Arc Welding Related Phenomena

Several researchers have devoted efforts on studying physics of arc and descriptive models are used to explain many arc welding related phenomena. However, due to the subject complexity, doubts still emerge about the mechanisms of some phenomena related to the arc. For instance, the description about electromagnetic interactions with the arc, which governs the arc trajectory and lead to plasma jet and arc blow formation, seems to be yet controversial. Thus, the present study aimed a better understanding of these phenomena. An e-mail survey was carried out to confirm discordant descriptions of the phenomena. Some points were raised about the actual physical explanation used in the current literature. Some experimental work with arcs at different levels of current was developed and shows that plasma jet has an important role in the welding arc trajectory, but there are other factors acting at the same time. Using electromagnetic theory and flow mechanics explanation, more comprehensive models were eventually presented to explain plasma jet formation and the arc blow phenome...

The great Greek thinker Aristotle was born in 384 B.C. in Stagirus, a city in ancient Macedonia in northern Greece. At the age of eighteen Aristotle went to Athens to begin his studies at Plato's Academy. He stayed and studied at the Academy for nineteen years and in that time became both a teacher and an independent researcher. After Plato's death in 347 B.C. Aristotle spent twelve years traveling and living in various places around the Aegean Sea. It was during this time that Aristotle was asked by Philip of Macedon to be a private tutor to his son, Alexander. Aristotle privately taught Alexander for three years before he returned to Athens after Philip gained control of the Greek capital. During this period back in Athens Aristotle founded his own school, the Lyceum, where he taught for twelve years. In 323 B.C. Alexander the Great died and the Macedonians lost control of Athens. Aristotle was forced to leave and he died one year later in Chalcis, north of Athens, at the age of 62.