Volume 19 Issue 3

Lignin, renowned for its abundance of hydroxyl groups, was utilized in three dimensions to fabricate a hydrogel matrix. In this study, the optimal conditions for the preparation of a lignin-crosslinked hydrogel and its potential for dye and antioxidant removal were investigated. The hydrogel was synthesized through a cross-linking reaction, with varying amounts of cross-linking agent (poly(ethylene glycol) diglycidyl ether) added to adjust for the lignin content. Chemical structure analysis of the lignin-crosslinked hydrogel was conducted using Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy, confirming successful hydrogel formation. Additionally, thermal analysis revealed an increase in the maximum thermal decomposition temperature with increasing cross-linker content. The lignin cross-linked hydrogel demonstrated a significantly higher swelling ability at pH 7 compared to pH 3. The dye adsorption capacity of the lignin-crosslinked hydrogel, which was evaluated using crystal violet (CV), showed a maximum adsorption capacity of 106 mg∙g^-1. The CV adsorption behavior followed Freundlich isotherms and pseudo-first-order kinetics. Moreover, the lignin-crosslinked hydrogel exhibited notable antioxidant activity, which was attributed to the phenolic hydroxyl groups of lignin macromolecules. Therefore, lignin-crosslinked hydrogels prepared using cross-linking agents have promising application potential in various fields.

Global regulations are guiding society towards more sustainable material solutions. This increasing awareness of the need for environmentally friendly alternatives has led to a greater emphasis on biocomposites, which combine natural fibers with bio-based polymers. This study investigates how bleached softwood pulp fibers (BSWPF) and unbleached softwood pulp fibers (UBSWPF) affect the characteristics of poly(lactic acid) (PLA)-based biocomposites. UBSWPF is a more cost-effective option because it is manufactured with less processing steps than BSWPF. However, it is largely unexplored as a reinforcement in biopolymers. Through investigating the mechanical, thermal, and morphological aspects of the biocomposites, this study showed that UBSWP increased the modulus and impact strength of the PLA biocomposites better than BSWPF. The impact strength, modulus, and tensile strength of PLA-BSWPF and PLA-UBSWPF improved as the fiber content increased. However, a decrease in tensile strength was seen at higher percentages of UBSWPF in PLA. Despite the decrease in tensile strength at higher UBSWPF concentrations, both types of fibers improved the mechanical properties of the biocomposites, demonstrating a potential sustainable reinforcing material for PLA biocomposites.

Mulch was prepared using composted sugarcane leaves, with polyvinyl alcohol and cationic starch as adhesives, through compression molding. The study aimed to investigate the effects of different adhesives on the mechanical properties, thermal oxidative degradation performance, and biodegradability of the covering materials. The results indicated that, when the adhesive dosage was consistent, cover material A, which utilized polyvinyl alcohol as the adhesive, exhibited higher tensile strength and elongation at break compared to cover material B, which employed a blend of polyvinyl alcohol and cationic starch. Specifically, at an adhesive dosage of 20%, cover material A achieved a tensile strength of 0.46 MPa and an elongation at break of 7.72%, representing the highest values among all experimental groups. There was minimal disparity in the thermal oxidative degradation performance between materials prepared with either adhesive; however, a higher quantity of adhesive led to decreased biodegradability performance. After being buried in soil for 120 days, the degradation exceeded 40% for both materials, resulting in loss of their original shape and strength properties. In conclusion, while sugarcane leaves-based biodegradable materials demonstrate favorable degradation performance, further enhancements are necessary to improve their mechanical properties. These materials have potential applications as substitutes for plastic mulch.

Effects of adding different boron compounds to the urea-formaldehyde resin were evaluated relative to the physical, mechanical, and other properties of medium-density fiberboard (MDF). While the chemical addition of boric acid to the urea-formaldehyde resin increased the modulus of rupture and modulus of elasticity values of MDF boards, the physical and chemical additions of other boron compounds decreased those values. While there were no significant decreases in internal bond values, the chemical addition of boric acid and borax decahydrate to urea-formaldehyde resin increased the internal bond values of MDF boards. It was observed that in both types of addition, borax pentahydrate reduced the formaldehyde emission values of MDF boards the most and also reduced the burnt area by up to 30%. When the type of addition of boron compounds to urea-formaldehyde was compared, the addition of boron compounds at the resin formation stage showed better results in the properties of MDF boards than physical addition.

A study was conducted in sandy clay loam soils in a subtropical zone of Bihar to evaluate the effect of frequent application of organic amendments on sulphur fractions. Different organic amendments, including farmyard manure (FYM), vermicompost, azotobacter, phosphate solubilizing bacteria (PSB), panchagawya, and neem cake, were applied through nine treatments that resulted in a significant increase of water-soluble S, available S, heat-soluble S, adsorbed S, and organic S in organic treatment compared to the recommended dose of fertilizer (RDF) and control treatment. The maximum increment was observed in the treatment where the recommended dose of nitrogen was replaced by 75% recommended dose of nitrogen substituted farmyard manure + 25% recommended dose of nitrogen (vermicompost) along with azotobacter + PSB + one foliar spray of panchagawya. The total S content varied widely from 382 to 736 mg kg^-1. Increment in all the forms of sulphur is observed as a result of the application of different organic nutrient sources. All the forms of sulphur share a mutual positive and significant correlation with each other. Regression analysis suggested that the availability of sulphur was dominated by organic sulphur, which alone can explain 97.8% of the variation in availability of available sulphur in soil.

Tannases are industrial enzymes used in cosmetic, pharmaceutical, food, and environmental management. In the present study, 11 tannase-producing Bacillus spp. were isolated from agricultural soil, banana root soil, vegetable garbage, and fruit garbage. These isolated bacteria were screened using tannic acid agar plates. The zone of hydrolysis varied from 9 mm to 21 mm, and the strain Bacillus xiamenensis BR1 exhibited the highest activity. The dried unripe banana peel (Robusta) was powdered, and particles between 1 and 1.5 mm were used as substrate. The banana peel consists of 7.84 ± 0.15% hydrolysable tannin, which induces the production of tannase. The production medium was prepared at 10% (w/v) unripe banana peel powder. The screening experiments revealed that fermentation period, pH, inoculums, and tannic acid improved tannase production. A two-level full factorial design revealed the influence of pH, inoculums, and incubation time on tannase production (F-value=8.99; p-value=<0.0001). The optimum concentration was analyzed using a central composite design, and the model was significant (F-value = 17.03; p-value = 0.0001). Under optimal bioprocess conditions, tannase yield was 2.4-fold higher than in an unoptimized medium. The unripe banana peel can be used as a substrate for the production of tannase by Bacillus sp.

The mortise and tenon structure is a pivotal component of ancient Chinese architecture and furniture, encapsulating a rich history of evolution, cultural shifts, and productivity developments. Engaging modern individuals with this historical context through innovative product design provides a way to advance the cultural and creative industries and promote the sustainable development of mortise and tenon culture. This study conducted sentiment analysis on consumer reviews of three types of mortise and tenon cultural and creative products in the Chinese market, revealing consumer needs and expectations regarding functionality, quality, and design. Utilizing Norman’s Emotional Design Theory, the study analyzed the design elements of mortise and tenon cultural and creative products across the instinctive, behavioral, and reflective levels. A systematic design model was put together, providing both theoretical support and practical guidance for the future design of these products, thereby offering inspiration and aid for the modernization and transformation of traditional culture.

Transparent smart nanocomposites, which are among the advanced materials, were developed with the synergistic effect of nanofibrillated cellulose (NFCs) as a natural bionanomaterial, polymethyl methacrylate (PMMA) as a biocompatible microcapsule, methyl methacrylate (MMA) as a monomer, and benzoyl peroxide (BPO) as an initiator and catalyst. Epoxy resin was reinforced with NFC, PMMA, MMA, and BPO. Casting, which appears to be an industrially promising method that allows for cost-effective and high-quantity production, was used for producing transparent advanced nanocomposites. The properties of the nanocomposites, including yield strength, modulus of elasticity, hardness, impact energy, and self-healing capability, were determined. Increases in the yield strength (136.4%), modulus of elasticity (260%), hardness (28.3%), and impact energy (75%) were observed in the transparent smart nanocomposites reinforced with NFC, PMMA, MMA, and BPO, compared to pure epoxy composites. Furthermore, the transparent advanced smart nanocomposites self-healed by about 7% after the notch/scratch defect. It has the potential to be used in a variety of applications, such as interior and structural components for the aerospace and automotive industries, packaging, flexible screens, and lightweight transparent materials.

To address the current inefficiencies and subjective nature of manual observation in maize cultivation, with the aim of achieving high efficiency and productivity, this study focused on the DeMaya D3 maize variety. It proposes a maize growth stage recognition method based on the MobileNet model, which is a lightweight convolutional neural network architecture. The method was tested and achieved recognition accuracies of 0.98, 0.96, 0.92, 0.85, and 0.97 for different growth stages, respectively. Additionally, a maize growth prediction model was developed. Based on data collected from experimental plots regarding maize plant height and stem diameter, the Prophet model and an optimized version of the Prophet model were used to forecast maize growth trends. The Prophet model is an open-source tool for time series forecasting. Comparative analysis was conducted between the predictions of the original Prophet model and the optimized version. The relative errors of the Prophet model predictions were 0.85%, 2.11%, and 0.79%, while those of the optimized Prophet model were 0.76%, 0.47%, and 0.71%. Compared to the Prophet model, the optimized model reduced errors by 0.09%, 1.64%, and 0.08%, respectively. The maize plant growth control system was designed to obtain the information through the collection layer. The decision-making layer judged the soil nutrient absorption and growth status. Finally, the management layer controlled water and fertilizer.

Rhizophora-based particleboard was evaluated for its suitability as phantom material, especially in medical physics applications. The elemental composition, effective atomic number, micrographic structures, computed tomography (CT), and attenuation properties of Rhizophora-based particleboards were examined. These investigations considered three different particle sizes and three distinct adhesive mixtures. Rhizophora sample at particle sizes of 0 to 103 µm, with 4.5% soy flour and 1.5% lignin (C₆) presented with a homogenous compound with better uniformity compared with other samples, and Rhizophora sample at particle sizes of 104 to 210 µm, with 9% soy flour and 3% lignin (B₁₂) demonstrated an effective atomic number of 8.15, which is similar to water. C₆ also presented with a density distribution profile with close proximity to water. The measured attenuation coefficients of samples were aligned closely with those of water, as determined by XCOM. The results suggest that the formulation of soy flour and lignin as adhesives for Rhizophora-based particleboard is suitable for the fabricating of phantom material for medical physics applications, especially mainly due to its natural origin.