24 research outputs found
Solar supergranulation revealed by granule tracking
Full text linkContext: Supergranulation is a pattern of the velocity field at the surface
of the Sun, which has been known about for more than fifty years, however, no
satisfactory explanation of its origin has been proposed. Aims: New
observational constraints are therefore needed to guide theoretical approaches
which hesitate between scenarios that either invoke a large-scale instability
of the surface turbulent convection or a direct forcing by buoyancy. Method:
Using the 14-Mpixel CALAS camera at the Pic-du-Midi observatory, we obtained a
7.5h-long sequence of high resolution images with unprecedented field size.
Tracking granules, we have determined the velocity field at the Sun's surface
in great detail from a scale of 2.5Mm up to 250Mm.
Results: The kinetic energy density spectrum shows that supergranulation
peaks at 36Mm and spans on scales ranging between 20Mm and 75Mm. The decrease
of supergranular flows in the small scales is close to a -power law,
steeper than the equipartition Kolmogorov one. The probability distribution
function of the divergence field shows the signature of intermittency of the
supergranulation and thus its turbulent nature.Comment: 4 pages, accepted in Astronomy and Astrophysics (Letters
Synergies between the constitutive relation error concept and PGD model reduction for simplified V&V procedures
Get PDFDetector Technologies for CLIC
Full text linkThe Compact Linear Collider (CLIC) is a high-energy high-luminosity linear
electron-positron collider under development. It is foreseen to be built and
operated in three stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3
TeV, respectively. It offers a rich physics program including direct searches
as well as the probing of new physics through a broad set of precision
measurements of Standard Model processes, particularly in the Higgs-boson and
top-quark sectors. The precision required for such measurements and the
specific conditions imposed by the beam dimensions and time structure put
strict requirements on the detector design and technology. This includes
low-mass vertexing and tracking systems with small cells, highly granular
imaging calorimeters, as well as a precise hit-time resolution and power-pulsed
operation for all subsystems. A conceptual design for the CLIC detector system
was published in 2012. Since then, ambitious R&D programmes for silicon vertex
and tracking detectors, as well as for calorimeters have been pursued within
the CLICdp, CALICE and FCAL collaborations, addressing the challenging detector
requirements with innovative technologies. This report introduces the
experimental environment and detector requirements at CLIC and reviews the
current status and future plans for detector technology R&D.Comment: 152 pages, 116 figures; published as CERN Yellow Report Monograph
Vol. 1/2019; corresponding editors: Dominik Dannheim, Katja Kr\"uger, Aharon
Levy, Andreas N\"urnberg, Eva Sickin
Comparative Survival Rates of Lactic Acid Bacteria Isolated from Blood, Following Spray-drying and Freeze-drying
No full textSupergranulation, Network Formation, and TFGs Evolution from Hinode Observations
No full textInternational audienc
Supergranulation, Network Formation, and TFGs Evolution from Hinode Observations
No full textInternational audienc
Supergranulation, Network Formation, and TFGs Evolution from Hinode Observations
No full textInternational audienc
