Seoltacht theirmeach

Is éard is seoltacht theirmeach ábhair ann ná tomhas ar a chumas teas a sheoladh. Cuirtear in iúl í go coitianta ag $k$, $\lambda$, nó $\kappa$ .

Seoltacht theirmeach

Foirmle	${\boldsymbol {q}}=-\lambda \operatorname {grad} (T)$