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Electric wire enclosures to protect livestock represent one intervention to mitigate negative impacts of large carnivores. However, appropriate fence construction and voltage level in the live wires are crucial to deter carnivores. To ensure that the voltage level remains sufficiently high, maintenances and clearing the wires from tall or growing vegetation is regularly needed. In this study, we investigate the performance of a fence wire coated with conductive rubber, claimed by the supplier not to short circuit and drop in voltage due to contact with e.g. ground and vegetation. We examine the voltage of the rubber‐coated wire during contact with soil, ground, and wet vegetation and observed a voltage loss comparable to that of the standard metal fence wire. Our results imply that the rubber‐coated wire does not perform better than a conventional metal fence wire when in contact with growing grass and other elements that usually short circuit an electric fence.

A comprehensive guide to cable materials, markets, and products  The Global Cable Industry  presents a comprehensive overview of the most recent developments in automotive cables, nuclear power station cables, undersea cables, coaxial cables, optical wires, medium- and high-voltage cables.

Wire electrical discharge machining (WEDM) is a non-conventional machining process renowned for precision in machining complex profiles, especially in high-strength and hard materials. This process also found other functions in machining cylindrical workpieces, known as wire electrical discharge turning (WEDT). The material removal mechanism of this process is based on electrical discharges, and evaluating the productivity of the continuous process to a great extent depends on the material removal of individual single discharges. In order to study the influence of rotational speed in material removal of erosion in cylindrical workpieces, theoretical and experimental studies of each single spark are necessary. This comprehensive study delves into the influence of rotational speed in WEDM processes applied to cylindrical workpieces. The research includes a series of single discharge experiments, and introduces a computational fluid dynamics (CFD) thermal model. The developed thermal model demonstrates the capability to predict the material removal rate of a single discharge with an error of 8.6% relative to experimental data. Furthermore, the investigation extends to continuous erosion studies, analyzing the material removal rate under varying rotational speeds. The overall material removal rate decreases 13% due to the declining material removal rate of each single discharge. Additionally, a removal efficiency parameter of erosion of cylindrical workpieces is introduced to provide an evaluation of the process and the influence of crater overlaps. The removal efficiency for various rotational speeds ranges between 22 and 24%, influenced by the proportion of normal discharges and the efficiency of crater overlaps.

Inconel 718 is a high-nickel-content superalloy which possesses excellent strength at elevated temperatures and resistance to oxidation and corrosion. This alloy has wide applications in the manufacturing of aircraft engine parts such as turbine disks, blades, combustors and casings, extrusion dies and containers, and hot work tools and dies, but the inherent problems in machining of superalloys with conventional techniques necessitate the use of alternative machining processes. The wire electrical discharge machining (WEDM) process has been recently explored as a good alternative of conventional machining methods, but there is lack of data and suitable models for predicting the performance of WEDM process particularly for Inconel 718. In the present work, empirical modeling of process parameters of the WEDM has been carried out for Inconel 718 using a well-known experimental design approach called response surface methodology. The parameters such as pulse-on time, pulse-off time, peak current, spark gap voltage, wire feed rate, and wire tension have been selected as input variables keeping others constant. The performance has been measured in terms of cutting rate and surface roughness. The models developed are found to be reliable representatives of the experimental results with prediction errors less than ±5 %. The optimized values of cutting rate and surface roughness achieved through multi-response optimization are 2.55 mm/min and 2.54 μm, respectively.

Wire electrical discharge machining (WEDM) is one of the promising methods to produce precision dies and machine tools. In the present work, die corner accuracy achievable through trim cutting operation has been analyzed in the presence of a higher wire lag arising due to the higher workpiece thickness, acute corner angle, and higher flushing nozzle height. The influence of the corner error (uncut area left between the actual profile and the desired profile) generated in the first cut (rough cut) on the considered responses, namely volume removal rate, corner accuracy, surface roughness, and dimensional shift, has been analyzed by setting three different parameters during the first cut of the trim cutting operation. It is established that the trim cutting operation is a superior strategy for improving die corner accuracy than the pulse parameter modification strategy. Nevertheless, the high pulse parameter setting in rough cut was preferred for achieving greater productivity while the low pulse parameter setting in rough cut was chosen to achieve better corner accuracy at the cost of lower productivity.

Novel aluminum–silicon (Al–Si) nanoparticles (11 ~ 12 wt.% silicon) with core–shell structure were designed and prepared by electric wire explosion in argon atmosphere. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to characterize the structure and composition of Al–Si powders. Oxygen bomb calorimeter was used to obtain the combustion heat released, whereas thermo-gravimetric analysis and differential scanning calorimetry (TG-DSC) were used to study the thermal oxidation process. Results showed that the particle size of Al–Si powders with d50 of 311.8 nm was mainly in the nanometer range, although some large particles of several micrometers were observed. The nanoparticles had a typical “core–shell” structure. The shell consisted of silicon chips and aluminum oxides, whereas core is mainly composed of silicon frameworks filled with aluminum. TG-DSC results showed that the thermal oxidation reaction of Al–Si nanoparticles in the air proceeded in three stages. The first stage involves the slow oxidation reaction, whereas in the second step there is a violent oxidation reaction of Al, which started at about 535.5 ℃. The third step involves the mild oxidation of Al and Si. The weight gain was 72%. The oxygen bomb calorimeter tests showed that the heat release of Al–Si powders was higher than that of pure nano-Al powders. Therefore, the Al–Si nanoparticles prepared in the present work can be considered as a promising candidate in composite energetic materials such as explosives and propellants.

Discharge state detection is a key aspect of the high-speed wire electrical discharge machining (HS-WEDM) control system, as it is strongly correlated with the cutting performance. This paper presents a method for the online detecting discharge state in the process of HS-WEDM based on the voltage and current with the PSO-SVM algorithm. According to the eigenvalues in the regional integral location of the voltage and current waveforms, five discharge states (open circuit, near open circuit, normal spark discharge, near short circuit, and short circuit) that occur in HS-WEDM are discriminated. The proposed classification method has a high accuracy rate and a moderate running time in the identification and classification of discharge state. In test experiments, the above detection system of discharge state was successfully employed to study the finishing characteristics of HS-WEDM in atmospheric and water mist media under different processing parameters. And the spark rate was used as a process index to evaluate the process characteristics of HS-WEDM with surface roughness and cutting speed.

Ventilation-controlled fires tend to be the worst for toxicity, because they produce large amounts of fire effluent containing high yields of toxic products. In order to examine the dependence of the amount of chosen few main combustion gases under ventilation-controlled conditions, a PVC-insulated copper electric wire with unknown composition (PVC filled with chalk) was studied by mean of a steady state tube furnace. For the tested wire, lower values of CO2 yields at different ventilation conditions were obtained than for the reference pure polymer unplasticized PVC and additionally tested pure LDPE, the yields were higher three times in the case of PVC and two times in the case of LDPE than those received for wire at the same ventilation conditions, which pointed out decreasing contribution of hyperventilation effect to human during cable fire. In contrast, higher values of toxic CO yields, four times higher, were obtained for the PVC-insulated electric wire rather than for the pure polymers. The maximum value of CO yield (0.57 g/g) was determined in the case of 5 L/min of primary airflow and decreased with increasing ventilation. The measured yields of hydrocarbons were similar to the reference values except for the equivalence ratio ϕ = 0.27, where hydrocarbon yield was equal to 0.45 g/g. The HCl yield of fire effluents from the PVC-insulated wire was shown to be independent of ventilation conditions. The corrosive reaction between copper and the HCl species and the flame-retardant mechanisms of the additives, caused the lower values of HCl in the fire effluent of the PVC-insulated copper wire than for pure polymer.

In this investigation, the effect of wire electrical discharge machining (WEDM) parameters such as pulse-on time ( T ON ), pulse-off time ( T OFF ), gap voltage ( V ) and wire feed ( F ) on material removal rate (MRR) and surface roughness ( R a ) in metal matrix composites (MMCs) consisting of aluminium alloy (Al6063) and silicon carbide (SiC p ) is discussed. The Al6063 is reinforced with SiC p in the form of particles with 5%, 10% and 15% volume fractions. The experiments are carried out as per design of experiments approach using L 9 orthogonal array. The results were analysed using analysis of variance and response graphs. The results are also compared with the results obtained for unreinforced Al6063. From this study, it is found that different combinations of WEDM process parameters are required to achieve higher MRR and lower R a for Al6063 and composites. Generally, it is found that the increase in volume percentage of SiC resulted in decreased MRR and increased R a . Regression equations are developed based on the experimental data for the prediction of output parameters for Al6063 and composites. The results from this study will be useful for manufacturing engineers to select appropriate WEDM process parameters to machine MMCs of Al6063 reinforced with SiC p at various proportions.

Nitinol-shape memory alloys (SMAs) are widely preferred for applications of automobile, biomedical, aerospace, robotics, and other industrial area. Therefore, precise machining of Nitinol SMA plays a vital role in achieving better surface roughness, higher productivity and geometrical accuracy for the manufacturing of devices. Wire electric discharge machining (WEDM) has proven to be an appropriate technique for machining nitinol shape memory alloy (SMA). The present study investigated the influence of near-dry WEDM technique to reduce the environmental impact from wet WEDM. A parametric optimization was carried out with the consideration of design variables of current, pulse-on-time (Ton), and pulse-off-time (Toff) and their effect were studied on output characteristics of material removal rate (MRR), and surface roughness (SR) for near-dry WEDM of nitinol SMA. ANOVA was carried out for MRR, and SR using statistical analysis to investigate the impact of design variables on response measures. ANOVA results depicted the significance of the developed quadratic model for both MRR and SR. Current, and Ton were found to be major contributors on the response value of MRR, and SR, respectively. A teaching–learning-based optimization (TLBO) algorithm was employed to find the optimal combination of process parameters. Single-response optimization has yielded a maximum MRR of 1.114 mm3/s at Ton of 95 µs, Toff of 9 µs, current of 6 A. Least SR was obtained at Ton of 35 µs, Toff of 27 µs, current of 2 A with a predicted value of 2.81 µm. Near-dry WEDM process yielded an 8.94% reduction in MRR in comparison with wet-WEDM, while the performance of SR has been substantially improved by 41.56%. As per the obtained results from SEM micrographs, low viscosity, reduced thermal energy at IEG, and improved flushing of eroded material for air-mist mixture during NDWEDM has provided better surface morphology over the wet-WEDM process in terms of reduction in surface defects and better surface quality of nitinol SMA. Thus, for obtaining the better surface quality with reduced surface defects, near-dry WEDM process is largely suitable.