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2.
Rev Sci Instrum ; 84(3): 033904, 2013 Mar.
Article En | MEDLINE | ID: mdl-23556827

Great effort is currently being put into the development and construction of the second generation, advanced gravitational wave detectors, Advanced Virgo and Advanced LIGO. The development of new low thermal noise suspensions of mirrors, based on the experience gained in the previous experiments, is part of this task. Quasi-monolithic suspensions with fused silica wires avoid the problem of rubbing friction introduced by steel cradle arrangements by directly welding the wires to silica blocks bonded to the mirror. Moreover, the mechanical loss level introduced by silica (φfs ∼ 10(-7) in thin fused silica wires) is by far less than the one associated with steel. The low frequency dynamical behaviour of the suspension can be computed and optimized, provided that the wire bending shape under pendulum motion is known. Due to the production process, fused silica wires are thicker near the two ends (necks), so that analytical bending computations are very complicated. We developed a tool to directly measure the low frequency bending parameters of fused silica wires, and we tested it on the wires produced for the Virgo+ monolithic suspensions. The working principle and a set of test measurements are presented and explained.

5.
Manage Rev ; 74(1): 30-3, 1985 Jan.
Article En | MEDLINE | ID: mdl-10269809

Creativity and entrepreneurship are vital to any organization, but bureaucracy and organizational restrictions can discourage these important traits in a company's employees. Often, attitudes and the general gestalt within a group can be more important than policies or pronouncements by management, but translating intangibles into concrete results is a mystery to many managers. This article, while it contains no revolutionary new ideas, is a summary of proven methods for igniting creative sparks in any organization.


Creativity , Personnel Management , Humans , Organizational Innovation
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