notifications behaviour

[O. Sinclair]

Anyone knows if there is way to configure notifications behaviour? I 
mean the "pop-up" messages from the tray icons.

Some of them are half below/behind the panel and more or less invisible, 
others seem to fade out too fast etc etc.

I see no "default" manner so to speak. I would like them to appear above 
the panel and sit there for a specified amount of time before they 
disappear/fade

Kind regards
Sinclair