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INDEX first order

Multichannel time-resolved spectral data are best analysed in a global fashion using nonlinear least squares algoritlims, e.g., a simplex search, to fit multiple first order processes to all wavelengtli data simultaneously. The goal in tliis case is to find tire time-dependent spectral contributions of all reactant, intennediate and final product species present. In matrix fonn tliis is A(X, t) = BC, where A is tire data matrix, rows indexed by wavelengtli and columns by time, B contains spectra as columns and C contains time-dependent concentrations of all species arranged in rows. [Pg.2967]

Linmations are over the atoms in the molecule. This particular index does not encode information about the structure. The first-order chi index involves a summation over... [Pg.688]

Strkcttire inflkence. The specificity of interphase transfer in the micellar-extraction systems is the independent and cooperative influence of the substrate molecular structure - the first-order molecular connectivity indexes) and hydrophobicity (log P - the distribution coefficient value in the water-octanole system) on its distribution between the water and the surfactant-rich phases. The possibility of substrates distribution and their D-values prediction in the cloud point extraction systems using regressions, which consider the log P and values was shown. Here the specificity of the micellar extraction is determined by the appearance of the host-guest phenomenon at molecular level and the high level of stmctural organization of the micellar phase itself. [Pg.268]

On the basis of data obtained the possibility of substrates distribution and their D-values prediction using the regressions which consider the hydrophobicity and stmcture of amines was investigated. The hydrophobicity of amines was estimated by the distribution coefficient value in the water-octanole system (Ig P). The molecular structure of aromatic amines was characterized by the first-order molecular connectivity indexes ( x)- H was shown the independent and cooperative influence of the Ig P and parameters of amines on their distribution. Evidently, this fact demonstrates the host-guest phenomenon which is inherent to the organized media. The obtained in the research data were used for optimization of the conditions of micellar-extraction preconcentrating of metal ions with amines into the NS-rich phase with the following determination by atomic-absorption method. [Pg.276]

The macroscopic optical analysis of these effects requires the introduction of two complex indexes of refraction for the ferromagnetic material, one for lefr-circu-larly polarized light and another for right-circularly polarized light, which to first order, are given by... [Pg.726]

The first-order energy involves only the perturbation operator and the unperturbed wavefunction. In an HF-LCAO treatment, the integrals would be over the LCAOs, and this implies a four-index transformation to integrals over the basis functions. [Pg.199]

The index 0 indicates that the derivatives are taken for zero perturbation strengths. The equations for the first-order amplitudes and multipliers are obtained as ... [Pg.117]

The x -test discussed in the preceding needs a graphical counterpart for a fast, visual check of data. A useful method exists for normally distributed data that could also be adapted to other distributions. The idea is to first order the observations and then to assign each one an index value /n, 2/n,... [Pg.80]

In Section II, we presented the computational model involved in branching from a node, cr, to a node aa,. In this model, it was necessary to interpret the alphabet symbol a, and ascribe it to a set of properties. In the same way, we have to interpret o- as a state of the flowshop, and for convenience, we assigned a set of state variables to tr that facilitated the calculation of the lower-bound value and any existing dominance or equivalence conditions. Thus, we must be able to manipulate the variable values associated with state and alphabet symbols. To do this, we can use the distinguishing feature of first-order predicates, i.e., the ability to parameterize over their arguments. We can use two place predicates, or binary predicates, where the first place introduces a variable to hold the value of the property and the second holds the element of the language, or the string of which we require the value. Thus, if we want to extract the lower bound of a state o-, we can use the predicate Lower-bound Ig [cr]) to bind Ig to the value of the lower bound of cr. This idea extends easily to properties, which are indexed by more than just the state itself, for example, unit-completion-times, v, which are functions of both the state and a unit... [Pg.304]

The spatially periodic temperature distribution produces the corresponding relxactive index distribution, which acts as an optical phase grating for the low-power probing laser beam of the nonabsorbed wavelength in the sample. The thermal diffusivity is determined by detecting the temporal decay of the first-order diffracted probing beam [°o exp(-2t/x)] expressed by... [Pg.189]

The first-order equations (9.22) and (9.24) apply here provided the additional index a and the correct unperturbed eigenfunctions are used... [Pg.250]

The columns are indexed by the three states of bond i, the rows are indexed by the three states of bond i—1, and the order of indexing is t, g+, g. The statistical weight denoted by cr, which is approximately exp (-250/T), is the first-order weight of a gauche state relative to a trans state. The second-order interaction, which arises from the pentane effect where a bond pair is g gT, is weighted by to, which is approximately exp (-1000/T). [Pg.90]

E I is a kinetic chimera Kj and kt are the constants characterizing the inactivation process kt is the first-order rate constant for inactivation at infinite inhibitor concentration and K, is the counterpart of the Michaelis constant. The k,/K, ratio is an index of the inhibitory potency. The parameters K, and k, are determined by analyzing the data obtained by using the incubation method or the progress curve method. In the incubation method, the pseudo-first-order constants /cobs are determined from the slopes of the semilogarithmic plots of remaining enzyme activity... [Pg.361]

FI = continued product where any term is defined as equal to 1 when the index takes a forbidden value, i.e., i = 1 in the numerator or m = j in the denominator X = summation where any term is defined as equal to zero when the index j takes a forbidden value, i.e., j = 1 ky, kji = first-order intercompartmental transfer rate constants Eh Em = sum of exit rate constants from compartments i or m n = number of driving force compartments in the disposition model, i.e., compartments having exit rate constants... [Pg.78]

The formation of the major UV degradation peak at about 287 nm in the weathered PC appears to correlate well with the formation of the yellow color in the weathered sample. In Figure 8 the formation of both the peak at 287 nm and the yellow color have been assumed to be products of a first order reaction. This figure shows a plot of the log of the percentage of a scaling constant minus the yellowness index divided by the constant, versus a measurement of the exposure. In this case, the exposure is expressed as cal/cm2, obtained from ENC0N data. [Pg.101]

A simple phenomenological method can be used to describe changing crystallinity from WAXS data of isotropic materials. It is based on the computation of areas in Fig. 8.2. First we search the border between first-order and second-order amorphous halo. For PET this is at 29 37° (vertical line in the plot). Then we integrate the area between the amorphous halo and the machine background. Let us call the area Iam. Finally we integrate the area between the crystalline reflections and the amorphous halo, call it Icr, and compute a crystallinity index... [Pg.118]

The factor f reduces the oscillation amplitude symmetrically about R - R0, facilitating straightforward calculation of polymer refractive index from quantities measured directly from the waveform (3,). When r12 is not small, as in the plasma etching of thin polymer films, the first order power series approximation is inadequate. For example, for a plasma/poly(methyl-methacrylate)/silicon system, r12 = -0.196 and r23 = -0.442. The waveform for a uniformly etching film is no longer purely sinusoidal in time but contains other harmonic components. In addition, amplitude reduction through the f factor does not preserve the vertical median R0 making the film refractive index calculation non-trivial. [Pg.237]

Equation [1] is an internally contracted configuration space, doubly excited with respect to the CAS reference function 0) = G4SSCF) one or two of the four indices p,q,r,s must be outside the active space. The functions of Eq. [1] are linear combinations of CFs and span the entire configuration space that interacts with the reference function. Labeling the compound index pqrs as (i or v, we can write the first-order equation as... [Pg.255]

The concept of the molecular connectivity index (originally called branching index) was introduced by Randic [266]. The information used in the calculation of molecular connectivity indices is the number and type of atoms and bonds as well as the numbers of total and valence electrons [176,178,181,267,268]. These data are readily available for all compounds, synthetic or hypothetical, from their structural formulas. All molecular connectivity indices are calculated only for the non-hydrogen part of the molecule [269-271]. Each non-hydrogen atom is described by its atomic 6 value, which is equal to the number of adjacent nonhydrogen atoms. For example, the first-order Oy) molecular connectivity index is calculated from the atomic S values using Eq. (38) ... [Pg.261]

The first-order molecular connectivity index has been used very extensively in various QSPR and QSAR studies [269, 272, 273]. Thus, the question of its physical meaning has been raised many times. It has been found, in several studies [103, 178-180, 266, 274, 275], that this particular index correlates extremely well with the molecular surface area. It seems this index is a simple and very accurate measure of molecular surface for various classes of compounds and consequently correlates nicely with the majority of molecular surface dependent properties and processes. [Pg.261]

Its counterpart, the first-order ( y") valence molecular connectivity index, is also calculated from the non-hydrogen part of the molecule and was suggested by several authors [103,276,277]. In the valence approximation, non-hydrogen atoms are described by their atomic valence <5 "values, which are calculated from their electron configuration by the following equation ... [Pg.261]

For molecular connectivity indices with orders higher than 2, it is also necessary to specify the subclass of index. There are four subclasses of higher order indices path, cluster, path/cluster, and chain. These subclasses are defined by the type of structural subunits they are describing, a subunit over which the summation is to be taken when the respective indices are calculated. Naturally, the valence counterparts of all four subclasses of higher order indices can be easily defined by analogy, described above for the first-order valence molecular connectivity index. [Pg.262]

The planar form of phosphole is a first-order saddle point on the potential energy surface, 16—24 kcal/ mol above the minimum (at different levels of the theory). ° (The calculated barriers are the highest at the HF level, which underestimates aromatic stabilization of the planar saddle point, while the MP2 results are at the low end.) It has been demonstrated by calculation of the NMR properties, structural parameters, ° and geometric aromaticity indices as the Bird index ° and the BDSHRT, ° as well as the stabilization energies (with planarized phosphorus in the reference structures) ° and NIGS values ° that the planar form of phosphole has an even larger aromaticity than pyrrole or thiophene. [Pg.9]


See other pages where INDEX first order is mentioned: [Pg.659]    [Pg.1657]    [Pg.689]    [Pg.689]    [Pg.423]    [Pg.256]    [Pg.463]    [Pg.426]    [Pg.488]    [Pg.235]    [Pg.306]    [Pg.615]    [Pg.215]    [Pg.39]    [Pg.327]    [Pg.34]    [Pg.41]    [Pg.262]    [Pg.754]    [Pg.139]    [Pg.394]    [Pg.39]    [Pg.59]    [Pg.236]    [Pg.62]   
See also in sourсe #XX -- [ Pg.220 ]




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