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Université de Fribourg

Hybrid ligand-field theory/quantum chemical calculation of the fine structure and ZFS in lanthanide(III) complexes

Borel, Alain ; Helm, Lothar ; Daul, Claude A.

In: Chemical Physics Letters, 2004, vol. 383 (5-6), p. 584-591

Ligand field effects in lanthanide ions compounds have consequences for optical and magnetic spectroscopy. In the analysis of electron paramagnetic resonance spectra of Gd³⁺ complexes, a major role is played by the zero field splitting (ZFS), which is a high order consequence of the ligand field and the spin–orbit coupling. We present a general parameterized method and a computer program for...

Université de Fribourg

Application of the density functional theory derived orbital-free embedding potential to calculate the splitting energies of lanthanide cations in chloroelpasolite crystals

Zbiri, Mohamed ; Atanasov, Mihail ; Daul, Claude A. ; Garcia-Lastra, Juan Maria ; Wesolowski, Tomasz A.

In: Chemical Physics Letters, 2004, vol. 397(4-6), p. 441-446

Ligand field splitting energies of lanthanides Ln³⁺ (Ln = from Ce to Yb) in octahedral environment are calculated using the Hohenberg–Kohn theorems based orbital-free embedding formalism. The lanthanide cation is described at orbital level whereas its environment is represented by means of an additional term in the Kohn–Sham-like one-electron equations expressed as an explicit functional...

Université de Fribourg

The tip60 HAT-complex is recruited to chromatin by the transcription factors E2F and Myc

Taubert, Stefan ; Conzelmann, Andreas (Dir.)

Thèse de doctorat : Université de Fribourg, 2003 ; no 1409.

The oncogenic transcription factors E2F and Myc bind to specific DNA sequences at distinct times during the G1 phase of the mammalian cell cycle, and regulate transcription of a plethora of target genes. E2F and Myc associate with TRRAP, a subunit of distinct macromolecular complexes that contain the histone acetyltransferases (HATs) Gcn5/PCAF or Tip60. During the course of my thesis I...

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

EMuds : adaptation in text-based virtual worlds

Robert, Antony ; Courant, Michèle (Dir.)

Thèse de doctorat : Université de Fribourg, 1999 ; no 1272.

This thesis introduces a methodological approach to artificial agent design. In an attempt to solve the symbol grounding problem of artificial intelligence, a new theoretical perspective on the agent-environment relation is explored and experimentation is led to motivate this methodology. From the original idea that in order to ground an agent in an environment, the agent’s representation...

Université de Fribourg

Towards active network management with "Ecomobile", an ecosystem-inspired mobile agent middleware : design, implementation, simulation and application to optical networks

Rossier-Ramuz, Daniel ; Hirsbrunner, Beat (Dir.) ; Scheurer, Rudolf (Codir.)

Thèse de doctorat : Université de Fribourg, 2002 ; no 1392.

The future multi-layer optical networks based on wavelength division multiplexing technology will lead to the creation of new value-added optical services, which is bound to transform the traditional passive transport network into an active and intelligent transport layer. The successful deployment of these complex networking services and the possibility of subjecting them to a dynamic control,...

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...

Université de Fribourg

Optimierung automatisierter Kompaktlager in Entwurf und Steuerung

Klinkert, Andreas ; Gröflin, Heinz (Dir.) ; Liebling, Thomas M. (Codir.)

Thèse de doctorat : Université de Fribourg, 2001 ; N° 1353.

This thesis investigates the optimization of automated high-density storage systems at design stage and in control logic development. In modern storage technology, automated high-density storage systems offer a space saving alternative to traditional storage rack systems. They comprise several floors subdivided into parallel storage aisles and linking cross-aisles. Pallet movements are...

Université de Fribourg

Substrate cycling between de novo lipogenesis and lipid oxidation: a thermogenic mechanism against skeletal muscle lipotoxicity and glucolipotoxicity

Dulloo, Abdul G. ; Gubler, Marcel ; Montani, Jean-Pierre ; Seydoux, Josiane ; Solinas, Giovanni

In: International Journal of Obesity, 2004, vol. 28 (Suppl. 4), p. S29-S37

Life is a combustion, but how the major fuel substrates that sustain human life compete and interact with each other for combustion has been at the epicenter of research into the pathogenesis of insulin resistance ever since Randle proposed a 'glucose-fatty acid cycle' in 1963. Since then, several features of a mutual interaction that is characterized by both reciprocality and dependency between...