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We discuss a characterization of countably expansive flows in measure-theoretical terms as in the discrete case [2]. More precisely, we define the countably expansive flows and prove that a homeomorphism of a compact metric space ...
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We discuss a characterization of countably expansive flows in measure-theoretical terms as in the discrete case [2]. More precisely, we define the countably expansive flows and prove that a homeomorphism of a compact metric space is countable expansive just when its suspension flow is. Moreover, we exhibit a measure-expansive flow (in the sense of [4]) which is not countably expansive. Next we define the weak expansive measures for flows and prove that a flow of a compact metric space is countable expansive if and only if it is weak measure-expansive (i.e. every orbit-vanishing measure is weak expansive). Furthermore, unlike the measure-expansive ones, the weak measure-expansive flows may exist on closed surfaces. Finally, it is shown that the integrated flow of a C-1 vector field on a compact smooth manifold is C-1 stably expansive if and only if it is C-1 stably weak measure-expansive. (C) 2018 Elsevier Inc. All rights reserved.
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In this paper the notion of asymptotic measure expansiveness is introduced and its relationship with dominated splitting is considered. It is proved that if a diffeomorphism admits a co-dimension one dominated splitting then it is...
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In this paper the notion of asymptotic measure expansiveness is introduced and its relationship with dominated splitting is considered. It is proved that if a diffeomorphism admits a co-dimension one dominated splitting then it is asymptotic measure expansive. Also, a diffeomorphism with a homoclinic tangency can be perturbed to a non-asymptotic measure expansive diffeomorphism. (C) 2015 Elsevier Inc. All rights reserved.
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In this article we are interested in energy estimates for hyperbolic initial boundary value problem when surface waves occur. More precisely, we construct rigorous geometric optics expansions for so-called elliptic and mixed frequ...
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In this article we are interested in energy estimates for hyperbolic initial boundary value problem when surface waves occur. More precisely, we construct rigorous geometric optics expansions for so-called elliptic and mixed frequencies and we show, using those expansions, that the amplification phenomenon is greater in the case of mixed frequencies. As a consequence, this result allow us to give a partial classification of weakly well-posed hyperbolic initial boundary value problems according to the region where the uniform Kreiss Lopatinskii condition degenerates.
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Coupled wavenumbers in infinite fluid-filled isotropic and orthotropic cylindrical shells are considered. Using the Donnell-Mushtari (DM) theory for thin shells, compact and elegant asymptotic expansions for the wavenumbers are fo...
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Coupled wavenumbers in infinite fluid-filled isotropic and orthotropic cylindrical shells are considered. Using the Donnell-Mushtari (DM) theory for thin shells, compact and elegant asymptotic expansions for the wavenumbers are found at an intermediate fluid loading for both the coupled rigid-duct modes (“fluid-originated”) and the coupled structural wavenumbers (“structure-originated modes”) over the entire frequency range where DM theory is valid. The coupled rigid-duct expansions are found to be valid for Oe1T orthotropy and for all circumferential orders, whereas the coupled structural wavenumber expansions are valid for small orthotropy and for low circumferential orders. These two above results are then used to derive the expansions for a set of multiple complex roots that display a locking behavior at this intermediate fluid-loading. The expansions are matched with the numerical solutions of the coupled dispersion relation and the match is found to be good over most of the frequency range.
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Coupled wavenumbers in infinite fluid-filled isotropic and orthotropic cylindrical shells are considered. Using the Donnell-Mushtari (DM) theory for thin shells, compact and elegant asymptotic expansions for the wavenumbers are fo...
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Coupled wavenumbers in infinite fluid-filled isotropic and orthotropic cylindrical shells are considered. Using the Donnell-Mushtari (DM) theory for thin shells, compact and elegant asymptotic expansions for the wavenumbers are found at an intermediate fluid loading for both the coupled rigid-duct modes (“fluid-originated”) and the coupled structural wavenumbers (“structure-originated modes”) over the entire frequency range where DM theory is valid. The coupled rigid-duct expansions are found to be valid for Oe1T orthotropy and for all circumferential orders, whereas the coupled structural wavenumber expansions are valid for small orthotropy and for low circumferential orders. These two above results are then used to derive the expansions for a set of multiple complex roots that display a locking behavior at this intermediate fluid-loading. The expansions are matched with the numerical solutions of the coupled dispersion relation and the match is found to be good over most of the frequency range.
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The relationship between two-dimensional SO(2,1) conformal anomalies in nonrelativistic systems and the virial expansion is explored using recently developed path-integral methods. In the process, the Beth- Uhlenbeck formula for t...
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The relationship between two-dimensional SO(2,1) conformal anomalies in nonrelativistic systems and the virial expansion is explored using recently developed path-integral methods. In the process, the Beth- Uhlenbeck formula for the shift of the second virial coefficient δb_2 is obtained, as well as a virial expansion for the Tan contact. A possible extension of these techniques for higher orders in the virial expansion is discussed.
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We evaluate the electrostatic interaction energy between two surfaces, one flat and the other slightly curved, in terms of the two-point autocorrelation functions for patch potentials on each one of them, and of a single function ...
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We evaluate the electrostatic interaction energy between two surfaces, one flat and the other slightly curved, in terms of the two-point autocorrelation functions for patch potentials on each one of them, and of a single function ψ which defines the curved surface. The resulting interaction energy, a functional of ψ, is evaluated up to the second order in a derivative expansion approach. We derive explicit formulas for the coefficients of that expansion as simple integrals involving the autocorrelation functions, and evaluate them for some relevant patch-potential profiles and geometries.
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There are different theories about the acting mechanisms of ettringite in the expansive behavior of Portland cement. While it is widely recognized that a reactive source of alumina, sulfate, and calcium hydroxide, along with suffi...
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There are different theories about the acting mechanisms of ettringite in the expansive behavior of Portland cement. While it is widely recognized that a reactive source of alumina, sulfate, and calcium hydroxide, along with sufficient water, is required for ettringite formation, there are still varying perspectives on the amount, size, and morphology of ettringite crystals. This work brings insights into the mechanisms underlying the expansion of ettringite. For this purpose, cement pastes containing an expansive mixture were analyzed using an expansion measuring device, in situ X-ray diffraction, isothermal calorimetry and scanning electron microscopy. The results revealed that the content and size of ettringite crystals at the beginning of the acceleration period are critical factors for the development of expansive behavior.
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In this paper we consider a general class epsilon of self-similar sets with complete overlaps. Given a self-similar iterated function system Phi =( E, {f(i)}(i=1)(m)) is an element of epsilon o n the real line, for each point x is...
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In this paper we consider a general class epsilon of self-similar sets with complete overlaps. Given a self-similar iterated function system Phi =( E, {f(i)}(i=1)(m)) is an element of epsilon o n the real line, for each point x is an element of E we can find a sequence (i(k)) = i(1)i(2) ... is an element of{1,..., m}(N), called a coding of x, such that
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Expansions in non-integer bases have been extensively investigated since a pioneering work of Renyi. We introduce a more general framework of alphabet-base systems that also includes Pedicini's general alphabets and the multiple-b...
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Expansions in non-integer bases have been extensively investigated since a pioneering work of Renyi. We introduce a more general framework of alphabet-base systems that also includes Pedicini's general alphabets and the multiple-base expansions of Neunhauserer and Li. We extend the Parry type lexicographic theory to this setup, and we improve and generalize various former results on unique expansions.
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