Line tension
The line tension () is attributed to the contact line along which three interfaces for the three thermodynamic phases, , and meet. It is defined as the line contribution to the grand potential per unit length of the contact line.
The line tension () is attributed to the contact line 
  along which  three interfaces for the three thermodynamic phases, 
, 
 and 
 meet. It is defined as the line contribution to the  grand potential  per unit length of the contact line.