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2. A spherical protein with a MW of 15,000 Da in an aqueous solution (u = 1 CP, p = 1 g/cm) is being filtered at 20C through a microporous membrane within a 25 mm diameter stirred ultrafiltration cell. The membrane has nominal molecular weight cutoff (NMWCO) of 30,000 Da. The stirring speed is 1000 RPM. The filtration flux (i.e., q) through the membrane is equal to 1.5 x 103 cm/s. For a stirred ultrafiltration cell, the following equation can be used to calculate the Sherwood number: kmrcell Sh 0.23Re0.567 Sc0.33 = 0.23 D H where rcell is the radius of the stirred ultrafiltration cell, and w is the stirring speed (in radians per second). Determine (A) the mass transfer coefficient (km) and (B) the observed sieving coefficient (S.) for the membrane. (Ans: km = 1.056 x 10-3cm, s, = 0.152) 0.567 (porfelt 0.33 050) 2. A spherical protein with a MW of 15,000 Da in an aqueous solution (u = 1 CP, p = 1 g/cm) is being filtered at 20C through a microporous membrane within a 25 mm diameter stirred ultrafiltration cell. The membrane has nominal molecular weight cutoff (NMWCO) of 30,000 Da. The stirring speed is 1000 RPM. The filtration flux (i.e., q) through the membrane is equal to 1.5 x 103 cm/s. For a stirred ultrafiltration cell, the following equation can be used to calculate the Sherwood number: kmrcell Sh 0.23Re0.567 Sc0.33 = 0.23 D H where rcell is the radius of the stirred ultrafiltration cell, and w is the stirring speed (in radians per second). Determine (A) the mass transfer coefficient (km) and (B) the observed sieving coefficient (S.) for the membrane. (Ans: km = 1.056 x 10-3cm, s, = 0.152) 0.567 (porfelt 0.33 050)