The paper presents experimental investigations of pressure fluctuations near the tip clearance region of the rotor blades of the axial-flow low-speed compressor stage in stable and unstable parts of the overall performance characteristic. In this investigation, unsteady pressure was measured with the use of high frequency pressure transducers mounted on the casing wall of rotor passage. The pressure signals and their frequency characteristics were analyzed during the steady-state processes, before the rotating stall, during the transition from the steady-state process to the rotating stall, and during a stabilized phenomenon of low-frequency rotating stall. As the operating point moves to the unstable region of flow characteristic, an inception of the rotating stall can be observed, which rotates with a speed of about 41.4% of the rotor speed. The results of this study confirm that in the low-speed axial compressor stage operating in a rotating stall regime there appears one stall cell that spreads over to adjacent rotor blade channels. As the flow rate is reduced further, the frequency of the rotating stall decreased to 34.8% of the rotor speed and the number of blade channels with the stall cell increases.

A two-scale numerical homogenization approach was used for granular materials. At small-scale level, granular micro-structure was simulated using the discrete element method. At macroscopic level, the finite element method was applied. An up-scaling technique took into account a discrete model at each Gauss integration point of the FEM mesh to derive numerically an overall constitutive response of the material. In this process, a tangent operator was generated with the stress increment corresponding to the given strain increment at the Gauss point. In order to detect a loss of the solution uniqueness, a determinant of the acoustic tensor associated with the tangent operator was calculated. Some elementary geotechnical tests were numerically calculated using a combined DEM-FEM technique.

Maria Hagen-Schwerin was a 19th-century novelist and poet. She was a prolific author of popular romances with aristocratic heroes and plots that revolve around love and marriage in high society. However, what kept Mrs Hagen in the public eye was her unconventional life style, her debts and an unending string of affairs whose sensational twists eclipsed anything that could be found her polite fiction. Her feuds, especially with another controversial woman of the fin-de- siècle Cracow, the playwright and novelist Gabriela Zapolska, were the talk of the town. Maria Hagen descended, on her father's side from a long line of nobles (Łoś) and on her mother's side from one of Cracow's wealthiest merchant families (Kirchmayer). Her elder brother Wincenty Łoś was an acclaimed writer and art collector. It is no exaggeration to say that Maria Hagen was heir to a family legacy of great achievements and of great scandals, too, in politics as well as in economic and social life. Some of her ancestors also ventured into literature thus building a family tradition which continued for three centuries. Maria Hagen picked up that thread and became a successful writer in her day. Now she belongs to that large category of writers once famous, but quickly forgotten. The problem lies not in the fact that nobody reads her books, but that her work has attracted virtually no attention from students of nineteenth-century literature and culture, and, astonishingly enough, no critical study of her work has been written for over 150 years since her death.