Dresden 2014 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 41: Poster - Pattern/ Nonlinear Dyn./ Fluids/ Granular/ Critical Phen.

DY 41.2: Poster

Donnerstag, 3. April 2014, 17:00–19:00, P3

Growth of Hair Ice — •Christina Inninger¹, Lorenz Eichler¹, Christian Mätzler², and Thomas Grillenbeck¹ — ¹Ignaz-Günther-Gymnasium Rosenheim, Rosenheim, Germay — ²University of Bern, Institute for Applied Physics, Switzerland

The hair-like or cotton-like ice formations known as hair ice are sometimes to be observed on rotten and humid beech wood or oak. Its origin is not quite clear. The supposition that an active fungus causes the growth to the strange phenomenon rests on some physical and wooden-anatomical facts: Saprophytic fungi feed on organic nutrients which they diminish enzymatically. The end products CO₂ and H₂0 as well as some warmth originate during the enzymatic degradation of starch and fat stored in the wooden body above all the wooden rays. The gas pressure of the CO₂ expels the water stored in the wooden body as well as the water produced in the degeneration process through the radial channels of the rays to the wood surface. On the surface it freezes at temperatures slightly below melting point due to the crystallization germs. We study the growth process and distinguish hair ice from related forms, such as ice ribbons and needle ice.