Research Articles

The modulus of elasticity (MOE) of structurally graded one-inch-thick red oak (Quercus rubra) and red maple (Acer rubrum) lumber was measured in this work. The center-point, third-point static loading tests, and the stress wave timer methods were used. The objective was to determine if there are statistical differences between three structural lumber grades based on their MOE values. The study considered both the within separated grades and the across combined grades. For red oak and red maple, significant differences in MOE values from center-point static loading tests were observed solely between Select Structural and Below-grade lumber. With the dynamic method, no significant differences were found between any visual grades, including Below-grade lumber. Regardless of the MOE determination method used, the MOE value was not useful for distinguishing the structural, No. 2, and No. 3 visual grades. The strongest correlation existed between the global MOE and the dynamic MOE, which was even higher when the analyses were conducted on separated visual grades. In the case of red maple, stronger correlations between the dynamic MOE, local MOE, and global MOE were observed when separated by visual classes, compared to the analysis conducted on the combined grades. The global MOE was found to be a better predictor of the local MOE than the dynamic MOE.

The global bamboo market reached USD 70 billion in 2022, and moso bamboo (Phyllostachys edulis) is the species with the greatest international impact. Guadua (Guadua angustifolia Kunth) is a promising species, that has been traditionally used for the construction and manufacture of handcrafts in several countries in Central and South America. In this research, progress was made in the morphological and anatomical characterization of mature guadua culms. On average the culms are 21 m in total length and there are 53.2 kg of dry biomass. The culm morphology was characterized throughout its length; the average diameter, wall thickness, and density at breast height are 14.8 cm, 21.5 mm, and 0.595 g/cm³, respectively. The fibers of the vascular bundles of internode number 7 have an average length of 2146 µm, a diameter of 20.4 µm, and a diameter of 8.7 µm wall thickness. The morphological and anatomical characteristics of guadua offer productive and comparative advantages and could be competitive in the bamboo market. The research, technological development, and innovation processes related to this material should be encouraged to promote the guadua industry.

‘Nirai’ instrument combined the ‘sanshin’ and guitar. It is a mix of the ‘sanshin’ and the guitar. Instead of using the guitar’s tuning, ‘nirai’ is tune like a ‘sanshin’. The ‘nirai’ sound were digitally captured using a PicoScope oscilloscope. The outcomes were subsequently examined utilizing PicoScope software (version 6), emphasizing Fast Fourier Transform FFT. The standard ‘sanshin’ tuning is a fifth, a root, and a fifth, so in the key of C, that would be G, C, G (GCG). When a low C (C) is added in ‘nirai’ it makes the tuning a root, fifth, root, fifth. In this work, the ‘nirai’ is being tune into the key of G, the 4^th string of ‘nirai’ can be identified as G2 (100Hz), 3^rd string as D3 (147 Hz), 2^nd string as G3 (197Hz), and 1^st string as D4 (296Hz). String 3 and 4 displayed 25 partials frequencies. String 1 and 2 displayed only 12 and 19 partials frequencies respectively. The partials of the overtones confirmed the typical sound quality of ‘nirai’ guitar. The thin string had less partials compared to the thick string. The partials are all integer number of harmonics with 24^th, 17^th and 13^th harmonics missing in string 4, 3 and 2. All harmonics appear in string 1. Even though the numbers of partials are different, with the sensation of a wooden guitar-like sound, the ‘nirai’ guitar displayed similar timbre from every string.

The oil palm frond (OPF) particleboard can be manufactured using bio-adhesive-based molasses and citric acid (MOCA) at different ratios. Before particleboard manufacture, each bio-adhesive was diluted in distilled water with a solid content of 59 wt% at three different mixture ratios of MO and CA (100:0, 75:25, and 50:50). Subsequently, the OPF particles were mixed with MOCA adhesives, oven-dried at 80 °C for 12 h, and then hot pressed at 200 °C for 10 min. In general, the basic properties and thermal behaviour of the MO adhesive changed with the increasing amount of CA. The MOCA adhesives had a lower gelation time, viscosity, pH, and a comparable solids content to that of the pure MO adhesive. The thermal behaviour of the MOCA adhesive showed an alteration in the melting point with slightly lower weight loss during thermal degradation. Applying MOCA adhesive in OPF particleboard manufacturing significantly increased its physical properties, including dimensional stabilization and mechanical properties. The OPF particleboard bonded with the MOCA adhesive at a 50:50 mixture ratio generated a product with higher dimensional stabilization and the best mechanical properties. The latter product fulfilled the JIS A 5908:2003 standard, except for the MOR and SHS parameters.

Wood plastic composites (WPCs) were produced from recycled polypropylene (RPP) matrix, giant reed (GR) flour, and magnesium oxide nanoparticles (nano-MgO). The physical, mechanical, and thermal properties were analyzed. Different amounts of GR flour from 10 wt% to 40 wt%, and nano-MgO from 1.0 wt% to 2 wt% were added into the RPP matrix. The water resistance, mechanical, and thermal properties of the injection molded WPCs were determined according to the ISO standards. The bending and tensile modulus of the WPCs were considerably enhanced with the addition of the GR flour up to 40 wt%, while this was found to be maximum at 30 wt% for the bending and tensile strengths. The water absorption of the WPCs increased with the addition of the GR flour, as expected. The results of thermal analysis revealed that the addition of the GR flour increased the thermal stability of the WPCs, especially the degree of crystallization and the melting enthalpies of the RPP matrix, due to the good adhesion between the GR flour and the RPP. The incorporation of the nano-MgO affected adversely the mechanical properties of the WPCs. Lower thermal stability was observed for WPCs containing nano-MgO. The inclusion of 30 wt% GR flour in the RPP matrix gave the best mechanical and thermal properties.

Gold nanoparticles (AuNPs) are known to have low toxicity and biocompatibility. Meanwhile, Andrographis paniculata (A. paniculata) is a medicinal plant known for its therapeutic benefits. Traditional methods for the synthesis of AuNPs frequently depend on toxic compounds, which present environmental and health hazards. In this work, A. paniculata was combined with AuNPs to enhance its antimicrobial, antioxidant, and wound healing effects, thereby offering a safer and more effective alternative compared to current available methods. Water-soluble gold metal ions were reduced to neutral metal nanoparticles in the course of reaction with aqueous A. paniculata extract. The biosynthesised AuNPs was examined using UV-Vis, FTIR Spectroscopy, TEM, XRD, SAED Diffraction, EDX, DLS, and zeta potential measurements. AuNPs were incorporated into nonionic surfactant to form a thick, readily spreadable hydrogel. The mixture was found to enhance the wound contraction rate with no skin irritation observed in treated mice. The study demonstrated a simple and environmentally safe approach to produce AuNPs with improved antimicrobial, antioxidant, antidiabetic and wound healing abilities. The AuNPs-PF127 hydrogel is a non-toxic and bio-friendly delivery technology that shows potential in promoting healing of wounds, burns, etc.

Children’s preferences for the design of consultation room furniture were evaluated with a focus on the emotional and aesthetic factors influencing these preferences. An evaluation model for children’s furniture in consultation rooms was developed using the Scenic Beauty Estimation (SBE) method and Kansei Engineering. Data were collected by gathering children’s aesthetic ratings and emotional assessments of furniture sample images, followed by statistical analysis to identify design preferences on both visual and emotional levels. The SBE results revealed a negative correlation between straight-line desks, backrest-free designs, and square seat surfaces with scenic beauty, suggesting that children prefer furniture with soft, rounded shapes. The Kansei Engineering results identified two principal factors influencing children’s preferences, further highlighting that soft, rounded forms, lightweight and comfortable experiences, and minimalist designs significantly enhance emotional engagement and attraction. The consistency between the two evaluation methods was high. In conclusion, furniture design for children’s consultation rooms should prioritize safety, comfort, and playfulness, incorporating soft, simple, and child-friendly designs to enhance children’s acceptance and comfort within the examination environment.

There is a major clinical problem associated with antimicrobial resistance. Rosmarinus officinalis L. is an effective medicinal source. Its oil has been extracted and tested for its multiple therapeutic capabilities. The oil extract was found to be a broad-spectrum antimicrobial agent against Bacillus subtilis and Staphylococcus aureus as Gram-positive bacteria, Escherichia coli and Klebsiella pneumonia as Gram-negative bacteria, and Candida albicans as the most common pathogenic mold. The minimum inhibitory concentration of the oil extract was found to be 15.6 μg/mL against B. subtilis, S. aureus, and C. albicans, and 62.5 μg/mL and 125 μg/mL against E. coli and K. pneumonia, respectively. The bactericidal activity started at 150 and 180 min against Gram-positive and Gram-negative bacteria, respectively, with clear time-killing kinetics. The oil extract was able to scavenge DPPH free radicals with an IC₅₀ of 4.0 μg/mL. The oil extract was found to have high toxicity on the Caco2 cell line (colon tissue) at high dose 1000 μg/mL with IC₅₀ of 75.39 ± 0.56 μg/mL. The chemical composition of the oil extract was determined employing gas chromatography/mass spectrometry, in which 53 compounds were named at different surface area ratios, retention times,  and probability ratios.

Magnetically recoverable iron-based catalysts were developed, with the goal of being cost-effective, reusable, and environmentally friendly. The use of iron-based magnetically recoverable catalyst enhances the catalytic process efficiency for the enhanced bio-oil yield and quality compared to non-catalytic and conventional catalytic methods. The present study aimed to evaluate the hydrothermal liquefaction (HTL) of Nannochloropsis sp. in the presence of Fe₃O₄ nanostructures for enhanced bio-oil production.  The use of a magnetic-supported catalyst that is low-cost, safe, and can be reused many times without requiring a regeneration step (by retrieving it magnetically from the solid material) can serve as a novel strategy to be used at an industrial scale. The maximum bio-oil yield 31.4% was obtained with a Fe₃O₄ catalyst dosage of 0.3 g at temperatures of 300 °C and biomass to solvent ratio of 100 g/L, respectively. The compositional analysis of the produced bio-oil was performed and showed notable characteristics for biofuel application. The synthesized Fe₃O₄ catalyst was recyclable for up to five repeated cycles and a fluctuated bio yield was achieved for the last three cycles of procreation capability for HTL of Nannochloropsis sp. Further improvisation in designing the next generation magnetically recoverable catalyst with improved stability, efficiency will pay wave way for cost–effective and scalable bio-oil production systems.

Urea formaldehyde (UF) and phenol formaldehyde (PF), the most commonly used thermosetting adhesives in the particleboard (PB) industry, release formaldehyde, which is harmful to both humans and the environment. This study aimed to reduce glue consumption in PB with lower formaldehyde content by foaming the glue. The UF and PF were foamed using gelatin (GL), an animal protein, and the results were compared with those performed using sodium bicarbonate (SB) foaming agent and neat (UF and PF as controls) glue. SB and GL foaming agents increased the volume of the UF and PF resins by 1.5 and 2 times, respectively. PB characterization was carried out mechanically, physically, and morphologically. A perforator analysis was performed to determine the formaldehyde content in PB. Results showed that the foaming process generally improved the mechanical properties except for 10% SB and 10% GL. Analysis showed that foaming reduced the PB moisture content and improved water absorption and thickness swelling, except for 10% SB and 10% GL. SEM analysis indicated a successful foaming process. GL and SB reduced the formaldehyde content of the PBs. In conclusion, PB can be produced using 10 to 20% less adhesive through the foaming method by GL.