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.

The 55th volume of "International Journal of Engineering Research in Africa" is compiled from the peer-reviewed manuscripts that present the research results in applied and fluid flow mechanics, computational analysis of heat and mass transfer processes, and investigation of the chaotic systems. This volume also considered the conceptual model for mitigating security vulnerabilities in smart grid electric energy distribution systems. The last research results in materials science and materials processing technologies, anti-corrosive coating, biodiesel synthesis, wastewater treatment technologies, and waste recycling are presented.

We are glad to present our readers with the 40th volume of International Journal of Engineering Research in Africa. This volume contains articles describing the research results in the fields of materials science, mechanical engineering, power distribution and power control, construction materials and technologies, technological processes in the wastewater treatment and industrial engineering. The articles will be useful for many engineers as well as for academic teachers and students majoring in these fields of engineering science.

This journal volume contains papers that reflect research results in materials science, power engineering, and environmental engineering. Additionally, under the focus of this volume is the study on reducing wastes formation in the construction industry. Furthermore, the presented research results may find useful for scientists and engineers deal with powder metallurgy issues and material characterization. Some papers are devoted to solving drilling issues in the oil and gas industry. Eventually, the volume presents an analysis of various algorithms that can find their application in civil and industrial engineering areas.

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

The 29th volume of the International Journal of Engineering Research in Africa presents the articles which describe the results of engineering research and solutions in the fields of structural materials, building materials and construction technologies, applied dynamics of fluid and flow, chemical engineering, and engineering management of modern production. The articles will be useful for professionals concerned with mechanical engineering, materials science, chemical engineering, engineering management and for students and academic teachers of the related specialties.

The 29th volume of the International Journal of Engineering Research in Africa presents the articles which describe the results of engineering research and solutions in the fields of structural materials, building materials and construction technologies, applied dynamics of fluid and flow, chemical engineering, and engineering management of modern production. The articles will be useful for professionals concerned with mechanical engineering, materials science, chemical engineering, engineering management and for students and academic teachers of the related specialties.