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1. An act that requires use of resources or time. In Program Evaluation and Review Technique (PERT), an activity is represented by an arrow on a PERT chart.

2. In investing, the amount of a security's relative trading volume; that is, the amount of money flowing into and out of a security in trading. A high amount of activity means that many shares of the security are being bought and sold at a high rate, while a low level of activity indicates the opposite.


The amount of relative trading volume in a security.
References in periodicals archive ?
Again, constants defining activity coefficients of each component are equivalent to those previously reported in literature, with error values below 1% [13].
In this case, fugacity and activity coefficients behave as shown in Figure 12 for a temperature of 25[degrees]C, and as shown in Figure 13 for a temperature of 40[degrees]C.
According to the obtained values it can be concluded that, in the case of PE-solvent mixtures, the more compatible solvents with this material are dispersion solvents (lower values of solvent activity coefficients and Flory Huggins parameters), followed by polar solvents, being the less compatible the association-type solvents.
Mass-based solvent activity coefficients and Flory Huggins parameters for PE--solvent mixtures.
Henry's constants and infinite dilution activity coefficients of propane, propene, butane, isobutene, 1-butene, isobutane, trans-2-butene and 1,3-butadiene in 1-propanol at T = (260 to 340) K.
Henry's law constants and infintite dilution activity coefficients of propane, propene, butane, 2-methylpropane, 1-butene, 2-methylpropene, trans-2-butene, cis-2-butene, 1,3-butadiene, dimethyl ether, chloroethane, and 1,1-difluoroethane in 2-propen-l-ol.
Hence, the VLE model itself is valid at low acid gas partial pressures even though the parameters of the activity coefficient model were not fitted in this range (Kundu, 2004).
2/kmol amine [gamma] activity coefficient [psi] objective function for regression Subscripts a, X anion c, M cation n,n' neutral solvent species cal calculated value ex experimental value s solvent i ionic or neutral solute w water solvent
Activity coefficient of hydrochloric acid from 0[degrees] to 90[degrees] C m 0[degrees] 10[degrees] 20[degrees] 25 [degrees] 30[degrees] 0.
The weight fraction activity coefficient (1) of the solute at infinite dilution can be calculated from following relation [28].
iota]] is calculated from the activity coefficients predicted by the polymer NRTL model.
Theoretical treatments of activity coefficients in nonideal solutions have been discussed for a century.