Passive representation

In the passive representation, symmetry operators act on the axes, and so on x y z, but leave configuration space fixed. Clearly, one should work entirely in one representation or the other here we shall work solely in the active representation, and we shall not use the passive representation. 

Fig. 2. Schematic representation of relevant electrolyte transport through the renal tubule, depicting the osmolar gradient ia medullary iaterstitial fluid ia ywOj yW where represents active transport, —passive transport, hoth active and passive transport, and passive transport of H2O ia the presence of ADH, ia A, the cortex, and B, the medulla. An osmole equals a mole of solute divided by the number of ions formed per molecule of the solute. Thus one mole of sodium chloride is equivalent to two osmoles, ie, lAfNaCl = 2 Osm NaCl. ADH = antidiuretic hormone.

Molecules can passively traverse the bilayer down electrochemical gradients by simple diffusion ot by facilitated diffusion. This spontaneous movement toward equilibrium contrasts with active transport, which requires energy because it constitutes movement against an electrochemical gradient. Figure 41-8 provides a schematic representation of these mechanisms. 

Modern representations of the virtual heart, therefore, describe structural aspects like fibre orientation in cardiac muscle, together with the distribution of various cell types, active and passive electrical and mechanical properties, as well as the coupling between cells. This then allows accurate reproduction of the spread of the electrical wave, subsequent contraction of the heart, and effects on blood pressure, coronary perfusion, etc. It is important to point out, here, that all these parameters are closely interrelated, and changes in any one of them influence the behaviour of all others. This makes for an exceedingly complex system. 

Figure 7. Schematic representation ofprocesses of electromigration / diffusion of ions and formation of insulation passive layer on the boundary current collector / conductive polymer.

Schematic representation of the hydrated passive film on iron (From Pou et at., 1984)...

Fig. 6.8. Schematic representation of a selective delivery obtained by targeting a cell-specific transporter, a) The drug itself does not permeate passively into cells and is not a substrate of the transporter, b) The prodrug does not permeate passively into cells but is a substrate of the transporter. An additional condition of success is for the prodrug to undergo intracellular... 

Figure 5. Filtered 3D representation of the triangular lattice on passivated and aged Fe-25Cr. (Reprinted from Ref. 40 by permission of The Institute of Materials, London.)...

The theory of solvent effects on the electronic structure of a given solnte leads to a representation of the subsystem embedded in a larger one with the help of effective Hamiltonians, wave functions, and eigenvalues. Since the whole electronic system is quantum mechanical in nature, and in principle nonseparable, the theory for the ground electronic state permits defining under which conditions the solnte and solvent separability is an acceptable hypothesis. It is possible to distinguish passive from... 

FI G U RE 10.2 Schematic representation of alveolar cells and possible mechanism of transport of molecules from the alveolar space into the circulation. Particles will release molecules of interest (gray circles) into the mucus in which the particle is embedded. The molecule can either be lost in the mucus, taken up by alveolar macrophages by phagocytosis or diffusion, taken up by alveolar epithelial cells by passive or active transport, or bypass the alveolar cells via paracellular transport depending upon the properties of the drug. Once a molecule has reached the extracellular space, the same mechanisms are possible for transport from the extracellular space into the blood. Molecules in the extracellular space may also reach to circulation via the lymph. 

Figure 21. A cartoon representation of active and passive walls of a reaction cavity. Active wall is characterized by inter guest-wall interactions. Such is absent in the case of passive walls.

Fig. 37. Schematic representation of the in-containment passive safety injection system (PS1S). 1RWST = in-containment refueling water storage tank. PRHR-HX = passive residual heat removal heat exchanger. ADS = automatic depressurization system (four stages). (Westinghouse)...

Figure 23.10 Representation of photocontrolled ion-binding at an SP-modified surface, (a) Colorless SP-immobilized surface, (b) On illumination with UV light, the surface becomes active and bright purple due to the photoisomerizalion of SPto MC. On illumination of this surface with visible light MC is switched back to SP. (c) Exposure of activated surface to an aqueous solution of divalent metal ions leads to formation of the complex MC-M+ and further color change of the surface. Irradiation of this surface with green light leads to transformation of MC-M+ to SP. The cycle is closed and the surface is returned to the passive, colorless state.

Fig. 3 Schematic representation of batch-wise passive membrane dialysis (A) and continuous membrane filtration dead-end-filtration (B) and loop reactor (C)...

Fig. 12.1 Schematic representation of the three transepithelial intestinal pathways (a) trans-cellular active transport, (b) transcellular passive transport, (c) paracellular transport (Fasano...

Figure 10 Representation of passive and active reaction cavities.

Figure 16.16 is a representation of Fig. 16.1 a in terms of the type of reaction it shows, as a function of pH, the zones where corrosion by dissolution occurs, where initial corrosion forms insoluble oxides on the surface that impede further reaction (passive zone) and the region where the metal is stable (immune zone). 

FIGURE 8.4 Schematic representation of a BTA passivating layer formed on copper. 

Fig. 10 Schematic representation of surface dangling bonds of diamond and passivation by hydrogen. ...

Sometimes it is useful to apply a combination of the descriptors based on the global properties of the molecule and those based on a pharmacophoric representation. Conceptually, the global properties would better describe the imtial passive membrane permeation required to reach the site of action. Then, the specific protein interactions could be explained by the pharmacophoric descriptors. This has been demonstrated successfully in the P-glycoprotein case [26], where two processes are important for the transport passive transport to the cell and active... 

Transmission, freeze-fracture, and scanning electron microscopy have contributed ultrastmctural information about passive transport, particularly within the stratum comeum. Advances in fixation protocols for transmission electron microscopy have preserved the intercellular bilayers of the SC and have corrobrated their role in both passive and enhanced dmg delivery. Scanning and freeze-fracture electron microscopy have supplemented transmission electron microscopy by supplying three-dimensional representations of the transport pathways within the SC. 

Fig. 17M Schematic representation of the corrosion and passivation of iron in sulfuric acid. The primary passivation potential and the corresponding critical current density for corrosion i are shown. Breakdown of the passive film occurs at potentials more positive than E. ...

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