The use of cutting fluids has played a vital role in machining operations in lubrication and cooling. Most cutting fluids are mineral oil-based products that are hazardous to the environment and the worker, cause severe diseases and pollute the environment. In addition, petroleum resources are becoming increasingly unsustainable. Due to environmental and health issues, legislations have been established to ensure that the consumption of mineral oil is reduced. Consequently, researchers are making efforts to replace these mineral oil-based products. Vegetable oils are grasping attention due to their better lubricating properties, ease of availability, biodegradability, low prices, and non-toxicity. In this study, a detailed review and critical analysis are conducted of the research works involving vegetable oils as cutting fluids keeping in view the shortcomings and possible solutions to overcome these drawbacks. The purpose of the review is to emphasise the benefits of vegetable oil-based cutting fluids exhibiting comparable performance to that of mineral oil-based products. In addition, an appropriate selection of non-edible vegetable oil-based cutting fluids along with optimum cutting parameters to avoid a scanty supply of edible oils is also discussed. According to this research, vegetable oils are capable of substituting synthetic cutting fluids, and this option might aid in the successful and cost-efficient implementation of green machining.

The world’s need for energy is increasing with the passage of time and the substantial energy demand of the world is met by fossil fuels. Biodiesel has been considered as a replacement for fossil fuels in automotive engines. Biodiesels are advantageous because they provide energy security, they are nontoxic, renewable, economical, and biodegradable and clean sources of energy. However, there are certain disadvantages of biodiesels, including their corrosive, hygroscopic and oxidative natures. This paper provides a review of automotive materials when coming into contact with biodiesel blended fuel in terms of corrosion. Biodiesels have generally been proved to be corrosive, therefore it is important to understand the limits and extents of corrosion on different materials. Methods generally used to find and calculate corrosion have also been discussed in this paper. The reasons for the occurrence of corrosion and the subsequent problems because of corrosion have been presented. Biodiesel production can be carried out by different feedstocks and the studies which have been carried out on these biodiesels have been reviewed in this paper. A certain number of compounds form on the surface of materials because of corrosion and the mechanism behind the formation of these compounds along with the characterization techniques generally used is reviewed.

Harvesting solar energy for water treatments has been considered a promising solution for a global community. The shortage of water is a great challenge for scientists due to the increased demand of the population–however, the low efficiency of absorber materials obstacles in practical applications. In addition, state-of-the-art conventional technologies require optical concentrators and multiple component-based systems, leading to lower efficiency and higher cost. In this review, a low-cost, more reliable, less energy-intensive, and more eco-friendly solar water purification system based on graphene-plasmonic hybrid nanocomposite has been demonstrated. Graphene-plasmonic-based hybrid nanocomposite has been utilized to achieve pure water from wastewater. Such hybrid nanocomposites have the ability to clean polluted water very efficiently due to their excellent properties such as higher surface area, low concentration, and working ability. Furthermore, the development of a solar water purification system has been achieved through optimized hybrid nanocomposites.