Tail addition definition

I-. - also head r.t rail addition definition 4. If) lail-to-tail linkages in PVAc 324... 

Most monomers have an asymmetric substitution pattern and the two ends of the double bond are distinct. For mono- and 1,1-disubstituted monomers (Section 4,3.1) it is usual to call the less substituted end "the tail" and the more substituted end "the head". Thus the terminology evolved for two modes of addition head and tail and for the three types of linkages hcad-to-tail, hcad-to-hcad and tail-to-ta.il. For 1,2-di-, tri- and tetrasubstituted monomers definitions of head and tail are necessarily more arbitrary. The term "head" has been used for that end with the most substituents, the largest substituents or the best radical stabilizing substituent (Scheme 4.4). 

Although additional analyses of the existing data and additional experiments are required to reach definitive conclusions on the phase changes of ferrihydrite in uranium mine tailings, preliminary XRD data suggest that in deionized water at elevated pH (pH=10) phase transformation of ferrihydrite can occur at elevated temperatures. In both elevated temperature experiments, hematite appeared to be the dominant transformation product. At room temperature, however, ferrihydrite remains stable after the duration of the experiment (seven days). 

An early attempt to resolve the discrepancy between the high values of Sugimura and Suzuki (1988) and more traditional analyses tailed to reach a definitive conclusion (Williams, 1992). The start of the Joint Global Ocean Flux Study (JGOFS) field program with the North Atlantic Bloom Experiment in 1989 put additional pressure on the various groups to resolve this issue quickly. The National Science Foundation (NSF) and the National Oceanic and Atmospheric Administration (NOAA) funded a workshop held in Seattle in July 1991 to resolve the issue. 

The seeds for the development of linear methods may be found in the 1971 paper by Andersen [1.21] which contains a definition of muffin-tin orbitals, an addition theorem for tails of partial waves, and the tail cancellation theorem. Soon after, these ideas were developed into a practicable band-calculation method, the linear combination of muffin-tin orbitals (LCMTO) method [1.22,... 

Other variants of MV optimization have been proposed to address some of its shortcomings. For example, MV analysis presumes normal distributions for asset returns. In actuality, financial asset return distributions sometimes possess fat tails. Alternative distributions can be used. In addition, the MV definition of risk as the standard deviation of returns is arbitrary. Why not define risk as first- or third-order deviation instead of second Why not use absolute or downside deviation ... 

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