Chemical interactions and reliability testing

Chemical Interactions and Reliability Testing for Lead-Free Solder Interconnects... 

The new methodology was tested extensively in practical work at The Dow Chemical Company. It was found to be able to predict the properties of novel polymers as accurately and reliably as can be reasonably expected from any scheme based on simple quantitative structure-property relationships. The only computational hardware required to perform these calculations is a good hand calculator. The method was, nonetheless, automated by implementation in a simple interactive computer program (SYNTHIA). This software implementation has enabled its much easier use, especially by non-specialists. It has thus resulted in much greater efficiency as well as significantly reducing the possibility of human error. 

A method which allows testing NMR data such as dipolar couplings, anisotropic chemical shieldings and quadrupolar interactions has been proposed by Zidek et aV The authors have used the fact that only a limited number of frequencies corresponding to these parameters can be measured indepedently in a rigid fragment of the macromolecule. Additional values can be predicted as linear combinations of a set of independent frequencies. Comparison of the experimental data with the predicted values of the parameters studied provides a test of the reliability of the former. 

Because of the interactive nature of aqueous solute specia-tion calculations, it would be desirable to enter at once into the chemical model the reactions and thermodynamic data for all elements whose inclusion might affect the computed activity or equilibrium solubility of other solute species. However, our experience is that the greatest reliability is obtained by adding only the data for one element, or for one ligand group, at a time then test data sets and real world water sample analyses are run before making further additions to or changes in the model. 

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