Université de Fribourg

Atomic level widths and shake probabilities as inferred from high-resolution measurements of x-ray emission spectra

Raboud, Pierre-Alexandre ; Dousse, Jean-Claude (Dir.) ; Weis, Antoine (Codir.)

Thèse de doctorat : Université de Fribourg, 2001 ; no 1362.

Two different projects related to Atomic Physics are contained in the present Ph.D. thesis. The first project concerns the natural widths of atomic core levels whereas the second one deals with the double KL excitation of gaseous argon resulting from impact with monoenergetic photons. The first project itself is divided in two parts: the first one is an experimental study of the L1 to N5 atomic...

Université de Fribourg

Arabidopsis-Phytophthora, un pathosystème modèle pour la caractérisation d'une interaction entre une plante et un pathogène oomycète

Roetschi, Alexandra ; Mauch, Felix (Dir.) ; Gisi, Ulrich (Codir.) ; Métraux, Jean-Pierre (Codir.)

Thèse de doctorat : Université de Fribourg, 2001 ; no 1345.

Oomycetes are pathogens responsible for many plant diseases over the world and the economical impact of their damage is quite important. Although these organisms show a mycelar growth, their biology is quite different from that of fungi. This makes them not easy to fight against and up to now no fungicide is able to stop an epidemy due to Oomycetes in a durable way. The particular biology of...

Université de Fribourg

A study of the photophysical and photochemical properties of metal complexes using density functional theory

Buchs, Matthieu ; Daul, Claude (Dir.) ; Schläpfer, Carl-Wilhelm (Codir.) ; Weber, Jacques (Codir.)

Thèse de doctorat : Université de Fribourg, 2001 ; no 1332.

The first objective of this thesis is the calculation of excited state energies and properties of transition metal complexes using Density Functional Theory (DFT). To explore this wide topic, we did choose three different chemical systems. The first one, presented in the chapter 4, is about the photodissociation of the tris(2,2’- bipyridine)ruthenium(II) ([Ru(bpy)3]2+) ion. Over the last two...

Université de Fribourg

Analyse de l'activité de glissements de terrain et relation avec les conditions climatiques : exemples dans les Préalpes fribourgeoises (Suisse)

Oswald, Daniel ; Caron, Christian (Dir.) ; Raetzo, Hugo (Codir.) ; Müller, Imre (Codir.) ; Strasser, André (Codir.)

Thèse de doctorat : Université de Fribourg, 2003 ; no 1417.

Deep landslides (> 10 m) are generally characterized by phases of acceleration alternating with periods of lull, but most often lack real stabilization. Due to the continuous movement, it is difcult to evaluate the evolution of the activity. Therefore, a new methodology has been developed in order to precisely identify the sub-recent (20th century) and present evolution of deep landslide...

Université de Fribourg

Modeling the properties of open d-shell molecules with a multi-determinantal DFT

Rauzy, Cédrick ; Daul, Claude (Dir.)

Thèse de doctorat : Université de Fribourg, 2005 ; Nr. 1465.

Ligand field theory has been used along decades with success to describe ground and excited electronic states originating from dn transition metals complexes. Experimental chemists use such a theory to interpret spectra. On the opposite side, computational chemists can describe with good accuracy the ground states properties but models to calculate excited states properties are still being...

Université de Fribourg

Phenotypic plasticity and genetic differentiation in ruderal and agricultural populations of the weed Senecio vulgaris L. : implications for its biological control

Leiss, Kirsten Anna ; Müller-Schärer, Heinz (Dir.) ; Schmid, Bernhard (Codir.)

Thèse de doctorat : Université de Fribourg, 2000 ; No 1304.

Phenotypic plasticity and genetic differentiation of the annual weed Senecio vulgaris L. from ruderal and agricultural habitats were investigated to evaluate the implications for its biological control with the rust fungus Puccinia lagenophorae Cooke using the system management approach. Weed demographic studies are a prerequisite to any weed control strategy. The population dynamics of S....

Université de Fribourg

Intracellular vesicle transport in "Arabidopsis thaliana" : functional characterization of the t-SNARE homologue AtSNAP33

Wick, Peter ; Sticher, Liliane (Dir.)

Thèse de doctorat : Université de Fribourg, 2002 ; no 1386.

The secretory pathway is a complex endomembrane system essential for all eukaryotic cells. It transports proteins to the extracellular space or to the vacuole. All proteins which are secreted are synthesized at the endoplasmic reticulum (ER) and have a signal peptide in common. The signal peptide is necessary for the transport into the lumen of the ER where the correct folding of the protein...

Université de Fribourg

Molecular analysis of the arabidopsis-Phytophthora pathosystem

Si-Ammour, Azeddine ; Mauch, Felix (Dir.) ; Métraux, Jean-Pierre (Codir.)

Thèse de doctorat : Université de Fribourg, 2002 ; No 1370.

In order to better understand the Phytophthora-plant interaction, we have developed a new pathosystem: Arabidopsis thaliana-Phytophthora porri. At present, the best studied Phytophthora species is P. infestans which caused the dramatic Irish late blight epidemics 150 years ago. Studying the pathosystem Phytophthora infestans-Solanum tuberosum has certain advantages mainly because potato is an...

Université de Fribourg

Inner-shell shake processes in light elements and 3s atomic-level widths of lanthanides

Mauron, Olivier ; Dousse, Jean-Claude (Dir.) ; Schaller, Lukas (Codir.)

Thèse de doctorat : Université de Fribourg, 2003 ; no 1399.

Three different parts related to experimental Atomic Physics are contained in the present Ph. D. thesis. In the three projects the measurements were performed by means of high-resolution x-ray spectroscopy, using a reflecting von Hamos-type bent crystal spectrometer. This experimental technique represents thus the common denominator of the three projects. The two first parts of the thesis are...

Université de Fribourg

Gamma-ray spectroscopy using the (n,γ) and (α,2nγ) reactions

Genilloud, Laurent ; Jolie, Jan (Dir.) ; Dousse, Jean-Claude (Codir.)

Thèse de doctorat : Université de Fribourg, 2000 ; no 1314.

One of the goals of gamma-ray spectroscopy is to study the structure of the atomic nuclei. To this aim, the nucleus has to be brought into excited states by a nuclear reaction. The study of the subsequent electromagnetic decay via the measurement of γ rays then allows one to establish the level scheme of the atomic nucleus. The comparison of this scheme with a theoretical model allows a better...