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, effects of direct-current (DC) electric fields on the flame propagation and combustion characteristics of premixed CH 4 /O 2 /N 2 mixtures were experimentally investigated at excess air ratios of 0.8, 1.0, and 1.2, room temperature, and atmospheric pressure. Results show that the existence of the DC electric fields significantly affects the flame propagation and combustion properties. Specifically, the flame shape becomes a prolate spheroid, with the major axis in the electric field direction as a result of the movement of positive ions by the electric body force, and a further increase in the applied voltage distorts the flame front more significantly. Additionally, the flame propagation speed in the electric field direction (S n ) and corresponding unstretched laminar burning velocity (u l ) are increased as the electric field becomes more intense, and this behavior is more pronounced for lean mixtures. Finally, the initial and main combustion durations defined by the pressure evolution profiles are shortened. The peak pressure and peak rate of pressure rise are increased with the increase of the electric field intensity just for lean mixtures. The observation of the laminar burning velocity and pressure evolution behavior substantiates the potential of the electric field in enhancing lean combustion.

Introduction: Irreversible electroporation (IRE) combined with a catheter-based electrode during endoscopy is a potential alternative treatment method for digestive tract tumors. The aim of this study was to investigate the electrical injury (EI) and thermal injury (TI) to the digestive tract via numerical analyses and to evaluate the role and impact of electrode configurations and pulse settings on the efficacy and outcomes of IRE. Materials and methods: A finite element method was used to solve the numerical model. A digestive tract model having 4-mm-thick walls and two catheter-based electrode configuration models were constructed. The distributions of electric fields, temperature, electrical conductivity, tissue injury and limitation on the pulse number required for IRE were calculated and compared. Results: Electrode length is an important geometric parameter for electrodes in the monopolar model (MPM), while electrode spacing affects the outcomes in the bipolar model (BPM). Increasing the pulse voltage reduces the pulse number required for tissue ablation, while increasing the risk of TI. In total, there were 6 NT-IRE protocols, 12 thermal-IRE protocols and 30 TI protocols. All of the NT-IRE protocols were set in BPMs with a voltage of 0.50 kV. With increasing electrode spacing, the minimum pulse number decreased. However, thermal effects were inevitable in the MPM. Conclusions: The electrode configuration and pulse settings are adjusted to achieve NT-IRE synergistically. The BPM is more reliable for achieving NT-IRE in 4-mm-thick digestive wall. Future in vitro and in vivo studies are needed to support and validate this conclusion. ARTICLE HISTORY

Abstract: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 Pmax increases and its appearance time tp is advanced with the increase of the input voltage. For the mixture of λ = 1.6 at the input voltage of −12 kV, Pmax increases by almost 12.3%, and tp 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. OPEN ACCESSEnergies 2015, 8 2588

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