Fractional activity

LIQUTD-PHASE MOLE FRACTION ACTIVITY COEFFICIENTS... [Pg.259]

The symbol used is dependent upon the method of expressing the concentration of the solution. The recommendations of the IUPAC Commision on Symbols, Terminology and Units (1969) are as follows concentration in moles per litre (molarity), activity coefficient represented by y, concentration in mols per kilogram (molality), activity coefficient represented by y, concentration expressed as mole fraction, activity coefficient represented by f... [Pg.23]

Autocatalytic rate constant for initiation Fraction active polymer in CFSTR with dead polymer Fraction by-pass in by-pass CFSTR... [Pg.324]

An analogous situation occurs in the catalytic cracking of mixed feed gas oils, where certain components of the feed are more difficult to crack (less reactive or more refractory) than the others. The heterogeneity in reactivities (in the form of Equations 3 and 5) makes kinetic modelling difficult. However, Kemp and Wojclechowskl (11) describe a technique which lumps the rate constants and concentrations into overall quantities and then, because of the effects of heterogeneity, account for the changes of these quantities with time, or extent of reaction. First a fractional activity is defined as... [Pg.404]

The parameter Z in Equation 17 is equivalent to the fractional activity at an infinite polymerization time. B and v can also be Interpreted in a similar way through Equation 18, where a has the same meaning as Z. [Pg.406]

The heterogeneity of the VN primary neurones is reflected in their modes of chemosensory preferences. The relative binding efficiencies for distinct odourant types onto the membrane sites is indeed functionally partitioned. When urinary fractions from male mice were applied to VN cells of females, stimulation by a lipophilic and volatile odourant fraction activated only the Gi protein-expressing cells. In contrast, Go activation was elicited by one of the lipocalin superfamily the MUP fraction containing an a-2-globulin (Krieger, 1999). This observation... [Pg.142]

Figure 5.2 Concentration-response plot for an enzyme inhibitor displayed on linear (A) and logarithmic (B) concentration scales. The IC50 is identified from the midpoint (i.e., fractional activity = 0.5) of the semilog plot.

$Figure 5.2 Concentration-response plot for an enzyme inhibitor displayed on linear (A) and logarithmic (B) concentration scales. The IC50 is identified from the midpoint (i.e., fractional activity = 0.5) of the semilog plot.$

The IC50 can thus be accurately determined by fitting the concentration-response data to Equation (5.1) through nonlinear curve-fitting methods. Some investigators prefer to plot data in terms of % inhibition rather than fractional activity. Using the mass-balance relationships discussed above, we can easily recast Equation (5.1) as follows ... [Pg.114]

The concentration of monomer present at any concentration of inhibitor is given by SC, and the concentration of dimer is given, considering mass balance, by (1 - 8)C. When an enzyme is treated simultaneously with two inhibitors, / and J, that bind in a mutually exclusive fashion, the fractional activity is given by (Copeland, 2000)... [Pg.121]

Figure 6.5 Concentratioin esponse plot of inhibition by a slow binding inhibitor that conforms to scheme B of Figure 6.3. The progress curves of Figure 6.4A were fitted to Equation (6.1). The values of vs thus obtained were used together with die velocity of the uninhibited reaction (v0) to calculate the fractional activity (vs/v0) at each inhibitor concentration. The value of Kf9 is then obtained as the midpoint (i.e., die IC50) of die isotherm curve, by fitting die data as described by Equation (6.8).

$Figure 6.5 Concentratioin esponse plot of inhibition by a slow binding inhibitor that conforms to scheme B of Figure 6.3. The progress curves of Figure 6.4A were fitted to Equation (6.1). The values of vs thus obtained were used together with die velocity of the uninhibited reaction (v0) to calculate the fractional activity (vs/v0) at each inhibitor concentration. The value of Kf9 is then obtained as the midpoint (i.e., die IC50) of die isotherm curve, by fitting die data as described by Equation (6.8).$

Figure 8.12 Titration of enzyme with an irreversible inactivator. The fractional activity is plotted as a function of the ratio [/]/[ ]. The point at which the fractional activity becomes zero indicates the number of moles of inactivator required to inactivate one mole of enzyme. From this value the partition ratio r can be determined.

$Figure 8.12 Titration of enzyme with an irreversible inactivator. The fractional activity is plotted as a function of the ratio [/]/[ ]. The point at which the fractional activity becomes zero indicates the number of moles of inactivator required to inactivate one mole of enzyme. From this value the partition ratio r can be determined.$

Thus the fractional activity remaining in the presence of a particular concentration of inhibitor is given by... [Pg.261]

Scheme 1.7 Active-site counting method based on H-labelling, in the zirconocene-catalyzed polymerization of 1-hexene. Lower left typical NMR of the quenched polymer according to method A. The integrals allow the quantification of the Zr-alkyl active sites. All labels are found in the terminal position. Lower right comparison of fractional active-site counts using Method A (open circles, o) or Method B (diamonds ).

$Scheme 1.7 Active-site counting method based on H-labelling, in the zirconocene-catalyzed polymerization of 1-hexene. Lower left typical NMR of the quenched polymer according to method A. The integrals allow the quantification of the Zr-alkyl active sites. All labels are found in the terminal position. Lower right comparison of fractional active-site counts using Method A (open circles, o) or Method B (diamonds ).$

Xj>0y0pL), where the symbols have their usual meaning of mole fraction, activity coefficient, and liquid vapor pressure, respectively, all in octanol. The mole fraction can be replaced in this expression, since Xj 0 C0(MW0) 103p(), where C0 is the... [Pg.421]

Starting compound Fractional activity Starting compound Fractional activity... [Pg.450]

Parameter Nerve ending fraction Activity (or concentration) total specific Synaptosomal membrane fraction Activity (or concentration) total specific Enrichment ... [Pg.329]

ODHE-ht-cat ComposedOf support-a-A1203 InProportion fraction-support, active-components InProportion fraction-actives PreparedUsing seq-prep, fraction-support Fromlnterval 0.6,0.9 WithPrecision 0.01 fraction-actives Fromlnterval 0.1,0.4 WithPrecision 0.01 fraction-support + fraction-actives = 1... [Pg.163]

Activity normalized by Pt-area and Pt-weight-fraction Activity normalized by Pt-area 3.31... [Pg.294]

Dispersed cells were incubated with increasing concentrations of the indicated secretogogue. The cells were sedimented, PTH was determined in the supernatant, and protein kinase activity was determined with and without cAMP in sonicates of the cellular pellet. Protein kinase activities are expressed as activity ratios [(activity — cAMP)/[activity + cAMP)J which is equivalent to the fractional activation of the enzyme. (Reproduced with permission from Ref. 20. Copyright 1982, The Endocrine Society.)... [Pg.14]

Equation (7) gives the fraction activity remaining in the presence of an inhibitor relative to its absence (vj/vo) ... [Pg.39]

A more complete and mechanistically explicit model has been described that allows for competitive adsorption to reactive and nonreactive sites on Fe°, as well as partitioning to the headspace in closed experimental systems and branching among parallel and sequential transformation pathways [174,175]. This model represents the distinction between reactive and nonreactive sites by a parameter called the fractional active site concentration. Simulations and sensitivity analysis performed with this model have been explored extensively, but application of the model to experimental data has been limited to date. [Pg.395]

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