Ceramics, cellular

Valdes-Solis T, Marban G, Fuertes AB. 2001. Low-temperature SCRof NOx with NH3 over carbon-ceramic cellular monolith-supported manganese oxides. Catal Today 69(l-4) 259-264. 

Some cooling towers operate with natural draft. This is possible because the warmer, humid air inside the tower is less dense than the colder, drier outside air. Many such towers are hyperbolic and may require an overall height of 220 ft. The fill used in such a column must be quite open to avoid any significant pressure drop. Such fill can have a tee- or vee-shaped cross section molded from perforated plastic sheets. Corrugated sheets made of asbestos and cement are popular in large natural draft towers. A ceramic cellular block that is stacked into the tower also is used. These fills, however, provide a small interfacial area per cubic foot so mass transfer is rather low per foot of packed depth. 

Jarcho, M., Kay, J.L., Gumaer, R.H. and Drobeck, H.P. (1977) Tissue, cellular, and subcellular events at a bone-ceramic apatite interface. Journal of Bioengineering, 1, 79-92. 

The term foam is defined as a gaseous void surrounded by a much denser continuous matrix, generally a liquid or a solid phase. As a result of the distinct characteristics of the two phases, such cellular materials are able to feature unique properties. Since nature successfully demonstrated their use in manifold examples, such as bones, wood, plant stalks, cork, and sponges, foams have also sparked interest for technical application. Nowadays, a broad range of cellular materials based on metals, ceramics as well as polymers, is readily available, and their structures are as versatile as their applications. 

Materials science associated with fracture mechanics has mainly been confined to composite materials such as concrete, ceramics and metals. Much of the emphasis of the research has been on preventing fatigue and failure rather than designing for it to occur. The way a structure deforms and breaks under stress is crucial for properties such as flow and fracture behaviour, sensory perception of structure, water release and the mobility and release of active compounds. In the case of foods, the ability to break down and interact with the mouth surfaces provides texture and taste attributes. The crack propagation in a complex supramolecular structure is highly dependent on the continuous matrix, interfacial properties and defects and the heterogeneity of the structure. Previous structure-fracture work has dealt with cellular plant foods, and it has been demonstrated that the fracture path differs between fresh and boiled carrots due to cellular adhesion and cell wall strength as well as cell wall porosity and fluid transport (Thiel and Donald 1998 Stoke and Donald 2000 Lillford 2000). 

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