U—internal energy

Fig ure 6-1. Energy balanoe in ohemioal reaotors, where G = mass flow-rate u = internal energy per unit mass P = pressure p = fluid density m = mass of fluid in the system Q = rate at whioh heat is transferred to the system and = rate at whioh work is done on the surroundings. 

R thermal resistance x specific entropy S entropy t time T temperature u specific internal energy U internal energy v specific volume velocity V volume W shaft work x coordinate distance... 

IL-5 There exists a macroscopic state property U ( internal energy ) whose infinitesimal changes in processes involving only differential absorption of heat dq or performance of work dw on the system are given by dU = dq + dw. 

U, U, u Internal energy, internal energy per mole (or particle), internal energy density J, J mol-1, J m-3... 

Rs = relative saturation RFi = relative humidity T = temperature, °F tw = wet-bulb temperature, °F U = internal energy, Btu/lb... 

These computed values compare well with exptl PCJ s in the previous tabulation. Ref 29 also gives computed values for density, particle velocity (U), internal energy and temps at pressures greater than PCJ- The following interpolation is proposed ... 

U Internal energy (J), applied or measured electric potential (V)... 

Symbol Helmholtz free energy is denoted in chemistry by A (German Arbeit, work), in physics by F, free energy. Equation A U — TS, where U = internal energy, T = Temperature, S = entropy. 

U = internal energy, e.g. as a result of the attraction forces between molecules T = absolute temperature,... 

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