Municipal solid waste (MSW) contains plastic waste that can be used as a sustainable green substitute to reduce oil footprints, CO₂ emissions, and environmental pollution. This study aims to recycle plastic waste by manufacturing wood-plastic composites and to improve its mechanical properties by using additives, coupling agents, and lubricants. These composites are prepared by mixing 40–70% of wood flour with 20–25% of a polymer matrix. Wood was degraded at 220 °C, and then the composites were processed at 50 °C. The manufacturing process carried out in the study involved wood waste meshing, drying, shredding, drying, trimming, filling, blending, compounding, and extrusion moulding. The compounding of composites was accomplished in twin-screw extruders. Once the mixture was uniformly mixed, its final shape was given by a two-step extrusion moulding. Previously, researchers aimed at enhancing the mechanical properties of the composites, but our research focus was to improve their durability for different industrial applications. The results suggest that the impact strength is 17 MPa with 50% of wood powder ratio while the maximum value for the tensile strength is 32.5 MPa. About 50% of an increase in wood powder resulted in 8.1% bending strength increase from 26.1 to 32.8 MPa. Reducing the plastic matrix and the wood-particles water swelling ratio resulted in better mechanical properties. The wood species also affected the mechanical properties with their excellent dimensional stability and less variability. A high proportion of wood fibre tends to increase its steady-state torque and viscosity. The mechanical properties against different wood-flour proportions indicate that composite materials exhibit superior water swelling behaviour and extrusion quality.

In this work, the effects of the electric fields on the flame propagation and combustion characteristics of lean premixed methane–air mixtures were experimentally investigated in a constant volume chamber. Results show that the flame front is remarkably stretched by the applied electric field, the stretched flame propagation velocity and the average flame propagation velocity are all accelerated significantly as the input voltage increases. This indicates that the applied electric field can augment the stretch in flame, and the result is more obvious for leaner mixture. According to the analyses of the combustion pressure variation and the heat release rate, the peak combustion pressure P_max increases and its appearance time t_p is advanced with the increase of the input voltage. For the mixture of λ = 1.6 at the input voltage of −12 kV, P_max increases by almost 12.3%, and t_p is advanced by almost 31.4%, compared to the case of without electric fields. In addition, the normalized mass burning rate and the accumulated mass fraction burned are all enhanced substantially, and the flame development duration and the rapid burning duration are remarkably reduced with the increase of the input voltage, and again, the influence of electric field is more profound for leaner mixtures. The results can be explained by the electric field-induced stretch effects on lean burn methane-air mixture.

An investigation was conducted of the ion current characteristics at various excess air ratios λ in a spark ignition engine fuelled with natural-gas–hydrogen blends. The Gaussian mathematical method was employed to fit the pure ion current signal without a spark tail generated by the ignition discharge. The cylinder pressure was recorded, and the Pauta criterion static threshold was used to deal with the outlier errors in the testing data for given cycles. The results show that the spark tail and the ion current can be separated by fitting the ion current with the Gaussian method, and the fitted pure ion current includes the flame-front stage and the post-flame stage. The timing with respect to the flame-front peak exhibits an irregular variation with λ. The maximum current in the flame-front stage increases with increasing λ.The timing of the maximum current in the post-flame stage occurs earlier at the stoichiometric ratio than at other air-to-fuel ratios. The correlation coefficient between the ion current in the post-flame stage and the pressure data treated with the Pauta criterion method increases. In addition, there are high correlation coefficients between the ion current and the pressure.