Tracing the mode and speed of intrageneric evolution a phylogenetic case study on genus Acer L. (Aceraceae) and genus Fagus L. (Fagaceae) using fossil, morphological, and molecular data /Grimm, Guido W. January 2005 (has links) (PDF)
Tübingen, University, Diss., 2003.
Charakterisierung der genetischen Variation europäischer Populationen von Acer spp. und Populus tremula auf der Basis der Chloroplasten-DNA : Rückschlüsse auf die postglaziale Ausbreitung und Differenzierung forstlicher Provenienzen /Bittkau, Christiane. January 2002 (has links) (PDF)
Techn. Univ., Diss.--München, 2002.
(has links) (PDF)
Purpose - The paper presents a theoretical framework that describes the aerodynamics of a falling maple (Acer pseudoplatanus) seed. --- Methodology - A semi-empirical method is developed that provides a ratio stating how much longer a seed falls in air compared to freefall. The generated lift is calculated by evaluating the integral of two-dimensional airfoil elements using a preliminary falling speed. This allows for the calculation of the definitive falling speed using Blade Element Momentum Theory (BEMT); hereafter, the fall duration in air and in freefall are obtained. Furthermore, the input-variables of the calculation of lift are transformed to require only the length and width of the maple seed. Lastly, the method is applied to two calculation examples as a means of validation. --- Findings - The two example calculations gave percentual errors of 5.5% and 3.7% for the falling speed when compared to measured values. The averaged result is that a maple seed falls 9.9 times longer in air when released from 20 m; however, this result is highly dependent on geometrical parameters which can be accounted for using the constructed method. --- Research limitations - Firstly, the coefficient of lift is unknown for the shape of a maple seed. Secondly, the approximated transient state is yet to be verified by measurement. --- Originality / Value - The added value of this report lies in the reduction of simplifications compared to BEMT approaches. In this way a large amount of accuracy is achieved due to the inclusion of many geometrical parameters, even though simplicity is maintained. This has been accomplished through constructing a simple three-step method that is fundamental and essentially non-iterative.
Vergleich dielektrisch behinderter Entladungen bezüglich der physikalischen Eigenschaften und der Wirkung auf Holz und Holzwerkstoffe / Comparison of dielectric barrier discharges regarding their physical properties and the influence on wood and wooden materialsPeters, Frauke 22 October 2018 (has links)
No description available.
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