Matches in SemOpenAlex for { <https://semopenalex.org/work/W2596032603> ?p ?o ?g. }
Showing items 1 to 73 of
73
with 100 items per page.
- W2596032603 abstract "We study a parabolic differential equation whose solution represents the atom dislocation in a crystal for a general type of Peierls-Nabarro model with possibly long range interactions and an external stress. Differently from the previous literature, we treat here the case in which such dislocation is not the superposition of transitions all occurring with the same orientations (i.e. opposite orientations are allowed as well). We show that, at a long time scale, and at a macroscopic space scale, the dislocations have the tendency to concentrate as pure jumps at points which evolve in time, driven by the external stress and by a singular potential. Due to differences in the dislocation orientations, these points may collide in finite time. More precisely, we consider the evolutionary equation $$(v_varepsilon)_t=frac{1}{varepsilon}left( mathcal{I}v_varepsilon-frac{1}{varepsilon^{2s}}W'(v_varepsilon)+sigma(t, x)right),$$where ({v_varepsilon=v_varepsilon(t, x)}) is the atom dislocation function at time t > 0 at the point ({x in mathbb{R}, {mathcal{I}_{s}}}) is an integro-differential operator of order ({2s in (0, 2), W}) is a periodic potential, ({sigma}) is an external stress and ({varepsilon > 0}) is a small parameter that takes into account the small periodicity scale of the crystal. We suppose that ({v_varepsilon(0, x)}) is the superposition of N−K transition layers in the positive direction and K in the negative one (with ({K in{0,dots,N}})); more precisely, we fix points ({x_1^0 < dots < x_N^0}) and we take $$v_varepsilon(0, x)= frac{varepsilon^{2s}}{W''(0)}sigma(0, x)+sum_{i=1}^N uleft(zeta_ifrac{x-x_i^0}{varepsilon}right).$$Here ({zeta_i}) is either −1 or 1, depending on the orientation of the transition layer u, which in turn solves the stationary equation ({mathcal{I}_{s} u=W'(u)}) . We show that our problem possesses a unique solution and that, as ({varepsilon to 0^+}) , it approaches the sum of Heaviside functions H with different orientations centered at points xi(t), namely $$sum_{i=1}^N H(zeta_i(x-x_i(t))).$$The point xi evolves in time from ({x_i^0}) , being subject to the external stress and a singular potential, which may be either attractive or repulsive, according to the different orientation of the transitions; more precisely, the speed ({dot x_i}) is proportional to $$sum_{jneq i}zeta_izeta_jfrac{x_i-x_j}{2s |x_i-x_j|^{1+2s}}-zeta_isigma(t, x_i).$$The evolution of such a dynamical system may lead to collisions in finite time. We give a detailed description of such collisions when N = 2, 3 and we show that the solution itself keeps track of such collisions; indeed, at the collision time Tc the two opposite dislocations have the tendency to annihilate each other and make the dislocation vanish, but only outside the collision point xc, according to the formulas $$begin{array}{ll}{} qquad lim_{t rightarrow T_c^-}lim_{varepsilonrightarrow0^+}v_varepsilon(t,x)=0 quad {mbox{when $xne x_c$,}} {rm and}quad limsup_{trightarrow T_c^-atop varepsilon rightarrow 0^+}v_varepsilon(t,x_c)geq1.end{array}$$We also study some specific cases of N dislocation layers, namely when two dislocations are initially very close and when the dislocations are alternate. To the best of our knowledge, the results obtained are new even in the model case s = 1/2." @default.
- W2596032603 created "2017-03-23" @default.
- W2596032603 creator A5038447050 @default.
- W2596032603 creator A5078447699 @default.
- W2596032603 date "2014-07-29" @default.
- W2596032603 modified "2023-10-16" @default.
- W2596032603 title "Crystal dislocations with different orientations and collisions" @default.
- W2596032603 hasPublicationYear "2014" @default.
- W2596032603 type Work @default.
- W2596032603 sameAs 2596032603 @default.
- W2596032603 citedByCount "0" @default.
- W2596032603 crossrefType "journal-article" @default.
- W2596032603 hasAuthorship W2596032603A5038447050 @default.
- W2596032603 hasAuthorship W2596032603A5078447699 @default.
- W2596032603 hasConcept C10138342 @default.
- W2596032603 hasConcept C114614502 @default.
- W2596032603 hasConcept C121332964 @default.
- W2596032603 hasConcept C149635348 @default.
- W2596032603 hasConcept C159122135 @default.
- W2596032603 hasConcept C162324750 @default.
- W2596032603 hasConcept C182306322 @default.
- W2596032603 hasConcept C199360897 @default.
- W2596032603 hasConcept C26873012 @default.
- W2596032603 hasConcept C27753989 @default.
- W2596032603 hasConcept C2781285689 @default.
- W2596032603 hasConcept C33923547 @default.
- W2596032603 hasConcept C37914503 @default.
- W2596032603 hasConcept C41008148 @default.
- W2596032603 hasConcept C58312451 @default.
- W2596032603 hasConcept C62520636 @default.
- W2596032603 hasConceptScore W2596032603C10138342 @default.
- W2596032603 hasConceptScore W2596032603C114614502 @default.
- W2596032603 hasConceptScore W2596032603C121332964 @default.
- W2596032603 hasConceptScore W2596032603C149635348 @default.
- W2596032603 hasConceptScore W2596032603C159122135 @default.
- W2596032603 hasConceptScore W2596032603C162324750 @default.
- W2596032603 hasConceptScore W2596032603C182306322 @default.
- W2596032603 hasConceptScore W2596032603C199360897 @default.
- W2596032603 hasConceptScore W2596032603C26873012 @default.
- W2596032603 hasConceptScore W2596032603C27753989 @default.
- W2596032603 hasConceptScore W2596032603C2781285689 @default.
- W2596032603 hasConceptScore W2596032603C33923547 @default.
- W2596032603 hasConceptScore W2596032603C37914503 @default.
- W2596032603 hasConceptScore W2596032603C41008148 @default.
- W2596032603 hasConceptScore W2596032603C58312451 @default.
- W2596032603 hasConceptScore W2596032603C62520636 @default.
- W2596032603 hasLocation W25960326031 @default.
- W2596032603 hasOpenAccess W2596032603 @default.
- W2596032603 hasPrimaryLocation W25960326031 @default.
- W2596032603 hasRelatedWork W192536927 @default.
- W2596032603 hasRelatedWork W1964104968 @default.
- W2596032603 hasRelatedWork W1964526381 @default.
- W2596032603 hasRelatedWork W2006502825 @default.
- W2596032603 hasRelatedWork W2017474725 @default.
- W2596032603 hasRelatedWork W2053854175 @default.
- W2596032603 hasRelatedWork W2054298794 @default.
- W2596032603 hasRelatedWork W2084122203 @default.
- W2596032603 hasRelatedWork W2480896710 @default.
- W2596032603 hasRelatedWork W2741671970 @default.
- W2596032603 hasRelatedWork W2808121858 @default.
- W2596032603 hasRelatedWork W2937050183 @default.
- W2596032603 hasRelatedWork W2949369241 @default.
- W2596032603 hasRelatedWork W2950587390 @default.
- W2596032603 hasRelatedWork W2988531932 @default.
- W2596032603 hasRelatedWork W3029707652 @default.
- W2596032603 hasRelatedWork W3085860061 @default.
- W2596032603 hasRelatedWork W3102278326 @default.
- W2596032603 hasRelatedWork W3103988304 @default.
- W2596032603 hasRelatedWork W635125770 @default.
- W2596032603 isParatext "false" @default.
- W2596032603 isRetracted "false" @default.
- W2596032603 magId "2596032603" @default.
- W2596032603 workType "article" @default.