GGU-CONTAM-RW: "In section" menu item

In a similar manner to the previous menu item, you can assign initial concentrations or concentration sources to sections of the system. This is done by clicking four points in an anti-clockwise direction with the left mouse button. The concentration, which you enter into the following dialog box, then applies to all nodes within the specified section.

Alternatively, it is possible to delete all defined initial concentrations, i.e. to set them to '0'.