Cholesteatoma the balance organs in the inner ear. Doctors' initial inspections may only reveal an ear canal full of discharge. Until the doctor has cleaned the ear and inspected the entire tympanic membrane, cholesteatoma cannot be diagnosed. Once the debris is cleared, cholesteatoma can give rise to a number of appearances. If there is significant inflammation, the tympanic membrane may be partially obscured by an aural polyp. If there is less inflammation, the cholesteatoma may present the appearance of 'semolina' discharging from a defect in the tympanic membrane. The posterior and superior parts of the tympanic membrane are most commonly affected.
Membrane gas separation when the pores in the polymer membrane appear and disappear faster relative to the movement of the particles. In a typical membrane system the incoming feed stream is separated into two components: permeant and retentate. Permeant is the gas that travels across the membrane and the retentate is what is left of the feed. On both sides of the membrane, a gradient of chemical potential is maintained by a pressure difference which is the driving force for the gas molecules to pass through. The ease of transport of each species is quantified by the permeability, P. With the assumptions of