Investigations Regarding Bear Cave Massif (Lower Silesia) Long-Term Stability

Bear Cave under Mt ¦nie¿nik is located near the Lower Sile­sian Village of Kletno in a wider tectonic fault zone of Sudeten, Klodzko Valley, South Poland. Stability requirements along the visitor’s path in the cave called for permanent checks of pos­sible rock movements in the massif, while mining operations in the neighbouring marble quarry represented major threat to cave stability. Precise levelling network for vertical movements in the cave and its vicinity was established about 20 years ago. Outside the cave in the Kle¶nica River valley levelling traverses were crossing tectonic faults. Periodical measurements have been repeated since 1984. In the cave two fault zones of major risk have been checked also with TM-71 crack gauges and re­cords have been taken with a month frequency. These two were the tectonic crack zones of the Water Corridor and the main fault structure of the cave found in the Cascade Alley. Fourteen years ago after finding that quarry blasts induced increased movements in the cave, quarry operations were stopped. Re­cently, gradual subsidence of some levelling bench-marks was observed, as well as some periods of increased micro-displace­ments on the tectonic crack zones. Such observations are dis­cussed

Entanglement preparation using symmetric multiports

We investigate the entanglement produced by a multi-path interferometer that is composed of two symmetric multiports, with phase shifts applied to the output of the first multiport. Particular attention is paid to the case when we have a single photon entering the interferometer. For this situation we derive a simple condition that characterize the types of entanglement that one can generate. We then show how one can use the results from the single photon case to determine what kinds of multi-photon entangled states one can prepare using the interferometer.Comment: 6 pages, 2 figures, accepted for publication in European Journal of Physics

Entanglement preparation using symmetric multiports

We investigate the entanglement produced by a multi-path interferometer that is composed of two symmetric multiports, with phase shifts applied to the output of the first multiport. Particular attention is paid to the case when we have a single photon entering the interferometer. For this situation we derive a simple condition that characterize the types of entanglement that one can generate. We then show how one can use the results from the single photon case to determine what kinds of multi-photon entangled states one can prepare using the interferometer.Comment: 6 pages, 2 figures, accepted for publication in European Journal of Physics

New records of teleosts from the Late Turonian (Late Cretaceous) of the Bohemian Cretaceous Basin (Czech Republik)

New discoveries of articulated partial skeletons of teleosts from Upper Turonian strata in the Bohemian Cretaceous Basin (BCB) are described. The infrequent occurrence of articulated skeletons is discussed and compared with comparable taxa from the same time-equivalent successions in southern England. The similarity suggests links between both regions during the Late Turonian. Some palaeoecological interpretations of the fishes are provided