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You searched for +publisher:"Freie Universität Berlin" +contributor:("Prof. Walter Franke"). One record found.

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Freie Universität Berlin

1. Gratz, Kristin. Determineation of the thermals diffusivity in water- free carbonates.

Degree: 2006, Freie Universität Berlin

With the available work succeeded in creating a data record of the anisotropic heat transport characteristics most important trigonal and orthorhombic carbonates. Usually the heat transport characteristics could be determined also as function of the temperature. The maximum thermal diffusivity became in the trigonalen magnesite toward c axis (6.3 mm²/s) and minimum thermal diffusivity in orthorhombischen cerussite in [001] - direction (0.6 mm²/s) measured. By the measurement of the thermal diffusivity as a function of orientation the anisotropy of the thermal diffusivity could be determined. The highest anisotropy became in the magnesite (128%) and the smallest in Rhodochrosit (7%) are determined. In order to determine the temperature dependence of the thermal diffusivity, two models were tested: the Eucken model and the model after Roufosse and Klemens (1973, 1974). With a suitable model the thermal diffusivity of the phonons in carbonates could be determined at temperatures above the dissociation temperature meaningfully. During the view of the middle thermal diffusivity as a function of the middle cation weights of the minerals a systematic connection is observed. With rising middle cation weight the thermal diffusivity of the carbonates sinks. Within the trigonal carbonates this dependence is stronger than with the orthorhombic carbonates. In first approximation for the trigonal carbonates a square was recognized, for the orthorhombic carbonates a linear connection. A nonlinear dependence is observed between the middle velocity of sound and the mean free path length. After Roufosse and Klemens (1974) follow that with rising middle phonon velocity also the mean free path lengths rise. The minerals magnesite, dolomite and calcite form a pseudobinary system. The dolomite exhibits an structure with alterating layers of magnesium and calcium atoms. It s possible to compute the thermal diffusivity of the dolomite with the help of the endmembers magnesite and Calcit, if the structural details are considered. To determine the middle thermal diffusivity toward the c-axis must the Reuss means, perpendicularly to the crystallographic c-axis the Voigt means, from the values of the endmemebers are used. During the investigation of the symmetry influence on the thermal diffusivity the chemically identical minerals calcit (trigonal) and aragonite (orthorhombisch) regards. The results show that the mineral with the higher symmetry, exhibits calcit, a higher middle thermal diffusivity (1.9 mm²/s) than lower symmetrical aragonite (1.4 mm²/s). Advisors/Committee Members: n (gender), Prof. Frank R. Schilling (firstReferee), Prof. Walter Franke (furtherReferee).

Subjects/Keywords: thermal diffusivity; heat transport; carbonates; mean free path length; 500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::550 Geowissenschaften

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APA (6th Edition):

Gratz, K. (2006). Determineation of the thermals diffusivity in water- free carbonates. (Thesis). Freie Universität Berlin. Retrieved from http://dx.doi.org/10.17169/refubium-4335

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Gratz, Kristin. “Determineation of the thermals diffusivity in water- free carbonates.” 2006. Thesis, Freie Universität Berlin. Accessed October 31, 2020. http://dx.doi.org/10.17169/refubium-4335.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Gratz, Kristin. “Determineation of the thermals diffusivity in water- free carbonates.” 2006. Web. 31 Oct 2020.

Vancouver:

Gratz K. Determineation of the thermals diffusivity in water- free carbonates. [Internet] [Thesis]. Freie Universität Berlin; 2006. [cited 2020 Oct 31]. Available from: http://dx.doi.org/10.17169/refubium-4335.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Gratz K. Determineation of the thermals diffusivity in water- free carbonates. [Thesis]. Freie Universität Berlin; 2006. Available from: http://dx.doi.org/10.17169/refubium-4335

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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