Migration pathways

Finally, it is worthwhile to note that the methylene-transfer pathway does not involve direct transfer of a CH2 group. An H atom migration pathway is a more accurate description of this pathway, given the experimental and theoretical evidence. 

In response to danger signals, a significant number of both mDC and pDC precursors appear de novo into the circulation (5,13). However, their migration pathways are flexible and are largely dependent on tissue microenvironments. In a cutaneous herpes simplex virus (HSV)-l infection model, newly appeared... 

Preferred fluid migration pathways are influenced by porosity and permeability, sedimentary sequences, facies architecture, and fractures. Porosity is a measure of pore space per unit volume of rock or sediment and can be divided into two types absolute porosity and effective porosity. Absolute porosity (n) is the total void space per unit volume and is defined as the percentage of the bulk volume that is not solid material. The equation for basic porosity is listed below ... 

FIGURE 3.4 Photograph showing small-scale sedimentary structures that can significantly affect migration pathways of contaminants. 

Figure 3.4). This results in preferred areas of higher permeability and, thus, preferred migration pathways of certain constituents considered hazardous. 

Migration pathways (i.e., soil type, depth to water table, utility trenches) ... 

Kister, P., Cuney, M., Golubev, V.N., Royer J.J., Le Carlier De Vesuld, C., Rippert, J.C. 2004. Radiogenic lead mobility in the Shea Creek unconformity-related uranium deposit (Saskatchewan, Canada) migration pathways and Pb loss quantification. Comptes Rendus Geosciences, 336, 205-215. 

Fig. 2.2 Key features of the computational pathway for rhodium-catalyzed hydroboration, with energies in kcal/mol. Similar results were obtained for the related dioxaborolidine pathway. The isomeric intermediate C does not have access to a low energy H-migration pathway but rather eliminates B-H.

Adams, St. and Maier, J. (1998). Ag migration pathways in crystalline and glassey solid electrolytes Agl, AgM , 0. Solid State Ionics 105, 61-lA. 

Adams, St. and Swenson, J. (2000 ). Migration pathways in Ag-based superionic glasses and crystals investigated by the bond valence method. Phys. Rev. B 6, 054201. 

A number of disilanes have been investigated for their suitability as potential silene precursors. The formation of silenes by the 1,3-silyl migration pathway competes with dehydrosilylation, which also gives silenes, and with homolytic Si—Si bond cleavage to give silyl radicals. 

Sediment stratigraphy controls the hydrate distribution at Hydrate Ridge. The methane-rich migration pathway of Horizon A provides enriched hydrate formation relative to other sediments. In Figure 7.26, the remote sensing logs (gamma ray, density, RAB, and Archie water saturation) are most sensitive to hydrates. 

The HRS system is based on risk to health and the environment. The criteria examined include the groundwater migration pathway, surface water migration pathway, soil exposure pathway, and air migration pathway (Hen-drichs, 1991). The ranking attempts to quantify the risk each site poses on a relative scale. Only those sites placed on the NPL will receive CERCLA funds however, regulations in the CERCLA can still be applied to non-NPL sites. 

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