This ranking seems to be based on the number of research papers in the TOP 10% of citations and the h-index by examining research papers in each country.
For this reason, it is not unnatural that Iran, which has a large number of papers in the field of nanotechnology, comes relatively high in the ranking.
Turkey, on the other hand, does not rank high because the quality of its papers tends to be low.
The single crystal turbine blades used in jet engines can only be manufactured in six countries: Japan, U.S, U.K, France, Russia, Italy.
In recent years, India, Iran, South Korea, and China have finally entered the market.
In addition, only Japan, U.S, Germany, Italy, Iran, and South Korea are currently capable of manufacturing large single crystal turbine blades for power generation.
Therefore, it is natural that India, UK are at the top of the list of engine papers.