Research Articles

Additive manufacturing (AM) using wood-based materials offers new bioeconomic possibilities for sustainable product design and waste valorization. This study examined the influence of wood particle size and shape on the properties of pastes processed by Liquid Deposition Modeling (LDM). Softwood sawdust separated into nine particle size ranges and ground wood powder were analyzed. The materials were mixed with water and methylcellulose as a natural binder, printed into test specimens, and evaluated for shrinkage, density, and flexural strength. Finer particles led to higher densities (up to 0.38 g/cm³), flexural strengths (up to 4.8 MPa), and elastic moduli (up to 436 MPa), while larger particles limited the filler content and reduced mechanical performance. Grinding decreased particle slenderness and promotes greater material density, thereby improving mechanical strength. These findings demonstrate that particle characteristics strongly influence paste printability and mechanical performance, providing a basis for the further development of resource-efficient wood-based materials for sustainable manufacturing.

This study assessed the suitability of four Miscanthus cultivars as alternative raw materials for pulp and paper production. A field evaluation revealed that cultivars 1 and 6 achieved the highest biomass yield ratios, at 2.4 and 2.0, compared to Miscanthus x giganteus. Chemical characterization identified cultivar 6 as favorable for pulping, exhibiting low extractives (1.35%), Klason lignin (14.5%) and moderate ash contents (1.37%). Pulp yields of up to 61.5% were achieved by soda pulping at 160 °C for 90 min and the addition of 15% NaOH by weight of the raw material. Cultivar 23 had the lowest residual lignin content at 1.1%. After refining to 500 PFI revolutions, sheets (30 gsm basis weight) produced from cultivar 6 achieved a tensile index of 43.9 N·m/g. The same tensile index as eucalyptus (44.0 N·m/g) was exhibited after 3000 rotations in the PFI mill. Overall, the results demonstrated that the selected Miscanthus cultivars, especially cultivar 6, is a promising source of fiber, particularly for products that require high absorbency and strength.

Using polylactic acid (PLA) and nanocellulose (NFC) as raw materials, and glycidyl methacrylate (GMA) as the modifier, the PLA/NFC-GMA composite was prepared by solution blending. The addition of GMA effectively improved the dispersion of NFC in PLA, with NFC being grafted onto the PLA molecular chain through a reaction with GMA. The tensile strength of PLA/NFC-GMA composites increased with NFC loading, while GMA improved interfacial compatibility and dispersion, leading to a non-monotonic strength trend and reduced elongation at break. The PLA/NFC-GMA composite with 0.7 wt.% NFC and 6.0 wt.% GMA had the best mechanical properties, with the tensile strength of 27.7 MPa and the elongation at break of 78.4%. The PLA/NFC-GMA composite exhibited excellent UV shielding. Its transmittance was nearly zero below 280 nm and it maintained high transparency within the wavelength range of 400 to 800 nm, with a transmittance exceeding 85%. The transparency of the composite reached its maximum when the NFC and GMA loadings were 0.7 and 1.5 wt.% relative to PLA, respectively. GMA significantly enhanced the thermal stability of PLA/NFC-GMA composites. The thermal stabilization effect of GMA became saturated at ~3.0 wt.%, beyond which additional GMA primarily promoted more complete volatilization without further improving thermal resistance.

The nirai is a four-string hybrid instrument that combines characteristics of the Okinawan sanshin with those of a standard guitar, developed by the brand K. Yairi. Designed for ease of performance, the instrument employs a default open-fifth tuning in the key of G (G2–D3–G3–D4, from the fourth to the first string). Owing to its non-standard tuning and simplified design, conventional Western notation systems-such as standard guitar tablature-are less commonly applied. As a result, performers typically rely on aural learning or adapt musical materials to suit the instrument’s tuning, which yields a diatonic rather than a fully chromatic scale. Knowledge is generated through the act of composing, arranging, and performing original musical works as research artefacts. The research methods include the development of customized notation scores specific to nirai, as well as duet performances with selected local traditional instruments. The findings demonstrate that the timbral and modal characteristics of the Nirai integrate effectively with indigenous Bornean instruments, the sape, revealing its potential as a mediating tool for intercultural musical dialogue. This study contributes practice-led insights into alternative tuning systems, compositional strategies, and notation approaches, reinforcing the value of creative practice as a mode of musical knowledge production.

Acoustics plays a significant role in the classification of a wide range of products in wood science and technology, from standing trees to structural elements. The study of wood acoustics involves the use of mechanical waves that are sensitive to several factors, including sample dimensions, intrinsic characteristics of the wood species, and the presence of defects. This study aimed to estimate the modulus of elasticity in juvenile wood of Tectona grandis using three different non-destructive wave-based evaluation methods: ultrasound, impulse vibration, and stress waves, with the goal of identifying the most suitable technique for predicting this mechanical property. Additionally, the study evaluated the impact of knots on wave propagation velocity and, consequently, on the estimation of the modulus of elasticity. Specimens measuring 20 × 20 × 300 mm (width, thickness, and length, respectively) were used, totaling 42 samples divided into two groups: with knots and without knots. The results indicated that all evaluated methods were effective and exhibited strong correlations with the estimated modulus of elasticity. Furthermore, the presence of knots in young, fast-growing teak wood did not significantly influence wave propagation.

A rapid, eco-friendly, and cost-effective green synthesis route was established for the fabrication of gold nanoparticles (Au NPs) utilizing aqueous extracts derived from Punica granatum L. (pomegranate) agricultural peel waste, thereby valorizing agro-industrial by-products. The proposed method eliminates the need for hazardous reducing agents and external stabilizers, offering a fully biogenic and waste-to-value nanomanufacturing approach. The synthesized AuNPs were extensively characterized using UV–Vis spectroscopy, FTIR, XRD, TEM, STEM, DLS, zeta potential analysis, and EDX, confirming the formation of crystalline, spherical, and highly stable nanoparticles with a surface plasmon resonance peak at 532.3 nm, an average hydrodynamic diameter of 47.1 nm, and a zeta potential of −16.2 mV. The integration of multiple complementary analytical techniques further validated the structural and colloidal stability of the nanostructures. The AuNPs exhibited strong, dose-dependent antimicrobial activity against pathogenic microorganisms and significant cytotoxic effects against human cancer cell lines in vitro. The novelty of this work lies in the dual contribution of (i) transforming agricultural waste into a functional nanomaterial platform and (ii) producing biologically active AuNPs via a single-step, green, and scalable synthesis route without chemical additives.

Acetoin is a valuable by-product of glucose metabolism with wide applications in the chemical, food, cosmetic, and pharmaceutical industries. This study investigated acetoin production using both wild-type and mutant strains of Bacillus paralicheniformis MT039446.1. Production was optimized by varying incubation time to determine conditions that maximized yield. UV-visible spectroscopic analysis showed distinct absororption peaks at 350 nm for the wild strain and 450 nm for the resistant mutant strain. Functional group characterization was further validated using Fourier transform infrared analysis confirmed the presence of carbonyl compounds. Structural and morphological changes in the solid substrate (press mud) during fermentation were examined through scanning electron microscopy and X-ray diffraction techniques, indicating substrate modification during microbial activity. Kinetic analysis demonstrated a significant improvement in the mutant strain (NA-cys3), with volumetric productivity (Qp) reaching 0.33 g/L·h compared to 0.16 g/L·h in the wild strain. This enhancement reflects  improved efficiency of the acetoin biosynthetic pathway following mutagenesis. Overall, the study highlights an environmentally sustainable and economically viable approach for acetoin production using agro-industrial waste. This strategy supports the development of circular bio-economy models and offers potential for scalable bio-manufacturing applications.

Sarawak woodcarving has long been discussed within fixed cultural, ritual, and ethnographic frameworks that emphasize preservation, authenticity, and continuity of tradition. While such readings are important, they risk positioning woodcarving as a static cultural artefact rather than a dynamic and evolving practice. This paper applies deconstruction as a critical and methodological approach to examine Sarawak woodcarving through three interrelated conditions: carved, uncarved, and re-carved, drawing conceptually from Derrida’s critique of fixed meaning. These conditions function as analytical lenses to examine how meaning is constructed, disrupted, and reconstituted through material presence, absence, and transformation. Drawing on arts-informed qualitative methods and visual inquiry, the study foregrounds tacit knowledge embedded in material, process, and erasure. The findings suggest that Sarawak woodcarving operates as a fluid cultural text in which meanings are continually negotiated rather than fixed, repositioning woodcarving as an active and contemporary cultural practice rather than a closed tradition.

Owing to their low cost, availability, and biodegradability, natural fibers can be suitable alternatives to synthetic fibers. Replacing traditional synthetic fiber-reinforced polymer composites with natural fiber-reinforced composites can substantially reduce environmental impact by lowering the reliance on non-renewable reinforcements, while still using industrially feasible polymer matrices such as unsaturated polyester. The present study utilised biodegradable reinforcements, sugar palm fiber (SPF) in unsaturated polyester (UPE), and silica aerogel (SA) as a filler material. A range of SA concentrations was tested, and an optimal concentration was identified to achieve the best thermal performance of SPF/UPE composites. The thermal properties were examined by dynamic mechanical analysis (DMA), whereas thermogravimetric analysis (TGA) was employed to assess thermal degradation of the samples. DMA results revealed that the best mechanical performance under thermal conditioning was achieved with 3 wt. % SA content. Similarly, the TGA study indicated that the onset temperature of thermal decay was highest in the 3 wt. % SA composites. Under extreme heat exposure, the composite with the highest SA content (5 wt. %) experienced the least decomposition. Across all samples, thermal performance was generally significantly improved compared to the control sample.

The mechanical strengths of wood samples from three species were tested and compared – Uludağ fir (Abies bornmüelleriana Mattf.), oak (Quercus robur L.), and Oriental beech (Fagus orientalis L.) – after cryogenic treatment with liquid nitrogen (LN, −196 °C). Bending deformations were recorded by the ordinary method and two-dimensional digital image correlation (2D DIC) during bending tests. To apply the 2D DIC technique, a stochastic speckle pattern was sprayed onto the surface of each specimen and the displacement of these reference points was observed through non-contact during the bending tests. Deformation data obtained from the mechanical tests were compared with corresponding values ​​determined via 2D DIC for the control samples and the samples treated with LN for 15 and 30 min, to evaluate the accuracy and reliability of the method. The results demonstrated that LN treatment influenced the mechanical behavior of the wood to varying degrees depending on the treatment duration. Furthermore, the deformation measurements obtained via 2D DIC showed excellent agreement with the results from conventional measurement methods. These findings indicate that the 2D DIC technique can be a reliable and effective non-contact measurement method for investigating the mechanical behavior of cryogenically treated wood materials.