metals that retain a high order of ductility and resistance to brittle fracture down. to very low temperatures, and a much larger class of metals that, at some temperature. or in some range of temperature, undergo a transition from ductile to brittle.behavior. As pointed out above, the temperature level where this transition in fracture behavior. occurs is influenced by the test conditions.
If you are a moderate vaper, whereby you vape fairly consistently through most of the day, but only take a couple drags each time, your coils should last you about 14 days or so. If you are a very light vaper, where you take a few hits here and there throughout the day, your coil could last you 3 weeks or so.
The warranty conditions for PV panels typically guarantee that panels can still produce at least 80% of their initial rated peak output after 20 (or sometimes 25) years. So manufactures expect that their panels last at least 20 years, and that the efficiency decreases by no more than 1% per year. What makes talking about lifetimes for PV panels difficult is the fact that very few panels have been installed for long enough.