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 technology utilized for gas separations (removal of CO from natural gas, separating N from air, organic vapor removal from air or a nitrogen stream) and sometimes in membrane distillation. The later process helps in the separation of azeotropic compositions reducing the costs of distillation processes. The pore sizes of technical membranes are specified differently depending on the manufacturer. One common distinction is by "nominal pore size". It describes the maximum pore size distribution and gives only vague information about the retention capacity of a membrane. The exclusion limit or "cut-off" of the membrane is usually specified in the form of "NMWC"