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Calculation software products

Calculation of eigenvectors requires an iterative procedure. The traditional method for the calculation of eigenvectors is Jacobi rotation (Section 3.6.2). Another method—easy to program—is the NIPALS algorithm (Section 3.6.4). In most software products, singular value decomposition (SVD), see Sections A.2.7 and 3.6.3, is applied. The example in Figure A.2.7 can be performed in R as follows ... [Pg.315]

Although the SIMCA method is very versatile, and a properly optimized model can be very effective, one must keep in mind that this method does not use, or even calculate, between-class variability. This can be problematic in special cases where there is strong natural clustering of samples that is not relevant to the problem. In such cases, the inherent interclass distance can be rather low compared to the mtraclass variation, thus rendering the classification problem very difficult. Furthermore, from a practical viewpoint, the SIMCA method requires that one must obtain sufficient calibration samples to fully represent each of the J classes. Also, the on-line deployment of a SIMCA model requires a fair amount of overhead, due to the relatively large number of parameters and somewhat complex data processing instructions required. However, there are several current software products that facilitate SIMCA deployment. [Pg.397]

There are two separate but interrelated aspects to QSAR modeling of antibacterial peptides the choice of QSAR descriptors and the choice of numerical analysis techniques used to relate these values to antibacterial activity. A simple example of a QSAR descriptor is the total charge of a peptide. A large number of QSAR descriptors is available for small compounds in the literature and from commercial software products that may be considered. A smaller subset is used in QSAR studies of antibacterial peptides and may be separated into two categories descriptors based on empirical values and calculated descriptors. An example of an empirical value is HPLC retention time, which is a surrogate measure of solubility or hydrophilicity/hydrophobicity. An example of a calculated descriptor is total peptide charge at pH 7. [Pg.135]

Chemical speciation in soil solutions and other natural waters can be calculated routinely with a number of software products offered in a variety of computational media.27 30 Five examples of these products are listed in Table 2.5. They differ principally in the method of solving the chemical equilibrium problem numerically, or in the chemical species and equilibrium constants considered, or in the model used to estimate single-species activity coefficients. Irrespective of these differences, all the examples follow a similar algorithm ... [Pg.71]

Based on the size (sample volume and number of vials) of the lot, the software must take into account that the calculated ideal product temperature may exceed the collapse temperature. [Pg.22]

There is a variety of software that can be used to process pseudo-single crystal experimental diffraction data represented in a form of individual structure factors or their squares (consult http //www.iucr.org and/or http //www.ccpl4.ac.uk). The most commonly used software products are SHELXS-90 and SHELXL-97 (author G.M. Sheldrick), which are distributed free for academic use (consult SHELX home page at http //shelx.uni-ac.gwdg.de/SHELX/index.html for details). Unless noted otherwise, processing of the individual structure factor data, direct phase determination, Patterson-, Fourier- and E-map calculations shown in this chapter were performed using WinCSD software, which is available from STOE Cie, Gmbh (http //www.stoe.com/products/index.htm). [Pg.515]

The semi-empirical molecular orbital calculation software MOPAC in the CAChe Work System for Windows ver. 6.01 (Fujitsu, Inc.) was used in all of calculations for optimization of geometry by the Eigenvector Following method, for search of potential energies of various geometries of intermediates by use of the program with Optimized map, for search of the reaction path from the reactants to the products via the transition state by calculation of the intrinsic reaction coordinate (IRC) [10]. [Pg.302]

Since the peak areas in the mass spectra are used for quantitation, the mass spectrometers must produce reliable and reproducible data to calculate meaningful product yields and allow a comparison of data collected on multiple mass spectrometers and collected at different times. Therefore, each mass spectrometer undergoes a comprehensive daily standardization and calibration, which has been automated by in-house software. [Pg.246]

Major reasons for drug candidates to fail in early clinical phases are unpropitious pharmaco-kinetic properties (such as a lack of bioavailability) or toxicity. Therefore, estimation of these properties is an important part of a combinatorial library profile. An increasing number of publications [6, 42-45] demonstrate the importance of ADME parameters (ADME = absorption, distribution, metaboHsm, and ehmina-tion). Several commercial software packages are available. The ways in which ADME parameters are derived are similar in most available software products. In a first step, simple descriptors are calculated and in a second step, these descriptors are correlated with experimental data [46]. The parameters must describe properties that are important for pharmaco-kinetics (lipophilicity, size, and polarity of molecules, etc.). Standard correlation methods can be used, because the type of correlation has only secondary effects on the results. Generally, the predictivity of classification methods (the output from which can only be good or bad ) is slightly better compared to a quantitative correlation. [Pg.574]

Our calculations using an equilibrium stage model agreed well with the experiments based on separation performance measurements using catalytic rings as internals (Fig. 2.6). On the basis of these results, we have to contradict various publications that attribute the decrease to reaction-kinetic effects. The primary effect is the saddle-point character of the products and the associated choice of a second feed point. The options for calculation and especially interpretation of RD lines, which have merely been outlined here are implemented in the program SYNTHESISER, a software product from the first EU-project. [Pg.37]

Microsoft Excel and Visual Basic for Application (VBA) are also frequently used for scientific calculations. They are convenient to use and generally available but suffer from the fact that the calculations performed in Basic code or the Excel sheet are not easy to read and understand by users other than the developer. Several examples employ Excel and/or VBA and demonstrate applications where they offer great advantages due to their flexibility and the ability to easily interface to COM components of other software products. For the less-trained or infrequent... [Pg.616]

Only the development of the methods of automatic design calculation of simple columns and distillation complexes with branching of flows described in the previous chapters and the increase of performance of computers makes real the creation of such a software product. Traditional methods of design calculation based on calculation investigations with the help of simulation software are of no use when solving a synthesis task. [Pg.264]

This method can be applied in all cases. The Fourier transform procedure is included commonly in mathematical software products and is easily available for everyone. The drawbacks of this procedure lie in its laborious course and abstract nature because the calculations are performed in Fourier space. Those who lack experience in numerical Fourier transforms are advised to study some pitfalls such as the break-off effect and the sampling theorem, both obtained by numerical treatment. Under specific conditions, this simulates periodicities and fluctuations that do not reflect any actual processes in the sample. Furthermore, the signal-to-noise ratio turns worse for further details, readers are referred to the literature (Bracewell, 2000 Davies, 2002). [Pg.118]

Probabilistic methods are not commonly used in design practice despite calculation procedures and software products already enable a direct verification of structural reliability. Detailed guidance is provided by the Joint Committee on Structural Safety Probabilistic Model Code, JCSS (2014). [Pg.2176]

Potential customers usually want to know how they will benefit if they hire a usability professional, and they may want numbers to measure those benefits, or calculate a return on investment. However, many professionals become confused when customers ask them to measure the usability of a software application, software program, web site, or other software product. In order to clarify Ae process of measuring usability, this tutorial first offers a definition of software usability metrics, gives examples of usability metrics, and reviews reasons for usability metrics. Next, the tutorial steps through the process of deciding what metrics and methods to use as well as when, where, and how to use them. [Pg.710]

Kochevsky, A.N. Raschet of internal currents of a liquid in channels by means of software product flow vision. Bull. SumGu.2004, 2(61), 25-36, (in Russian). Kochevsky, A.N. and Nenja, V.G. Modem the approach to modelling and calculation of currents of a hquid in bladed hydromachines. Bull. Sum. Gu.2003,13(59), 195-210, (in Russian). [Pg.58]

We are confident that any user of this combined evaluation technique, as well as the development of future test standards for manual ultrasonic testing will benefit from this result, because it allows a greater flexibility in the applicable method without loosing reliability. Often an expensive production of a reference block can be avoided and therefore testing costs are reduced. Since all calculations are performed by a PC, the operator can fully concentrate on his most important duty scanning the workpiece and observing the A-scan. Additional time will be saved for the test documentation, since all testing results are stored in the instrument s memory (the PC s hard drive) with full link to the Software World (Microsoft Word, Excel, etc.). [Pg.818]

Some of these software packages also have semiempirical or molecular mechanics functionality. However, the primary strength of each is ah initio calculation. There are also ah initio programs bundled with the Unichem, Spartan, and Hyperchem products discussed previously in this appendix. [Pg.332]

The Rheo-Tex rheometer is an inexpensive, automated instmment using load cell technology to measure indentation and creep. Available software calculates hardness/softness, brittleness, plasticity, and tensile strength. This instmment is particularly valuable for measurements on foods and personal care products. [Pg.194]


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