deletions | additions       diff --git a/Introduction.tex b/Introduction.tex  index 5dc08a4..7b29e12 100644  --- a/Introduction.tex  +++ b/Introduction.tex 
...
The absorption of the laser beam by the medium gives then rise to an absorbed optical energy $q = \gamma I$. Assuming that all the optical energy is converted to heat, a local increase of temperature appears. Temperature distribution $T$ in absence of melting can be computed using heat equation:  \begin{equation}  \frac{\partial T}{\partial t} = \kappa \nabla ^2 T + \frac{q}{\rho C}  \label{eq:eqChaleur} %\label{eq:eqChaleur}  \end{equation}  where $\rho$ is the density, $C$ the heat capacity and $\kappa$ the thermal diffusivity. If melting temperature is reached, a part of the absorbed heat will melt the solid without increase of temperature. 
...