We present the 53rd volume of the "International Journal of Engineering Research in Africa" to our readers. This volume contains the articles reflecting the research results in the fields of structural alloys, applied mechanics and mechanical engineering, assessment of the potential efficiency of use the cleaner electricity generation, materials and technologies in construction, biofuel production and chemical treatment of the industrial wastewater, remote sensing, and industrial engineering. The articles will be useful for many engineers as well as for academic teachers and students majoring in the mentioned fields of engineering science.

We present to our readers the 46th volume of "International Journal of Engineering Research in Africa." This volume contains articles reflecting the research results in the fields of materials science, applied mechanics and mechanical engineering, power engineering and power efficiency, facial expression recognition and optical communication, industrial engineering. The articles will be useful for many engineers as well as for academic teachers and students majoring in the mentioned fields of engineering science.

The 51st volume of "International Journal of Engineering Research in Africa" includes peer-reviewed manuscripts reflecting the research results in the fields of materials science, applied mechanics, mechanical and power engineering, biomass processing, communication, construction, engineering management, and applied use of computational procedures and optimization methods in the research practice. The presented scientific articles can be appreciated by the majority of engineers, academic teachers, and students majoring in the fields of engineering science.

This 68th issue of the journal contains articles reflecting the latest research results in powder metallurgy of cermets, green building materials for wide applications in modern construction, analysis of existing maximum solar power point tracking algorithms and components and techniques of solar radiation level prediction in Sahara region of Algeria based on machine learning. This volume will be helpful to many engineers in machinery, renewable energy production and construction.

This issue of the journal includes articles that described the last research results in materials science, mechanical engineering and machine design, heat transfer, treatment of the aqueous environment and solid waste aerobic degradation, power engineering, cloud computing, inventory management, crop production.

This periodical edition includes peer-reviewed papers based on results of scientific research and engineering solutions in different areas of modern engineering science.

In this issue of journal "International Journal of Engineering Research in Africa" are collected articles which describe the results of engineering solutions of actual problems in mechanical engineering and processing technologies, researching and designing of machines, in the practice the designing of the communication systems and construction and engineering management of modern production. Published articles will be useful for professionals from field of mechanical engineering, students and academic teachers of the related specialties.