Solar drying methods use solar radiation to collect the solar energy by heating up the air volume in collectors and then transferring the hot air to an enclosure, where the products are laid out for drying. The use of phase change materials (PCM) will be able to fulfil efficient management of solar energy by considerably boosting the intensity of the heat stored. The use of PCMs is not only ecofriendly but also effectively reduces the cost of energy production. In the second paper, "Energy and Exergy Analysis of a Solar Drying System Using Sodium Thiosulphate Pentahydrate as PCM", the authors, Vaishnav Vishwanathan, Deepak V Menon, Sajith Babu C and Sajith Gopi, have carried out an exergy analysis (based on second law of thermodynamics) to determine the usefulness of sodium thiosulfate pentahydrate as PCM. The energy and exergy studies were done during charging and discharging period of PCM with heat input and different mass flow rates of heat transfer fluid. The authors have carried out the energy and exergy analysis of cinnamon leaf drying process using cabinet type solar dryer. The energy utilization ratio is assumed to be an important parameter for analyzing the utilization of energy in a drying process.

Spinodal decomposition is a phase transition mechanism in which two or more components are formed into two distinct phases of different compositions. The spinodal decomposition is of interest primarily in the field of phase transformation in solids since the diffusion is well defined, occurring uniformly throughout the material, and finds a wide range of applications in the modern-day design-in altering the design of material properties useful for structural and energy applications, and strengthening of alloys for lightweight automotive applications, including data storage and thermoelectric properties of phase-change alloys. In the third paper, "Estimation of the Effect of Spinodal Decomposition in Thin Films", Rahul Basu has basically presented a study based on the available mathematical models in the literature. The author has described second-order diffusion with additional terms of fourth-order coupled with a constant. The model was applied to describe the deposition and thermal regions where solutions were analyzed by simulation, including the fourth-order derivatives of the spinodal decomposition applications for commercially viable compounds. Various functional approximations and dependencies of the transformation rates were obtained for small incremental values, which may not differ in the nanoregion.

Plastic waste is generated in millions of tons every year all over the world, and is getting dumped into drainages and water bodies, causing a lot of environmental pollution and nuisance to the society. The waste in a way is nonbiodegradable and tends to remain in the environment for a very long time. Huge amounts of plastic waste will become a serious problem if no solution is found. The present-day challenge is to develop suitable techniques to convert plastic waste into useful energy to alleviate the demand for energy from fossils. Several researchers, therefore, are focusing on techniques for converting waste plastic into biofuels to replace the fossil-based fuels, and thereby contributing to the development of conversion technologies that are both economically viable and energy-efficient. The last paper is "Conversion of Plastic Waste into Useful Energy: An Overview", by Sagar KG and Rajesh AM. The authors have presented a brief review of the optimized approaches for converting certain kinds of plastic trash into high-energy.