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Formula generation

A mathematical device, the NSS, which can be related to Artificial Intelligence techniques, has been defined and applied in order to solve or reformulate some quantum chemical problems. This symbol is related to computer formulae generation. It has been shown that by means of the use of NSS s many applications of such symbols can be found in mathematics as well as in Mathematical Chemistry in particular. [Pg.246]

In this way, all the coefficients Ar of the Frobenius series can be determined step by step. The recursion formula generates two independent series for odd and even values of r. For... [Pg.40]

For example, to determine the empirical formula of di-n-octylphthalate, the daughter spectrum of the containing molecular ion (392) was obtained (Figure 7). The relative peak areas of adjacent peak pairs at m/z 149 and 150 is 2 1. This indicates that the M+1 ion is twice as likely to lose a atom as retain it. Thus the ratio of the number of carbon atoms lost to those retained is 2 1. Since the identified phthalate substructure contains 8 carbons, the unknown compound (di-n-octylphthalate) must contain 24 carbon atoms. These data, along with the molecular weight of 390 as determined from the conventional Cl mass spectrum of the unknown was fed into the empirical formula generator and the output was one empirical formula C24H38O4. [Pg.335]

The detailed mathematical formula generating the SED-TOX score are provided in the Appendix. [Pg.260]

The restricted graphical potential of a line printer puts limitations on the quality of the constitutional formulas. The line printer cannot put symbols just anywhere on the drawing-plane but is restricted to a rectilinear grid and directions which are multiples of 45°. Furthermore, many line printers have only a small selection of symbols available. Therefore, to represent bonds, only centro-symmetric symbols are used. Figs. 15 and 16 show examples of constitutional formulas generated. If... [Pg.115]

Rationalization of known compounds provides a level of usefulness that justifies the rule. But the rule also permits observed molecular stoichiometries of newly synthesized compounds to be translated into acluster shape. For example, [Al Bu ]2-has eve = 50 or sep =13 consistent with n = 12 and a deltahedral structure. The compound has been synthesized and an X-ray diffraction study reveals an icosahe-dral shape. The ability to suggest reasonable structures based on knowledge of a molecular formula generated by a technique like mass spectrometry accelerated the development of cluster chemistry simply because rapid spectroscopic methods can be more productively applied. Although efficient X-ray crystallographic structure determination reduces its importance for compounds that can be isolated in pure crystalline forms, transient intermediates detected in a reaction mixture can now be given reasonable structures. [Pg.45]

Prime numbers do not occur in a predictable way. There are sequences of primes which can be partially described in a formula, but sooner or later the formula breaks down. One formula, invented by Marin Mersenne (1588-1648) is 2P - 1, where p is a prime number. Although this formula generates many primes, it also misses many primes. Another formula, invented by Leonhard Euler (1707-1783), generates prime numbers regularly for the series of consecutive numbers from 0 to 15 and then stops. The formula is + x + 17, in which x is any number from 0 to 15. [Pg.609]

With reference to the stability of the ion at the center of the line joining two sources from the two chains, we have already seen that for the parameters chosen, axial motion is stable. As the number of sources in the walls of the channel increase, the position of mechanical stability shifts to a position midway between wall sources along the z-axis. This fact can be accounted for with the formulae generated above [32]. [Pg.64]

Last but not least ACDLabs have MS capability in their SpecManager product (http //www.acdlabs.com). Their MS module reads single spectra or GC/(LC)/MS data files and can be used for the subsequent analyses including ESI LC/MS minor components recovery, GC/MS separation of co-eluting components as well as structure/substructure formula generation from mass and ion data (24, 25]. [Pg.1095]

Given a linearly convergent series of t , the Aitken formula generates a new and more efHcient series z ... [Pg.6]

Table 8.2 includes 60 of the compounds identified using all of the information acquired during analysis retention time, observed signals in both ionization modes, molecular formula generated, and avocado samples containing the metabolite. [Pg.183]

MOLGEN-MS/MS was used for formula generation, MS and MS/MS match value calculation. MOLGEN-MS/MS is implemented in C++ and is available from www. [Pg.379]

Figure 8.46 sketches a simplified flowchart of MOLGEN-MS/MS. MS and MS/MS data are passed to the program as peak lists. The user can specify various parameters that were introduced in Subsections 8.8.1-8.8.3, as well as ionization type, adducts, etc. (see [203] for details). Unless specified otherwise by the user, the mass of the base peak in the MS is used as starting point for the generation of candidate formulas as described in Subsection 8.8.1. For each formula generated, MS and MS/MS match values are calculated as described in Subsections 8.8.2 and 8.8.3. In addition to these two match values, a combined match value (the multiplication of both match values) is also calculated for each candidate formula. [Pg.380]

Table 7.6. Numbers of isomers of circular single coronoids explicit formulas / generating functions I x). Table 7.6. Numbers of isomers of circular single coronoids explicit formulas / generating functions I x).
Most of the formulas generated out of these studies will not appfy to other organizations. For this reason, an accurate costing of loss experience mnst be conducted within individual organizations. Current, most organizations do not rrse a proper cost arraly-sis technique to identify major loss factors resirlting from workplace accidents and injuries. [Pg.27]

For central film thickness, however, the power on the dimensionless load parameter is significantly different from previously reported values [6], as is the power on the materials parameter (G). The central film thickness formula generated from solutions obtained by the new method gives slightly higher film thickness values, but in the range for which the film thickness predictions are valid (G > 2500), such errors are generally less than 10%. [Pg.186]

The flow properties of a colloidal system are very much dependent on its microstructure, as determined by the molecular arrangement and interaction of its components. ME systems show flow typical of a Newtonian liquids, for which the shear stress is directly proportional to the shear rate. Since viscosity measurements are dynamic experiments, they will give information on dynamic properties of the ME. These will depend on the miCTOStructure, type of aggregates, or interactions within the ME, which in turn are determined by the concentration of the various components and the temperature. The dispersion of one component in another, e.g., water in oil, will generally increase the bulk viscosity in comparison to the individual components (oil and water) [58]. For at true colloidal dispersion, viscosity will increase with increasing volume fraction of dispersed phase according to the formula generated by Einstein ... [Pg.259]


See other pages where Formula generation is mentioned: [Pg.229]    [Pg.333]    [Pg.195]    [Pg.525]    [Pg.70]    [Pg.78]    [Pg.219]    [Pg.286]    [Pg.472]    [Pg.242]    [Pg.256]    [Pg.268]    [Pg.269]    [Pg.229]    [Pg.934]    [Pg.42]    [Pg.2638]    [Pg.934]    [Pg.397]    [Pg.2711]    [Pg.401]   
See also in sourсe #XX -- [ Pg.29 , Pg.30 ]

See also in sourсe #XX -- [ Pg.164 ]




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Constrained generation and fuzzy formulas

Formula structure generation

Formula-based structure generation

Generating molecular formulas

Generation formula-based

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