Ice growth

Recently Meng17 developed a transient, multiphase, multidimensional PEFC model to elucidate the fundamental physics of cold start. The results showed the importance of water vapor concentration in the gas channels, which implies that large gas flow rates benefit cold-start performance. They also found that ice growth in the cathode catalyst layer during cold start was faster under the land than under the gas channels, and accumulated more at the interface between the cathode catalyst layer and GDL. 

Fig. 5.4 Microstructures of porous ceramic from a 28 vol.% slurry concentration, cross-section parallel to the macroscopic ice growth direction (Figure 4b from [5.15])...

Antifreeze proteins (AFPs) are ice-binding proteins found in some organisms (such as fish, insects, plants and soil bacteria) that live at the temperature of their surroundings and encounter freezing conditions. AFPs help organisms to survive below 0°C by inhibiting ice growth. AFPs are structurally diverse, each is radically different from the others in its primary,... 

Harding, M.M., L.G. Ward, and A.D.J. Haymet (1999). Type I antifreeze proteins Structure-activity studies and mechanisms of ice growth inhibition. Eur. J. Biochem. 264 653-665. 

Mix A. C. (1992) The marine oxygen isotope record constraints on timing and extent of ice-growth events (120-65 ka). In The Last Interglacial Transition in North America, Geological Society of America Special Paper (eds. P. U. Clark and P. D. Lea). GSA, Boulder, Co. vol. 270, pp. 19-30. 

FIGURE 4.17 Samples of ceramics with oriented porosity obtained using cryochemical processing (A) Ti02 cross-sections of AljOj ceramics perpendicular (B) and parallel (C) to the macroscopic ice growth direction. ... 

The heat conductivity of snow will therefore change in many areas, affecting ground temperature, permafrost extent and sea ice growth. Resulting effects on climate include ... 

Modification of sea ice growth and areal extent and thus of the albedo of polar oceans. 

Results are shown in Figure 5 b. At the end of April, the ice thickness is 37 cm with the cold scenario and 58 cm with the warm scenario, so that changes in snow kj more than offset atmospheric warming. This increased sea ice thickness clearly constitutes a negative snow-climate feedback loop that deserves consideration in climate models. Of course, this fast ice example cannot be taken at face value, as sea ice growth is much more complex than described here. Other effects must be taken into account such as convection in the water that depend on growth rate, lateral heat fluxes in the ice and turbulent fluxes at the snow-air and sea-ice interfaces. " However, this example does illustrate the importance of one factor, the heat conductivity of snow, that will be affected by climate change. 

The predicted growth velocity dependence of the critical far-field salinity Coo for cellular ice growth is in agreement with observations. 

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