4,781 research outputs found
Jettisoning system for a parachute's canister
Three-point automatically released suspension and jettisoning system operates independently of lander's power system and releases parachute on touchdown. The system is based on a ball-lock device operated by the shock of the parachute's opening and by the subsequent decay in the load on the main cord
Separation of two bodies in space. A machine programmed analysis using the Lagrange equations and Eulerian angles
Fortran computer program and Lagrangian motion equations for separation analysis of two bodies in spac
Separation of two bodies in space
Computer program analyzes the motion of two rigid bodies in space, separating as a result of any one, or a combination of, the following mechanisms - springs with ball ends, springs with one end guided, pyrotechnics, rockets, cold-gas jets, air pistons, and Coulomb drag
Factorizing Numbers with the Gauss Sum Technique: NMR Implementations
Several physics-based algorithms for factorizing large number were recently
published. A notable recent one by Schleich et al. uses Gauss sums for
distinguishing between factors and non-factors. We demonstrate two NMR
techniques that evaluate Gauss sums and thus implement their algorithm. The
first one is based on differential excitation of a single spin magnetization by
a cascade of RF pulses. The second method is based on spatial averaging and
selective refocusing of magnetization for Gauss sums corresponding to factors.
All factors of 16637 and 52882363 are successfully obtained.Comment: 4 pages, 4 figures; Abstract and Conclusion are slightly modified.
References added and formatted with Bibte
Development of mechanisms for a planetary landing parachute system
Development and testing of planetary landing parachute syste
Detrimental adsorbate fields in experiments with cold Rydberg gases near surfaces
We observe the shift of Rydberg levels of rubidium close to a copper surface
when atomic clouds are repeatedly deposited on it. We measure transition
frequencies of rubidium to S and D Rydberg states with principal quantum
numbers n between 31 and 48 using the technique of electromagnetically induced
transparency. The spectroscopic measurement shows a strong increase of electric
fields towards the surface that evolves with the deposition of atoms. Starting
with a clean surface, we measure the evolution of electrostatic fields in the
range between 30 and 300 \mum from the surface. We find that after the
deposition of a few hundred atomic clouds, each containing ~10^6 atoms, the
field of adsorbates reaches 1 V/cm for a distance of 30 \mum from the surface.
This evolution of the electrostatic field sets serious limitations on cavity
QED experiments proposed for Rydberg atoms on atom chips.Comment: 4 pages, 3 figures Submitted to Phys. Rev.
Center vortex properties in the Laplace center gauge of SU(2) Yang-Mills theory
Resorting to the the Laplace center gauge (LCG) and to the Maximal-center
gauge (MCG), respectively, confining vortices are defined by center projection
in either case. Vortex properties are investigated in the continuum limit of
SU(2) lattice gauge theory. The vortex (area) density and the density of vortex
crossing points are investigated. In the case of MCG, both densities are
physical quantities in the continuum limit. By contrast, in the LCG the
piercing as well as the crossing points lie dense in the continuum limit. In
both cases, an approximate treatment by means of a weakly interacting vortex
gas is not appropriate.Comment: reference added, submitted to Phys. Lett.
Signatures in a Giant Radio Galaxy of a Cosmological Shock Wave at Intersecting Filaments of Galaxies
Sensitive images of low-level, Mpc-sized radio cocoons offer new
opportunities to probe large scale intergalactic gas flows outside clusters of
galaxies. New radio images of high surface brightness sensitivity at
strategically chosen wavelengths of the giant radio galaxy NGC 315 (Mack et al.
1997,1998) reveal significant asymmetries and particularities in the
morphology, radio spectrum and polarization of the ejected radio plasma. We
argue that the combination of these signatures provides a sensitive probe of an
environmental shock wave. Analysis of optical redshifts in NGC 315 vicinity
confirms its location to be near, or at a site of large-scale flow collisions
in the 100 Mpc sized Pisces-Perseus Supercluster region. NGC 315 resides at the
intersection of several galaxy filaments, and its radio plasma serves there as
a `weather station' (Burns 1998) probing the flow of the elusive and previously
invisible IGM gas. If our interpretation is correct, this is the first
indication for a shock wave in flows caused by the cosmological large scale
structure formation, which is located in a filament of galaxies. The
possibility that the putative shock wave is a source of gamma-rays and ultra
high energy cosmic rays is briefly discussed.Comment: accepted by Astrophysical Journal Letters, 4 pages, 3 figures (incl.
2 color), uses emulateapj5.sty (included), aastex.sty (included) and
psfig.st
Center Vortex Model for the Infrared Sector of SU(3) Yang-Mills Theory - Confinement and Deconfinement
The center vortex model for the infrared sector of Yang-Mills theory,
previously studied for the SU(2) gauge group, is extended to SU(3). This model
is based on the assumption that vortex world-surfaces can be viewed as random
surfaces in Euclidean space-time. The confining properties are investigated,
with a particular emphasis on the finite-temperature deconfining phase
transition. The model predicts a very weak first order transition, in agreement
with SU(3) lattice Yang-Mills theory, and also reproduces a consistent behavior
of the spatial string tension in the deconfined phase. The geometrical
structure of the center vortices is studied, including vortex branchings, which
are a new property of the SU(3) case.Comment: 22 pages, 12 figures (30 eps-files), uses LaTeX package "psfrag
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