Underlying Notions

As the subject of the present book lies at the junction of several sciences, it will be expedient to give some principle terms to be used in further narration. There are three groups of terms related to metal corrosion, composite materials and tribology. 

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At several points in the foregoing description of electron-transfer models, it was found convenient to make a distinction between so-called "intrinsic and "thermodynamic contributions to the reaction barrier. Since such a distinction is central to both the theoretical treatment and data interpretation of electron-transfer processes [6, 65], it is worthwhile to clarify further the underlying notions that are involved. 

For private cars with an engine capacity of 1.4 litres and more the directive provides, as an alternative to the European test procedure limited in time, for transposition of the relevant parts of the American certification process - basically the FTP-75 driving cycle. The underlying notion here is that manufacturers with vehicle types meeting the US specifications will first of all have to adapt these to European test conditions before they may, on this basis, apply for type approval, while on the other hand it is desirable for environmental protection purposes to offer such vehicles on the European market in the near future. The limit values are those of the 1983 federal " 49 states") standards, i.e. for CO 2.11g/km, for HC 0.25g/km and for NOx 0.62g/km. These limit values will apply both to type-approval and to control of production conformity according to the American sampling procedure. 

The underlying notion in bilinear modeling is that something causes the systematic variabilities in the X data. But we may not correctly know what it is there may be surprises in the data due to unexpected interferents, chemical interactions, nonlinear responses, etc. An approximate model of the subspace spanned by these phenomena in X is created. This X model is used for stabilizing the calibration modeling. The PLS regression primarily models the most dominant and most y-relevant of these X phenomena. Thus neither the manifest measured variables nor our causal assumptions about physical laws are taken for granted. Instead we tentatively look for systematic patterns in the data, and if they seem reasonable, we use them in the final calibration model. 

Direct Aldol Reactions The most frequently applied direct aldol reactions in which unmodified achiral methyl ketones can be directly activated by catalysts were reported by Trost [26] and Shibasaki [27] (Scheme 2.117). Both used bimetalUc catalysts as enzymatic numetics for ketone activation. Shibasaki reported the use of LuLi tris (binaphthoxide) to perform aldol reactions between methyl ketones and branched aldehydes. The underlying notion was that this catalyst mimics enzymatic activity through Lewis acid activity based on the lanthanum ion and Brpnsted basic activity due to the lithium binaphtoxide. The enantiomeric selectivity ranges from modest to excellent ratios. 

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