It is desired to determine the membrane area needed to separate an air stream (Oxygen & Nitrogen). using a membrane 2.54 x 10-3 cm thick with an oxygen permeability of P'A= 500 x 10-10 cm3(STP)·cm/(s·cm2 ·cm Hg). The ideal separation factor is assumed to be 10. The feed rate is Mf = 1 x 106 cm3(STP)/s and the fraction cut is 0.20. The pressure selected for use are ph = 190 cm Hg and pl = 19 cm Hg. The feed composition of A is 0.209. *Again, assuming the complete-mixing model, calculate the permeate composition, the reject composition, and the area.

49. A composite material is 57% resin (density of 2.3 g/cm³) and 43% unidirectionally placed carbon fibers (1.05 g/cm³)v by volume. The material has a composite modulus of elasticity of 400 GPa parallel to the carbon fibers. What is most nearly the density of the composite material? (A) 1.3 g/cm³ B 1.8 g/cm³ (C) 1.9 g/cm³ (D) 2.2 g/cm³

A piece of hollow fiber membrane shows a flux value of 5.70 cm³/cm².s based on the outside area of the membrane when tested in an air separation. The hollow fiber membrane has an inside diameter of 250 µm and a length of 4 m. If the flux value of the hollow fiber membrane is 7.98 cm³/cm?.s based on the inside area of the membrane, calculate the outer diameter and outer surface area of hollow fiber membrane in the unit µm and m², respectively.

Calculate the radial velocity of a 60-μm-diameter soluble coffee particle in air at 250 °C entering a 0.5-m-diameter cyclone. The tangential velocity of the particle is 200 cm/s and the specific gravity of the solid is 1.05.

2. In 3D printing, small liquid droplets are formed when a liquid jet breaks up in spray and fuel injection processes. The resulting droplet diameter d is thought to depend on liquid density p, viscosity µ, and surface tension o, as well as jet speed V and its diameter D. How to use dimensional analysis to characterize this process (using p, V and D as the repeating parameters)?

For a diffusion couple with D=1×10^−14 m^2/s,  calculate the composition of metal A (at %A) at a position of x=−10μm after 1 hour of interdiffusion.

(3) A wet cake of solids has a thickness of 0.8 cm is dried by blowing air with a moisture content of 5 wt% across the top surface. The moisture content of the wet cake is measured as 50 wt% and the aim is to reduce the water content to 12 wt%. The diffusion coefficient of water in the cake has been estimated as 7x10° cm? s. You have been asked about how much time the process would require. Check to see if your long drying assumption is correct.

A 4.00 x 104 M solution of aniline in H₂0 has absorbance A = 0.504 at 280 nm, when measured in a 1.00 cm cell. Find the transmittance of a 1.50 x 10-³ M solution of aniline in water when measured at the same wavelength but in a 0.500 cm cell.

Consider doping of silicon with gallium.Assume that the diffusion coefficient of gallium in Si at 1100℃ is 7*10-13 cm2/s.calculate the concentration of Ga at depth of 2.0 micrometer if the surface concentration of Ga is 1023 atom s/cm3.The diffusion times are 1,2 and 3 hours.

17.29 An engineered tissue system consists of a slice of cell mass immobilized on a scaffold measuring 5 cm in length and 0.5 cm in thickness. The top face of the tissue scaffold is exposed to water, dissolved oxygen, and organic nutrients maintained at 30 C. The bottom face of the tissue is thermally insulated. At present, the specific oxygen consumption of the tissue mass is 0.5 mmol O₂/cm³cells-hr, and from respiration energetics, the energy released by respiration is 468 J/mmol O₂ consumed. We are interested in knowing the temperature at the bottom face of the tissue next to the insulated boundary. If this temperature remains below 37 C, the tissue will not die. The thermal conductivity of the tissue scaffold is k = 0.6 W/m. K. a. Using the information given predict the temperature profile within the tissue slab the slab. b. C. What is the heat generated per unit volume of tissue? Estimate the temperature at x =L (the insulated boundary).