During expansion, the microbubbles quickly enlarge beyond their compressive size, a phenomenon known as microbubble overgrowth. A large amount of the ultrasound's energy is accumulated and built up within a very small volume of microbubbles in this type of cycle. Specific "hot spots" that reach pressures of up to 1000 atm and temperatures of up to 5000 K are created when microbubbles suddenly rupture, releasing tremendous amounts of energy . Depending on the effectiveness of the ultrasound, the percentage of power that reaches the liquid can range from "80% to 90%". This is because there are a series of losses that occur between the power plug and the liquid, which might hinder the catalytic process as illustrated in Fig.