Tight layer

The addition of some metal ions, such as Mg2+,Zn2+, In3+,orGa3+, and some organic additives, such as 2-thiophene, 2-methylfuran, or benzene, to propylene carbonate-LiC104 improved the coulombic efficiency for lithium cycling [112]. Lithium deposition on a lithium surface covered with a chemically stable, thin and tight layer which was formed by the addition of HF to electrolyte can suppress the lithium dendrite formation in secondary lithium batteries [113]. 

The results of the above-mentioned Langmuir analysis of the SHG responses may be interpreted in terms of a tightly packed monolayer of the SHG active cation complexes at the membrane surface. The tight layer may, however, also be a layer thicker than a monolayer in which the potential aligns the complexes to the electric field. As a consequence of the increase of the potential near the surface, the oriented complexes would on the average be nearer to the surface than the average of all complexes. 

As DDTC adsorbs on jamesonite electrode chemically, the double electric charge layer is treated as a plate capacitor, the capacitance C of the tight layer as a constant, and the change of the capacitance of the double electric charge layer is designated to the capacitance Ct of the diffusion layer. Thereby, the tight layer and the diffusion layer are looked upon as two series capacitances according to the method from Cooper and Harrison, then ... 

Fig. 7.12 Two reciprocal space plots (projection along I with h down and k to the right) for 2,2,4,4,6,6-hexa-t-butylcyclotrisiloxane. Left Layer / = 0 tight Layer / = 2.

The original gas in coal seam has even pressure distribution. As the permeabiUty of the roof and floor of coal seam is much smaller than the coal seam, the rock mass of the roof and floor is, therefore, supposed to be gas-tight layers, completely free from gas ... 

Some of the membranes are composite structures. These have a thin tight layer that provides high current efficiencies (i.e., high transport numbers for cations) backed by a thicker layer of looser polymer to provide low resistance combined with strength and convenience of handling. Typical resistances range from 2 to 4 ohm-cm at room temperature depending on the solutions in which they are used. Typical transport numbers are 0.94-0.97, which provide current efficiencies of 94-97%. 

The permeability properties of cerebral capillaries are quite different from those of capillaries in other organs and tissues. Water-filled channels, which can be demonstrated in the walls of most non-nervous capillaries, are absent from cerebral capillaries. A hydrostatically promoted transcapillary flow of fluid into tissue on the arterial side, with the reverse process on the venous side (i.e. Starling-type transcapillary flow) has never been demonstrated in the brain. The central nervous system does not possess lymphatics. Cerebral capillary endothelial cells have no pino-cytotic activity. Furthermore, the central nervous system and various compartments of cerebrospinal fluid are also excluded from the extracellular fluid of the rest of the body by the tight choroid epithelium and the tight layer of arachnoid. 

The cracks in reinforced and non-prestressed concrete elements subjected to tension are unavoidable due to differences in Young s moduli and in values of ultimate strain in concrete and steel. It is the task of the designer to select appropriate remedies for the serviceability and safety reasons by adequate reinforcement or prestressing. If perfect impermeability is required, then the cracks are inadmissible or their width is strongly limited. In that case, also, the pore system in concrete should be completely blocked by special admixtures. Another method is to provide protective coatings or tight layers of other materials. 

The studied molybdenum rods were actually covered by a thin tight layer of one of their (yellow) oxides, which were in equilibrium with each other during their application for reference purposes. They function thus on the basis of their oxide formation, Eq. (8.111),... 

The chill-roll touched surface of the cast film consists of a-rich layer which is air-ti t after stretching in spite of the inner layer being porous. Consequently, the whole film behave as less porous film. During the electron-microscopic observation electron beam etched the air-tight layer, then the porous stnicture of film can be viewed. 

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