Volume 21 Issue 4

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.

Microalgae-derived biodiesel is increasingly regarded as a next-generation renewable fuel because microalgae combine rapid biomass growth, high lipid productivity, carbon dioxide capture, and cultivation on non-arable land or nutrient-rich wastewater. This review critically integrates recent progress in strain improvement, cultivation engineering, harvesting, lipid extraction, and conversion technologies for scalable biodiesel production. Advances in genome editing, two-stage cultivation, hybrid photobioreactor-open pond systems, and microwave- or ultrasound-assisted extraction have improved lipid yield and process efficiency. Digital tools, including artificial intelligence, predictive monitoring, digital twins, and machine-learning-based contaminant control, are also emerging as important enablers of automation and scale-up. Embedding microalgae production within circular biorefineries can support flue-gas utilization, nutrient recycling, and co-production of high-value compounds such as astaxanthin, omega-3 fatty acids, phycobiliproteins, proteins, and biodegradable biopolymers. Nevertheless, commercialization remains constrained by high cultivation costs, energy-intensive dewatering, variable outdoor productivity, and uncertain policy incentives. Integrated techno-economic optimization, carbon-credit mechanisms, and multi-product biorefinery models are therefore essential for advancing microalgae biodiesel toward industrial deployment.

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.

The mechanical behavior of hybrid composite materials was studied based on a matrix composed of 50 wt.% Abies alba exudate and 50 wt.% epoxy resin, reinforced with cotton and silk fabrics. Composite plates were manufactured using a hand lay-up technique with a 40/60 resin-to-reinforcement ratio. Mechanical characterization included tensile, flexural, vibration, and Shore D hardness tests, supported by statistical analysis using one-way ANOVA and Bonferroni post hoc comparisons. The results showed that the introduction of textile reinforcement significantly improved all investigated properties compared to the unreinforced hybrid resin. Cotton-reinforced composites exhibited the highest tensile and flexural strength, as well as the highest hardness values, indicating increased stiffness and load-bearing capacity. In contrast, silk-reinforced composites demonstrated superior deformation capacity and higher damping behavior, reflecting enhanced ductility and energy dissipation. Statistical analysis confirmed a highly significant influence of material configuration on all properties (p < 0.05). An exception was observed in flexural deformation, where no significant difference was found between cotton- and silk-reinforced composites, suggesting a similar global deformation response. The results demonstrate that hybrid epoxy systems modified with Abies alba exudate can be successfully used for the development of bio-based composites.

Ming-style armchairs represent a distinctive form of Chinese classical furniture, yet systematic methods for linking their morphological features to users’ affective responses remain limited. Conventional Kansei Engineering (KE) models treat design components as equally weighted, neglecting differences in visual attention. This study proposes an attention-weighted KE framework that integrates eye-tracking data with partial least squares (PLS) regression modelling. Five representative Ming-style armchairs were evaluated by 200 Generation Y participants across five Kansei dimensions using semantic differential scales. A subsequent eye-tracking experiment with 30 participants derived visual attention weights for nine morphological components via the coefficient of variation of total fixation duration. These weights were embedded into binary morphological coding and analysed using partial least squares (PLS) regression. Results indicated that the stretcher, apron, and spindle showed stronger associations with affective differentiation than the dominant backrest, which served as a stable perceptual anchor. Plain aprons and slightly curved spindles enhanced perceptions of simplicity and naturalness, while step-by-step stretchers and carved aprons were associated with complexity. The regression coefficients were translated into preference-avoidance design rules, suggesting that redesign may benefit from a two-fold strategy of preserving simple, recognisable treatment of the dominant category-defining component while concentrating tasteful elaboration on one selected secondary feature.

Carbon dioxide biomethanation offers a promising route for energy storage via biological conversion of renewable surplus electricity and CO₂ into methane. To improve the gas production efficiency and instability, bioaugmentation strategies are commonly employed by using biochar and trace elements individually. However, their coupled effect remains underexplored. In this study, the CM400 (biochar produced from cattle manure under 400 °C) showed superior performance in cumulative methane yield (138 mL·gVS⁻¹). Response surface optimization identified an optimal trace element combination (Fe: 15.1 mg·L⁻¹, Co: 1.5 mg·L⁻¹, Ni: 0.6 mg·L⁻¹), increasing methane yield by 12.9%. Subsequently, a novel modified biochar (CM400 pre-soaked in the optimal Fe/Co/Ni solution and pyrolyzed) was synthesized and significantly enhanced the volumetric methane production (VMP) by 19.8%. Experimentally, it enhanced the removal of total solids (TS), volatile solids (VS), and total chemical oxygen demand (TCOD) by 21.1%, 20.9%, and 3.4%, respectively, while strengthening pH buffering and preventing volatile fatty acid (VFA) accumulation. The modified biochar enriched electroactive bacteria (e.g., Synergistota, Chloroflexota) and key methanogens (Methanothrix). Collectively, these physiological and compositional changes are consistent with improved syntrophic metabolism and suggest the possible involvement of direct interspecies electron transfer.

The tongkungon is a plucked bamboo zither of the Kadazan-Dusun community in Sabah, Malaysia, reflecting both material ingenuity and cultural resilience. Historically used as a substitute for gong ensembles and as accompaniment to dances such as Magarang, its practice has declined due to modernization and the erosion of oral transmission. This study applies a postmortem framework, combining acoustic analysis, organological classification, and ethnomusicological interpretation. Acoustic measurements based on Fast Fourier Transform (FFT) and time-frequency analysis (FTA) reveal a pentatonic tuning system (F, A, B, C, E), with tonal instability caused by bamboo fiber variations. The tongkungon is classified organologically as an idiochord tube zither, linking it to wider Southeast Asian bamboo traditions. Culturally, it has functioned both as a pedagogical tool and as a symbol of Kadazan-Dusun identity. Although its active role has diminished, documentation and revitalization through education, cultural festivals, and creative collaborations offer pathways for safeguarding it as intangible cultural heritage.