One-second criterion

The role of turbulence in assisting with suspension stability is described in Section 10.3.1. For example, a rule of thumb for the role of turbulence in maintaining sufficient suspension stability for mineral flotation is the one-second criterion which states that the particles in a suspension are sufficiently well dispersed for flo-... 

Practical flotation processes, however, take place under conditions of turbulence. Turbulent flow, as opposed to laminar flow (see Section 6.1), is characterized by rapid, almost random, fluctuations in flow velocity. Turbulence helps keep the solid particles suspended, helps disperse the injected air phase into bubbles, and helps induce particle-bubble collisions and attachments. With regard to the role of turbulence in mineral flotation, a rule of thumb for suspension stability is the one-second criterion which states that the particles in a suspension are sufficiently well dispersed for flotation if individual particles do not remain settled at the bottom of the flotation vessel for longer than one second [53]. 

Due to the second criterion, time-to-tumor models were eliminated from consideration. These models require more detailed experimental data than is generally available. Moreover, it is difficult and unproductive to interpret the distribution of time-to-tumor in the context of human exposures. In most cases, the time-to-tumor variable would be integrated over a human lifetime, thus reducing the model to a purely dose-dependent one. Therefore we restrict our attention to quantal response models that estimate lifetime risks. 

This is one example of the second criterion mentioned previously. However, the other OH substituents, depending upon the furanose ring conformation, are either eclipsed or in the anti conformation. In the former they are disposed to form a strong intramolecular hydrogen bond in the latter they are incapable of such bonding. Further evidence to support the contention that free / -D-fructofuranose is nearly tasteless is seen in the thermal mutarotation (3) of D-fructose. As the temperature of D-fruc-... 

The second criterion for stability implies that even polyhedra should be preferred to odd ones. One way to check the parity label automatically is to calculate the eigenvectors of the adjacency matrix obtained by deletion of the six pentagon-pentagon links of the original fullerene. Since the cut fullerene is an alternant,... 

Aristode s account of number thus places two requirements on any numerical plurality. First, there must be some unit in the plurality. This requires there to be some criterion by which something can be said to numerically one. Second, each of the members of the plurality must fall under some single universal F. With both these conditions satisfied, it is possible for each single member to be numerically one— this is made possible by the existence of a criterion for numerical oneness—for each member to fall under the single universal F—this is made possible by the fact that F is a universal—and hence for there to be some number n of F s in the plurality. 

As homogeneous suspension in nonaerated stirred vessels can hardly be achieved, even with very high stirrer speeds, mainly Nc, needed for complete suspension, is of interest for the design purposes. This value, by definition, is characterized by the just-suspended criterion, i.e., the state where only a small fraction of the solids remains at the bottom of the reactor for one second at maximum (Einenkel, 1979). Zwietering (1958) proposed the following correlation to predict Nc, the minimum rotational speed of agitation required for the complete suspension ... 

If all molecular orbitals were filled, then there would have to be one electron in each spin state on each atom, and this gives rise to a second criterion for c-values, namely that the sum of the squares of all the c-values on any one atom in all the molecular orbitals must also equal one. Thus the antibonding orbital of hydrogen will have c-values of 0.707 and —0.707, because these values make the whole set fit both criteria. 

Stoichiometry. At present the observed limit of two halide ions per metal does not seem particularly important as a necessity for close approach of the cations and hence suitable band formation rather, it more probably results from other characteristics of this formal oxidation state for these elements. One possible fact to the contrary is that thorium (III) iodide is evidently not metallic (4), though it would probably meet the second criterion below. The general electronic conduction in sulfide vs. chloride melts in the metal-rich region (as well as in the solid state) may be attributed to the lower anion to cation ratio and therefore closer approach of the cations (5), although covalency as discussed below may be more significant. 

These observations and one further criterion start to define quantum dot systems. The second major possibility is the coating of the central particle with a second material e.g. CdS or ZnS on top of CdSe. When a wider band gap material is coated onto the outside of a narrow band gap material the confinement on the core is enhanced, leading to enhanced optical properties, especially photoluminescence efficiencies. 

We must now look at the coefficients, c, of equation 2-1. When there are electrons in the orbital, the squares of the c-values are a measure of the electron population in the neighbourhood of the atom in question. Thus in each orbital the sum of the squares of all the c-values must equal one, since only one electron in each spin state can be in the orbital. Now the orbitals in hydrogen are symmetric about the mid-point of the H—H bond in other words c2 must equal c2. Thus we have defined what the values of c, and c2 in the bonding orbital must be, namely 1/ /2 = 0-707. If all molecular orbitals were filled, then there would have to be one electron in each spin state on each atom, and this gives rise to a second criterion for c-values, namely that the sum of the squares of all the c-values on any one atom in all the molecular orbitals must also equal one. Thus the antibonding orbital of hydrogen, [Pg.7]

Several criteria must be considered in the selection of the diluent solvent. The first one is biocompatibility, that is, the solvent must not be toxic to the biodegrading microorganism [10]. The second criterion is the resistance to biodegradation and/or utilization by the active microorganism used, that is, so-caUed (non)bioavailability [8]. Third criterion is the favorable mass-transfer characteristics for the biodegraded pollutant [1], and the fourth criterion is the mutual immiscibility of the diluent with the treated waste-water [1]. The fifth criterion is the hmited volatility of the diluent [11]. 

The second one is the diffusion stability criterion, which imposes the net and spontaneous diffusion (i.e. in the absence of any external forces) of species from concentrated regions to less concentrated ones. This criterion is formulated by ... 

The second criterion for mechanism-based enzyme inactivation concerns the stoichiometry of enzyme modification. If mechanism-based inactivation of an enzyme is the result of specific covalent modification of an essential active site amino acid residue, then one radiolabeled inactivator molecule should be incorporated per active site. The stoichiometry of specific radiolabeling should also correlate with the extent of inactivation. In multimeric enzymes which display negative cooperativity, it is possible to observe complete inactivation following substoichiometric modification of the enzyme (Johnston et al., 1979). 

The Polymer Data Handbook offers, in a standardized and readily accessible tabular format, concise information on the syntheses, structures, properties, and applications of the most important polymeric materials. Those included are currently in industrial use or they are under study for potential new applications in industry and in academic laboratories. Considerable thought was given to the criteria for selecting the polymers included in this volume. The first criterion was current commercial importance—the use of the polymer in conunercial materials—for example, as a thermoplastic, a thermoset, or an elastomer. The second criterion was novel applications—a polymer that is promising for one or more purposes but not yet of conunercial importance—for example, because of its electrical conductivities, its nonlinear optical properties, or its suitability as a preceramic polymer. The hope is that some readers wiU become interested enough in these newer materials to contribute to their further development and characterization. Finally, the handbook includes some polymers simply because they are unusually interesting—for example, those utilized in fundamental studies of the effects of chain stiffness, self-assembly, or biochemical processes. 

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