlike traditional design approaches that rely on intuition, this study first quantified user attributes through the Kano model, identifying “material traceability” as a high-priority “Attractive” attribute alongside “Must-be” safety requirements. AHP is then utilized to construct a hierarchical weighting system, revealing a “Safety-First, Ecology-Second” preference structure among stakeholders (Weights: Safety 0.482 > Ecology 0.273). Finally, the VIKOR method was used to rank five alternative schemes, identifying a modular furniture-toy combination as the compromise optimal solution due to its superior performance in high-weight indicators. This research provides a verifiable pathway for translating vague sustainable concepts into actionable design indicators.

The high-intensity noise generated during high-speed milling of wood-plastic composites, due to the material properties of anisotropy and non-uniformity, seriously affects the working environment and operator comfort. The influence of axial depth of cut, radial depth of cut, cutting speed, and feed per revolution on the sound pressure level of milling noise in wood-plastic composites was analyzed through single-factor milling experiments. Furthermore, a principal component variance analysis was conducted using multi-level factorial milling experiments to investigate the interaction effects of milling parameters on milling noise variation. The results showed that, for a fixed milling length, the significance of milling parameters on milling noise sound pressure level decreased in the order of cutting speed, axial depth of cut, radial depth of cut, and feed per revolution. A smaller axial depth of cut was suggested to control noise emission while ensuring machining efficiency. With a constant axial depth of cut, lower feed per revolution and radial depth of cut helped achieve reduced noise levels. This study provides a theoretical basis for addressing the challenge of high-intensity noise generated during high-speed milling of wood-plastic composites.

Scots pine (Pinus sylvestris L.) grows from sea level up to 2700 m as small groups or individually in Türkiye. Cone and seed production is the main tool in sustainability of forest tree species. However, many biotic and abiotic factors such as stand structure and forestry practices could impact production. The impact of thinning levels (unthinned or known control, moderately thinned, and heavily thinned in 2021) together with growth characteristics on mature cone production was examined based on two-year cone data (2024 and 2025) in natural stands. Stands and individuals within stands were evaluated for both cone production and growth. Heavily thinned stands had higher cone production for both years (16.8 and 96.6) than moderately thinned (9.7 and 40.7) and unthinned (9.5 and 32.6). The year 2025 produced more abundant cones (55.4) than 2024 (11.9). Significant (p < 0.05) differences were found with respect to thinning level for growth characteristics and cone productions except for tree and crown heights. Years showed significant (p < 0.05) differences among grades and within grade for cone productions. Additionally, growth characteristics had generally significant (p < 0.05) impact on cone production in both grade and years.

This study reports silver nanoparticles (AgNPs) synthesis through a green, facile, and eco-friendly route using aqueous leaf extract of Phyllanthus amarus as both reducing and stabilizing agent. GCMS screening of the plant extract affirmed the presence of phytochemicals such as   flavonoids, polyphenols, and other biomolecules responsible for the reduction and stabilization of synthesized nanoparticles. The biosynthesis was confirmed with a visible color change from pale yellow to brown with UV–Visible spectroscopy indicated AgNPs formation within 400 to 450 nm. X-ray diffraction (XRD) revealed three distinct peaks corresponding to (111), (200), and (220) crystal planes, while transmission electron microscopy (TEM) indicated circular-shaped particles with particle size in the range of 10.02 to 28.5 nm. The optical activity of the synthesized nanoparticles was confirmed by its ability to sense the presence of selected metals such as manganese, iron, lead, arsenic, and cadmium ions, demonstrating potential environmental applications. In addition, the as-prepared AgNPs exhibited antimicrobial effects against gram-positive and gram-negative bacteria. The green synthesis method using P. amarus offers a low-cost and sustainable route to stable AgNPs with bi-functional properties suitable for biological and environmental applications.

Drawing on Google Trends data from 2015 to 2024, this study examined patterns of digital attention toward lignocellulosic packaging materials, including paper, wood, and bamboo. Search activity was interpreted as an indicator of evolving sustainability-related public interest rather than simple query frequency. The analysis revealed sustained growth across all packaging-related terms, with “biodegradable packaging” exhibiting the highest compound annual growth rate (CAGR = 16.86%), substantially exceeding that of “paper packaging” (6.84%). This pattern suggests that public attention is expanding more rapidly toward broad sustainability concepts rather than toward individual material categories. Interpreted within the framework of Signaling Theory, rising search intensity reflects increasing cognitive engagement with environmentally responsible packaging. However, because Google Trends provides relative rather than absolute measures of search volume, the results should be understood as indicators of digital attention rather than direct evidence of purchasing behavior.

The compressive strength and dynamic bending resistance were tested for solid wood reinforced with glass and carbon fiber fabrics perpendicular to the fibers. The obtained data were used to predict the structural suitability of fiber-reinforced systems, especially for strengthening vertical load-bearing elements of historical buildings. Scotch pine (Pinus sylvestris L.) and Turkish beech (Fagus orientalis Lipsky), which are widely used in the construction and furniture industries in Türkiye, were coated with 200, 300, and 400 g/m² glass fiber fabric, carbon fiber fabric, and glass chip using epoxy resin. Compression tests conducted in the direction perpendicular to the fibers were applied according to the TS ISO 13061-5 (2021) standard. The highest compressive strength was obtained in the KK group (84.6 N/mm²), while the lowest value was obtained in group ÇCW1 (48.6 N/mm²). Dynamic (shock) bending strength tests were conducted in accordance with the TS ISO 13061-10 (2021) standard, and the highest dynamic bending strength was measured in the KCW2 group (70.2 kJ/mm²), while the lowest value was measured in the Scotch pine control group (35.6 kJ/mm²). Fiber-reinforced systems, with their mechanically weak properties, offer a viable solution for improving the compressive and dynamic bending strength of wood materials.

A sustainable green synthesis technique was employed to synthesize selenium-based nanoparticles (SeNPs) and a nanoemulsion (NE) from ginger oil (Gr). The nanoparticles were analyzed by DLS, UV-visible, and TEM techniques. The “emulsion inversion point” (EIP) method, a cornerstone of low-energy nanoemulsion (NE) production at constant temperature, was utilized. The liquid phases and surfactant choice determined whether a different mixing sequence was preferable. Using an oil-in-water (O/W) system, ginger oil was transformed into ginger nanoemulsion (Gr-NE). Gr-NE consists of dispersed immiscible phases containing kinetically stable droplets of a liquid phase, with sizes ranging from 36.6 to 51.1 nm. This technique resulted in a high surface area, excellent optical clarity, outstanding stability, and tunable rheology. An environmentally friendly method of synthesizing selenium-based nanoparticles (SeNPs@Gr) with particle sizes ranging from 64.2 to 90.6 nm was developed by utilizing ginger oil. Antimicrobial and antioxidant properties of all the components, as well as SeNPs@Gr, were evaluated. By synthesizing Gr-NE and SeNPs@Gr with minimal environmental impact and using renewable resources, this work achieved alignment with principles of the circular bioeconomy. In particular, the work contributes to Sustainable Development Goals 3 (Improving People’s Health) and 12 (Encouraging Responsible Production and Consumption).

The joint strength that develops in ultrasonic bonding of fiber-based materials is governed by multiple macro- and microscopic structural parameters whose interactions complicate the isolation of individual effects. In this study, paper made from cellulose-containing natural fibers was examined with respect to three structural factors: fiber orientation, paper side, and refining degree (°SR). Fiber orientation proved to be the dominant parameter. Samples with fibers aligned along the vibration direction exhibited significantly higher joint strengths than those with fibers oriented perpendicularly. The effect of paper side varied depending on fiber type and basis weight, indicating additional influences from factors such as porosity, surface roughness, and fiber distribution. Consequently, no universal relationship between paper side and joint strength was established. The refining degree showed no distinct influence within the typical range (°SR 24 to 36); however, at an exceptionally high value (°SR 80), a clear effect was observed. The impact of refining degree was found to depend strongly on basis weight: at 170 g/m², increased fibrillation enhanced bonding due to larger specific surface area, while at 80 g/m², shortened fibers and fewer contact points reduced joint strength. These findings highlight the need for a differentiated evaluation of structural parameters in optimizing ultrasonic bonding of fiber-based materials.

Perovskite CaTiO₃ mineral was synthesized from natural materials of Tebalan seashells and their structural and morphological characteristics were explored. The solids were calcined at temperatures of 900 °C and 1100 °C. The analysis by X-ray diffraction (XRD) demonstrated that the dominant phase of CaTiO₃ exhibited an orthorhombic structure, characterized by lattice parameters a = 5.388 Å, b = 5.446 Å, and c = 7.651 Å, at a temperature of 1100°C. This observation signifies an enhancement in crystallinity and an augmentation in phase purity. Scanning electron microscopy (SEM) showed that the morphology was homogeneous, with uniform grains and increased density at high temperatures. This morphology is indicative of the material’s potential for use in VOC gas sensor applications, based on the observed regularity and density of the surface structure. It is hypothesized that the intrinsic porosity of shell-derived CaTiO₃, when coupled with the hierarchical porous architecture of lignocellulosic biomass, can synergistically enhance VOC adsorption and mass transfer, thereby significantly improving sensor sensitivity and detection performance. This outcome validates its promise as an eco-friendly and cost-effective VOC gas sensor material.

Cellulose nanofibrils (CNF) are increasingly explored for biomedical applications; however, the relationship between surface functionalization and biological responses remains incompletely understood. In this study, CNF were carboxymethylated to controlled degrees of substitution (DS) using kraft pulp as a starting material, and their physicochemical properties and in vitro biosafety were evaluated. Increasing DS altered crystallinity and surface charge, resulting in measurable changes in zeta potential and structural characteristics. Cell viability was assessed in HepG2, HEK293, and RAW 264.7 cells across a concentration range of 100 to 1000 µg/mL using complementary assays. All tested materials exhibited concentration-dependent trends in cell viability. However, under the tested conditions, the observed effects remained within the non-cytotoxic range. Among the tested samples, CM CNF with DS 0.2 showed stable cell viability and limited apoptosis-related responses comparable to those of hyaluronic acid (HA), while samples with lower or higher substitution levels showed modest reductions in viability at higher concentrations. Apoptosis-related gene and protein expression analyses further indicated limited transcriptional and translational changes relative to the vehicle-treated control. Overall, the findings suggest that the degree of carboxymethylation influences cell–material interactions in a concentration-dependent manner, while maintaining biosafety within the tested DS range.