11,936 research outputs found
Development of dry coal feeders
Design and fabrication of equipment of feed coal into pressurized environments were investigated. Concepts were selected based on feeder system performance and economic projections. These systems include: two approaches using rotating components, a gas or steam driven ejector, and a modified standpipe feeder concept. Results of development testing of critical components, design procedures, and performance prediction techniques are reviewed
Space capsule Patent
Manned space capsule configuration for orbital flight and atmospheric reentr
Multibody aircraft study, volume 2
The potential benefits of a multibody aircraft when compared to a single body aircraft are presented. The analyses consist principally of a detailed point design analysis of three multibody and one single body aircraft, based on a selected payload of 350,000 kg (771,618 lb), for final aircraft definitions; sensitivity studies to evaluate the effects of variations in payload, wing semispan body locations, and fuel price; recommendations as to the research and technology requirements needed to validate the multibody concept. Two, two body, one, three body, and one single body aircraft were finalized for the selected payload, with DOC being the prime figure of merit. When compared to the single body, the multibody aircraft showed a reduction in DOC by as much as 11.3 percent. Operating weight was reduced up to 14 percent, and fly away cost reductions ranged from 8.6 to 13.4 percent. Weight reduction, hence cost, of the multibody aircraft resulted primarily from the wing bending relief afforded by the bodies being located outboard on the wing
Dynamics of Enceladus and Dione inside the 2:1 Mean-Motion Resonance under Tidal Dissipation
In a previous work (Callegari and Yokoyama 2007, Celest. Mech. Dyn. Astr.
vol. 98), the main features of the motion of the pair Enceladus-Dione were
analyzed in the frozen regime, i.e., without considering the tidal evolution.
Here, the results of a great deal of numerical simulations of a pair of
satellites similar to Enceladus and Dione crossing the 2:1 mean-motion
resonance are shown. The resonance crossing is modeled with a linear tidal
theory, considering a two-degrees-of-freedom model written in the framework of
the general three-body planar problem. The main regimes of motion of the system
during the passage through resonance are studied in detail. We discuss our
results comparing them with classical scenarios of tidal evolution of the
system. We show new scenarios of evolution of the Enceladus-Dione system
through resonance not shown in previous approaches of the problem.Comment: 36 pages, 12 figures. Accepted in Celestial Mechanics and Dynamical
Astronom
Hybrid Reflection-transmission Surface Light-scattering Instrument with Reduced Sensitivity to Surface Sloshing
A hybrid reflection-transmission surface light-scattering instrumental design is presented, examined theoretically, and tested experimentally. The purpose of the design is to reduce the sensitivity of the instrument to vibration in general and surface sloshing in particular while sacrificing Little performance. Traditional optical arrangements and two new optical configurations with varying trade-offs between slosh resistance and instrumental simplicity and accuracy are examined by use of Fourier optics methods. The most promising design was constructed and tested with acetone, ethanol, and water as subject fluids. The test involved backcalculation of the wave number of the capillary wave examined with the known physical parameters for the test fluids. The agreement of the computed wave number was +/-1.4%. (C) 1997 Optical Society of America
Wavelet treatment of the intra-chain correlation functions of homopolymers in dilute solutions
Discrete wavelets are applied to parametrization of the intra-chain two-point
correlation functions of homopolymers in dilute solutions obtained from Monte
Carlo simulation. Several orthogonal and biorthogonal basis sets have been
investigated for use in the truncated wavelet approximation. Quality of the
approximation has been assessed by calculation of the scaling exponents
obtained from des Cloizeaux ansatz for the correlation functions of
homopolymers with different connectivities in a good solvent. The resulting
exponents are in a better agreement with those from the recent renormalisation
group calculations as compared to the data without the wavelet denoising. We
also discuss how the wavelet treatment improves the quality of data for
correlation functions from simulations of homopolymers at varied solvent
conditions and of heteropolymers.Comment: RevTeX, 19 pages, 7 PS figures. Accepted for publication in PR
Quantum random walks in optical lattices
We propose an experimental realization of discrete quantum random walks using
neutral atoms trapped in optical lattices. The random walk is taking place in
position space and experimental implementation with present day technology
--even using existing set-ups-- seems feasible. We analyze the influence of
possible imperfections in the experiment and investigate the transition from a
quantum random walk to the classical random walk for increasing errors and
decoherence.Comment: 8 pages, 4 figure
Polarised target for Drell-Yan experiment in COMPASS at CERN, part I
In the polarised Drell-Yan experiment at the COMPASS facility in CERN pion
beam with momentum of 190 GeV/c and intensity about pions/s interacted
with transversely polarised NH target. Muon pairs produced in Drel-Yan
process were detected. The measurement was done in 2015 as the 1st ever
polarised Drell-Yan fixed target experiment. The hydrogen nuclei in the
solid-state NH were polarised by dynamic nuclear polarisation in 2.5 T
field of large-acceptance superconducting magnet. Large helium dilution
cryostat was used to cool the target down below 100 mK. Polarisation of
hydrogen nuclei reached during the data taking was about 80 %. Two oppositely
polarised target cells, each 55 cm long and 4 cm in diameter were used.
Overview of COMPASS facility and the polarised target with emphasis on the
dilution cryostat and magnet is given. Results of the polarisation measurement
in the Drell-Yan run and overviews of the target material, cell and dynamic
nuclear polarisation system are given in the part II.Comment: 4 pages, 2 figures, Proceedings of the 22nd International Spin
Symposium, Urbana-Champaign, Illinois, USA, 25-30 September 201
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