22,043 research outputs found
Expulsion bladder-equipped storage tank structure Patent
Expulsion bladder equipped storage tank structur
The linear boom actuator designed for the Galileo spacecraft
Because the linear boom actuator is to be used on a flight spacecraft, as opposed to a ground based application, there is a comprehensive set of requirements. First, of course, the actuator must be capable of positioning and holding the load. Initially the load as predicted to be 4448 N (1000 lb) but with subsequent spacecraft configuration changes the load has been greatly reduced to a constant tensile pull of 1477 N (332 lb) due to centrifugal force. Lesser compressive loads of 1317 N (296 centrifugal lb) may be experienced during launch and deployment. This actuator must have the maximum redundancy possible. Life requirements were defined by the 10.16 to 15.24 cm (4 to 6 in.) total liner travel expected during the five-year flight duration. Liner range required of the actuator was set at plus and minus 5.08 cm to accommodate configuration changes
Remotely operated gas-pressure regulator and shuttle valve
Valve features precise gas-pressure regulation and shuts off flow by remote control. Valve is made up of regulator valve cavity and spring-compression adjusts cavity. Elements in regulator cavity are conventional and include high-pressure inlet, ball which mates with seat, push rod, and pressure-sensing diaphragm
Combined pressure regulator and shutoff valve
A remotely operable pressure regulator and shutoff valve particularly suited for achieving high resolution and flow control, and positive shutoff is described. The valve is characterized by a spring-loaded ball coaxially aligned with a fluid port to be sealed, a spring-loaded pintle extended through the port into engagement with the ball, for controlling the position, a spring-loaded diaphragm for controlling the position of the pintle, and an axially displaceable spring supported by a movable stop which, in turn, is repositioned by a selectively operable stepper motor. Thus, the pressure-response characteristics for the valve can be varied through a selective repositioning of the stop
Extended Gibbs ensembles with flow
A statistical treatment of finite unbound systems in the presence of
collective motions is presented and applied to a classical Lennard-Jones
Hamiltonian, numerically simulated through molecular dynamics. In the ideal gas
limit, the flow dynamics can be exactly re-casted into effective time-dependent
Lagrange parameters acting on a standard Gibbs ensemble with an extra total
energy conservation constraint. Using this same ansatz for the low density
freeze-out configurations of an interacting expanding system, we show that the
presence of flow can have a sizeable effect on the microstate distribution.Comment: 7 pages, 4 figure
The chemical equilibration volume: measuring the degree of thermalization
We address the issue of the degree of equilibrium achieved in a high energy
heavy-ion collision. Specifically, we explore the consequences of incomplete
strangeness chemical equilibrium. This is achieved over a volume V of the order
of the strangeness correlation length and is assumed to be smaller than the
freeze-out volume. Probability distributions of strange hadrons emanating from
the system are computed for varying sizes of V and simple experimental
observables based on these are proposed. Measurements of such observables may
be used to estimate V and as a result the degree of strangeness chemical
equilibration achieved. This sets a lower bound on the degree of kinetic
equilibrium. We also point out that a determination of two-body correlations or
second moments of the distributions are not sufficient for this estimation.Comment: 16 pages, 15 figures, revtex
Pauli susceptibility of A3C60 (A=K, Rb)
The Pauli paramagnetic susceptibility of A3C60 (A= K, Rb) compounds is
calculated. A lattice quantum Monte Carlo method is applied to a multi-band
Hubbard model, including the on-site Coulomb interaction U. It is found that
the many-body enhancement of the susceptibility is of the order of a factor of
three. This reconciles estimates of the density of states from the
susceptibility with other estimates. The enhancement is an example of a
substantial many-body effect in the doped fullerenes.Comment: 4 pages, revtex, 2 figures, submitted to Phys. Rev. B more
information at http://www.mpi-stuttgart.mpg.de/dokumente/andersen/fullerene
A Method for the Detection and Determination of Arsenic and Antimony in the Presence of Organic Matter.
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A Fast Global Feedback System to Correct the Beam Position Deviation in the ESRF Storage Ring
The immature stages and biology of two Xenapates species in West Africa (Hymenoptera, Tenthredinidae)
The immature stages and host plants of Xenapates Kirby, 1882 were hitherto unknown. We describe the larvae, prepupae and pupae of X. braunsi (Konow, 1896) and X. gaullei (Konow, 1896), and record observations on aspects of their biology. The relationship of Xenapates to other taxa currently placed in the Allantinae and Blennocampinae of the Tenthredinidae remains unclear. Most larval characters of Xenapates resemble those described for West Palaearctic Allantini (Allantinae) and some Blennocampinae, but unique amongst exophytic larvae of Tenthredinoidea is the complete absence of cuticular appendages on the dorsum of the trunk in the two Xenapates species studied. The setose outer surface of the abdominal prolegs of Xenapates, and the presence of a mesal ridge only on the left mandible, are character states that have not so far been recorded in other genera currently placed in the Allantinae or Blennocampinae. Larval host plants of X. braunsi are Digitaria horizontalis, Pennisetum purpureum, Setaria barbata and Zea mays (all Poaceae). X. gaullei larvae feed on two Commelina species (Commelinaceae). Larvae of both species are easy bleeders
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