Search

DIe Dissertationsschrift enthält mehrere teils in wissenschaftlichen Journals veröffentlichte Studien, die im Rahmen der kumulativen Dissertation entstanden. Im Fokus dieser Studien und der vorliegenden Dissertationsschrift steht die Untersuchung und Rekonstruktion Quartärer Umweltveränderungen in terrestrischen Ökosystemen. Dabei wurden Äolianit-paläobodensequenzen untersucht, anhand derer mithilfe von fossilen Gastropoden und deren stabilen Isotopensignalen Umweltinformationen abgeleitet werden.:TABLE OF CONTENT ACKNOWLEDGEMENT ABSTRACT KURZFASSUNG TABLE OF CONTENT 1 INTRODUCTION 1.1 RELEVANCE AND OBJECTIVE OF STUDYING FOSSIL GASTROPODS IN QUATERNARY DEPOSITS 1.2 MAJOR RESEARCH QUESTIONS AND METHODOLOGICAL APPROACH 1.3 STUDY SITES 1.4 REFERENCES 2 QUATERNARY GASTROPOD FAUNAS ON THE EASTERN CANARY ISLANDS AND INDICATIONS OF ENVIRONMENTAL CHANGES 2.1 INTRODUCTION 2.2 GEOGRAPHICAL SETTING 2.3 METHODS 2.4 RESULTS 2.5 DISCUSSION 2.6 CONCLUSIONS 2.7 ACKNOWLEDGEMENT 2.8 REFERENCES 2.9 SUPPLEMENTARY MATERIAL 3 QUATERNARY GASTROPOD FAUNAS IN SOUTHERN CAUCASIA AND INDICATIONS ON ENVIRONMENTAL CHANGES 3.1 INTRODUCTION 3.2 STUDY AREA 3.3 METHODS 3.4 RESULTS 3.5 DISCUSSION 3.6 CONCLUSION 3.7 ACKNOWLEDGEMENT REFERENCES 3.9 SUPPLEMENTARY MATERIAL 4 MALACOLOGICAL INVESTIGATIONS ON EASTERN CANARY SEDIMENT ARCHIVES –STABLE ISOTOPE INTERPRETATION IN AN OZEANIC SETTING 4.1 INTRODUCTION 4.2 GEOGRAPHICAL SETTING AND STATE OF KNOWLEDGE 4.3 METHODS 4.4 RESULTS 4.5 DISCUSSION 4.6 CONCLUSIONS 4.7 ACKNOWLEDGEMENT 4.8 REFERENCES 4.9 SUPPLEMENTARY MATERIAL 5 MALACOLOGICAL INVESTIGATIONS AT SOUTH CAUCASIAN SEDIMENT ARCHIVES –STABLE ISOTOPE INTERPRETATION IN A CONTINENTAL SETTING 5.1 INTRODUCTION 5.2 GEOGRAPHICAL SETTING AND STATE OF KNOWLEDGE 5.3 METHODS 5.3.1 Fieldwork 5.3.2 Laboratory Analyses 5.4 RESULTS 5.6 CONCLUSION 5.7 REFERENCES 5.8 SUPPLEMENTARY MATERIAL 6 SUMMARY AND SYNTHESIS 6.1 COMPARATIVE CONSIDERATION OF THE DIFFERENT SETTINGS 6.2 MAJOR CONCLUSIONS 6.3 PERSPECTIVE 6.4 REFERENCES

The archaeological site Qurayyah, situated in the NW of the Tabuk Province of Saudi Arabia, has been repeatedly described as one of the largest and most significant oases of Northwestern Arabia. Human occupation in the oasis started at least from the early Holocene and continued to the Nabatean, Roman and late Byzantine period. The hydrologically favored position results from its specific geomorphological location where the plateaus fade towards the east and the landscape opens towards the Tabuk Basin so that a balanced water supply was ensured. We present a geomorphological map (1:20,000; main map) based on the interpretation of a high-resolution satellite image and detailed control in the field. The map integrates archaeological, hydraulic and natural features in order to show how the people at Qurayyah structured their landscape and developed water management strategies in relation to prevailing geomorphological processes during the incipient phase (Bronze Age) of the oasis.

Aufgaben, die kontextuell eingebettet sind, bestimmte Lernschrittfolgen unterstützen und Differenzierungen anbieten, werden als Mittel diskutiert, Schüler/innen kognitiv anzuregen sowie Lernprozesse zu initiieren und am Laufen zu halten. Um solche Lernaufgaben in Lehrerbildung und Schulpraxis zu verankern, wurden die subjektiven Überzeugungen von Lehrkräften zur potentiell lernfördernden Funktion von Aufgaben und zum tatsächlichen Ein satz von Aufgaben untersucht. Ebenfalls wurde erhoben, wie sich die Fähigkeit der Einschätzung von Aufgaben entwickeln lässt. Nur mit dem Wissen um diese Überzeugungen können Prozesse der Professionalisierung unterstützt werden. Die Ergebnisse aller Erhebungen und die Evaluation der genutzten Fortbildungskonzepte sind zur Optimierung von Lehreraus- und -fortbildung genutzt worden. Als theoretische Grundlage wurde das Modell der Didaktischen Rekonstruktion verwendet.

In most microfluidic applications, pressure-driven Poiseuille flow in a contained cross-section with no-slip boundary conditions is the underlying fluid- mechanical model. Solutions for this problem exist for many known cross- sections. We have recently demonstrated a simple method to solve the relevant Poisson equation using a finite difference scheme in a spreadsheet analysis tool such as Microsoft Excel. The numerical solutions obtained from such a spreadsheet are close-to-exact to the analytical solutions with errors on the order of only a few percent. However, there are numerous applications in microfluidics for which the no-slip boundary condition is not valid. Examples include drag-reducing air-retaining surfaces as well as open-channel flow. For these scenarios few to no analytical models exist. In this paper, we derive an analytical model for mixed boundary conditions (slip/no-slip) in two dimensions in a rectangular channel cross-section. We also demonstrate that the equivalent numerical solution can be derived conveniently by adaption of the spreadsheet. In general, mixed boundary-type flow scenarios are especially difficult to solve analytically whereas numerical solutions can be derived using Microsoft Excel within seconds.

Arrays with polymer-coated acoustic sensors, such as surface acoustic wave (SAW) and surface transverse wave (STW) sensors, have successfully been applied for a variety of gas sensing applications. However, the stability of the sensors��� polymer coatings over a longer period of use has hardly been investigated. We used an array of eight STW resonator sensors coated with different polymers. This sensor array was used at semi-annual intervals for a three-year period to detect organic solvent vapors of three different chemical classes: a halogenated hydrocarbon (chloroform), an aliphatic hydrocarbon (octane), and an aromatic hydrocarbon (xylene). The sensor signals were evaluated with regard to absolute signal shifts and normalized signal shifts leading to signal patterns characteristic of the respective solvent vapors. No significant time-related changes of sensor signals or signal patterns were observed, i.e., the polymer coatings kept their performance during the course of the study. Therefore, the polymer-coated STW sensors proved to be robust devices which can be used for detecting organic solvent vapors both qualitatively and quantitatively for several years.

International audience; This paper presents a new methodology for generating doubly-curved shapes covered with planar facets. The proposed method, called marionette method relies mainly on descriptive geometry, and it is shown that specifying appropriate projections, e.g. plane view and elevations, defines uniquely a free-form shape. This methodology is highly intuitive and can be used in real-time, mainly because only linear systems of equations are solved. The design-space offered by the marionette method is extremely large, and easily parameterized. Some applications show the potential of this technique for the parameterization of a fabrication-aware design space for structural optimization.