3,236 research outputs found
Investigation of analytical methods for efficient partitioning of on-board processing functions for remote sensing applications
Risk decomposition and ring theory, lattice techniques and universal algebras, and unary functions are considered
Full scale visualization of the wing tip vortices generated by a typical agricultural aircraft
The trajectories of the wing tip vortices of a typical agricultural aircraft were experimentally determined by flight test. A flow visualization method, similar to the vapor screen method used in wind tunnels, was used to obtain trajectory data for a range of flight speeds, airplane configurations, and wing loadings. Detailed measurements of the spanwise surface pressure distribution were made for all test points. Further, a powered 1/8 scale model of the aircraft was designed, built, and used to obtain tip vortex trajectory data under conditions similar to that of the full scale test. The effects of light wind on the vortices were demonstrated, and the interaction of the flap vortex and the tip vortex was clearly shown in photographs and plotted trajectory data
The photospheric solar oxygen project: IV. 3D-NLTE investigation of the 777 nm triplet lines
The solar photospheric oxygen abundance is still widely debated. Adopting the
solar chemical composition based on the "low" oxygen abundance, as determined
with the use of three-dimensional (3D) hydrodynamical model atmospheres,
results in a well-known mismatch between theoretical solar models and
helioseismic measurements that is so far unresolved. We carry out an
independent redetermination of the solar oxygen abundance by investigating the
center-to-limb variation of the OI IR triplet lines at 777 nm in different sets
of spectra with the help of detailed synthetic line profiles based on 3D
hydrodynamical CO5BOLD model atmospheres and 3D non-LTE line formation
calculations with NLTETD. The idea is to simultaneously derive the oxygen
abundance,A(O), and the scaling factor SH that describes the cross-sections for
inelastic collisions with neutral hydrogen relative the classical Drawin
formula. The best fit of the center-to-limb variation of the triplet lines
achieved with the CO5BOLD 3D solar model is clearly of superior quality
compared to the line profile fits obtained with standard 1D model atmospheres.
Our best estimate of the 3D non-LTE solar oxygen abundance is A(O) = 8.76 +/-
0.02, with the scaling factor SH in the range between 1.2 and 1.8. All 1D
non-LTE models give much lower oxygen abundances, by up to -0.15 dex. This is
mainly a consequence of the assumption of a -independent microturbulence.Comment: 25 pages, 17 figures, 7 tables (Accepted for publication in A&A
Topological Hysteresis in the Intermediate State of Type-I Superconductors
Magneto-optical imaging of thick stress-free lead samples reveals two
distinct topologies of the intermediate state. Flux tubes are formed upon
magnetic field penetration (closed topology) and laminar patterns appear upon
flux exit (open topology). Two-dimensional distributions of shielding currents
were obtained by applying an efficient inversion scheme. Quantitative analysis
of the magnetic induction distribution and correlation with magnetization
measurements indicate that observed topological differences between the two
phases are responsible for experimentally observable magnetic hysteresis.Comment: 4 pages, RevTex
Technical Design Report for PANDA Electromagnetic Calorimeter (EMC)
This document presents the technical layout and the envisaged performance of the Electromagnetic Calorimeter (EMC) for the
PANDA target spectrometer. The EMC has been designed to meet the physics goals of the PANDA experiment. The performance figures are based on extensive prototype tests and radiation hardness studies. The document shows that the EMC is ready for construction up to the front-end electronics interface
Technical Design Report for the PANDA Micro Vertex Detector
This document illustrates the technical layout and the expected performance of the Micro Vertex Detector (MVD) of the PANDA experiment. The MVD will detect charged particles as close as possible to the interaction zone. Design criteria and the optimisation process as well as the technical solutions chosen are discussed and the results of this process are subjected to extensive Monte Carlo physics studies. The route towards realisation of the detector is
outlined
Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets
This document is the Technical Design Report covering the two large spectrometer magnets of the PANDA detector set-up. It
shows the conceptual design of the magnets and their anticipated performance. It precedes the tender and procurement of the magnets and, hence, is subject to possible
modifications arising during this process
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