Tight contact

TABLE 4. Hyperfine splitting constants (gauss) of thioxanthone S-(mono or dijoxide radical anions as free or tight contact ion-pair ... 

Micro reaction channels can be operated in tight contact with cooling channels so that large reaction heats can be removed. By this means, formerly uncontrollable reaction conditions may be realized. 

A sealing of U-section which is located in a housing so that the fluid pressure tends to expand the flanges of the U into fluid-tight contact with the walls of the housing. 

The cel used for formation of SPE electrodes is shown in Fig. 2-12. To make a tight contact between the membrane and platiniun layer, small amount of platinum partides were deposited as nudei. Then a thick layer of platinum was deposited. This is a new way to fabricate a SPE electrode. 

The main focus in studies of this type lies on ion pairing and the presence of hydrogen bonds in these ILs. To this end, the variation of chemical shifts can be used as an indicator isolated ions show different chemical shifts as opposed to ions with tight contact to other ions or molecules. 

Because of the combination of physical, mechanical, and architectural properties of the mineral core, which is in tight contact with the organic phase, it is difficult for attacking agents to permeate the whole system. This may be the major reason why investigators have become discouraged with this approach. 

Perhaps the most noteworthy feature of many anionic polymerizations conducted in ethereal solvents is that the propagation reaction is a dual process, i.e., ion pairs and free ions coexist and exhibit distinctly different reactivies 240 24% The free ion concentration is generally limited to 1 % or less of the total active center concentration while the relative reactivities diminish in the sequence free anion S loose (solvent-separated) ion pair > tight (contact) ion pair. 

Put the blot sandwich in the gel holder and hold it firmly, to ensure a tight contact between gel and membrane. 

One further unique diarylstannylene which is worth discussing in more detail is the polycyclic derivative (22)34. This particular molecule possesses three divalent Sn atoms, two of them being coordinated by two amido ligands and the remaining one by two aryl substituents. The Sn atom (SnA) of the bis(aryl)stannylene fragment shows no unusual tight contacts to any other atom — there are close intramolecular contacts to the other Sn atoms, but they are most probably superimposed by the geometric needs of a bicyclic... 

Why is a loose, solvent-separated pair more reactive than a tight contact pair A contact pair involves a small, bare cation which becomes partially dissociated in the transition state as shown in the following diagram. This hinders the propagation. The partial dissociation may be unnecessary for the separated pair because the cation is large (owing to its solvation). 

A class of related complexes are the Pt(II) bis(dithiooxamide) cations. Rosace et al. (63) reported the luminescence properties of tight contact ion... 

Solid-phase reactions are usually activated by high-temperature treatment [1-4]. However, the practical efficiency of this process is rather low since the diffusion rate through a product layer is small, no tight contacts between the particles of components are provided, a particle size distribution is non-uniform, etc. Therefore, the search for new methods of performance of solid-phase reactions is carried out. Some new methods are successfully used for these purposes. These methods include, for example, self-propagating high-temperature synthesis [5], shock waves [6,7], mechanical activation of mixtures in grinding apparatus [8-15]. The latter method becomes more widely used at present due to its relative simplicity and availability. 

Shape change of the attached platelets, spreading along the fibrils permits multiple tight contacts with the matrix and there is simultaneous release of thromboxane-A2 (TXA2) and adenosine diphosphate (ADP) which recruit additional platelets. 

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