The sintering kinetics of real systems has been viewed as a process of transport of activated volume. Activated volume is a parameter that can be used to describe mass transport during the sintering process. It defines the movement of point defects and dislocations during the sintering process. https://www.roneverhart.com/Turbosound-TS-18SW700-8A-18-Low-Frequency-Loudspeaker-p31480/