Secondary migration efficiency

Vd = drainage volume = volume of carrier-reservoir rock through which 

Sr = apparent residual saturation of the carrier-reservoir rock to 

In addition to the losses of hydrocarbons during secondary migration indicated by Equation 4.25, additional losses of hydrocarbons can be expected to occur by accumulation of small non-economic volumes of hydrocarbons in miniature traps present along the migration path, and by dissolution and diffusion of especially hydrocarbon gases after their expulsion from the source rock (Chapter 3.2 Slvdjk and Nederlof, 1984). 

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We assume that petroleum products from the Are Formation could conceivably have helped in saturating laterally extensive migration avenues in the basins, so that secondary migration from the Spekk Formation, when turned on millions of years later, would proceed which much increased efficiency (cf. Fig. 10, and figure 8 in Paper 1). 

Primary alkyl, secondary alkyl, and aryl groups all migrate readily, and migration occurs with retention of configuration. The reaction is thus more versatile than the deprotonation/alkylation approach to substituted alkynes, which is generally only efficient for primary electrophiles and does not proceed at all for aryl halides. For example, triphenylborane may be used to incorporate a phenyl group into an alkyne (Equation B4.6). 

Even without deposition of a metal island, wide band-gap semiconductor powders often maintain photoactivity, as long as the rates or the positions of the oxidative and reductive half reactions can be separated. Photoelectrochemical conversion on untreated surfaces also remains efficient if either the oxidation or reduction half reaction can take place readily on the dark semiconductor upon application of an appropriate potential. Metalization of the semiconductor photocatalyst will be essential for some redox couples, whereas, for others, platinization will have nearly no effect. Furthermore, because the oxidation and reduction sites on an irradiated particle are very close to each other, secondary chemical reactions can often occur readily, as the oxidized and reduced species migrate toward each other, leading either to interesting net reactions or, unfortunately, sometimes to undesired side reactions. 

In PVA-coated capillaries it was possible to separate at pH 2.5 the standards of poly-2-vinylpyridinium hydrochloride (p(2-VPy)) in the molecular mass range between 1500 and 1,730,000 g mol-1 with dextran T70 as sieving matrix [20]. An example is shown in Fig. 4, where a 5% solution of dextran T70 has been used. The efficiency of the monomolecular basic marker 4-aminopyridine is excellent, demonstrating the exclusion of secondary adsorptive effects at the capillary surface. Hence, the broad peaks of the polymeric standards are due to their polydispersity. As in CE the width of the peaks depends on their migration velocity through the detection window, no direct comparison of broadness of the individual peaks and analyte polydispersity is possible. However, for each individual peak the methods applied in SEC for calculation of the different molecular mass averages can be applied. 

The syrc-isomer (272) is less specific in its secondary rearrangements alkyl migration in (270b) would be expected to trap the twisted cation less efficiently than double bond participation in (270a). 

The dynamics of adsorbed species over MgO(OOl) surface was studied by MD method. The migration of the adsorbed species was found to depend on the morphology of MgO and the thermal vibration of surface atoms in MgO lattice. Further, the situation where the supercritical fluid and adsorbed species exist together was simulated. The collision of supercritical fluid with the adsorbed species was identified as the primary cause of extraction. Additionally, the supercritical fluid form clusters around the desorbed species avoiding the readsorption. Thus, clustering is the secondary cause for the increased efficiency of supercritical extraction even above the critical conditions. The details of these simulation studies are given in the following section. 

After ionising the gas molecules, the positive ions generated migrate to the cathode and can liberate secondary electrons. The efficiency of this secondary electron production is given by the second Townsend coefficient 7 which is the fraction of secondary electrons liberated. This coefficient depends on the material of the cathode and is typically in the range around 0.1 [14]. 

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