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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

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.
2

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.
3

Aerodynamics of the Maple Seed

Desenfans, Philip January 2019 (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.
4

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 materials

Peters, Frauke 22 October 2018 (has links)
No description available.

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