11,236 research outputs found
Integration of the VIMOS control system
The VIRMOS consortium of French and Italian Institutes (PI: O. Le Fevre,
co-PI: G. Vettolani) is manufacturing two wide field imaging multi-object
spectrographs for the European Southern Observatory Very Large Telescope (VLT),
with emphasis on the ability to carry over spectroscopic surveys of large
numbers of sources: the VIsible Multi-Object Spectrograph, VIMOS, and the Near
InfraRed Multi-Object Spectrograph, NIRMOS. There are 52 motors to be
controlled in parallel in the spectrograph, making VIMOS a complex machine to
be handled. This paper will focus on the description of the control system,
designed in the ESO VLT standard control concepts, and on some integration
issues and problem solving strategies.Comment: 3 pages, 3 figures, ICALEPCS 2001 Conference, PSN#TUBT00
Reconstructing the density operator by using generalized field quadratures
The Wigner function for one and two-mode quantum systems is explicitely
expressed in terms of the marginal distribution for the generic linearly
transformed quadratures. Then, also the density operator of those systems is
written in terms of the marginal distribution of these quadratures. Some
examples to apply this formalism, and a reduction to the usual optical homodyne
tomography are considered.Comment: 17 pages, Latex,accepted by Quantum and Semiclassical Optic
The VST telescope control software in the ESO VLT environment
The VST (VLT Survey Telescope) is a 2.6 m Alt-Az telescope to be installed at
Mount Paranal in Chile, in the European Southern Observatory (ESO) site. The
VST is a wide-field imaging facility planned to supply databases for the ESO
Very Large Telescope (VLT) science and carry out stand-alone observations in
the UV to I spectral range. This paper will focus mainly on control software
aspects, describing the VST software architecture in the context of the whole
ESO VLT control concept. The general architecture and the main components of
the control software will be described.Comment: 3 pages, 2 figures, ICALEPCS 2001 Conference, PSN#THAP05
Forgetfulness of continuous Markovian quantum channels
The notion of forgetfulness, used in discrete quantum memory channels, is
slightly weakened in order to be applied to the case of continuous channels.
This is done in the context of quantum memory channels with Markovian noise. As
a case study, we apply the notion of weak-forgetfulness to a bosonic memory
channel with additive noise. A suitable encoding and decoding unitary
transformation allows us to unravel the effects of the memory, hence the
channel capacities can be computed using known results from the memoryless
setting.Comment: 6 pages, 2 figures, comments are welcome. Minor corrections and
acknoledgment adde
A strongly interacting gas of two-electron fermions at an orbital Feshbach resonance
We report on the experimental observation of a strongly interacting gas of
ultracold two-electron fermions with orbital degree of freedom and magnetically
tunable interactions. This realization has been enabled by the demonstration of
a novel kind of Feshbach resonance occurring in the scattering of two 173Yb
atoms in different nuclear and electronic states. The strongly interacting
regime at resonance is evidenced by the observation of anisotropic hydrodynamic
expansion of the two-orbital Fermi gas. These results pave the way towards the
realization of new quantum states of matter with strongly correlated fermions
with orbital degree of freedom.Comment: 5 pages, 4 figure
Density Matrix From Photon Number Tomography
We provide a simple analytic relation which connects the density operator of
the radiation field with the number probabilities. The problem of
experimentally "sampling" a general matrix elements is studied, and the
deleterious effects of nonunit quantum efficiency in the detection process are
analyzed showing how they can be reduced by using the squeezing technique. The
obtained result is particulary useful for intracavity field reconstruction
states.Comment: LATEX,6 pages,accepted by Europhysics Letter
No country for young people. Poverty and Age in Italy, 1948-2018
The paper explores the changing risk of poverty for older and younger generations of Italians throughout the republican period, 1948 to the present day. We show that poverty rates have decreased steadily for all age groups, but that youth has been left behind. The risk of poverty for children aged 0-17, relative to adults over 65, has increased steadily over time: in 1977, children faced a risk of poverty 30 percent lower than the elderly, but by 2016 they are 5 times likelier to be poor than someone in the age range of their grandparents. This intergenerational reversal of fortune is unprecedented in Italy’s postWW2 history. We also assess the impact of the Great Recession on living standards by age, finding that the young have been hit hardest, particularly in Southern regions. What explains the extra poverty risk associated with young age? Our analysis points to the welfare state, which offers better protection for the elderly than it does for the young and their families. We find that the impact of cash transfers on the incidence of child poverty is considerably lower in Italy than in most comparable countries. Overall, in the last seven decades, Italy has become no country for young people
Molecular detection of parasites (Trematoda, Digenea: Bucephalidae and Monorchiidae) in the European flat oyster Ostrea edulis (Mollusca: Bivalvia)
Members of the globally distributed bivalve family Ostreidae (oysters) have a significant role in marine ecosystems and include species of high economic importance. In this work, we report the occurrence of digenean parasites of the families Bucephalidae (Prosorhynchoides sp.) and Monorchiidae (Postmonorchis sp.) in Mediterranean native populations of Ostrea edulis (but not in the introduced Magallana gigas). Molecular detection was based on DNA sequencing of the ribosomal intergenic spacer 2 (ITS2) marker. The importance of detecting the presence of overlooked digenean parasites in Mediterranean oysters is discussed. © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
VST - VLT Survey Telescope Integration Status
The VLT Survey Telescope (VST) is a 2.6m aperture, wide field, UV to I
facility, to be installed at the European Southern Observatory (ESO) on the
Cerro Paranal Chile. VST was primarily intended to complement the observing
capabilities of VLT with wide-angle imaging for detecting and
pre-characterising sources for further observations with the VLT.Comment: 2 pages, 2 figures, conferenc
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