activity(redirected from purposeful activity)
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1. the number of disintegrations of a radioactive substance in a given unit of time, usually expressed in curies or disintegrations per second
a. the capacity of a substance to undergo chemical change
b. the effective concentration of a substance in a chemical system. The absolute activity of a substance B, λB, is defined as exp (μBRT) where μB is the chemical potential
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The use or modification of information contained in a file.
The intensity of a radioactive source. Also known as radioactivity.
A thermodynamic function that correlates changes in the chemical potential with changes in experimentally measurable quantities, such as concentrations or partial pressures, through relations formally equivalent to those for ideal systems.
The representation in a PERT or critical-path-method network of a task that takes up both time and resources and whose performance is necessary for the system to move from one event to the next.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
In CPM terminology, a task or item of work that must be performed in order to complete a project.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.