Many volcanoes exhibit temporal changes in their degassing process, from rapid gas puffing to lava fountaining and long-lasting quiescent passive degassing periods. This range of behaviors has been explained in terms of changes in gas flux and/or magma input rate. We report here a simple laboratory experiment which shows that the nonNewtonian rheology of magma can be responsible, alone, for suc...

11 The Orapa Diamond Mine (Republic of Botswana) exposes a bi-lobate kimberlite 12 pipe that erupted during the Late-Cretaceous epoch (∼93 Ma) through Archaean 13 basement and volcano-sedimentary rocks of the Karoo Supergroup. Geological map14 ping of the crater zone of the South Pipe has revealed a 15–25 m thick in-situ 15 kimberlite pyroclastic flow deposit. The pyroclastic deposit fills in t...

conclusions the ammonia degassing is a simple and suitable technology for ammonia removal at high concentration. undesirable removal efficiency (17%, 35.5% and 31%) can be occurred in suitable ph 11 in the presence of lower ammonia concentrations (50, 100 and 200 mg/l). results according to obtained results, the maximum removal efficiencies were determined 17%, 35.5%, 31%, 66%, and 85.5%, for 5...

Magma degassing plays a fundamental role in controlling the style of volcanic eruptions. Whether a volcanic eruption is explosive, or effusive, is of crucial importance to approximately 500 million people living in the shadow of hazardous volcanoes worldwide. Studies of how gases exsolve and separate from magma prior to and during eruptions have been given new impetus by the emergence of more a...

SO2 emission rates from Erebus volcano show periodicity, which directly relates to lava lake convection and magma and conduit processes. Mt. Erebus is a 3794 m stratovolcano with a persistently degassing convecting, phonolite lava lake. Lava lake SO2 emission rates were collected from 1992 to 2003 using the correlation spectrometer (COSPEC) and in 2003 and 2005 using a miniature ultra-violet di...

6.2.

The effect of secondary steelmaking processes such as desulphurization, removal of inclusions and vacuum degassing followed by hot forging and hardening heat treatment on the microstructure and mechanical properties of a hot-work w500 tool steel have been studied in details. In order to follow the progress of secondary steel making, the content of impurity elements such as S, P, O, H and N were...