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When exposed to a surface fire, the probability of a tree to survive widely varies, depending on its capability to protect the cambium from lethal temperatures above 60 °C. Thereby, the bark, the entirety of all tissues outside the cambium, serves as an insulation layer. In laboratory experiments, the heat production of a surface fire was simulated and the time span Tau₆₀ until the temperature of 60 °C is reached in the inner bark surface was measured. Thereby, Tau₆₀ - as a measure of the fire resistance - was quantitatively determined for seven tree species. In addition, the influence of bark thickness and moisture content on bark heat insulation capacities was examined. Independent of the tree species and bark moisture content a power function correlation between bark thickness and Tau₆₀ was found. Our results also show that fire resistance increases with decreasing bark density. The seven tree species examined can be classified in two groups differing highly significant in their bark structure: (1) tree species with a faintly structured bark, which show a low fire resistance, and (2) tree species with an intensely structured bark, showing a high fire resistance. Furthermore a mathematical model simulating heat conduction was applied to describe the experimental results, and some ideas for a transfer into biomimetic materials are presented

Hollow microspheres are spherically symmetrical particles consisting of at least two phases. Their sales are continuously increasing because of a large number of well-known and new applications. While most of the current needs for hollow microspheres are met by inorganic byproducts of combustion processes (cenospheres), the fabrication of tailor-made hollow sphere structures by processes like spray-drying as well as dripping, emulsion and suspension techniques is gaining more and more interest. Surface phenomena play an important role as far as formation, properties and stability of hollow microspheres are concerned. Template techniques can be used to yield structures that have not been available so far. Modeling and simulation of the formation processes are useful tools to understand the formation mechanisms and to simplify the scaleup.

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