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1. Modified shape of the Eiffel Tower determined for an atmospheric boundary-layer wind profile.

Author

Weidman, P. D.

Subjects
*TOUR Eiffel (Paris, France), *BOUNDARY layer (Aerodynamics), *WINDS, *TURBULENCE
Abstract

The design and construction of the Eiffel Tower was based, in part, on a uniform horizontal wind model giving 300 kg m-2 kinematic pressure acting on the surface of the tower. Eiffel received a patent for his method of construction that eliminates the need for diagonal trellis bars used to resist the moment of an oncoming wind. At the end of the 19th century boundary-layer theory, laminar or turbulent, was nonexistent. Now, however, models for atmospheric flow over rough landscapes are available, the simplest being a power-law distribution of velocity with height. In this paper we deduce the shape of the tower had Eiffel incorporated this information into the design and construction of his world famous tower. Moreover, we prove Eiffel’s observation that the tower profile conforms to the moment distribution wrought by the wind. [ABSTRACT FROM AUTHOR]

Published
2009
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2. The Simbol-X Anticoincidence.

Author

Chabaud, J., Laurent, P., Colonges, S., Barbay, J., Baronick, J. P., Benallou, M., Ferrando, P., Gilliot, M., Jaeger, J. J., Nicolas, M., Ollivier, E., Waisbard, J., and Yoffo, B.

Subjects
*TELESCOPES, *ARTIFICIAL satellites, *OPTICAL detectors, *ROCKET payloads, *PHOTONS, *SCINTILLATORS
Abstract

The Simbol-X telescope will be constitued by two satellites in formation flight. One will host the mirror module and the other the detector payload. This payload will be built with two main detectors able to measure the position, energy and arrival time of each focused photon, between 0.5 and 80 keV. The high sensitivity required by Simbol-X will necessitate low noise background detectors. To achieve this goal, those detectors will be surrounded by a passive graded shield, aimed to stop the out of field of view photons, and an active anticoïncidence system to tag the passing particles. This anticoïncidence detector, whose conception, optimisation and realization are under responsibility of the APC Laboratory, Paris, is based on plastic scintillator plates associated to multi-anodes photo-multipliers via optical fibers. In this paper, we will present the present status of the anticoïncidence system and its expected performances. [ABSTRACT FROM AUTHOR]

Published
2009
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