"Thermal engineering applications involve the process of heat transfer, when energy either enters or leaves a system through a smaller area of contact that can be either perfect or imperfect. If it is perfect, thermal spreading (or constriction) occurs. If it is imperfect, the thermal transport occurs over a much smaller region of real contact within the apparent area of contact. This is contact resistance. It's a phenomenon that is important for engineers to understand for many industry applications in the fields of mechanical, aerospace, chemical, and nuclear engineering, with particularly critical applications in areas like electronics cooling, aerospace systems, and tribology"-- Provided by publisher.