Between 1930 and 2012what was the increase of the American farmer's ability to feed people without changing the amount of land used?

Steam at a pressure of 100 kpa and a quality of 50% initially fills a rigid vessel having a volume of 0.5 m^3. the steam is then heated, causing the pressure in the vessel to rise to 150 kpa. determine: i. the mass of the steam in the vessel. ii. the temperature and quality of the steam after the heating process. ii the mass of the vapour, mg and liquid, m in the vessel after the heating process. if the steam in the vessel is now further heated, what would the pressure and temperature in the vessel be when all steam has turned into saturated vapour? b. sketch the processes in part (a) and part (b) on p-v and t-v diagrams, indicating clearly the temperatures, pressures and the paths. c. (0.59kg, 111.4°c, 73%, 0.4307kg, 0.1 593kg, 2.11 bar, 121.84°c)