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.
Truman was sure that USSR wanted to spread communism. Britain could no longer afford to support Royalist side in Greek civil war against the communists. USA stepped in with necessary aid to prevent communism spreading. Truman did not want to use military forces to prevent communism. He believed in economic help to countries that were at a risk of becoming communist. Increase US exports when Europe recovered. It was in response to the Truman Doctrine to organise Eastern European communist governments. It was set up in response to the Marshall Plan.