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The effects of using a blend of hydroprocessed vegetable oil (also known as green diesel) and heavier naphtha obtained from catalytic processing of non-edible oils in a small displacement passenger car were evaluated in this paper. Prior to the vehicle tests, the blend was optimized to meet the cetane number and flashpoint specifications of commercial diesel. A blend of neat naphtha (10%) and the green diesel (90%) fuel met the specification of cetane number, but could not meet the flashpoint specifications. To improve the flash point, naphtha was distilled to extract the heavier fractions to produce the heavier naphtha blendstock with an initial boiling point (IBP) of 120°C that was used for blending with green diesel. Vehicle tests were conducted with a blend of 90% green diesel and 10% heavier naphtha (GD90N10) and were compared with a fossil-based diesel fuel (DF).

Tapping is an important process in assembly of aircraft structures because on an average one millions of tapped holes are made on an aircraft structure. However, sudden breakage of the tap is the most undesirable event frequently encountered during the tapping process. In particular, this can mostly occur when small diameter internal threads are made in a ‘difficult-to-cut’ material like titanium. For this reason, it has been a topic of industrial interest in the manufacturing sector for many years. The ultrasonic vibrations assisted tapping (UVAT) is a novel manufacturing technology, where ultrasonic vibrations are provided to the work piece in the axial direction. The present work is a comprehensive study involving experimental characterization. The experimentation shows that UVAT reduces the torque during tapping as compared to that of in conventional process. There is a 19.1% reduction in torque and about 20.3% reduction in cutting temperature in UVAT over that of in CT.