9,889 research outputs found
Heat pipes for spacecraft temperature control: An assessment of the state-of-the-art
Various heat pipe temperature control techniques are critically evaluated using characteristic features and properties, including heat transport capability, volume and mass requirements, complexity and ease of fabrication, reliability, and control characteristics. Advantages and disadvantages of specific approaches are derived and discussed. Using four development levels, the state of-the-art of the various heat pipe temperature control techniques is assessed. The need for further research and development is discussed and suggested future efforts are projected
Non-equilibrium concentration fluctuations in binary liquids with realistic boundary conditions
Because of the spatially long-ranged nature of spontaneous fluctuations in
thermal non-equilibrium systems, they are affected by boundary conditions for
the fluctuating hydrodynamic variables. In this paper we consider a liquid
mixture between two rigid and impervious plates with a stationary concentration
gradient resulting from a temperature gradient through the Soret effect. For
liquid mixtures with a large Lewis number, we are able to obtain explicit
analytical expressions for the intensity of the non-equilibrium concentration
fluctuations as a function of the frequency and the wave number of
the fluctuations. In addition we elucidate the spatial dependence of the
intensity of the non-equilibrium fluctuations responsible for a non-equilibrium
Casimir effect.Comment: 9 pages, 2 figure
Anderson-Mott Transition in a Magnetic Field: Corrections to Scaling
It is shown that the Anderson-Mott metal-insulator transition of
paramagnetic, interacting disordered electrons in an external magnetic field is
in the same universality class as the transition from a ferromagnetic metal to
a ferromagnetic insulator discussed recently. As a consequence, large
corrections to scaling exist in the magnetic-field universality class, which
have been neglected in previous theoretical descriptions. The nature and
consequences of these corrections to scaling are discussed.Comment: 5pp., REVTeX, no figs, final version as publishe
Quantum critical behavior in disordered itinerant ferromagnets: Logarithmic corrections to scaling
The quantum critical behavior of disordered itinerant ferromagnets is
determined exactly by solving a recently developed effective field theory. It
is shown that there are logarithmic corrections to a previous calculation of
the critical behavior, and that the exact critical behavior coincides with that
found earlier for a phase transition of undetermined nature in disordered
interacting electron systems. This confirms a previous suggestion that the
unspecified transition should be identified with the ferromagnetic transition.
The behavior of the conductivity, the tunneling density of states, and the
phase and quasiparticle relaxation rates across the ferromagnetic transition is
also calculated.Comment: 15pp., REVTeX, 8 eps figs, final version as publishe
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