Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Additional Parameters

In pure CA, each cell can adopt one of a small number of discrete states. However, it is possible to loosen this limitation on the number of states and permit the state of a cell to include the values of some continuous variables. If the simulation was of a reacting liquid, the state of a cell could contain details of the temperature of the liquid in the cell, its direction of motion, the concentration of all chemicals within it, and so on. The state of the cell may also be subject to universal rules that apply equally to every cell, e.g., gravity that pulls cells downward real time, which ages the contents of the cells, moving them toward a dying state or a level of illumination, which affects the chance that they will be photochemically excited, or to local rules, such as a local electric field. [Pg.195]

If not all cells are to be treated in the same way, this can be accomplished in a simple fashion by including an additional state for each cell that specifies what combination of rules will apply to the cell. [Pg.195]


When an explorationist constructs an expectation curve, the above approach for the volumetries of an accumulation is taken, but one important additional parameter must be taken into account the probability of there being hydrocarbons present at all. This probability is termed the Probability of Success" (POS), and is estimated by multiplying together the probability of there being ... [Pg.164]

HyperChem supplements the standard MM2 force field (see References on page 106) by providing additional parameters (force eon slants) using two alternative schemes (see the second part of th is book. Theory and Melhod.s). I h is exten ds th e ran ge of chem ical compounds that MM-t-can accommodate. MM-t-also providescut-offs for calcu latin g nonbonded in teraction s an d periodic bou n d-arv condition s. [Pg.102]

Note MM-i- is derived from the public domain code developed by Dr. Norm an Allinger, referred to as M.M2( 1977), and distributed by the Quantum Chemistry Program Exchange (QCPE). The code for MM-t is not derived from Dr. Allin ger s present version of code, which IS trademarked MM2 . Specifically. QCMPOlO was used as a starting point Ibr HyperChem MM-t code. The code was extensively modified and extended over several years to include molecular dynamics, switching functuins for cubic stretch terms, periodic boundary conditions, superimposed restraints, a default (additional) parameter scheme, and so on. [Pg.102]

K) were investigated. From an equation of state for iron the densities at these temperatures could be predicted to enable the simulations to be performed. A periodic system containing 64 atoms was used and the simulation run for 2 ps after equilibration. The calculated pressure agreed within 10% with the experimental values (330 GPa at the inner core boundary and 135GPa at the core-mantle boundary). Additional parameters could also be calculated, including the viscosity, the values for which were at the low end of previous suggestions. [Pg.638]

The catalytic effect on unimolecular reactions can be attributed exclusively to the local medium effect. For more complicated bimolecular or higher-order reactions, the rate of the reaction is affected by an additional parameter the local concentration of the reacting species in or at the micelle. Also for higher-order reactions the pseudophase model is usually adopted (Figure 5.2). However, in these systems the dependence of the rate on the concentration of surfactant does not allow direct estimation of all of the rate constants and partition coefficients involved. Generally independent assessment of at least one of the partition coefficients is required before the other relevant parameters can be accessed. [Pg.129]

Chem comes with default parameter sets, Amber2 and Amber3 in the case of the AMBER method. It is possible, however, to define an arbitrary number of additional parameter sets for the AMBER method (or for any of the other three force field methods). These user-defined parameter sets can be specified in the Parameters dialog box and integrated into HyperChem, in the same way as the default sets. [Pg.197]

As a device for describing the effect of temperature on solution nonideality, it is entirely suitable to think of Eq. (8.115) as offering an alternate notation which accomplishes the desired effect with p and as adjustable parameters. We note, however, that the left-hand side of Eq. (8.115) contains only one such parameter, x, while the right-hand side contains two p and . Does this additional parameter have any physical significance ... [Pg.566]

The constant s depends on impeller configuration and C is solids concentration. Several other researchers have since developed similar correlations which include effects of a few additional parameters such as D/T, C/D, and H/T. The corresponding exponents of these parameters vary in range —1 to —1.7 for D/T, 0.15 to 0.2 for CjD, and -- 0.33 for DJT. [Pg.429]

Two additional parameters, the mean cellular hemoglobin concentration (MCHC) and the mean cellular hemoglobin (MCH), can be obtained. [Pg.400]

The formulation of a carrier depends on four considerations (/) the carrier-active chemical compound (2) the emulsifier (J) special additives and (4) environmental concerns. Additional parameters to be considered in the formulation of a carrier product with satisfactory and repeatable performance arise from the equipment in which the dyeing operation is to be carried out. The choice of equipment is usually dictated by the form in which the fiber substrate is to be processed, eg, loose fiber, staple, continuous or texturized filament, woven or knot fabric, yam on packages or in skeins (see Textiles). [Pg.266]

This gives two choices ia interpreting calculated NRR values, ie, a direct comparison of NRR values for different options or a comparison of the NRR value of each option with a previously defined NRR cutoff level for acceptabiUty. The NPV, DTC, and NRR can be iaterpreted as discounted measures of the return, iavestment, and return rate, analogous to the parameters of the earher example. These three parameters characterize a venture over its entire life. Additional parameters can be developed to characterize the cash flow pattern duting the early venture years. Eor example, the net payout time (NPT) is the number of operating years for the cumulative discounted cash flow to sum to zero. This characterizes the early cash flow pattern it can be viewed as a discounted measure of the expected operating time that the investment is at risk. [Pg.447]

Note that only Er, which is actually the sum of the reorganization energies for all degrees of freedom, enters into the high-temperature rate constant formula (2.62). At low temperature, however, in order to preserve E, one has to fit an additional parameter co, which has no direct physical sense for a real multiphonon problem. [Pg.31]

The additional parameter r is adjusted from reaction to reaction it reflects the extent of the additional resonance contribution. A large r corresponds to a reaction with a large resonance component, whereas when r goes to zero, the equation is identical to the original Hammett equation. When there is direct conjugation with an electron-rich reaction center, an equation analogous to Eq. (4.17) can be employed, but a is used instead of [Pg.210]

Influence parameters are especially the press temperature and the moisture content in the mat. Additional parameters are the wood density, the porosity, the swelling and shrinking behavior of the wood, the structure at the surface and the wetting behavior. During the press cycle several mechanisms are in operation ... [Pg.1090]

Permeability and porosity are related to each other if the porosity is zero the permeability is zero. Although a correlation between these two parameters may exist, permeability cannot be predicted from porosity alone, since additional parameters that contain more information about the pore structure are needed. These additional parameters are tortuosity and cormectivity. [Pg.68]

A water body is considered to be a one-diiuensional estuary when it is subjected to tidal reversals (i.e., reversals in direction of tlie water quality parameter are dominant). Since the describing (differential) equations for the distribution of eitlier reactive or conserv ative (nomciictive) pollutants are linear, second-order equations, tlie principle of superposition discussed previously also applies to estuaries. The principal additional parameter introduced in the describing equation is a tid il dispersion coefficient E. Methods for estimating this tidiil coefficient are provided by Thomaim and Mueller... [Pg.361]

For each bond type, i.e. a bond between two atom types A and B, there are at least two parameters to be determined, and /fg . The higher-order expansions and the Morse potential have one additional parameter (a or D) to be determined. [Pg.11]

The last example brings out very clearly that knowledge of only the mean and variance of a distribution is often not sufficient to tell us much about the shape of the probability density function. In order to partially alleviate this difficulty, one sometimes tries to specify additional parameters or attributes of the distribution. One of the most important of these is the notion of the modality of the distribution, which is defined to be the number of distinct maxima of the probability density function. The usefulness of this concept is brought out by the observation that a unimodal distribution (such as the gaussian) will tend to have its area concentrated about the location of the maximum, thus guaranteeing that the mean and variance will be fairly reasdnable measures of the center and spread of the distribution. Conversely, if it is known that a distribution is multimodal (has more than one... [Pg.123]

Although the above treatment is based on the assumption of perfect mixing, it was found experimentally that deviations from this ideal situation can be taken into account by introducing the additional parameters of Wolf and Resnick (W5) into the kernel (253). [Pg.386]

Additional parameters should be taken into account for polyester networks and hyperbranched polyesters, for example, crosslink density and degree of branching. [Pg.33]

The energy of the bond for this function too is essentially resonance energy. Dickinson2 introduced an additional term, dependent on two additional parameters, in order to take polarization into account. He wrote for the (not yet normalized) variation function... [Pg.213]

The intensity curves I, II, III, and IV of Fig. 4 are calculated for coplanar trans models with C-H = 1.06 A., the angle H - C=C = 115°, and the angle H—C—H = 109.5°. Although these hydrogen parameters are so chosen as to agree as well as possible with minor peaks of the radial distribution function, no great reliance can be placed on them, and indeed it is likely that for this molecule the C-H bond distance is 1.09 A. The models have the following additional parameters... [Pg.661]

Additional parameters must be considered for a reaction medium used for industrial purposes, such as price, explosiveness, inflammability, viscosity, toxicity, corrosiveness and recyclability. [Pg.251]

Many current multidimensional methods are based on instruments that combine measurements of several luminescence variables and present a multiparameter data set. The challenge of analyzing such complex data has stimulated the application of special mathematical methods (80-85) that are made practical only with the aid of computers. It is to be expected that future analytical strategies will rely heavily on computerized pattern recognition methods (79, 86) applied to libraries of standardized multidimensional spectra, a development that will require that published luminescence spectra be routinely corrected for instrumental artifacts. Warner et al, (84) have discussed the multiparameter nature of luminescence measurements in detail and list fourteen different parameters that can be combined in various combinations for simultaneous measurement, thereby maximizing luminescence selectivity with multidimensional measurements. Table II is adapted from their paper with the inclusion of a few additional parameters. [Pg.12]


See other pages where Additional Parameters is mentioned: [Pg.622]    [Pg.848]    [Pg.1570]    [Pg.197]    [Pg.130]    [Pg.406]    [Pg.12]    [Pg.773]    [Pg.2002]    [Pg.2083]    [Pg.378]    [Pg.5]    [Pg.190]    [Pg.1347]    [Pg.31]    [Pg.32]    [Pg.71]    [Pg.181]    [Pg.419]    [Pg.515]    [Pg.128]    [Pg.110]    [Pg.120]    [Pg.122]    [Pg.97]   


SEARCH



1,4-addition activation parameters

Activation parameters addition reactions

Additional parameters, significance

Additional refinement parameters

Additive electrochemical ligand parameter

Additive models, intermolecular interactions interaction potential parameters

Additives characteristic parameters

Additivity of parameters

Conjugate addition activation parameters

Effect of Additives and Operating Parameters

Hammett equation additional parameters

Hammett parameters, oxidative addition

Partition additive constitutive parameter

© 2024 chempedia.info