Prohibition factors

Cost-prohibitive factors associated with the very large volume of some large-volume parenterals required for animals, and... 

The rate determining step in intersystem crossing is the transfer from the thermally relaxed singlet state to the vibronically excited triplet state S/ >7 (j > k). This is followed by vibrational relaxation. The spin-orbital interaction modifies the transition rates. A prohibition factor of 10 — 10 is introduced and the values of kiSc lie between 101 and 107 s-1. The reverse transfer from the relaxed triplet to vibronically excited singlet is also possible. 

The cost of molybdenum is in normal times around 2.50 per pound. This seems like a prohibitive factor in itself, but considering the small amount required to produce any desired result, the small per cent of rejections, the long life and efficient performance, the friends of this alloy steel claim that it can compete successfully with other steels in final cost. 

Full-face masks (Fig. 6.28) include protection of the eyes, as they completely enclose the face. They are excellently suitable for use with ambient air-indep>en-dent respiratory devices. Because the sealing line runs from the forehead, over the cheeks, and down below the chin, leak problems may occur with persons with a beard. This could be a prohibiting factor for this group of persons. The... 

In this chapter, the development and usefulness of many amino acid- and protein-based surfactants has been discussed. The cost of amino acids and proteins and complicated manufacturing processes were the prohibiting factors for the broad utilization of this class of surfactants. Large-scale production and market consumption of certain amino acids, such as glutamic acid and lysine, have helped to alleviate this limiting factor. 

One of the prohibiting factors against the use of PHAs as a resin for packaging materials is that it is economically uncompetitive in the current... 

Intersystem crossing, viz, the spin-orbit-coupling-dependent internal conversion , distinguished from the former by a prohibition factor of about 10 but probable in many molecules, and strongly affected by the introduction of heavy atoms, as Kasha extensively documented in the following years [44,46]. 

The observed rate constant obs for a transition between two levels is given by the zero point motion limited rate constant AiSmx, modified by a series of prohibition factors (j) for changes that occur in transitions between states ... 

It has to be emphasised that all techniques presented here have been successfully used in the research environment or pilot plant scale (y-ray tomography). Their use in an industrial environment is a separate issue. One has to remember that commercial vessels may operate at high temperatures (say 700°C - 850°C) and pressures, which may reach a few tens of bars. Their walls are made of steel and the vessel diameter may be within 1-5 m range. When such considerations are taken into account, the likelihood of using optical or X-ray in the process environment is rather small. A natural choice would be y-ray techniques, which have a long history of industrial use. The prohibitive factor here could be the size of equipment and radiological hazards. 

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