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Université de Fribourg

Characterization of chrysotile, tellurium and iImogolite nanotubes

Métraux, Cédric ; Grobéty, Bernard (Dir.) ; Jenny, Titus (Codir.)

Thèse de doctorat : Université de Fribourg, 2008.

The discovery of C60 (R. Smalley et al.) and carbon nanotubes CNTs (S. Iijima) in 1985 and 1991 respectively was a milestone in the field of nanoscience. Since 1991, WS2, MoS2, BN, Se, Te nanotubes were synthesized and analyzed. These nanotubes are promising materials for many applications in the field of catalysis, electronic, polymer synthesis, etc. In this study, we characterized the...

Université de Fribourg

Spatio-temporal variations of rockfall activity into forests results from tree-ring and tree analysis

Stoffel, Markus ; Monbaron, Michel (Dir.) ; Kienholz, Hans (Codir.) ; Strunk, Horst (Codir.) ; Raetzo, Hugo (Codir.)

Thèse de doctorat : Université de Fribourg, 2005 ; Nr. 1480.

Rockfall represents one of the most common geomorphological processes in mountain regions and has extensively been studied in the past. Nonetheless, detailed data on frequencies (how often), volumes (how large), spatial distributions (where) or the seasonality (when) of rockfall activity remain scarce and most of the time fragmentary. Similarly, tree-ring analysis has only exceptionally been used...

Université de Fribourg

Carbonate sedimentology, sequence stratigraphy, and cyc-lostratigraphy of the Tithonian in the Swiss and French Jura Mountains : a high-resolution record of changes in sea level and climate

Rameil, Niels ; Strasser, Andreas (Dir.) ; Bosence, Daniel W.J. (Codir.) ; Bläsi, Hansruedi (Codir.)

Thèse de doctorat : Université de Fribourg, 2005 ; Nr. 1493.

The present study aims at a better understanding of the development of the Swiss and French Jura platform during the Jurassic/Cretaceous (J/K) boundary interval, with a special focus on the Tithonian stage. Nine reference sections were measured in the Jura Mountains of northwestern Switzerland and eastern France, in the Helvetic Alps, and in the Subalpine Ranges in south-eastern France. Their...

Université de Fribourg

Sequenzielle Faziesentwicklung der Karbonatplattform des Schweizer Jura im Späten Oxford und frühesten Kimmeridge

Hug, Wolfgang Alexander ; Strasser, André (Dir.)

Thèse de doctorat : Université de Fribourg, 2003 ; Nr. 1407.

Im Späten Oxford und frühesten Kimmeridge herrschten im Bereich des heutigen zentralen Schweizer Juras Karbonat-dominierte Ablagerungsbedingungen auf einer flachen Plattform. An der Schwelle zwischen borealen Ablagerungsäumen im Norden und der Tethys im Süden entwickelten sich dynamische Sedimentationssysteme, unter subtropischem und semiaridem bis aridem Klima (Paläobreite von 33° bis 38°...

Université de Fribourg

Analyzing rockfall activity (1600–2002) in a protection forest—a case study using dendrogeomorphology

Stoffel, Markus ; Schneuwly, Dominique M. ; Bollschweiler, Michelle ; Lièvre, Igor ; Delaloye, Reynald ; Myint, Moe ; Monbaron, Michel

In: Geomorphology, 2005, vol. 68(3-4), p. 224

For the first time, dendrogeomorphology has been used to investigate spatial and temporal variations of rockfall activity in a protection forest. We report results of 564 cores from 135 severely injured Larix decidua Mill. trees on the west-facing Täschgufer slope, Swiss Alps. While trees sampled reached an age of 297 years on average, the oldest one attained breast height in AD 1318. For...

Université de Fribourg

Mont Blanc and Aiguilles Rouges geology of their polymetamorphic basement (external massifs, Westerns Alps, France-Switzerland)

Raumer, Jürgen F. von ; Bussy, François

In: Mémoires de Géologie (Lausanne), 2004, vol. 42, p. 1-210

The Aiguilles Rouges and Mont Blanc external massifs belong to the pre-Mesozoic basement areas of the external domain of the Alps. Before their involvement into the Alpine building (basement nappes) they registered a multiple geological evolution comprising the deposition of Neoproterozoic to Cambrian sediments and emplacement of granitoid and metabasic to ultramafic magmatic rocks of Early...

Université de Fribourg

The Aptian, Albian and Cenomanian of Roter Sattel, Romandes Prealps, Switzerland: a high-resolution record of oceanographic changes

Strasser, André ; Caron, Michèle ; Gjermeni, Maksim

In: Cretaceous Research, 2001, vol. 22 (2), p. 173

The Aptian–Lower Turonian hemipelagic sediments of Roter Sattel in the Swiss Prealps are well dated by planktonic foraminifera. Stacking pattern of the limestone-marl alternations and facies evolution allow the identification of sequence boundaries, transgressive surfaces, and maximum-flooding events or condensed sections on at least two hierarchical levels. Calibrated by a precise...

Université de Fribourg

The stratigraphic architecture and evolution of the Burdigalian carbonate—siliciclastic sedimentary systems of the Mut Basin, Turkey

Bassant, P. ; Buchem, F.S.P. van ; Strasser, André ; Görür, N.

In: Sedimentary Geology, 2005, vol. 1-4(3), p. 187

This study describes the coeval development of the depositional environments in three areas across the Mut Basin (Southern Turkey) throughout the Late Burdigalian (early Miocene). Antecedent topography and rapid high-amplitude sea-level change are the main controlling factors on stratigraphic architecture and sediment type. Stratigraphic evidence is observed for two high-amplitude (100–150 m)...

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.

Les glissements de terrain profonds (> 10 m) sont généralement caractérisés par des phases d'accélération alternant avec des périodes d'accalmie, mais le plus souvent sans montrer de réelle stabilisation. Il est donc difcile d'étudier l'évolution de l'activité compte tenu de la continuité des mouvements. Pour cela, une méthode d'analyse a été mise en place an de reconnaître...