A synthesis of iron oxide (β-Fe2O3) nanoparticles (NPs) made using a simple chemical method from a mixture of iron (III) chloride (FeCl3) solution and Iraqi grape extract has applications in the biomedical field. Iraqi grape extract was used to reduce iron (III) chloride salt to iron oxide (β-Fe2O3) NPs. The green synthesis method was cheap, non-toxic, safe, and eco-friendly. The iron oxide (β-Fe2O3) NPs were diagnosed using x-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FT-IR), ultraviolet spectrophotometry (UV-VIS), and scanning electron microscopy (SEM). The UV-VIS spectrophotometry analysis showed the energy gap (Eg) was 2.9 eV. The peak of strong absorption at 526 cm−1 indicated that a Fe-O vibration band was reported on the FT-IR spectrum. The XRD showed the highest peaks at 102 and 222, with average crystallize sizes between 29–37 nm. Besides, XRD spectrum analysis revealed a cubic structure. The surface morphology of the sample, which was identified using the SEM analysis, found the average grain size was from 49 to 50 nm with a cubic shape. After investigating the inhibition of zones, the synthesized (β-Fe2O3) NPs showed antibacterial activity of 18 mm for positive-gram aureus staphylococcus bacteria and 19 mm for negative-gram Escherichia coli baceria.

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Variable valve timing (VVT) is an advanced modern technique applied in internal combustion engines by altering the valve lift event timing. This work aims to contribute to the continuing industrial VVT development to improve engine efficiency, fuel consumption and performance. To observe the influence on the spark-ignition (SI) engine’s performance, four valve timing strategies are selected carefully by varying the intake and exhaust valve timing. Lotus Engine Simulation, a simulation engineering software, is adapted in this study. The engine characteristics used in this modelling are spark engine, multicylinder, four strokes, port injection fuel system and constant compression ratio. A comparison between a conventional standard exhaust/intake valve timing and three other different timing cases is carried out. Results reveal that the overlap case of 98° showed a good brake-specific fuel consumption by approximately 3% less than the conventional case. An improvement of 6.2% for volume efficiency and 2.9% in brake thermal efficiency is also reported.

Four grades of gasoline fuel – obtained from Iraqi oil refineries – are used in this research to investigate their performance in spark-ignition (SI) engines. These grades are RON 77, RON 82, RON 87, and RON 93. We used a four-stroke, four-cylinder SI engine laboratory rig to conduct the experiments and calculate the engine performance for each gasoline grade. We compared the experimental results with the predicted numerical simulations carried out using a well-known commercial software called Lotus Engine Simulation (LES). The numerical results obtained using LES show good agreement with experimental findings. A higher gasoline grade shows better engine performance than lower grades owing to its superior quality and purity, better combustion characteristics and performance, and lower amount of gasoline inclusions. Gasoline fuel RON 93 provided the best engine performance in comparison to the remaining grades. The variation between the numerical and experimental results in all tested conditions was below 3%.