5,878 research outputs found
All Sky Camera for the CTA Atmospheric Calibration work package
The All Sky Camera (ASC) is a passive non-invasive imaging system for rapid night sky atmosphere monitoring. By design, the operation of the ASC will not affect the measurement procedure of the CTA observatory, for which we discuss its application in this report. The data collected should enable improved productivity and increased measurement time for the CTA observatory. The goal of ASC is to identify cloud position, atmosphere attenuation and time evolution of the sky condition, working within the CTA Central Calibration Facilities (CCF) group. Clouds and atmosphere monitoring may allow near-future prediction of the night-sky quality, helping scheduling. Also, in the case of partly cloudy night sky the cameras will identify the uncovered regions of the sky during the operation time, and define potential observable sources that can be measured. By doing so, a higher productivity of the CTA observatory measurements may be possible
Experimental Tests of the New Paradigm for Laser Filamentation in Gases
Since their discovery in the mid-1990s, ultrafast laser filaments in gases
have been described as products of a dynamic balance between Kerr self-focusing
and defocusing by free electric charges that are generated via multi-photon
ionization on the beam axis. This established paradigm has been recently
challenged by a suggestion that the Kerr effect saturates and even changes sign
at high intensity of light, and that this sign reversal, not free-charge
defocusing, is the dominant mechanism responsible for the extended propagation
of laser filaments. We report qualitative tests of the new theory based on
electrical and optical measurements of plasma density in femtosecond laser
filaments in air and argon. Our results consistently support the established
paradigm.Comment: 4 pages, 4 figure
Quantum adaptation of noisy channels
Probabilistic quantum filtering is proposed to properly adapt sequential
independent quantum channels in order to stop sudden death of entanglement. In
the adaptation, the quantum filtering does not distill or purify more
entanglement, it rather properly prepares entangled state to the subsequent
quantum channel. For example, the quantum adaptation probabilistically
eliminates the sudden death of entanglement of two-qubit entangled state with
isotropic noise injected into separate amplitude damping channels. The result
has a direct application in quantum key distribution through noisy channels.Comment: 6 pages, 4 figure
The legal structure of households in Serbia and Bulgaria in the 19th century
This scholarly work treats only the legal structure of households in Serbia and Bulgaria in the 19th century. The author's intention is to describe and present similarities and differences between the most important household's structural elements (Household Council, Household Head, Household Woman and Household Members), their relationships and status in the Ottoman legal-political order
Ozenda, P. Biogéographie végétale. Doin, Paris, 1964. Collection Biologie, publiée sous la direction de M. Albert Obré. 374 pp., 130 fig., 16 planches en noir, 2 cartes en couleurs hors texte, 21 cm.
Viers, G. Géographie des forêts. Collection « Les précis de l’enseignement supérieur, section Le Géographe ». Paris, Presses Universitaires de France, 1970. 222 p. 19 fig., 11.5 X 17.5 cm. Broché.
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