Induced heterogeneity

Nonstoichiometry can be caused by oxygen deficiency (or excess) or by fractional valences of the metal components. For example, the existence of Cu " in nonstoichiometric cuprates has been widely discussed [9,10]. It is essential that in nonstoichiometric oxides the microscopic fluctuations of the composition should proceed (the so-called phase separation). The characteristic size of heterogeneities induced can exceed atomic dimensions by an order of magnitude. This phenomenon is attributable to the fact that the electron-nonuniform state of such chemically singlephase materials appears to be energetically more advantageous. 

It is therefore not unreasonable to ascribe the wide observation of the Elovich behaviour in chemisorption to the occurrence of one or the other of the considered models (surface heterogeneity, induced heterogeneity, or surfaee reconstruction), and to ascribe the smaller set of systems following the Elovich behaviour in desorption to a unique model — fixed surface heterogeneity. 

It is important that the wine should really neutralize the CaCOs/CaT mixture and not the reverse, as the formation of the stable, crystalUzable, double tartromalate salt is only possible above pH 4.5. Below this pH, precipitation of the endogenous calcium tartrate occurs, promoted by homogeneous induced nucleation with the added calcium tartrate, as well as precipitation of the potassium bitartrate by heterogeneous induced nucleation (Robillard et al., 1994). 

Fig. 1.12. Repetitive bubble formation on a microcavity in a tartrate microcrystal in a sparkling wine. Heterogeneous induced nucleation, according to the Casey model (1988)...

Solubilization of the membrane-bound cytochrome has little effect on its spectrum. The cytosolic cytochrome, however, has a somewhat different set of -values. This difference may reflect heterogeneity in the cytochrome vivo or heterogeneity induced by the different purification protocols. 

Depth profiling studies Grossette and co-workers [347] used microthermal analysis and FT-IR spectroscopy to study the physical heterogeneity induced by the photooxidation of PP at a sub-micrometric level. 

As our model system, we consider the mixing of equal portions of two buffer solutions, one of which contains a concentration, cq, of a species of interest in a T-mixer type channel geometry (see Fig. 2a), 200 xm in width and 8 xm in depth. In general the introduction of surface heterogeneity induces flow in all three coordinate directions, thus necessitating the use of a full 3D numerical simulation. The length of the mixing channel used in our simulations... 

In addition to household and conventional products, possible use of roughness-or heterogeneity-induced superhydrophobicity in nano- and biotechnology applications is often discussed. This includes, for example, nonsticky surfaces for the components of micro/nanoelectromechanical systems (NEMS/MEMS). Since adhesion plays an important role for small devices, the so-called stiction of two component surfaces is a significant problem in that industry, which may lead to device failure. Making a surface hydrophobic can reduce meniscus force and stiction. 

Several models have been proposed for both the time-logarithm and time-power laws based on the hypotheses of fixed surface heterogeneity, induced surface heterogeneity, and surface reconstruction. For the time-logarithm law, they are extensively reviewed in Ref. 39. The following analysis (strictly based on Refs. 36) considers how the time-logarithm and time-power laws are accounted for by the condensation approximation in the flame of fixed heterogeneity. 

Xu L, Sharma A, Joo SW. Substrate heterogeneity induced instability and slip in polymer thin films Dewetting on silanized surfaces with variable grafting density. Macromolecules 2010 43 7759-7762. 

The hole burning data obtained for P870 establish that the P870 lifetime (from total zero-point) is invariant to excitation frequency within the heterogeneity-induced zero-phonon line frequency distribution of P870. This is consistent with, but does not prove, an absence of dispersive kinetics from a distribution of values for the pure electronic coupling matrix element V. The proposed studies mentioned above may allow for a definite conclusion to be reached on this point. 

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