During de novo pyrimidine synthesis, the pyrimidine ring is assembled and then joined to phosphoribosyl pyrophosphate (PRPP), forming orotidine monophosphate. Orotidine monophosphate is next converted to uridylate, or UMP. UMP can then be converted to another pyrimidine ribonucleotide, CTP. Identify the source of each atom in the pyrimidine ring.

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.