92,921 research outputs found
A Characterization of Subspaces and Quotients of Reflexive Banach Spaces with Unconditional Bases
We prove that the dual or any quotient of a separable reflexive Banach space
with the unconditional tree property has the unconditional tree property. Then
we prove that a separable reflexive Banach space with the unconditional tree
property embeds into a reflexive Banach space with an unconditional basis. This
solves several long standing open problems. In particular, it yields that a
quotient of a reflexive Banach space with an unconditional finite dimensional
decomposition embeds into a reflexive Banach space with an unconditional basis
Commutators on
The main result is that the commutators on are the operators not of
the form with and compact. We generalize
Apostol's technique (1972, Rev. Roum. Math. Appl. 17, 1513 - 1534) to obtain
this result and use this generalization to obtain partial results about the
commutators on spaces \X which can be represented as \displaystyle \X\simeq
(\bigoplus_{i=0}^{\infty} \X)_{p} for some or . In
particular, it is shown that every compact operator on is a commutator. A
characterization of the commutators on
is given. We also show
that strictly singular operators on are commutators.Comment: 17 pages. Submitted to the Journal of Functional Analysi
Surface flux pinning in superconducting amorphous (Mo0.6Ru0.4)B18
Superconducting critical current density was measured as a function of a perpendicular applied magnetic field in glassy (Mo0.6Ru0.4)82B18. The pinning force density was observed to depend linearly on 1/w, where w is the sample width measured perpendicular to both the current and field. This dependence is attributed to pinning by the sample edges. The bulk pinning contribution can be separated from the edge pinning contribution by extrapolation of the Fp vs 1/w curve. The edge contribution of the flux pinning was nearly eliminated by electrolytically polishing the sample. The contribution of the flux pinning profile due to edge pinning is analyzed in terms of the dynamic pinning model modified for edge pinning
Aerodynamic characteristics at low Reynolds numbers of several heat-exchanger configurations for wind-tunnel use
In response to design requirements of the National Transonic Facility, aerodynamic tests were conducted to determine the pressure-drop, flow-uniformity, and turbulence characteristics of various heat-exchanger configurations as a function of Reynolds number. Data were obtained in air with an indraft flow apparatus operated at ambient temperature and pressure. The unit Reynolds number of the tests varied from about 0.06 x 10 to 6th power to about 1.3 x 10 to 6th power per meter. The test models were designed to represent segments of full-scale tube bundles and included bundles of round tubes with plate fins in both staggered and inline tube arrays, round tubes with spiral fins, elliptical tubes with plate fins, and an inline grouping of tubes with segmented fins
Solid-state interdiffusion reactions in Ni/Ti and Ni/Zr multilayered thin films
We have performed a comparative transmission electron microscopy study of solid-state interdiffusion reactions in multilayered Ni/Zr and Ni/Ti thin films. The Ni-Zr reaction product was amorphous while the Ni-Ti reaction product was a simple intermetallic compound. Because thermodynamic and chemical properties of these two alloy systems are similar, we suggest kinetic origins for this difference in reaction product
A measurement of energetic test electron interactions with a plasma
Interaction of energetic test electrons with dense high temperature plasma and energy dissipation distributio
Electron and metastable density measurements in argon with a laser heterodyne interferometer
Electron and metastable density measurements in argon discharge tube using laser heterodyne interferomete
Frequency Shifts Inherent in the 6328 a Helium-neon Laser
Frequency shifts inherent in helium neon lase
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