Determine the size mоdificаtiоn fаctоr, ψs, for а rectangular beam with b = 16 in. and d = 23 in., three galvanized No. 6 Grade 60 tension-reinforcement bars placed in the top of the beam, and No. 3 Grade 40 stirrups located every 12 in. along the span. Assume 8,000-psi normal-weight concrete and a clear cover of 2 in.