addenda

efficiency with which work is done with respect to heat gains or losses.

exponent k in the equation pv^k = constant, representing an adiabatic change (k is the ratio of the specific heat at constant pressure to the specific heat at constant volume).

thermodynamic process during which no heat is extracted from or added to the system.

material that has the ability to cause molecules of gases, liquids, or solids to adhere to its surfaces without changing the adsor­bent physically or chemically. Certain commercially available solid mater­ials, such as silica gel, activated carbon, and activated alumina, have this property.

1. process in which fluid molecules are concen­trated on a surface by chemical or physi­cal forces, or both.

2. surface adherence of a material in extracting one or more substances present in an atmosphere or mixture of gases and liquids, unaccom­panied by physical or chemical change.

time varying loads acting on the blades of a fan due to nonconform­ities of the air flow. Note: Spatial non­uniformities of airflow which are steady in time give rise to harmonic excitation at frequencies which are integer multi­ples of the rotation rate of the fan. Time excita­tions of the airflow give rise to random excita­tion.