In a previous homework, we determined that a tunnel (through-thickness) crack (Y=3.36) of length 16 mm growing from a 12 mm radius hole in a thick plate of 302 stainless steel (18Cr-8Ni) that has the properties listed below, could withstand a stress of 260 MPa perpendicular to the crack before instantaneous failure? What much lower nominal stress would cause the initiation of stress corrosion cracking in this same situation if the sample were exposed to a 42% MgCl2 solution?

Determine the time of the day and month of the year at which the peak sensible cooling load occurs for a top floor, north-eastern corner room of an office building in durban for the following conditions: floor area: 8 x 8 x 3 m east and north walls: 115 mm face brick (outside), 20 mm air space, 115 mm ordinary brick (inside) with 15 mm plaster roof construction: suspended plasterboard ceiling, 450 mm air space, 150 mm concrete, 75mm screed, waterproofing no heat transfer across other surfaces window area 3x 1,5 m high in north wall only. ordinary glass with venetian blinds. lights and occupants : from 07: 00 to 18: 00 average light density: 25 w/m2 number of occupants : 5 seated, light office work room temperature 24°c