15,431 research outputs found
On inertial-range scaling laws
Inertial-range scaling laws for two- and three-dimensional turbulence are
re-examined within a unified framework. A new correction to Kolmogorov's
scaling is derived for the energy inertial range. A related
modification is found to Kraichnan's logarithmically corrected two-dimensional
enstrophy-range law that removes its unexpected divergence at the injection
wavenumber. The significance of these corrections is illustrated with
steady-state energy spectra from recent high-resolution closure computations.
Implications for conventional numerical simulations are discussed. These
results underscore the asymptotic nature of inertial-range scaling laws.Comment: 16 pages, postscript (uncompressed, not encoded
Design and Evaluation of Menu Systems for Immersive Virtual Environments
Interfaces for system control tasks in virtual environments (VEs) have not been extensively studied. This paper focuses on various types of menu systems to be used in such environments. We describe the design of the TULIP menu, a menu system using Pinch Glovesā¢, and compare it to two common alternatives: floating menus and pen and tablet menus. These three menus were compared in an empirical evaluation. The pen and tablet menu was found to be significantly faster, while users had a preference for TULIP. Subjective discomfort levels were also higher with the floating menus and pen and tablet
A Reciprocity Result for Projective Indecomposable Modules of Cellular Algebras and BGG Algebras
We show that an adaptation of Landrock's Lemma for symmetric algebras also
holds for cellular algebras and BGG algebras. This is a result relating the
radical layers of any two projective modules. The reason it holds in our
setting is that there is a duality between injective hulls and projective
covers. As a corollary we deduce that BGG reciprocity respects Loewy structure
Bases of quasi-hereditary covers of diagram algebras
We extend the the combinatorics of tableaux to the study of diagram algebras
and give a uniform construction of their quasi-hereditary covers.Comment: Examples now include the classical Brauer, walled Brauer, and
partition algebra
Metallic Hydrides I: Hydrogen Storage and Other Gas-Phase Applications
A brief survey is given of the various classes of metal alloys and compounds that are suitable for hydrogen-storage and energy-conversion applications. Comparisons are made of relevant properties including hydrogen absorption and desorption pressures, total and reversible hydrogen-storage capacity, reaction-rate kinetics, initial activation requirements, susceptibility to contamination, and durability during long-term thermal cycling. Selected applications are hydrogen storage as a fuel, gas separation and purification, thermal switches, and sorption cryocoolers
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