There are prominent differences between traditional surface science underUHV conditions and catalysis in the real world, focusing on the so-called"materials gap"and "pressure gap".

To maximize energy output, the tapered towers funnel wind between them, creating a negative pressure zone behind the buildings that draws more air through the gap.

A small gap that can form between the casing or liner and the surrounding cement sheath, most commonly formed by variations in temperature or pressure during or after the cementing process.