Cluster significance clusters

In each of the studies described above, the reader is encouraged to watch the development of the two phases from the original homogeneous mixture. Note that there is significant clustering of like molecules well before two discrete phases form. Another observation is the ragged nature of the interface. It is not a smooth discrete separation in this molecular system level model. 

Cronin MTD. The use of cluster significance analysis to identify asymmetric QSAR data sets in toxicology. An example with eye irritation data. SAR QSAR Environ Res 1996 5 167-75. 

In the tetranuclear clusters significant steric control of substitution with tertiary phosphines and phosphites is generally only observed in the fourth substitution step. The synthesis of tetra-substituted derivatives, therefore, requires more severe conditions22,46,86,248 and then breaking of the cluster can become important. 

The coefficients of equation 57 are not significantly different from those of equation 56. Unfortunately, 5 of the 6 points in the data set lie in the range 9.22 to 9.48, thus there is significant clustering. While the L value is about what is expected for w = 4, indicating that in water, hydroxamic acids in the range of cr studied are oxygen acids, it does not constitute proof. 

The reason for this effect has to be attributed to a better and adequate ratio between sample size and array dimensionality. For a significant clustering of the patterns, with an array of six sensors a sample size of at least 18 is required [149, 184]. As a consequence, the discrimination based on only 12 measurements has poor statistical relevance. Most of the applications with sensor arrays found in the literature do not consider this fact frequently discriminations with 12-32 sensors in an array and with a sample size of three to four are described. All of them are of limited feasibility with concurrent poor validation, especially in terms of reproducibility and predictive ability. In other words, if there are not enough calibration measurements one can separate data in a predetermined way, but will fail to verify the result using independent test samples. 

As mentioned in my report, an ionic guest molecule in a host lipid bilayer (VIII) does not cluster significantly, whereas a similar but neutral guest (VII) clusters extensively as hexamers. I would expect this clustering to depend strongly on ionic strength only if the host lipids were charged. 

The effects of reactor type, process variables and feedstock type, catalysts, and feedstock composition (Chapters 5 and 6) on the desulfurization process provide a significant cluster of topics through which to convey the many complexities of the process. In the concluding chapters, examples and brief descriptions of commercial processes are presented (Chapter 7) and, of necessity, some indications of methods of hydrogen production (Chapter 8) are also included. 

CA indicates three clusters of variables according to the less restrictive criterion of Sneath s index of cluster significance (2/3 of Dmax, where Dmax is the maximum distance) N02 and 02 Fe2+, SO -, NII4, N-DISS, COD, OXIS, and BOD and CP, NO3, DISS, Ca2+, and pH (Figure 15.3). 

Travel experience variables Cluster 1 Cluster 2 Cluster 3 ANOVA Significance level... 

There are exceptions from this trend. A noted example is the polarizability of sodium clusters significantly underestimated by semi-local functionals.73... 

This can be ascribed to the fact that Li atoms are virtually in the Li+ state and make slight covalent interaction with the surrounding atoms. The location of Li+ therefore does not affect the electronic states of the clusters significantly. 

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