Good to Know is a new feature that allows members of the community to answer questions from WebMD experts, doctors, staff, and other community members. We're testing this new feature and we'd like your feedback.
the cylinder (known as Bottom Dead Centre or BDC) the exhaust valve starts to open. As the piston now moves up the cylinder, the hot gases (consisting mostly of nitrogen, carbon dioxide, water vapour and unused oxygen) are expelled from the cylinder. As the Piston approaches TDC again the inlet valve starts to open and the cycle repeats itself.
During a volcanic eruption a mixture of gases and particulates are expelled. The discharge of gases can also occur between major eruption events; volatile gases such as hydrogen fluorine(HF) and carbon monoxide(CO) trickle out of cracks and fissure along the surface of the volcano (SDSU, 2000).uring a volcanic eruption a mixture of gases and particulates are expelled. The discharge of gases can also occur between major eruption events; volatile gases such as hydrogen fluorine(HF) and carbon monoxide(CO) trickle out of cracks and fissure along the surface of the volcano (SDSU, 2000).