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Parameters dummy

The following example shows how this can be modeled in PHREEQC. First of all, a master- ami a solution species tritium T or T1 have to be defined. Since the input of data for log k und -gamma within the key word SOLUTION SPECIES is required, but unknown, any value can be entered here as a free parameter ( dummy , e g. 0.0). This value is not used for kinetic calculations and thus, does not cause any problems. However, all results based on equilibrium calculations (e.g. the calculation of the saturation index) are nonsense for this species . The tritium values have to be entered in tritium units. However, in order not to have to define or convert them in an extra step, they are entered fictitiously with the unit umol/kgw instead of TU in PHREEQC. As no interactions of tritium with any other species are defined, the unit is eventually irrelevant. After modeling, remember that the result is displayed in mol/kgw as always in PHREEQC and has to be recalculated to the fictitious tritium unit umol/kgw. Entering mol/kgw in the input file, the solution algorithm quits due to problems with too high total ionic strengths. [Pg.133]

Intrinsic parameters. Dummy data with Madymo, the model was almost ready to be used. A database for the dummy we employed for the sled test, namely the Part 572 dummy, was provided with the code. It contains all the validated dynamic properties of the dummy. We found useful to modify the ellipsoids and the location of the accelerometers proposed in the previous database. [Pg.270]

Subscript i identifies species, and J is a dummy index all summations are over all species. Note that Xp however, when i = J, then Xu = = 1. In these equations / (a relative molecular volume) and (a relative molecular surface area) are pure-species parameters. The influence of temperature on g enters through the interaction parameters Xp of Eq. (4-261), which are temperature dependent ... [Pg.533]

Again subscript i identifies species, and J and I are dummy indicies. Values for the parameters r, qi, and (up — tip) are given by Gmehhng, Onken, and Ant (Vapor-Liquid Equilibrium Data Collection, Chemistry Data Series, vol. I, parts 1-8, DECHEMA, FrankfurUMain, 1974-1990). [Pg.533]

A number of parameters have to be chosen when recording 2D NMR spectra (a) the pulse sequence to be used, which depends on the experiment required to be conducted, (b) the pulse lengths and the delays in the pulse sequence, (c) the spectral widths SW, and SW2 to be used for Fj and Fi, (d) the number of data points or time increments that define t, and t-i, (e) the number of transients for each value of t, (f) the relaxation delay between each set of pulses that allows an equilibrium state to be reached, and (g) the number of preparatory dummy transients (DS) per FID required for the establishment of the steady state for each FID. Table 3.1 summarizes some important acquisition parameters for 2D NMR experiments. [Pg.156]

The applicability of Eq. (45) to a broad range of biological (i.e., toxic, geno-toxic) structure-activity relationships has been demonstrated convincingly by Hansch and associates and many others in the years since 1964 [60-62, 80, 120-122, 160, 161, 195, 204-208, 281-285, 289, 296-298]. The success of this model led to its generalization to include additional parameters in attempts to minimize residual variance in such correlations, a wide variety of physicochemical parameters and properties, structural and topological features, molecular orbital indices, and for constant but for theoretically unaccountable features, indicator or dummy variables (1 or 0) have been employed. A widespread use of Eq. (45) has provided an important stimulus for the review and extension of established scales of substituent effects, and even for the development of new ones. It should be cautioned here, however, that the general validity or indeed the need for these latter scales has not been established. [Pg.266]

The incorporation and relaxation of dummy elements for the simultaneous solution of parameter optimization problems can be embedded easily within the subproblems solved by the SQP algorithm. Again, both the model and optimization problem need only be solved once. [Pg.226]

The ideal point model is useful when a point in the space can be found that is most like the physicochemical parameter. Thus, the ideal point is the hypothetical stimulus, if it existed, that would contain the maximum amount of the physicochemical attribute. The attribute reaches its maximum at the ideal point and falls off in all directions as the square of the distance from the ideal point. The ideal point is located in an MDS space by a special kind of regression proposed by Carroll ( ) that correlates the physicochemical attribute values with the stimulus coordinates and a dummy variable constructed from the sums of squares of the coordinates for each point ... [Pg.42]

Results from these experimental runs were used as x, q data records to fit the parameters of six ANNs. In the experimental effort, a different feedforward ANN was used after each intermediate secondary measurement was obtained in the simulation-based effort, only one ANN accommodates all secondary measurements, and averaged dummy inputs are used for those secondary measurements not yet obtained. In addition in the experimental effort, a different ANN was used for final thickness and final void content predictions in the simulation-based effort, one ANN was used to predict both final thickness and final void content. The advantage of using one ANN to predict all values of q is that the parameters of only one ANN need be fitted. Fitting the parameters of an ANN for each variable in q is much more time-consuming. The disadvantage, however, is that the parameters A and abias are the same for each variable in q when just one ANN is used as an on-line model. When a different ANN is used for each variable in q, the parameters in A and abias are unique for each of those output variables, which results in increased on-line prediction accuracy. Similar speed-versus-accuracy arguments apply to the choice of one ANN for all secondary measurements versus an ANN for each secondary measurement. [Pg.287]

As four parameters were studied, three dummy variables X5, X6 and X7 were included to build a Hadamard matrix H(8) composed of seven parameters ... [Pg.48]

The regression results for the various models are listed below, (d is the dummy variable equal to 1 for the last seven years of the data set. Standard errors for parameter estimates are given in parentheses.)... [Pg.24]

Food is a binary dummy variable indicating whether the dose was taken wifeO ibf with food (=1), and0Food is the estimable parameter associated with a food effect. [Pg.98]

The principle aim of the reported studies was to model structures, conformational equilibria, and fluxionality. Parameters for the model involving interactionless dummy atoms were fitted to infrared spectra and allowed for the structures of metallocenes (M = Fe(H), Ru(II), Os(II), V(U), Cr(II), Cofll), Co(ni), Fe(III), Ni(II)) and analogues with substituted cyclopentadienyl rings (Fig. 13.3) to be accurately reproduced 981. The preferred conformation and the calculated barrier for cyclopentadienyl ring rotation in ferrocene were also found to agree well with the experimentally determined data (Table 13.1). This is not surprising since the relevant experimental data were used in the parameterization procedure. However, the parameters were shown to be self-consistent and transferable (except for the torsional parameters which are dependent on the metal center). An important conclusion was that the preference for an eclipsed conformation of metallocenes is the result of electronic effects. Van der Waals and electrostatic terms were similar for the eclipsed and staggered conformation and the van der Waals interactions were attractive 981. It is important to note, however, that these conclusions are to some extent dependent on the parameterization scheme, and particularly on the parameters used for the nonbonded interactions. [Pg.134]

Thus, at high I, the pair population is a considerably smaller fraction of the total OH population than the initial fraction given by a Boltzmann distribution at the flame temperature. For example, for the nominal values of 14 and 0.4 A for Oq and Oy, the infinite-intensity fraction is < 1% of the total while the zero-intensity value is 4%. This result is generally valid for the entire range of parameters inserted into the model, which represent physically realistic energy transfer rates. However, the precise numerical values depend sensitively on the actual parameters inserted. These facts form the central conclusions of this study (4). A steady state model with no dummy level and a different set of rate constants and level structure (5) shows some similar features. [Pg.144]

Dummy level population. With no laser, the population of the dummy level is set at 11% of the total, the thermal equilibrium fraction in v=l at 2000°K. Because vibrational energy transfer rates are generally slow, the laser excitation causes a sizeable fraction of the total to be pumped into the dummy level. Fig. 3 shows the dummy level population for three laser intensities as a function of assumed a. (In the imensionless notation used in the computer, 1=1 corresponds to 10 erg sec- cm Hz-, or that of the unfocussed output of the fundamental from an efficient dye pumped by a powerful doubled Nd YAG laser). At the nominal 0.4 A, nearly 40% of the population is driven into the dummy level at high I. Clearly the value of C, a poorly known parameter, is important for a quantitative description of fluorescence saturation. [Pg.144]

The differences in the two subseries are accounted for with the aid of the dummy parameter D-j which was made zero in the 2,6-dichlorobenzoyl subseries (R-, = Cl) and unity in the 2,6-dif luorobenzoyl subseries (R = F). In this analysis also a number of compounds were included in which the aniline nitrogen was substituted with a methylgroup here the dummy parameter was used, with D = 0 if R2 = H, and D2 = 1 if R2 = CH The resulting regression equations were ... [Pg.241]

It can be concluded that these equations are very similar to the equations discussed earlier for the 2,6-dichlorobenzoyl subseries as far as the electronic, hydrophobic, and steric influences are concerned. The coefficients of the dummy parameters lead to the conclusion that the 2,6-difluorobenzoyl subseries is about 25 times more active on Pieris brassicae than the 2,6-dichlorobenzoyl series, whereas methyl substitution at the aniline nitrogen systematically decreases the activity by a factor of about five (2. ). [Pg.241]


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