Big Chemical Encyclopedia

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

Articles Figures Tables About

Matrix factor

The Hamiltonian matrix factorizes into blocks for basis functions having connnon values of F and rrip. This reduces the numerical work involved in diagonalizing the matrix. [Pg.139]

Enantiomer separation factors (a values) for valine and phenylalanine as well as their esters of 5-10 for phenylalanine and 4-10 for valine have been shown at the 0.1-1 g ChiraLig scale. These a values vary as a function of solvent and other loading matrix factors (pH, salts, etc.). However, all of these cases show a values high enough to obtain reasonable enantiometric purity in less than or equal to three stages. The system with a value of = 6 for the valine methyl ester enantiomers has the ability to load the valine onto the resin in H,0 containing LiClO and also to... [Pg.212]

Among the usual advantages of such expressions as Eq. (7-80) and (7-81), one is salient they show forth the invariance of p and w with respect to the choice of the basis functions, u, in terms of which p, a, and P are expressed. The trace, as will be recalled, is invariant against unitary transformations, and the passage from one basis to another is performed by such transformations. The trace is also indifferent to an exchange of the two matrix factors, which is convenient in calculations. Finally, the statistical matrix lends itself to a certain generalization of states from pure cases to mixtures, required in quantum statistics and the theory of measurements we turn to this question in Section 7.9. [Pg.420]

Estimate the LOQ using any of the methods described earlier and equate the value in terms of amount in the matrix, factoring in any concentration and dilution factors from the extraction procedure. [Pg.71]

Thus, these methods are suitable for problems with a very large number of parameters. They are essential in circumstances when methods based on matrix factorization are not viable because the relevant matrix is too large or too dense (Gill etal. 1981). [Pg.77]

Not all samples consist of binary mixtures, and difficulties exist with the extension of the matrix factor approach to multi-component systems. [Pg.30]

A monolayer matrix factor QAB can be defined such that ... [Pg.30]

Conventional Systems. In the conventional antifouling compositions, the organotin compound (TBTO, TBTF, TBTC1, TBTOAc) is mechanically mixed into the paint vehicle. When the TBT species is completely soluble in the polymer matrix, factors (a) and (b) become unimportant in most cases. The mobile species is already present its diffusion in the matrix, phase transfer and migration across the boundary layer into the ocean environment may be represented by Figure 2a. When the organotin compound forms a dispersed second phase, rate of its dissolution in the polymer matrix becomes another factor to consider. [Pg.172]

For process optimization problems, the sparse approach has been further developed in studies by Kumar and Lucia (1987), Lucia and Kumar (1988), and Lucia and Xu (1990). Here they formulated a large-scale approach that incorporates indefinite quasi-Newton updates and can be tailored to specific process optimization problems. In the last study they also develop a sparse quadratic programming approach based on indefinite matrix factorizations due to Bunch and Parlett (1971). Also, a trust region strategy is substituted for the line search step mentioned above. This approach was successfully applied to the optimization of several complex distillation column models with up to 200 variables. [Pg.203]

Alternative mathematical methods such as artificial neural networks (ANN), maximum likelihood PCA and positive matrix factorization have also proved effective for calibration transfer, but are much more complex than the previous ones and are beyond the scope of this chapter. For more information about this topic see Chapter 12. [Pg.478]

The in vitro bioassay for dioxins with cleaned sediment extracts (DR-CALUX) proved to comply with the QA/QC criteria needed to guarantee the reliability of data in an inter- and intralaboratory study (Besselink et al., 2004). The chemical stability of dioxins makes it possible to apply destructive clean-up procedures which remove all matrix factors. Sample extraction and cleanup for other in vitro bioassays for specific mechanisms of toxicity require further development to make sure that the chemicals of interest are not lost or unwanted chemicals included in the sediment extract to be tested. Table 4 summarizes possible bioassays that could be performed in addition to chemical analyses with the dredged sediment in a licensing system. [Pg.100]

Bioassays using cleaned sediment extracts are much more distinctive than bioassays with whole sediment for decision making in a licensing system. This is mainly due to the interference of matrix factors with the assessed endpoint when applying whole sediment instead of cleaned extracts. [Pg.123]

Multivariate methods, on the other hand, resolve the major sources by analyzing the entire ambient data matrix. Factor analysis, for example, examines elemental and sample correlations in the ambient data matrix. This analysis yields the minimum number of factors required to reproduce the ambient data matrix, their relative chemical composition and their contribution to the mass variability. A major limitation in common and principal component factor analysis is the abstract nature of the factors and the difficulty these methods have in relating these factors to real world sources. Hopke, et al. (13.14) have improved the methods ability to associate these abstract factors with controllable sources by combining source data from the F matrix, with Malinowski s target transformation factor analysis program. (15) Hopke, et al. (13,14) as well as Klelnman, et al. (10) have used the results of factor analysis along with multiple regression to quantify the source contributions. Their approach is similar to the chemical mass balance approach except they use a least squares fit of the total mass on different filters Instead of a least squares fit of the chemicals on an individual filter. [Pg.79]

SUCCESSFUL DECOMPOSITION 1 SINGULAR MATRIX MATRIX FACTORS IN PACKED FORM... [Pg.30]

Suppose S and B were uncoupled before t = 0, so that the total density matrix factorizes as in (1.23),... [Pg.436]

Paatero P, Tapper U (1994) Positive matrix factorization a nonnegative factor model with optimal utilization of error estimates of data values. Environmetrics 5 111-126... [Pg.138]

Lee E, Chan CK, Paatero P (1999) Application of positive matrix factorization in source apportionment of particulate pollutants in Hong Kong. Atmos Environ 33 3201-3212... [Pg.138]

Yue W, Stolzel M, Cyrys J, Pitz M, Heinrich J, Kreyling WG, Wichmann FIE, Peters A, Wang S, Hopke PK (2008) Source apportionment of ambient fine particle size distribution using positive matrix factorization in Erfurt, Germany. Sci Total Environ 398(1-3) 133-144... [Pg.185]

Beuck H, Quass U, Klemm O, Kuhlbusch TAJ (2011) Assessment of sea salt and mineral dust contributions to PM10 in NW Germany using tracer models and positive matrix factorization. Atmos Environ 45(32) 5813-5821... [Pg.186]

Nicolas J, Chiari M, Crespo J, Orellana IG, Lucarelli F, Nava S, Pastor C, Yubero E (2008) Quantification of Saharan and local dust impact in an arid Mediterranean area by the positive matrix factorization (PMF) technique. Atmos Environ 42(39) 8872-8882... [Pg.186]

Karanasiou AA, Siskos PA, Eleftheriadis K (2009) Assessment of source apportionment by Positive Matrix Factorization analysis on fine and coarse urban aerosol size fractions. Atmos Environ 43 3385-3395... [Pg.186]

Gu J, Pitz M, Schnelle-Kreis J, Diemer J, Reller A, Zimmermann R, Soentgen J, Stoelzel M, Wichmann H-E, Peters A, Cyrys J (2011) Source apportionment of ambient particles comparison of positive matrix factorization analysis applied to particle size distribution and chemical composition data. Atmos Environ 45(10) 1849-1857... [Pg.190]

Matrix multiplication is based on the dot product defined for any two vectors of equal size. The product matrix P of two conformally sized matrices K and L is a matrix of size number of rows of K by number of columns of . To be compatible for multiplication, the rows of K and the columns of L must have the same length. If this is so then the entries pij of the matrix product P = K L = (pij) are computed as the dot products of row i of the first matrix factor K with the column j of the second matrix factor L. We refer the reader to the annex on matrices. [Pg.16]

Here the MATLAB on-screen term Inner matrix dimensions refers to the underlined inner size numbers of the matrix factors of D such as depicted by our underlining in 3x5 = -1 /M C 4x5- These inner dimensions are both equal to 4 for the matrix product D = A - C. [Pg.16]


See other pages where Matrix factor is mentioned: [Pg.30]    [Pg.178]    [Pg.333]    [Pg.226]    [Pg.202]    [Pg.205]    [Pg.47]    [Pg.47]    [Pg.47]    [Pg.591]    [Pg.91]    [Pg.96]    [Pg.99]    [Pg.27]    [Pg.675]    [Pg.100]    [Pg.115]    [Pg.128]    [Pg.191]    [Pg.68]    [Pg.22]    [Pg.62]   
See also in sourсe #XX -- [ Pg.191 ]

See also in sourсe #XX -- [ Pg.562 ]




SEARCH



Correction factor matrix

Factor analytical techniques matrices

Factor contributions, matrix

Factor score matrix

Factorization of filter coefficient matrices

Factorization of matrices

Factorization, matrix elements

Factors Influencing Processing of Metal Matrix Composites

Franck-Condon factor matrix elements

Hessian matrix Cholesky factorization

Matrices factor analysis

Matrices, varimax rotated factor

Matrix Cholesky factorization

Matrix Gauss factorization

Matrix elements 8 decay probability, factorization

Matrix elements molecular, factorization

Matrix factorization

Matrix post-factor

Matrix rate factors

Matrix selection factors

Matrix stripping factors

Negative matrix factorization

Negative matrix factorization analysis

Positive matrix factorization

Reduced density-matrix spin factors

Statistical weight factors matrices

© 2024 chempedia.info