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

We are glad to present the 34th volume of International Journal of Engineering Research in Africa to our readers. This volume contains articles describing the research results in the fields of materials science in the mechanical engineering, construction materials, technological processes in the chemical production, power distribution, communication engineering and engineering management. The articles will be useful for many engineers as well as for academic teachers and students majoring in these fields of engineering science.

The 69th volume of the journal includes articles dedicated to the latest research results in properties and processing technologies of structural materials such as steel, polymers, and composites, analysis and design of sliding mode controllers and automation of centrifugal pumps, designing of geothermal heat exchangers, investigation of seismic behaviour of soil-based structure and analysis mechanics of river's sediments transfer in conditions of Wadi Skhirate, Morocco. The issue will be useful to specialists in mechanical engineering and construction.

We present to our readers the 38th volume of the International Journal of Engineering Research in Africa which contains scientific articles describing the results of engineering research and solutions in the fields of materials and processing technologies in the mechanical engineering, construction and chemical technologies, ergonomics, environmental engineering and engineering management. The articles will be useful for the professionals concerned with mechanical engineering, materials science, chemical engineering, engineering management as well as for academic teachers and students majoring in these fields of engineering science.

This volume of the journal represents the research results of properties and synthesis technologies for a multifunctional hydrogel material, concrete with aggregate from plastic waste, numerical modelling of natural convection processes in the elliptical cylinders, analysed the wastewater treatment technologies based on the use of natural chemicals and based on electroflotation and electrocoagulation. There are articles devoted to communication engineering, energy management in microgrids and potential assessment of wind energy in conditions of Ethiopia. The volume will be helpful to specialists in machinery, communication and construction, environmental protection and energetics.

The 50th volume of "International Journal of Engineering Research in Africa" contains peer-reviewed manuscripts reflecting the research results in the fields of materials science, applied mechanics and mechanical engineering. Such issues as Steel Reinforcement, Strain Based Approach, Temperature, Thermo-Physical Properties, Vehicle Dynamics, Water Resources are raised in the volume. The presented scientific papers can be appreciated by the majority of engineers, researchers, academic teachers and students majoring in the fields of engineering science.

Principles of Automation and Control is a concise textbook that explains the basics of robust automation and control strategies. It demonstrates the essentials for meeting consumer needs and ensuring cost-effective manufacturing processes without compromising product quality. With a focus on Industry 4.0, this book explores the principles and applications of automation in industrial systems, emphasizing efficiency, profitability, and flexibility. The thirteen chapters cover automated processes, control theory, computer control devices, industrial automation tools, and practical examples of system automation. The text uses a multidisciplinary approach with simple language to cater to the needs of readers at all levels (learners, beginner engineers, and professionals) seeking to expand their knowledge in automation and control theory and practice. Real-world case studies and empirical findings are also highlighted, which show how automated business solutions can enhance performance.