Oranges with a diameter of about 3 inches are to be cooled from room temperature of 25°C to a surface temperature of 3°C using an air-convection environment with h = 45 W/m2-K and T[infinity] = -5°C. Assuming that the oranges have the properties of water at 10°C, calculate the time required for the cooling. What is the center temperature at that instant?

Describe one experiment in which the glass transition temperature and melting temperature of a totally amorphous thermoplastic material can be determined. show the relevant experimental results in a diagram which should be properly annotated with the two temperatures clearly marked. what is likely to happen to the curve in the diagram if the amorphous polymer is replaced by a thermosetting type?