93,006 research outputs found
Comment on: I-Shih Liu: Constitutive theory of anisotropic rigid heat conductors
In I-Shih Liu's paper \C{1}, the compatibility of anisotropy and material
frame indifference of a rigid heat conductor is investigated. For this purpose,
the deformation gradient is introduced into the domain of the constitutive
mapping. Because of the presupposed rigidity, the deformation gradient is here
represented by an orthogonal tensor. The statement, that the usual procedure --
not to introduce the deformation gradient into the state space of rigid heat
conductors -- causes isotropy because of the material frame indifference, is
misleading.Comment: 8 page
Noncommutativity in Effective Loop Quantum Cosmology
We construct a noncommutative extension of the Loop Quantum Cosmology
effective scheme for the open FLRW model with a free scalar field via a theta
deformation. Firstly, a deformation is implemented in the configuration sector,
among the holonomy variable and the matter degree of freedom. We show that this
type of noncommutativity retain, to some degree, key features of the Loop
Quantum Cosmology paradigm for a free field. Secondly, a deformation is
implemented in the momentum sector, among the momentum associated to the
holonomy variable and the momentum associated to the matter field. We show that
in this latter case the scalar field energy density is bounded and has the same
maximum as in standard Loop Quantum Cosmology, signaling a higher degree of
compatibility
Two disjoint aspects of the deformation programme: quantizing Nambu mechanics; singleton physics
We present briefly the deformation philosophy and indicate, with references,
how it was applied to the quantization of Nambu mechanics and to particle
physics in anti De Sitter space.Comment: 4 pages; to be published with AIP Press in Proceedings of the 1998
Lodz conference "Particles, Fields and Gravitation". LaTeX (compatibility
mode) with aipproc styl
Perturbation theory for plasmonic eigenvalues
We develop a perturbative approach for calculating, within the quasistatic
approximation, the shift of surface resonances in response to a deformation of
a dielectric volume. Our strategy is based on the conversion of the homogeneous
system for the potential which determines the plasmonic eigenvalues into an
inhomogeneous system for the potential's derivative with respect to the
deformation strength, and on the exploitation of the corresponding
compatibility condition. The resulting general expression for the first-order
shift is verified for two explicitly solvable cases, and for a realistic
example of a deformed nanosphere. It can be used for scanning the huge
parameter space of possible shape fluctuations with only quite small
computational effort
Deformation compatibility in a single crystalline Ni superalloy
Deformation in materials is often complex and requires rigorous understanding to predict engineering component lifetime. Experimental understanding of deformation requires utilization of advanced characterization techniques, such as high spatial resolution digital image correlation (HR-DIC) and high angular resolution electron backscatter diffraction (HR-EBSD), combined with clear interpretation of their results to understand how a material has deformed. In this study, we use HR-DIC and HR-EBSD to explore the mechanical behaviour of a single-crystal nickel alloy and to highlight opportunities to understand the complete deformations state in materials. Coupling of HR-DIC and HR-EBSD enables us to precisely focus on the extent which we can access the deformation gradient, F, in its entirety and uncouple contributions from elastic deformation gradients, slip and rigid body rotations. Our results show a clear demonstration of the capabilities of these techniques, found within our experimental toolbox, to underpin fundamental mechanistic studies of deformation in polycrystalline materials and the role of microstructure
Construction of a Lax Pair for the -Painlev\'e System
We construct a Lax pair for the -Painlev\'e system from first
principles by employing the general theory of semi-classical orthogonal
polynomial systems characterised by divided-difference operators on discrete,
quadratic lattices [arXiv:1204.2328]. Our study treats one special case of such
lattices - the -linear lattice - through a natural generalisation of the big
-Jacobi weight. As a by-product of our construction we derive the coupled
first-order -difference equations for the -Painlev\'e
system, thus verifying our identification. Finally we establish the
correspondences of our result with the Lax pairs given earlier and separately
by Sakai and Yamada, through explicit transformations
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