Tympanic membrane retraction over the surface and move out along the ear canal. Even if migration along the ear canal is blocked, new cells continue to grow so the surface of the eardrum becomes larger. This process of proliferation and migration can result in enlargement of a retraction pocket so that the eardrum expands and grows deeper into the ear. The majority of tympanic membrane retractions remain stable for long periods of time, or may even resolve spontaneously so that eardrum becomes normal again. Not all retractions are able to resolve even if middle ear pressure normalizes, as the retracted segment may become
Membrane gas separation can be economically competitive with older and more common technologies such as amine-based absorption. Currently, both membrane and amine-based absorption processes can be designed to yield a 90% CO capture rate. For carbon capture at an average 600 MW coal-fired power plant, the cost of CO capture using amine-based absorption is in the $40–100 per ton of CO range, while the cost of CO capture using current membrane technology (including current process design schemes) is about $23 per ton of CO. Additionally, running an amine-based absorption process at an average 600 MW coal-fired power plant consumes about 30% of the