The Ambiguity Problem

To eliminate the ambiguities in the subject of electricity and magnetism, it is convenient to add charge q to the traditional I, m and t dimensions of mechanics to form the reference dimensions. In many situations permittivity S or permeabiUty ]1 is used in Heu of charge. For thermal problems temperature Tis considered as a reference dimension. Tables 2 and 3 Hst the exponents of dimensions of some common variables in the fields of electromagnetism and heat. 

The results from EQCM studies on conducting polymer films can be ambiguous because the measured mass change results from a combination of independent ion transport, coupled ion transport (i.e., salt transport), and solvent transport. In addition, changes in the viscoelasticity of the films can cause apparent mass changes. The latter problem can be minimized by checking the frequency response of the EQCM,174 while the various mass transport components can be separated by careful data analysis.175,176... 

Even if we forget, for a moment, the overlap problem and assume that we obtained a pure sensitized emission image, interpretation of this image is still ambiguous. That is because first, the intensity of S varies linearly with the excitation intensity and with the detector sensitivity. The exact same preparation will, when measured on a different microscope, yield different s.e. intensities. In fact, as much as renewing the arc lamp would impede comparison of results obtained on the same microscope. Second, the interpretation... 

One way of copying with the ambiguity trade-off problem forced by Moyal s Identity (8) is to use a technique called Doppler processing. There are several issues associated with the accurate measurement of range and Doppler ... 

Another approach to evaluating homoaromaticity is to compute various reaction properties such as heats of reaction. A typical example of this approach is a recent paper by Storer and Houk (1992) using molecular mechanics calculations (MM2) of the heats of hydrogenation of triquinacene [118]. In this study they conclude that the anomalous heat of hydrogenation can be explained without invoking homoaromaticity. The use of this type of computational data suffers the same problems as experimentally measured values there is an ambiguity with regard to separation of structural and electronic effects and how to choose appropriate reference systems. 

The discussion of the stability of various electronic situations in these molecules and solids has focussed on the balance of one- and two-electron forces. One of the big problems of course is to actually calculate the magnitude of these, and then to decide how the structure of these materials determines the details of the overall electronic structure. In addition there is the other problem, which we mentioned in connection with the molecular Huckel model, of the frequent ambiguity in what the parameters of these models actually mean. The... 

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