Snowball mechanism

The liquid-phase requirement for the snowballing mechanism may be computed in the following manner (S10). It is assumed that the liquid withdrawal is negligible (i.e., g = 0) and the fractional saturation in the deposited... 

Fig. 10. Four elementary pellet growth mechanisms (a) snowballing (b) crushing and layering (c) coalescence (d) abrasion transfer. [From Sastry and Fuerstenau (S5).]...

Bagchi and co-workers [47-50] have explored the role of translational diffusion in the dynamics of solvation by employing a Smoluchowski-Vlasov equation (see also Calef and Wolyness [37] and Nichols and Calef [42]). A significant contribution to polarization relaxation is observed in certain cases. It is found that the Onsager inverted snowball model is correct only when the rotational diffusion mechanism of solvation dominates the polarization relaxation. The Onsager model significantly breaks down when there is an important translational contribution to the polarization relaxation [47-50]. In fact, translational effects can rapidly accelerate solvation near the probe. In certain cases, the predicted behavior can actually approach the uniform continuum result that rs = t,. 

In our model, cap carbonates are explained as a result of high carbonate alkalinity in an ice-covered ocean, regardless of the specific mechanism for melting the snowball Earth. Ice could melt for a variety of reasons (e.g., greenhouse gases, a positive perturbation in solar forcing, a decrease in planetary albedo), but cap carbonates are expected to be produced as a result of the transition from high to low oceanic carbonate alkalinity. 

Sorby (1879) put forth one of the earliest non-biological hypotheses for the mechanism of odid formation. His basic idea was that odids with a concentric structure form by a process similar to that which forms a snowball. In his model, an organic coating is biologically deposited (the infamous "mucilagenous slime") on... 

Grievance cells and other mechanisms for resolution of conflicts with workforce shall always be in force. No legitimate problem shall be ignored. Officers of this department as well as other senior engineers and managerial staff shall be alert to see that any discontent brewing in the organisation does not snowball into a major conflict. 

The step up in oxygen was followed by a swift step down in temperature, an event called Snowball Earth in which ice covered most of the Earth. The mechanism is not entirely worked out, but each Great Oxidation Event was accompanied by a Great Freezing, and each time, the planet came disturbingly close to becoming a lifeless chunk of icy rock. Oxygen turned Eden into Hoth. 

Figure 2-9 Representation of growth mechanisms (a) coalescence, (b) breakage, (c) abrasion transfer, (d) snowballing and nucleation. The symbol represents a green pellet of mass rrif (= ih) Pqi represents a freshly added nuclei of mass h (Sastry and Fuerstenau, 1973). Reproduced by permission of Powder Technology, Elsevier Sequoia S.A.

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