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The effect of tungsten, aluminum, and cobalt on the mechanical properties of iron-based composites prepared by powder technology was studied. Five samples with different contents of tungsten, aluminum, and cobalt were established. The five samples have the following chemical compositions: (I) full iron sample, (II) 5wt.% tungsten, (III) 5wt.% tungsten-4wt.% cobalt-1wt.% aluminum, (IV) 5wt.% tungsten-2.5wt.% cobalt-2.5wt.% aluminum, and (V) 5wt.% tungsten-1wt.% cobalt-4wt.% aluminum. The mixed composite powders were prepared by mechanical milling, in which 10:1 ball to powder ratio with 350 rpm for 20 h was cold compacted by a diaxial press under 80 bars, then sintered at temperatures ranging from 1050 °C to 1250 °C in an argon furnace. The samples were characterized mechanically and physically using XRD, SEM, a density measuring device, a hardness measuring device, a compression test device, and a tribological device for wear and friction tests. XRD results refer to the formation of different intermetallic compounds such as Fe7W6, Al5Co2, Fe2W2Co and Co7W6 with the main peaks of Fe. The good combination of tribological and mechanical properties was recorded for sample number five, which contained 5% W, 4% Al, 1% Co and Fe base, where it obtained the highest wear resistance, largest hardness, acceptable compressive strength, and lowest friction coefficient due to the good combination of hard and anti-friction intermetallic action compared with the other samples. This sample is a good candidate for applications which require high wear resistance and a moderate friction coefficient accompanied with high toughness, like bearing materials for both static and dynamic loading with superior mechanical and tribological properties.

In recent years, industries in the suburb have retrofitted their power supply units with solar power supply systems. Using solar power supply systems for various applications, such as food processing, enables energy expense saving. A promising opportunity in the food industry is solar-powered Pulsed Electric Field (PEF) used in the treatment of fruits and their by-products. For this application, a converter is proposed in this paper with a combination of a passive switched inductor cell and a switched capacitor cell. Furthermore, the derived topology possesses an extendable feature. This topology generates high voltage repetitive pulses with a single semiconductor switch and a reduced component count. Dynamic study of the converter is also performed with the derivation of the transfer function. Cost effective, reliable, and simple circuitry are the critical features of this topology. The circuit topology can generate high voltage pulses by increasing the number of switched inductors and switched capacitor cells. A correlation study on the impact of the switched inductor/capacitor cell is also performed and analyzed, which is not usually performed. A 50 W prototype is designed and tested to validate the performance of the converter

The difficulty of delivering electrical power to rural areas motivated the researchers to explore more accessible power sources. Hydropower is considered a desirable option due to its sustainability and lower costs. Pelton turbines have been widely used in hydropower plants because of their low installation and maintenance costs. This study provides a computational fluid dynamics (CFD) model for Pelton turbine performance under various flow conditions. The model is based on the conservation of mass principle, Newton’s second law, and the first law of thermodynamics. It is used to predict the torque produced by a turbine at different rotational speeds. Previously published experimental results for the same turbine geometry and flow parameters were used to validate the model’s predictions. Validation revealed that the model can reproduce the experimental results. This provides the required robustness for its use as a tool for turbine design and modification.

This study is intended to investigate and analyze the operational performances of the Conventional Tubular Solar Still (CTSS), Tubular Solar Still with Phase Change Material (TSS-PCM) and Tubular Solar Still with Nano Phase Change Material (TSS-NPCM). Paraffin wax and graphene plusparaffin wax were used in the CTSS to obtain the modified solar still models. The experimental study was carried out in the three stills to observe the operational parameters at a water depth of 1 cm. The experiment revealed that TSS-NPCM showed the best performance and the highest yield in comparison to other stills. The distillate yield from the CTSS, TSS-PCM and TSS-NPCM was noted to be 4.3, 6.0 and 7.9 kg, respectively, the daily energy efficiency of the stills was observed to be 31%, 46% and 59%, respectively, and the daily exergy efficiency of the stills was recorded to be 1.67%, 2.20% and 3.75%, respectively. As the performance of the TSS-NPCM was enhanced, the cost of freshwater yield obtained was also low in contrast to the other two types of stills.