Chemical features compaction

Thus, we considered a number of examples of application of the sensor technique in experiments on heterogeneous recombination of active particles, pyrolysis and photolysis of chemical compounds in gas phase and on the surface of solids, such as oxides of metals and glasses. The above examples prove that, in a number of cases, compact detectors of free atoms and radicals allow one to reveal essential elements of the mechanisms of the processes under consideration. Moreover, this technique provides new experimental data, which cannot be obtained by other methods. Sensors can be used for investigations in both gas phase and adsorbed layers. This technique can also be used for studying several types of active particles. It allows one to determine specific features of distribution of the active particles along the reaction vessel. The above experiments demonstrate inhomogeneity of the reaction mixture for the specified processes and, consequently, inhomogeneity of the... 

Consider first the main characteristic features of formation of the layers of chemical compounds, common to solid-solid, solid-liquid and solid-gas systems (Chapters 1 to 4). Then, the effect of dissolution of a solid in the liquid phase of a solid-liquid system or of its evaporation into the gaseous phase of a solid-gas system on the growth kinetics of a chemical compound layer will be analysed in Chapter 5. Thus, under the conditions of occurrence of a chemical reaction its product will be assumed to be solid and to form a continuous compact layer adherent at least to one of the initial phases. 

A typical globular protein adopts a unique minimum energy conformation that is compact with few or no internal water molecules. Hydrophobic (nonpolar) R groups tend to be on the inside (away from water) and most hydrophilic (polar) R groups tend to be on the outside where they can be solvated by hydrogen bonding with H20. In the case of enzymes (proteins that catalyse specific chemical reactions) there may be special structural features of which the best known are active site depressions or grooves on the surface that bind the chemical substrates of the enzyme-catalysed reaction. 

The first feature concerns the structure of the terms in Eq. (A.33). Each term can be viewed as the product between a generalized (driving) force Xk and a generalized flux Jk. The first term in Eq. (A.33) has the temperature gradient as a force and heat transfer rate as a flux. The second term has a composition gradient and a mass transfer flux. The third term has affinity as a force (indicative of the distance away from chemical equilibrium) and reaction rate as the flux. The fourth term is already a composite related to pressure drop and fluid flow. Equation (A.33) can therefore be written compactly as... 

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