Study, fabrication and testing of a foil-bearing rotor support system

High speed foil bearing rotor support syste

The dynamic behavior of a foil in the presence of a lubricating film

Dynamic response of foil to lubricating fluid fil

The "African humid period" and the record of marine upwelling from excess ^(230)Th in Ocean Drilling Program Hole 658C

Using a high-resolution ^(230)Th normalized record of sediment flux, we document the deglacial and Holocene history of North African aridity and coastal upwelling at Ocean Drilling Program Hole 658C. At both the end of the Younger Dryas and after the 8.2 ka event, there are significant drops in terrigenous accumulation at our site, indicating an increase in the monsoon moisture flux over Africa at this time. At 5.5 ka, there is an abrupt end to the “African humid period” and a return to stronger upwelling conditions. For carbonate and opal fluxes the ^(230)Th normalization completely changes the shape of each record based on percentage variations alone. This site is a clear example of how variations in one sediment component can obscure changes in the others, and it demonstrates the need for radionuclide measurements more generally in paleoceanography. By taking our new records and a large amount of previous data from this site we conclude that increases in African moisture are tightly coupled to decreases in coastal upwelling intensity

Gregarious Behaviour of Evasive Prey

Lecture on the first SFB/TR 15 meeting, Gummersbach, July, 18 - 20, 2004We model the formation of a herd as a game between a predator and a prey population. The predator receives some information about the composition of the herd when he chases it, but receives no information when he chases a solitary individual. We describe situations in which the herd and its leader are in conflict and in which the leader bows to the herd’s wish but where this is not to the benefit of the herd