Results 1 to 10 of about 6,623 (297)
Arthritis Care &Research, EarlyView.Objective The aim of this study was to determine the differences in demographic, serologic, and clinical characteristics between male and female patients with systemic sclerosis (SSc) in an Australian cohort. Methods This was a retrospective observational study using data from the Australian Scleroderma Cohort Study.
Emily Lin +14 more
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ATOMIC CLOCKS AND COLD ATOM SCATTERING
Laser Spectroscopy, 2002We demonstrate a Rb fountain clock which has a small cold collision shift that is cancelled by detuning the microwave cavity. To further enhance the stability and accuracy, we are currently developing a new state detection technique that directly measures population differences and are juggling atoms in the fountain. Fountain clocks also enable a novel
Fertig, C. +5 more
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Atomic and gravitational clocks
Nature, 1982Atomic and gravitational clocks are governed by the laws of electrodynamics and gravity, respectively. While the strong equivalence principle (SEP) assumes that the two clocks have been synchronous at all times, recent planetary data seem to suggest a possible violation of the SEP.
V. M. Canuto, I. Goldman
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CHARACTERIZATION OF NONSTATIONARY ATOMIC CLOCKS
Fluctuation and Noise Letters, 2007Atomic clocks are the core of a navigation system. Since an error in time results in an error in the user localization, it is fundamental that the stability is very high and constant with time. In this paper we discuss the dynamic Allan variance, or DAVAR, a representation of the time-varying stability of an atomic clock.
GALLEANI L., TAVELLA, PATRIZIA
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Synchronized to an optical atomic clock
Science, 2020Microwave generation using optical frequency comb technology hits new ...
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Detection of Anomalies in the Behavior of Atomic Clocks
IEEE Transactions on Instrumentation and Measurement, 2007In this paper, the problem of identifying variations in the nature of atomic clock noise is addressed. Two methods are proposed. One method is based on a generalized likelihood ratio test (GLRT), and the other is based on the dynamic Allan variance (DAVAR), which is a representation of the instantaneous clock stability that is able to point out ...
Emilia Nunzi +3 more
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18th IEEE International Conference on Micro Electro Mechanical Systems, 2005. MEMS 2005., 2005
We summarize the development of microfabricated atomic frequency references at NIST. The physics packages of these devices have volumes near 10 mm/sup 3/ and power dissipation below 150 mW, and can potentially achieve a fractional frequency instability in the range of 10/sup -11/ over long periods.
J. Kitching +6 more
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We summarize the development of microfabricated atomic frequency references at NIST. The physics packages of these devices have volumes near 10 mm/sup 3/ and power dissipation below 150 mW, and can potentially achieve a fractional frequency instability in the range of 10/sup -11/ over long periods.
J. Kitching +6 more
openaire +1 more source
Atomic Clocks and Atom Interferometry
2002We show that the language of atom interferometry [1] provides a unified picture for microwave and optical atomic clocks as well as for gravito-inertial sensors. The sensitivity and accuracy of these devices, is now such that a new theoretical framework [2] common to all these interferometers, is required and which includes: 1 - A fully quantum ...
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