Research Articles

The acoustic properties of a custom-built bamboo bass guitar (BBG) were examined in this study as a sustainable substitute for traditional wooden instruments. To evaluate tonal and harmonic behavior, the BBG which was made completely of bamboo components was contrasted with the Fender Jazz Bass ’70s (FJB70s). While spectrograms from Adobe Audition offered visual insight into overtone distribution, frequency spectrum data were recorded using a PicoScope oscilloscope and subjected to Fast Fourier transform (FFT) analysis. Although the BBG’s pitch and harmonic series matched those of the FJB70s, its timbre was noticeably different, with less radiation and more damping. Throughout the spectrum, its overtone amplitudes gradually decreased, while the FJB70s’ harmonic presence remained increasingly distinct and steady. In the BBG signal, random partials that show up in between harmonic peaks indicate variations in structural resonance. These results lend credence to bamboo’s potential as an acoustic material for bass instruments, providing unique sound textures and encouraging environmental sustainability.

Palm-leaf manuscripts use palm leaves as their medium. The inherent poor dimensional stability of this biological material is the main reason for ink and pigment detachment. As a valuable cultural heritage, the detachment of ink or pigment on the surface of palm leaf manuscripts under humid-dry cycling poses a critical challenge in the field of conservation. This study simulated traditional palm leaf manuscript preparation and employed accelerated humid-dry cycling to elucidate ink/pigment detachment mechanisms. The substrate—composed of cellulose, lignin, hemicellulose, waxes, and pectin—exhibits anisotropic deformation during cycling: thickness/tangential expansion significantly exceeds longitudinal direction. Chromatic analysis showed minor ΔE* increases in substrate, ink, and pigment, confirming stable chemistry. Color changes primarily resulted from interfacial microcracks and light scattering due to physical deformation. Detachment area escalated with cycles, driven by substrate-ink/pigment expansion mismatch. This induces interfacial tensile-compressive stress cycling, causing mechanical fatigue, adhesion loss, and eventual powdering/flaking. Key conservation strategies include stabilizing environmental humidity and developing flexible protective coatings to buffer interfacial stress. This provides theoretical foundations for scientific preservation of palm leaf manuscripts and conservation material design.

The active ingredients present in Galium species, especially Galium verum, are represented by antioxidant compounds in variable proportions. This study aimed to obtain, by solid-liquid extraction of G. verum, biologically active compounds with antioxidant properties, such as polyphenols and flavonoids. Four classic extraction techniques were used (maceration-M, refluxation-R, sonoextraction-US and a combined method: sonoextraction with maceration – US+M). In the extraction process, glycerin was used in different forms: hydro-glycerin; and water and glycerin-ethanol mixtures with different concentrations. Other monitored parameters were the solid-liquid ratio (S/L) and the extraction time. The best results were obtained using the hydro-glycerin solution as extraction solvent: 85.0 µg GAE/g polyphenols (R: 50% concentration, 60 min, S/L=1:15) and 117 mg QE/g flavonoids ((R: 80% concentration, 60 min, S/L=1:15). This study brings new data about obtaining plant extracts from G. verum with important antioxidant properties, based on the use of a green solvent extraction.

The concept of the “olfactory economy” has recently emerged as a novel consumer trend. Flooring has been observed to emit an undesirable olfactory sensation during its initial use. The implementation of scented flooring has been demonstrated to mitigate this concern. This study examines the problem of undesirable odors emitted by engineered wood flooring during its initial application. A Kano-AHP model in conjunction with TRIZ theory was used to investigate market demand for fragranced flooring and to offer novel insights into its advancement. A questionnaire survey was administered to ascertain market demand for aromatic flooring. The Kano model was employed to assess user requirements, with a focus on individuals seeking aromatic flooring. This finding emerged after the investigation of fragrance intensity, comfort, and suitability. The aromatic flooring surface was then subjected to artificial olfactory testing, and the findings were statistically analyzed using the Hierarchical Analysis Method to rank user olfactory preferences by weight and priority. TRIZ theory was ultimately employed to transform these requirements into enhancement strategies for aromatic flooring. The findings demonstrate the efficacy of this research approach in translating user requirements into research and development trajectories, thereby enhancing the relationship between users and goods and offering novel insights for the research and development of indoor furniture panels.

Distillers’ grain (DG) was used as an ingredient in paperboard made in the laboratory from recycled containerboard fibers. The chemical composition and physico-chemical properties of DG fractions that had been isolated using varied screens were investigated. The effect of DG incorporation on the properties of the recycled paperboard was compared relative what was obtained with either precipitated calcium carbonate (PCC) or talc powder as fillers. The DG was found to mainly contain cellulose, hemicellulose, lignin, protein, and fat. At a filler addition level of 5%, the 100- to 140-mesh DG-filled handsheet exhibited the most satisfactory physical properties, with a tensile index of 25.4 N·m·g^-1 and a ring crush index of 7.95 N·m·g^-1. The strength values were generally higher than those of paper filled by PCC or talc powder at the same addition levels. The tensile index and ring crush index of hybrid-filled handsheets increased with increasing ratios of DG. The results suggest that DG can be used as a substitute for fiber content in some grades of paperboard, especially where a low-cost, bulky material could provide an advantage. Such usage of DG can resolve environmental challenges associated with storage and transportation of excess DG that is presently discarded.

Effects of thermal modification were investigated relative to the surface and adhesive bonding of coatings to tannin-rich oak (Quercus petraea) and chestnut (Castanea sativa) woods. Samples were heat-treated for 2 hours at different temperatures (160 °C, 180 °C, and 200 °C) and then coated sequencially with linseed oil followed by poly(vinyl acetate) (PVAc) varnish. Increasing heat treatment temperature led to a significant darkening of the wood and a decrease in gloss and surface roughness. While thermal modification alone caused a reduction in adhesion strength, the subsequent application of linseed oil was effective in mitigating this adverse effect. The oil created a more favorable bonding interface by reducing the negative influence of tannins and hydrophobicity on the adhesive. The combined thermal modification and linseed oil treatment achieved favorable adhesive bonding performance of tannin-rich wood species with the varnish. This study suggests that low heat treatment temperatures combined with a linseed oil coating can be recommended for applications where good adhesion strength is desired.

Microcrystalline cellulose (MCC) is a purified partially depolymerized nonfibrous form of cellulose, a crystalline powder composed of porous particles. In this study, the drying of MCC was investigated with two different solids content MCCs by using three different drying methods: a high-velocity cyclone dryer, a spray dryer, and a fluidized bed dryer. The effects of the different drying techniques on the geometrical dimensions and morphology of the dried MCC particles and aggregates were researched. Based on the results, the dried MCC particle morphology is highly dependent on the used raw material properties as well as the liquid removal mechanism during drying. The preserving of the morphology of the raw material MCC was mostly achieved by fluidized bed drying, which facilitated MCC to dry as discrete particles with high surface area and lesser aggregation when using the MCC with 45% dry consistency as raw material. Spray drying was observed to produce small, most circular particles with the most homogenous size distributions and high velocity cyclone largest, most heterogenous and irregular shape particles and aggregates. All results have been presented as such after drying without screening.

Sweet potato peel, a lignocellulosic residue, was used as a sugar source for lactic acid production in solid-state fermentation. The dried sweet tuber peels were heated at 80, 90, and 100 °C for 15, 30, and 60 min. They were steamed three times, first at 68.9 KPa for 15 to 60 min, then at 86.2 KPa for 15 to 60 min, and lastly at 103.4 KPa for 15 to 60 min. Compared with the 15 min treatment, the steam treatment significantly improved the reducing sugar content after 60 min from 190.4 ± 2.2 to 245.4±3.5 mg/g biomass. Enzymatic hydrolysis afforded 29.5 g/L total sugars, including 22.7 g/L glucose, 3.5 g/L disaccharides, 0.1 g/L arabinose, and 3.2% xylose. The pretreated substrate was used as a solid medium to produce lactic acid in solid-state fermentation via Lactobacillus plantarum MTCC1325. Central composite rotatory design (CCRD) was used to optimize lactic acid production to improve the lactic acid yield. Fermentation of sweet potato peel hydrolysate by L. plantarum yielded 85.6 g lactic acid/kg substrate, which was an overall fourfold increase compared with that of the unoptimized medium. Compared with the untreated control, goat meat treated with 1.25% to 5% lactic acid presented a reduced aerobic bacteria count (p<0.001). These studies imply that the sweet potato peel substrate is a promising biomass for the production of lactic acid in the food industry.

Reducing the carbon footprint is a key objective in global sustainability policies to combat climate change. Wood-based composite panels, which are widely used in the construction and furniture industries, require environmental evaluation due to their production-related impacts. This study quantitatively assessed the carbon footprint of melamine-faced particleboard produced in Türkiye, following a cradle-to-gate system boundary based on the ISO 14067 (2018) standard and the IPCC 2006 Tier 1 methodology. The system boundary included raw material and process input transportation, energy consumption, melamine lamination, and waste management. Primary data were obtained directly from the production facility, while secondary data were sourced from the literature. The functional unit was defined as 1 m³ of melamine-faced particleboard, and emissions were categorized under Scope 1, Scope 2, and Scope 3. Results indicated that 67% of the total emissions originated from Scope 3 activities, with major contributors being raw material transport, electricity consumption, and adhesive production. The carbon footprint of melamine-faced boards was calculated as 462 kg CO₂e/m³, notably higher than that of non-coated particleboard (299 kg CO₂e/m³). This study provides valuable data for future carbon footprint assessments of coated wood-based panels and offers a scientific foundation for developing sustainable production strategies in the sector.

Argan oil exhibits promising pharmacological activities supported by its rich phytochemical composition, as confirmed by gas chromatography-mass spectrometry analysis. Major constituents included trans-13-Octadecenoic acid (20.0%) and Isopropyl tetradecanoate (25.6%), along with antioxidant-rich terpenoids and phenolics. Antimicrobial assays demonstrated strong inhibition against Bacillus subtilis and Candida albicans, with low minimum inhibitory, minimum bactericidal, and minimum fungicidal concentration values (31.2 µg/mL), though limited activity was noted against Salmonella typhi. Argan oil showed dose-dependent inhibition of α-amylase and α-glucosidase, with IC₅₀ values of 15.1 µg/mL and 26.2 µg/mL, respectively, suggesting antidiabetic potential. It also inhibited butyrylcholinesterase (IC₅₀ = 15.9 µg/mL), indicating possible neuroprotective properties. Antioxidant activity assessed by 2,2-diphenyl-1-picrylhydrazyl assay showed a concentration-dependent increase, with IC₅₀ = 4.97 µg/mL, approaching the effectiveness of ascorbic acid at high doses. Lipase inhibition (IC₅₀ = 25.10 µg/mL) highlighted potential anti-obesity effects. Cytotoxicity on Caco-2 cells was significant (IC₅₀ = 36.17 µg/mL), with morphological damage correlating with dose, suggesting antiproliferative effects. These activities are likely due to bioactive compounds, such as unsaturated fatty acids and tocopherols, which influence inflammation, apoptosis, and enzyme regulation. Overall, the findings support the  therapeutic potential of argan oil as a natural agent in managing microbial infections, oxidative stress, diabetes, obesity, and cancer.