Volume 21 Issue 3

With the ultimate goal of facilitating in situ phytostabilization and ecological restoration of mining sites rather than agricultural use, the present study aimed to investigate the effects of wood ash and peat on the physicochemical properties and nitrogen mineralization in copper-mine-affected soils. To this end, soil samples were collected from copper mine waste rock dumpsites and amended with wood ash, peat moss, and their mixture, at various rates. Various soil properties were determined at two incubation periods (day 0 and day 63). To reveal differences among soil amendments, a post hoc test with the Bonferroni correction, principal component analysis (PCA), PCA biplot, and Log2 fold change heat map analyses were applied. As a result, all soil properties, except the ammonium level at day 63, differed significantly for at least one type of amendment (P < 0.05). The overall effects of the treatments on physicochemical soil properties and nitrogen mineralization, as determined by PCA, indicated that wood ash had the greatest effect on pH and EC. In contrast, peat moss dominated nitrogen dynamics, as reflected by organic carbon and organic matter. The results of this study could be used to remediate mine-polluted, acidified, and nutrient-depleted soils.

The bending strength and compressive strength properties of wooden laminated elements reinforced with various materials were investigated in this study. Veneers with 9 layers were prepared from Scots pine (Pinus sylvestris L.) wood, which is used extensively in Turkey. The veneers were glued with PVAc-D3 adhesive by placing support elements (PVC plastic mesh, fiberglass/PVC mesh, and aluminum wire mesh) between them. The density, bending strength perpendicular to the glueline and bending strength parallel to the glueline were determined in the specimens prepared in conformance with the TS 5497 EN 408 (1998) standards. All of the support materials increased the bending resistances of the specimens. The highest bending strength and compressive strength was obtained in the specimens reinforced with aluminum wire mesh, whereas, the lowest bending strength was obtained in the control specimens and the lowest compressive strength was obtained in the specimens reinforced with fiberglass/PVC mesh.

This study was carried out to examine the effects of Iranian natural zeolite application to poultry litter paperboard. To examine the effect of different amounts of zeolite on poultry litter paperboard’s properties, four levels of zeolite were used: 0 (control), 8.85, 14.77, and 22.34%. The results showed that zeolites had significant effects on the physical properties of the paperboard. Increases in the amount of zeolite resulted in increases in both the thickness and apparent density and decreased the air resistance of the paperboard. Also, zeolites significantly reduced the strength properties of the paperboard. The effect of increasing the amount of zeolite on the water absorption properties of the paperboard was significant at the 95% confidence level; by increasing the amount of zeolite, the capacity and rate of water absorption of the paperboard increased significantly.

Sodium caseinate (SC)-based barrier coatings containing tannic acid (TA) and ferulic acid (FA) were applied to paper substrates as biodegradable alternatives to synthetic polymer coatings. The objective was to evaluate the effects of phenolic compound type, phenolic compound loading, and coating weight on the structural, thermal, barrier, and mechanical properties of SC-coated papers and to establish suitable coating conditions for biodegradable paper-based packaging applications. FT-IR analysis indicated that TA and FA interacted with SC mainly through hydrogen bonding and other noncovalent intermolecular interactions, with no detectable evidence of ester bond formation under the investigated conditions. The addition of TA or FA shifted the thermal decomposition of the SC coating to a higher temperature range and improved air, grease, and water-related barrier properties. Barrier performance depended strongly on phenolic compound loading and coating integrity, with excessive TA loading causing surface cracking and reduced air resistance. All coated papers showed the maximum measurable oil resistance, and moderate increases in tensile strength were observed. These results suggest that TA- and FA-containing SC coatings are promising biodegradable barrier coatings for paper-based packaging, particularly for dry or grease-containing food applications requiring improved air and oil resistance.

Structural, thermal, and physicochemical performance were studied for sodium hydroxide (NaOH) (12 wt%)/itaconic acid polyamidoamine-epichlorohydrin (IA-PAE) (0 to 30 wt%) cross-linked tissue-equivalent composites made from defatted soy flour, soy protein concentrate, and soy protein isolate-bonded Rhizophora spp. (particle size: 149 µm), to enhance interfacial bonding, stability, and overall material performance. The Fourier transform infrared spectra confirmed effective crosslinking and a reduction in hydroxyl groups, with the formation of ester/ether linkages. Thermal analysis showed improved stability and a higher char yield. Microstructural analysis revealed denser, more homogeneous matrices with enhanced interfacial bonding. Average densities ranged (0.94 ± 0.11 to 1.04 ± 0.20 g/cm3), matched those of water and other commercial tissue substitute biomaterials, while moisture content (6.51 ± 0.19 to 8.06 ± 0.50%) was consistent with JIS A-5908 (2015) limits. Mechanical properties exceeded standards (internal bonding strength (IBS) up to 0.73 ± 0.01 MPa; modulus of rupture (MOR): 19.21 ± 0.50 MPa; modulus of elasticity (MOE): 7.70 ± 0.33 GPa), and dimensional stability improved significantly (water absorption: ≥ 20%, thickness swelling: ≥ 10%). Optimal performance was achieved at 20% IA-PAE. NaOH/IA-PAE crosslinking effectively enhances structural, thermal, and physicomechanical properties, producing sustainable composite particleboards suitable for tissue-equivalent and radiation-related applications.

Two kinds of cotton pulp fibers were used as raw materials to explore the relationship between beating process and cotton fiber properties through Hollander beating, Hollander/PFI beating, and enzyme pretreatment/ Hollander beating. The results showed that the medium consistency beating had a strong effect on the fibrillation of cotton pulp fibers, while the effect on the cutting of fibers was weak. However, the low consistency beating process had a strong cutting effect and a weak fibrillating effect on the fibers. With the increase of beating degree, the average length of cotton fiber decreased, the ratio of fibrillation degree and fine fibers increase markedly. In the range of beating degree from 30 to 60 °SR, the tensile index, folding endurance, and bursting index of cotton fiber-based paper generally increased with the beating degree increasing. Paper sheets produced by blending cotton pulp with hardwood pulp had superior tensile index, bursting index, and tearing index compared to those made from pure hardwood pulp. Furthermore, when the beating degree of the cotton pulp was 60°SR and its addition level was 40%, the resulting paper achieved optimal performance in tensile index, bursting index, tearing index, and folding endurance, yielding the best overall paper properties.

Rubberwood (Hevea brasiliensis), a widely utilised timber in Malaysia, is susceptible to degradation from fungi and termites, requiring effective preservation strategies to extend its service life. This study explores a novel approach for improving the delivery of tebuconazole (TEB), a triazole fungicide, into rubberwood using zein nanoparticles prepared via the nanoprecipitation method. The optimised zein nanoparticles achieved a hydrodynamic size of 146.4 ± 10.66 nm with a loading efficiency of 43.0%. The treated rubberwood samples were categorised as “easily treated” and showed sustained release of TEB from leaching tests. Results showed good protection against subterranean termites (Coptotermes gestroi) with promising resistance to brown rot (Gloeophyllum trabeum) and white rot (Trametes versicolor) fungi. The study highlights the potential of nanoprecipitation as a sustainable, efficient alternative to traditional wood preservation methods, offering reduced chemical usage and improved delivery efficiency.

With the transformation of agricultural production methods, it was expected that the enhancement of energy utilization efficiency would lead to a decrease in energy consumption. However, contrary to expectations, energy consumption has increased. This study delves into the mechanisms behind China’s agricultural energy rebound effect. By employing a systematic generalized method of moments (GMM) model, the agricultural energy rebound effect in China from 2003 to 2022 is quantified, and various models are utilized to verify contributing factors. The findings indicated that Random Forest and Gradient Boosted Regression Tree models outperformed others in forecasting the factors influencing China’s agricultural energy rebound effect. Among all the characteristic variables, the most influential factors were residents’ income (RLI) levels, advancements in agricultural technology, the structure of the agricultural industry, and the degree of urbanization. The prediction patterns of the above four influences on the rebound effect of China’s agricultural energy were further inferred through the accumulated local effects (ALE) Plot, respectively, and the results show distinctly different nonlinear characteristics.

Malva sylvestris L. was evaluated as a potential sustainable lignocellulosic filler for polypropylene-based composites. Composites containing two particle size fractions and filler loadings ranging from 5 wt% to 20 wt% were produced through thermokinetic mixing and compression molding. Chemical, morphological, thermal, and mechanical characterizations were performed to determine the influence of filler incorporation on composite performance. The results showed that increasing filler content reduced tensile and flexural strengths by up to 27.2% and 29.6%, respectively, due to limited interfacial compatibility between the hydrophilic filler and hydrophobic polymer matrix. In contrast, the tensile and flexural moduli increased by up to 15.6% and 18.0%, respectively, indicating enhanced stiffness through restricted polymer chain mobility. Thermal analysis revealed improved thermal stability, with the onset degradation temperature increasing by approximately 35 °C at the highest filler loading. The filler particles also acted as heterogeneous nucleating sites, promoting earlier crystallization without substantially altering the degree of crystallinity. Mechanical properties were successfully modeled using response surface methodology. Linear model provided the most accurate predictions for tensile strength, whereas quadratic models better represented tensile modulus and flexural behavior. These findings demonstrate that Malva sylvestris L. is a promising renewable filler for lightweight polymer composites.

The practical use of starch-based biodegradable composites is often limited by high moisture sensitivity and dimensional instability in humid environments. This study investigates the effect of Pennisetum purpureum fiber (PPF) loading on the physical properties, moisture behaviour, and biodegradation performance of thermoplastic cassava starch/candelilla wax (TPCS/CW) composites prepared by thermo-compression moulding with fiber contents ranging from 0 to 60 wt%. Increasing fiber loading reduced density and significantly improved resistance to moisture-related deterioration. Moisture content, water absorption, thickness swelling, and water solubility decreased progressively with higher PPF content, indicating enhanced dimensional stability and reduced water permeability. After seven days of exposure, equilibrium moisture absorption decreased from 8.3% in neat TPCS/CW to 3.8% at 60 wt% PPF, while water solubility decreased from 29.2% to 13.1%. Soil burial testing confirmed that all composites remained biodegradable, although higher fiber loading moderated the degradation rate, with weight loss reduced from 67.4% in the neat matrix to 43.4% at 60 wt% after four weeks. Slightly higher degradation at intermediate fiber contents was attributed to interfacial voids that facilitated moisture ingress. Overall, PPF incorporation improved moisture resistance and structural stability while preserving biodegradability, supporting the potential of this fully bio-based composite for biodegradable packaging films, disposable packaging liners, and paperboard coating applications requiring moderate moisture resistance under humid conditions.