The battery terminals are represented as electron-source and electron-sink in the user interface of the models. The function of this variable is to stop the model once a certain number of electrons reach the battery positive, and a monitor displays the time taken to fill the electron-sink.
Australia faced the threat of communism after WWII ended in 1945. The threat was known as the Red Menace which was caused by all the conflicts in Asia and also things that were going on in Australia at the time. The Australian government responded to the Red Menace in many ways.
To help prevent these two countries from falling into communist control. AT the end of WWII, Greece and Turkey were economically weak. This economic situation meant that the governments could collapse and be an open invitation for the communists to take control. The Russians were already meddling in the politics of the region. Truman viewed this as a great threat to the free world.