Consider relation r(a, b, c, d, e) with the following functional dependencies. 1. a + b 2. e + a 3. ce → d 1. find the key(s) of r? show that the key(s) is/are minimal. 2. find a minimal basis or prove the current basis is minimal. 3. perform a bcnf decomposition of r to find a lossless-join dependency-preserving decompo- sition.

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

Slip occurs via two partial dislocations because of (a) the shorter path of the partial dislocation lines; (b) the lower energy state through partial dislocations; (c) the charge balance.

Asteam is contained in a rigid tank with a volume of 1 m3. initially, the pressure and temperature are 7 bar and 500 oc, respectively. the temperature drops due to cooling process. determine: (1) the temperature at which condensation begins in °c, (2) the fraction of the total mass that has condensed when the pressure decreased to 0.5 bar. (3) the volume in m3 occupied by saturated liquid at the final state?