54,144 research outputs found
Development of deployable structures for large space platform systems. Volume 1: Executive summary
Candidate deployable linear platform system concepts suitable for development to technology readiness by 1986 are reviewed. The systems concepts were based on trades of alternate deployable/retractable structure concepts, integration of utilities, and interface approaches for docking and assembly of payloads and subsystems. The deployable volume studies involved generation of concepts for deployable volumes which could be used as unpressurized or pressurized hangars, habitats and interconnecting tunnels. Concept generation emphasized using flexible materials and deployable truss structure technology
Development of deployable structures for large space platform systems, volume 2
Ground test article design, deployable volumes concept development, habitat and hangar conceptual designs, and deployable volumes analyses are addressed
Central Exclusive Di-jet Production at the Tevatron
We perform a phenomenological analysis of dijet production in double pomeron
exchange at the Tevatron. We find that the CDF Run I results do not rule out
the presence of an exclusive dijet component, as predicted by Khoze, Martin and
Ryskin (KMR). With the high statistics CDF Run II data, we predict that an
exclusive component at the level predicted by KMR may be visible, although the
observation will depend on accurate modelling of the inclusive double pomeron
exchange process. We also compare to the predictions of the DPEMC Monte Carlo,
which contains a non-perturbative model for the central exclusive process. We
show that the perturbative model of KMR gives different predictions for the
di-jet ET dependence in the high di-jet mass fraction region than
non-perturbative models.Comment: 17 pages, 15 figure
Development of deployable structures for large space platform systems, part 1
Eight deployable platform design objectives were established: autodeploy/retract; fully integrated utilities; configuration variability; versatile payload and subsystem interfaces; structural and packing efficiency; 1986 technology readiness; minimum EVA/RMS; and Shuttle operational compatibility
Stability and photochemistry of ClO dimers formed at low temperature in the gas phase
The recent observations of elevated concentrations of the ClO radical in the austral spring over Antarctica have implicated catalytic destruction by chlorine in the large depletions seen in the total ozone column. One of the chemical theories consistent with an elevated concentration of the ClO is a cycle involving the formation of the ClO dimer through the association reaction: ClO + ClO = Cl2O2 and the photolysis of the dimer to give the active Cl species necessary for O3 depletion. Here, researchers report experimental studies designed to characterize the dimer of ClO formed by the association reaction at low temperatures. ClO was produced by static photolysis of several different precursor systems: Cl sub 2 + O sub 3; Cl sub 2 O sub 2; OClO + Cl sub 2 O spectroscopy in the U.V. region, which allowed the time dependence of Cl sub 2, Cl sub 2 O, ClO, OClO, O sub 3 and other absorbing molecules to be determined
Fully automatic telemetry data processor
Satellite Telemetry Automatic Reduction System /STARS 2/, a fully automatic computer-controlled telemetry data processor, maximizes data recovery, reduces turnaround time, increases flexibility, and improves operational efficiency. The system incorporates a CDC 3200 computer as its central element
Parrondo-like behavior in continuous-time random walks with memory
The Continuous-Time Random Walk (CTRW) formalism can be adapted to encompass
stochastic processes with memory. In this article we will show how the random
combination of two different unbiased CTRWs can give raise to a process with
clear drift, if one of them is a CTRW with memory. If one identifies the other
one as noise, the effect can be thought as a kind of stochastic resonance. The
ultimate origin of this phenomenon is the same of the Parrondo's paradox in
game theoryComment: 8 pages, 3 figures, revtex; enlarged and revised versio
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