Aggregation criterion

The temporal evolution of spatial correlations of both similar and dissimilar particles for d = 1 is shown in Fig. 6.15 (a) and (b) for both the symmetric, Da = Dft, and asymmetric, Da = 0 cases. What is striking, first of all, is rapid growth of the non-Poisson density fluctuations of similar particles e.g., for Dt/r = 104 the probability density to find a pair of close (r ro) A (or B) particles, XA(ro,t), by a factor of 7 exceeds that for a random distribution. This property could be used as a good aggregation criterion in the study of reactions between actual defects in solids, e.g., in ionic crystals, where concentrations of monomer, dimer and tetramer F centres (1 to 3 electrons trapped by anion vacancies which are 1 to 3nn, respectively) could be easily measured by means of the optical absorption [22], Namely in this manner non-Poissonian clustering of F centres was observed in KC1 crystals X-irradiated for a very long time at 4 K [23],... 

The result of the characterisation is the impact or environmental profile, consisting of impact scores obtained by the use of equivalency factors for each aggregation criterion. These scores are completed with the non-quantifiable impacts that were found in the inventory analysis. 

Vesicles [10, 11] these aggregates of insoluble natural or artificial amphiphiles in water can have various shapes (spherical, cylindrical). Depending on the preparation conditions, small unilamellar or large multilamellar vesicles can be produced. The structures meet the self-organization criterion, because they are, albeit on a long time scale, dynamic and not in thermodynamic equilibrium, which would in many cases be a macroscopically phase separated lamellar phase. 

Foscolo, P. U. Gibilaro, L. G. A Fully Predictive Criterion for the Transition between Particulate and Aggregate Fluidization, Chem. Eng. Sci., 39 1667... 

To prioritize the identified precursors in respect to safety, the perceived risk(precursor)=(likelihood, consequences) will be established and is taken as the prioritization criterion. To determine this perceived risk, the likelihood and consequences must be established. The likelihood of the identified precursors is established by establishing a relative frequency and an accompanying aggregation... 

In an early attempt to differentiate between the conditions leading to particulate or aggregative fluidisation, Wilhelm and Kwauk suggested using the value of the Froude number (u f/gd) as a criterion, where ... 

No precise correlation is available between the immersion-compression test and results to be expected from pavements in the field. The test provides comparative guidance on water damage susceptibility. For the diabase aggregate, the Sulphlex-233 mixtures measured dry, and after immersign in the case of wet specimens, exceed the 300 psi (2.07 x 10 pascal) minimum compressive strength usually considered necessary for acceptable mixture performance in the field. Retained strengths generally fall below the 70 percent criterion considered acceptable for asphaltic mixtures. 

To some individuals, especially those who recall their experiences in organic chemistry laboratory, the ultimate step in purification of a molecule is crystallization. The desire to obtain crystalline protein has long been strong and many proteins have been crystallized. However, there is a common misconception that the ability to form crystals of a protein ensures that the protein is homogeneous. For many reasons (entrapment of contaminants within crystals, aggregation of protein molecules, etc.), the ability to crystallize a protein should not be used as a criterion of purity. The interest in pro-... 

In conclusion, we should mention that in the description of the behavior of distinct alkoxides it appears very difficult to distinguish the influence of each of the two factors — the inhomogeneity of the molecular composition and the presence of oxoderivatives. In certain cases the reversibility of transformations and reproducibility of the properties of the oligomeric forms can be used as criterion (as for Al(OPr )3) indicating the constant chemical composition and the dominance of the first factor. At the same time, an irreversible aggregation/ polymerization can result from the both factors. 

A consequence of the cooperativity is that, as schematized in Fig. 2.23, the size distribution curve has a deep minimum the appearance of a pronounced minimum in the size distribution curve is a good criterion for the formation of proper micelles. However, aggregation of amphiphilic compounds is of course not restricted to micelle formation and as indicated in Fig. 2.23 different types of size distribution curves... 

In almost all kinds of amorphous silicas, there are silanol groups, not only on the surface, but throughout the particle structure. Such silanols, which are inaccessible to water are said to be internal (intraglobular). However, there is no clear-cut distinction between internal and surface silanols. The accessibility to water is not by itself a completely defined criterion, since water diffusion depends on physical conditions as effective temperature and state of aggregation of the powder.14... 

The three-digit designation affords a convenient descriptive classification of powders in terms of their bed collapsing behavior, but an additional criterion is desirable to show the entire spectrum of continuous transition of fluidized states from particulate to aggregative. 

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