A plate of 1020 steel (0.2 wt%C) is placed in a carburizing furnace at 900 \[Degree]C. The atmosphere forms a surface layer that is approximately 1.2 wt%C. The diffusion coefficient for C in 1020 steel follows the Arrhenius relationship, D=Subscript[D, 0]exp(-Q/(R T))where the activation energy, Q=80 kJ/mol, and the diffusion coefficient, Subscript[D, 0]=6.2 10^-7 m^2/sec. (a) Plot the concentration profile from the surface of the plate to a depth of 5 mm at times of 30 minutes, 2 hours, and 5 hours. These three curves should be plotted together on the same plot. (b) How long does it take for the carbon content to reach 0.8 wt% at a depth of 1 mm?

unlike the threaded fasteners which are used to clamp the machine members, power screws are used to transmit power. common applications of power screws are: screw jacks: to lift weight. lead screw of lathe: for axial movement of tool and its precise positioning.

answer:

explanation:

assault rifle is a rapid-fire, magazine-fed rifle designed for military use. it is a shoulder-fired weapon that allows the shooter to select between semi-automatic (requiring you pull the trigger for each shot), fully automatic (hold the trigger and the gun continuously fires) or three-shot-burst modes.

answer:

clock

explanation:

always running (on) sing each hour (chime) and the clock face (front)