11. This section rapidly heats by Joule heating, and the increase in temperature quenches adjacent regions. 12. This equation however neglects Joule heating, and ordinary thermal conductivity ( see full equations below ). 13. Thus the Joule heating amplifies a change in temperature, an effect known as positive electrothermal feedback. 14. The current flowing through the resistance of the metal heats it by Joule heating, causing significant power losses. 15. This is known as negative electrothermal feedback, as the change in Joule heating opposes the change in temperature. 16. There is an intimate relationship between Johnson Nyquist noise and Joule heating, explained by the fluctuation-dissipation theorem. 17. Joule heating frequency is kept well above 20 kHz to avoid feedback response and to separate topological and thermal effects. 18. This Joule heating reduces efficiency of iron-core transformers and electric motors and other devices that use changing magnetic fields. 19. Further, application of strong electric fields leads to resistive heating ( Joule heating ) of the buffer in the capillary. 20. The deflection signals are caused not only by sample topography, but also by the thermal expansion caused by Joule heating.