Volume 21 Issue 3

Titanium dioxide nanoparticles (TiO₂ NPs) were synthesized using a microwave-assisted green synthesis approach using lemon peel extract as a reducing and stabilizing agent. The synthesized nanoparticles were characterized using UV–Vis spectroscopy, FTIR, TEM, SEM–EDX, and DLS analyses, which confirmed the formation of predominantly spherical nanoparticles with average particle sizes ranging from 25.6 to 38.7 nm. The biological activities of the synthesized TiO₂ nanoparticles were evaluated through different in vitro assays. The nanoparticles exhibited promising anticancer activity against HepG2 and MCF-7 cancer cell lines, with IC₅₀ values of 85.8 and 104.7 µg/mL, respectively, while showing lower cytotoxicity toward normal Vero cells with an IC₅₀ value of 262.5 µg/mL. In antioxidant assays, the TiO₂ nanoparticles demonstrated DPPH and ABTS radical scavenging activities with IC₅₀ values of 319 and 211 µg/mL, respectively. The nanoparticles also showed significant antibiofilm activity against Escherichia coli and Klebsiella pneumoniae, achieving maximum inhibition rates of 76.4% and 57.5%, respectively. Furthermore, the synthesized TiO₂ nanoparticles displayed antidiabetic potential through inhibition of α-amylase and α-glucosidase enzymes, with inhibition percentages reaching 63.9% and 79.1%, respectively. Overall, the study showed that green-synthesized TiO₂ nanoparticles had multifunctional biological activities and may serve as promising eco-friendly nanomaterials for biomedical and therapeutic applications.

Infrared (IR) processing of chili oil significantly modulated its phytochemical composition and biological activity. GC–MS analysis revealed that unexposed chili oil was rich in eugenol (32.73%), caryophyllene (8.21%), and polyunsaturated fatty acids (PUFAs) such as 9,12-octadecadienoyl chloride (16.86%). Short-term IR exposure (5 min) reduced eugenol to 25.90% and generated a positional isomer (phenol, 2-methoxy-3-(2-propenyl), 10.93%) along with diynoic acid esters and alkyne fatty-acid derivatives, indicating isomerization and partial PUFA degradation. Prolonged IR exposure (10 min) further decreasd volatile phenolics and PUFA esters while enriching high-molecular-weight alcohols (1-heptatriacotanol, 7.65%) and chlorinated derivatives (9,12-octadecadienoyl chloride, 21.04%). The 5-min IR treatment produced the highest antimicrobial activity, with inhibition zones increasing for B. subtilis (25 ± 0.2 mm), S. aureus (23 ± 0.7 mm), E. coli (18 ± 0.5 mm), S. typhi (19 ± 0.2 mm), and C. albicans (25 ± 0.3 mm), and MIC/MBC values notably reduced (15.62 µg/mL for B. subtilis and C. albicans). IR-treated chili oil also displayed strong dose- and time-dependent biofilm inhibition, reaching up to 95.23 ± 2.0% at 75% MBC. 5-min IR-treated chili oil reduced B. subtilis from 3.2×10⁵ to 2.1×10³ and S. aureus from 2.4×10⁵ to 2.6×10³ CFU/mL. Furthermore, antioxidant activity peaked at 5 min exposure (96.4 ± 1.91% DPPH scavenging; IC₅₀ = 5.65 ± 0.20 µg/mL), while anti-inflammatory activity was enhanced (IC₅₀ = 2.72 ± 0.14 µg/g).

Physical and mechanical properties were measured of oil-palm-based hybrid laminated veneer lumber (LVL) from pressed oil-palm wood veneer (Elaeis guineensis Jacq.) combined with  jabon (Anthocephalus cadamba Miq.) or mahogany (Swietenia macrophylla King) veneers. Jabon and mahogany veneers were applied as the surface (face and back) and center-core of a 5-layer oil-palm-based hybrid LVL and glued with phenol-formaldehyde at a spread amount of 200 g/m². Different combinations of veneer layers were used to make oil-palm-based hybrid LVL. The hot-pressing phase occurred at 140 °C under a specific pressure of 10 kg/cm² for 7 min. All hybrid LVLs exhibited better properties than the oil-palm LVL. Specifically, the density, moisture content, horizontal shear flat, horizontal shear vertical, modulus of rupture, modulus of elasticity, compression strength, and hardness of all hybrid LVLs were higher than those of the oil-palm LVLs, showing improvements of about 7.8 to 19.6%, 8.8 to 17.6%, 35.0 to 44.9%, 35.4 to 79.4%, 35.7 to 76.1%, 5.3 to 46.8%, 19.9 to 68.4%, and 9.6 to 56%, respectively. Their thickness swelling and water absorption decreased 10.7 to 24.7% and 2.9 to 27.7%, respectively. The oil-palm-based hybrid LVL incorporating three mahogany veneers possessed the most favorable physical and mechanical properties among other LVLs.

Maleic anhydride grafted polypropylene (MAPP) was utilized as a coupling agent to prepare composites of Populus tomentosa wood flour (WF) and poly (β-hydroxybutyrate valerate) (PHBV) through the hot-pressing process. The impacts of this coupling agent on the interfacial compatibility and physical-mechanical properties of WF/PHBV composites (WPHBVs) were analyzed and discussed by making use of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). The results indicated that after adding MAPP, a grafting reaction would occur. This reaction improved the interfacial compatibility between Populus tomentosa WF, and PHBV boosted the thermal stability of WPHBVs. When the addition amount of MAPP was 2%, the flexural strength and elastic modulus of WPHBVs reached their maximum levels, up to 27.99 MPa and 3690.47 MPa, respectively, and the strength enhancements were all above 40%. At this stage, the cross-section of the WPHBVs exhibited a smooth surface with no visible gaps. Tight interfacial bonding between phases indicated the highest level of compatibility between Populus tomentosa WF and PHBV.

Increasing demand for bio-based fire-retardant products requires abundant agricultural waste. The nipa palm, found in Malaysian estuaries, especially Sarawak, is an important, underutilized lignocellulosic resource. This study investigates the physicochemical and fire-retardant properties of a composite made from nipa palm biomass. Polyvinyl alcohol (PVOH) was crosslinked with citric acid and reinforced with calcium carbonate to produce the composite with the nipa particles. Microstructural and compositional analyses were performed utilizing scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), while mechanical characteristics, dimensional stability, and fire performance were rigorously investigated. The improved composite met JIS A 5908 (2003) structural particleboard standards with a modulus of rupture of 14.8 MPa, an internal bond strength of 3.88 MPa, and a modulus of elasticity of 2.9 GPa. The SEM images showed a compact, uniform cross-section with minimal voids and strong fiber-matrix adhesion. The EDX demonstrated the consistent distribution of CaCO₃ within the composite matrix. Synergistic interactions between PVOH–citric acid crosslinking and mineral filler reinforcement increased flame resistance and char formation in the limiting oxygen index fire analysis. This research showed nipa palm biomass to be a sustainable feedstock for high-performance fire-retardant particleboards. The work offers insight into eco-friendly interior binder systems.

The biogenic amalgamation of P-gold nanoparticles (P-AuNPs) was achieved utilizing the unrefined extract of the endophytic organism Fusarium solani ATLOY-04 swarmed in Plumbago rosea. The synthesized AuNPs were characterized via UV‒Vis spectroscopy, transmission electron microscopy, and Dynamic light scattering, revealing that 8 to 15 nm nanoparticles were synthesized and were stable. The effects of anticancer cells (MCF-7) on colon cancer (HT-29) and human breast cancer were tested. After the P-AuNPs-treated cells hatched, the MTT test revealed a dose-dependent decrease in cell viability, with the greatest toxicity observed in the cells treated with the μ g/mL and 60 μ g/mL doses of P-AuNPs. The observation of additional apoptotic cells utilizing AO/EtBr, DAPI, and Rhodamine 123 revealed that P-AuNPs initiated apoptosis within the treated cells via atomic fracture, layer breakage, and disturbance of the MMP. Stream cytometry results revealed that cancer cells gathered within the G1 stage after treatment with P-AuNPs, which shows that P-AuNPs affected cancer cell cycle progression. Gold nanoparticles increased the expression of caspase 3 genes and downregulatedp53 protein in MCF-7 cell lines.

In this study, high-performance packaging paper was developed by dissolving softwood cellulose in a LiOH/urea system and incorporating nano-mica to enhance its mechanical properties and thermal stability. Characterization by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR) confirmed partial crystalline transformation in the regenerated cellulose films. Mechanical testing showed that the composite film with 10% mica exhibited a tensile strength of 87.69 MPa and a modulus of 6.82 GPa, demonstrating excellent tensile strength, rigidity, and tear resistance, making it suitable for high-strength packaging applications. Thermogravimetric analysis revealed that the composite paper underwent  major thermal degradation at approximately 350 °C, offering superior thermal stability over conventional cellulose-based packaging materials, making it ideal for industrial and electronic component packaging. This study successfully developed a sustainable, high-performance packaging material through the synergistic effects of nanocellulose and nano-mica, providing new insights for advanced cellulose-based packaging solutions.

While the rheological properties of low-consistency cellulose nanofibril (CNF) suspensions and the mechanical properties of dry CNF films have been reported, research on high-consistency suspensions and wet CNF mats remains limited. Understanding suspension behavior during dewatering over a wide range of solids contents is essential. In this study, CNF consistency was controlled up to 20% using pressurized dewatering, and rheological behavior was characterized up to 10.2% solids content. Tensile testing was applied at higher concentrations where mat-like behavior emerged. The network strength followed a consistent power-law relationship across the entire solids content range, with a scaling exponent of 2.74, indicating that CNF flocculation is fundamentally similar to that of pulp fiber behavior despite its higher aspect ratio and smaller dimensions. CNF initiated network formation at a consistency more than twice as low as that of pulp fiber and exhibited a 5- to 20-fold higher network strength. At high solids contents, tensile strength increased exponentially, while elongation reached a maximum at approximately 50% solids content, suggesting a transition from capillary-driven consolidation to a hydrogen-bonded network. Nanofibrillation enhanced both tensile breaking stress and strain-at-break across all investigated solids contents. These results provide a framework for controlling CNF structural properties during dewatering and consolidation.

This study investigated the feasibility of substituting Norway spruce (Picea abies) with European larch (Larix decidua) in structural applications, specifically in laminated strand lumber (LSL). Four types of experimental LSL panels were manufactured from these species. Two reference panels were produced exclusively from a single species: larch (LSL-L) and spruce (LSL-S). A third variant (LSL-L:S) consisted of a homogeneous mixture of 60% spruce and 40% larch strands. The fourth configuration (LSL-L:S:L) was designed as a mechanically differentiated three-layer structure, with larch strands in the surface layers. The mechanical and physical properties of the panels were evaluated by determining bending strength (MOR), modulus of elasticity (MOE), internal bond strength (IB), compression strength, water absorption (WA), and thickness swelling (TS). Statistically significant differences among panel types were identified for density and IB strength. The LSL-L:S:L configuration exhibited a significantly higher IB value (0.66 MPa) compared with the other variants. No statistically significant differences were observed in bending. Nevertheless, panels manufactured entirely from larch strands (LSL-L) and those containing 40% larch (LSL-L:S) demonstrated higher mean values than the spruce reference panels (LSL-S) in both bending and compression tests. Significant differences were also detected for WA and TS.

The static and cyclic structural behavior of the column-head Dougong bracket from the Memorial Hall of Confucius (Ming Dynasty, Shandong Province, China) was investigated using finite element analysis (FEA). An ANSYS model was developed based on the orthotropic constitutive law of Pinus sylvestris integrated with the Hill yield criterion. The bracket was subjected to vertical monotonic static loading (Z-axis) and horizontal low-cycle reciprocating loading (X- and Y-axes). Under vertical loading, the ultimate bearing capacity was 348.97 kN, with a peak stress of 13.21 MPa at the Huagong-Ludou interface. Under horizontal loading, symmetric hysteresis loops were observed, with peak thrusts of 394.52 kN (Y-axis) and 748.19 kN (X-axis). Ductility coefficients were 2.55 (Y) and 2.53 (X), and equivalent viscous damping coefficients were 0.123 (Y) and 0.104 (X). The vertical response followed a tri-linear stiffness degradation model, while multi-linear restoring force models characterized the horizontal behavior. These results provide a triaxial mechanical database for this high-grade Ming bracket, clarify the load-transfer path within the double-ang system, and offer practical restoring force models for heritage conservation. The study confirms that FEA is a reliable and cost-effective approach for assessing Dougong mechanics, supporting evidence-based preservation of historical timber structures.