Green coffee beans (rho=552 kg/m3, k = 0.184 W/m·K, c = 2.56 kJ/kg·K) are dried and roasted in a hot-air stream after harvesting. The hot air is typically at 250ºC, and the convection coefficient is 20 W/m2K. Beans are typically flat ellipsoids with average volume of 44 mm3 and average surface area of 66 mm2. For a flavorful and aromatic medium roast, the beans (initially at 22ºC) must be heated to 200ºC. Determine the required roasting time.

For the closed feedwater heater below, feedwater enters state 3 at a pressure of 2000 psia and temperature of 420 °f at a rate of ix10 ibhr. the feedwat extracted steam enters state 1 at a pressure of 1000 psia and enthalpy of 1500 btu/lbm. the extracted er leaves at an enthalpy of 528.7 btu/lbm steam leaves as a saturated liquid. (16) a) determine the mass flow rate of the extraction steam used to heat the feedwater (10) b) determine the terminal temperature difference of the closed feedwater heater

The drive force for diffusion is 7 fick's first law can be used to solve the non-steady state diffusion. a)-true b)-false

A-mn has a cubic structure with a0 0.8931 nm and a density of 7.47 g/cm3. b-mn has a different cubic structure, with a0 0.6326 nm and a density of 7.26 g/cm3. the atomic weight of manganese is 54.938 g/mol and the atomic radius is 0.112 nm. determine the percent volume change that would occur if a-mn transforms to b-mn.