If the extruder can withstand a pressure of no more than 15MN/m2, what is the maximum shear stress the polymer can be submitted to at the metering section of the screw? The screw has a channel depth of 5mm and the polyamide being used has a melt viscosity of 42Ns/m2.

An iron specimen is plastically deformed in shear by 1%, and it has u dislocation density of 1 10 14 m/ m 3 Assume that the dislocation density did not change in the 1% strain of thisspecimen, the Burger's vector (b) is a 2 [1 1 1] the slip plane is (110). the shear stress isapplied to the (110) plane, and the lattice parameter of the BCC iron is 0.286 nm. Calculate the magnitude of the Burger's vector for these dislocations in iron. Calculate the average distance moved by the mobile dislocations as a result of the 1% shear strain.