Volume 19 Issue 4

The biodegradation kinetics of paper materials with various chemical additives was studied, focusing on their potential tunability. Paper materials with additives, including retention aid, hydrophobic agent, and wet and dry strength agents, were explored in two forms: disintegrated fiber and paper form. Using the Gompertz equation, biodegradation kinetics were modeled to calculate the lag phase, initial biodegradation rate, and ultimate biodegradation extent. All paper materials showed higher biodegradation extents than microcrystalline cellulose (MCC) due to the highly biodegradable nature of hardwood bleached pulp. Disintegrated paper materials exhibited similar lag phase values and ultimate biodegradation to MCC regardless of treatment, while punched paper materials showed noticeable differences, suggesting that fiber disintegration plays a critical role in initiating biodegradation. Hydrophobic and wet strength treatments, such as alkyl ketone dimer (AKD) and wet-strength agents (PAE), respectively, significantly increased the lag phase, but their ultimate biodegradation extent remained intact. These findings highlight that the biodegradability of paper materials can be preserved even after chemical treatments, underscoring their environmentally friendly potential.

The high extractives content in rice straw severely hinders surface adhesion, resulting in poor strength and dimensional stability of rice straw particleboard bonded with castor oil-based polyurethane (CPUR) resin. In this study, rice straw was pretreated with liquid hot water (LHW) at 150 °C for 20 min to reduce its extractives content for particleboard production with CPUR resin. The effects of LHW pretreatment on the chemical composition of the rice straws was evaluated. In addition, effects of CPUR resin dosage and density on mechanical properties and dimensional stability of the rice straw particleboards were investigated. The results indicated that LHW pretreatment significantly reduced the extractives and hemicellulose contents of the rice straw. The LHW pretreatment significantly improved the mechanical properties and dimensional stability of the rice straw particleboards. The overall performances of the rice straw particleboards were enhanced as the CPUR dosage increased. Increase of density led to upgraded mechanical properties but lowered dimensional stability of the rice straw particleboards.

Development of scrimber composites and other engineered wood products from low-value wood and wood waste provides an effective opportunity to preserve natural resources, minimize waste, and innovate the production of higher-performance, environment-friendly construction materials. In this study, peeler cores, which are the center of poplar logs remaining after the peeling process in the veneer production, were utilized to develop scrimber composites. This study investigated the effects of different resins, including phenol-formaldehyde (PF) and urea formaldehyde (UF), as well as hydrothermal treatments at various temperatures (60 °C and 130 °C), on the physical and mechanical properties of the scrimber composites. Chemical changes in wood components and morphological changes in wood cell walls resulting from hydrothermal treatment were analyzed using Fourier transform infrared spectroscopy and scanning electron microscopy. To clarify how resin type and hydrothermal treatment affect structural performance, several physical and mechanical properties of scrimber composites, including thickness swelling, water absorption, internal bond strength, bending modulus of elasticity, and modulus of rupture, were measured. The test results revealed that hydrothermally treated wood scrims at 130 °C, when bonded with PF resin, produced scrimber composites with superior structural performance.

This research evaluated cow dung compost (CDC), goose dung compost (GDC), and duck dung compost (DDC) as peat addition in growing media used for the production of pumpkin seedlings. Commercial substrate (peat: vermiculite: perlite=3:1:1, v/v) was used as the control (CK). The partial addition in peat of each waste compost in the mixtures were 10%, 20%, and 30% (v/v). The results showed that all compost in mixtures increased bulk density, total porosity, electrical conductivity, and mineral content, but negatively affected the pH and organic matter of the growing media compared to CK. CDC in mixture increased ventilation porosity and gas-water ratio and decreased water-holding porosity compared to CK, which was the opposite of the effect of GDC and DDC. The mixtures elaborated with GDC showed better growth, biomass, gas exchange parameters, and physiological indicators of seedling plants than other treatments in varying degrees, which depended on the additional amount of GDC. DDC inhibited plant growth and gas exchange parameters, especially in high addition rate; however, it had a slight promotion effect on chlorophyll content and quality because DDC was rich in minerals. GDC was better than CDC and DDC as a partial addition for peat in the cultivation of pumpkin seedlings.

Although the market share of domestic children’s furniture is increasing annually, some potential problems limit its long-term and stable development, and there is still a gap in China compared with foreign countries. This study focused on the demand preferences for growable children’s beds and examined the design features that influence these preferences. This study introduces a combination of Hierarchical Analyses (AHP), Quality Function Development (QFD), and the Platts Conceptual Decision Matrix (PUGH) into the innovative design of a research model for children’s furniture (AHP-QFD-PUGH). This study screened and classified the decision-making indicators obtained from the research, ranked their importance by quantitative calculation, and finally proposed an optimal design solution. Additionally, to further study the structural characteristics, the function-behavior-structure (FBS) model served as a supplementary analysis tool to effectively circumvent subjective factors in product design. This integrated model accurately explored user needs and product characteristics, providing substantial guidance and new ideas for optimizing the design of growable children’s beds and enhancing growth of the children’s furniture industry.

A hybrid adhesive system composed of phenol-formaldehyde (PF) resin and polymeric methylene diphenyl diisocyanate (pMDI), modified with two types of alkaline catalysts, namely NaOH and CaCO₃ at 20% (w/v), was used for manufacturing the oriented strand board (OSB) from sengon (Paraserianthes falcataria L. Nielsen) wood. The catalyst was added at a concentration of 1% of the solids content of PF adhesive, and pMDI was added at 2.5% and 5.0% of the PF adhesive solids content. Adding catalysts and cross-linking agents increased the solids content and viscosity of the adhesive and accelerated the gelation time. The water absorption of OSB increased with the addition of catalysts and crosslinking agents compared to the control PF. Still, the CaCO₃ catalyst worked optimally in reducing the thickness swelling of OSB. The mechanical properties of the laboratory-fabricated OSB panels increased with the addition of catalyst and cross-linker, except for the modulus of elasticity parallel to the grain. The optimal performance of OSB was obtained by adding 1% CaCO₃ and 2.5% pMDI based on the PF’s solids content.

Sodium sulfite (Na₂SO₃) is known as a selective chemical agent for wood delignification. In this work, Scots pine (Pinus sylvestris) wood was pulped using alkaline sulfite (AS) with the addition of 1,4-dihydro-9,10-dihydroxy anthracene (DDA) [called also soluble anthraquinone (SAQ)] and ethylene glycol (G). The studies showed the possibility of obtaining Kappa number (KN) 24 to 26 alkaline sulphite-DDA pine pulps with total and screened yields higher by 3.4 to 3.9% and 1.4 to 2.6%, respectively, than in the case of kraft pulping. The AS-SAQ pulping process was also characterized by much higher brightness of pulps but worse defibreability of wood than the kraft process. Increasing the amount of Na₂SO₃ dosed to the wood from 25% to 30-35% (based on wood) and adding G to the cooking liquor increased the delignification of pine wood in the AS-SAQ method to Kappa number of 17 to 20 units (without G) and approximately 14.5 units (with G). Such a modification had a positive effect on the defibreability of wood after pulping and the brightness of pulps but a negative effect on the screened yield of AS-SAQ and AS-SAQG pulps.

Nanofertilizers release nutrients slowly and in a controlled manner, matching the plants’ growth needs. By reducing the need for chemical inputs such as fertilizers and pesticides, nanotechnology contributes to more sustainable agricultural practices. The present study used nano-urea with Azotobacter on strawberry cv. ‘Winter Dawn’ under protected cultivation to evaluate its impact on soil fertility status and leaf nutrient content. Formulations as per the treatment requirements were sprayed onto the strawberry plants. The plants provided with nano-urea formulations exhibited enhanced levels of nitrogen (2.49%), phosphorus (0.37%), and potassium (2.60%) compared to the plants treated with conventional urea. Soil nutrient analysis showed enhanced levels of NPK in soil samples from traditional application treatments. A higher concentration of microorganisms in the soil was observed when urea was applied at the nano level. Nano-urea combined with Azotobacter can significantly impact the soil’s NPK levels. This innovative blend enhances nutrient availability in the soil and promotes sustainable agricultural practices. By leveraging the nanotechnology-infused urea alongside the nitrogen-fixing process of Azotobacter bacteria, the soil experiences a synergistic boost in nitrogen, phosphorus, and potassium content. This dynamic duo fosters a conducive environment for plant growth while minimizing nutrient leaching and environmental degradation.

In order to ensure the reliability of the simulation test on the shelling process of ginkgo nuts, the physical parameters (characteristic dimensions, thousand grain mass, moisture content, density, Poisson’s ratio, elastic modulus, and shear modulus), contact parameters (restitution coefficient, static friction coefficient, and dynamic friction coefficient) and actual stacking angle of the ginkgo nuts were measured by physical test methods. A stacking angle test model was established, and simulation tests were performed. Parameter intervals for the simulation were selected according to the measured parameters. Three factors affecting the stacking angle significantly were determined using the Plackett–Burman test: static and dynamic friction coefficients of ginkgo nut–ginkgo nut and the restitution coefficient of the ginkgo nut–steel plate. Each factor’s range was selected using the steepest climbing test. A quadratic polynomial regression model of the stacking angle considering these factors was obtained using the Box–Behnken test. Taking the actual stacking angle of 39.59° as the optimization objective, the optimal combination was formed: the static and dynamic friction coefficients were 0.5 and 0.36, respectively, and the restitution coefficient was 0.42. This combination was used for the verification test. The stacking angle was found to be 41.12°. The relative error was 3.86%, indicating that the model is reliable and can provide a useful reference for relevant research.

This study was conducted over two growing seasons (2022-2023 and 2023-2024). Using a randomised block design, 16 treatments consisted of combinations of vermicompost, biochar, jaggery, poultry manure, farmyard manure, cow urine, and neem cake, and three replications were used in the study. The objective was to assess how these organic amendments affected the antioxidant, phenolic and flavonoid contents in guava fruit. The treatment T₆(Vermicompost 5 kg/tree + Biochar 7.5 kg/tree + Jaggery 1.25 kg/tree) produced the highest levels of antioxidant, phenolic and flavonoid, according to the results. T₆ in particular showed an increase in antioxidant activity from 46.48% to 48.14%, phenolic content from 29.72 mg TA/g to 30.93 mg TA/g and flavonoid content from 23.88 mg/g FW to 25.14 mg/g FW. This study provides important information for sustainable horticultural practices by highlighting the potential of organic amendments to enhance the nutritional qualities of guava cv. L-49.