A gear component (0.2% C) is carburized with C for increased hardness. By specification, a carbon concentration of 0.75% C is required at an 80 um depth. Calculate the time required (ir hours) at 1100°C with the gas surface concentration of 1.3 % C. D=5x10-13 m2/s. Show relevant steps how you arrived at the answer Comment on whether the suggested carburizing time of 3 hours is sufficient, also mention the calculated time in hours

During a steady flow process, the change of energy with respect to time is zero. a)- true b)- false

Ahot wire operates at a temperature of 200°c while the air temperature is 20°c. the hot wire element is a tungsten wire of 5 um diameter and 2 mm in length. plot using excel current, heat transfer and heat generated by the wire for air velocity varying from 1-10 m/s in steps of lm/s? matlab the sensor voltage output, resistance, or assume nu 0.989 re033pr13 take air properties at tr (200°c20°c)/2 = 110°c properties of tungsten: c 0.13 kj/kg.k 3 p 19250 kg/m k (thermal conductivity) = 174 w/m.k

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.