>>11135738
No. Even assuming perfectly reversible processes, the maximum efficiency of a cycle is η=1-TL/TH (which is strictly less than 1) where TH is the thermodynamic temperature of your hot reservoir, and TL the temp of your cold resv. See Carnot's theorem.
If you aren't talking about a thermodyanmic cycle, then yes, a particle can move through a potential field without losing energy. This is the definition of a conservative field.
>>11120997
check valves
>>11145472
acquire philosopher's stone